Oil and gas field report. General characteristics and organizational structure of ooo ngdu "aksakovneft": report of educational practice. Operation of oil and injection wells

Work description

The basis of the economic potential of the Okha region is the fuel and energy complex. Its base enterprise is the oil and gas production department Okhaneftegaz, which is part of the structure of OJSC NK Rosneft - Sakhalinmorneftegaz.
The history of the NGDU Okhaneftegaz enterprise began with the development of the Okha field in 1923. From 1923 to 1928, the Okha deposit was developed by Japan under a concession agreement. From 1928 to 1944, exploration and development of the field was carried out jointly by the Sakhalinneft Trust (formed in 1927) and the Japanese concessionaire

Introduction. General information about the company
2
1.
Theoretical part
3

1.1. Company structure
3

4

1.3. Classification of enhanced oil recovery methods
6

1.4. Waterflooding systems and conditions of their use
9

1.5. Injection wells survey
13

1.6. Underground repair of injection wells, types and reasons of repair
14
2.
Occupational safety during waterflooding
15
3.
Environmental protection when used for reservoir pressure maintenance of wastewater
16

Conclusion. How to determine the effectiveness of the application of RPM methods
18

Bibliography
19

Files: 1 file

Federal Agency for Education and Science of the Russian Federation

Development and operation of oil and gas fields

(name of specialty)

(surname, name, patronymic of the student)

Correspondence department sixth course.

code 130503.

in qualification (internship) practice

on ______________________________ _____________________________

(Company name)

Practice manager from the branch

Practice manager from the enterprise

____________________ ___________________________

(position) (signature) (acting)

The decision of the commission from "______" ____________________ 2010.

admit that the report

executed and protected with the rating "_____________________________"

Commission members

_____________________ ___________________________ ____________________

_____________________ ___________________________ ____________________

(position) (signature) (acting)

Introduction

General information about the company.

The basis of the economic potential of the Okha region is the fuel and energy complex. Its base enterprise is the oil and gas production department Okhaneftegaz, which is part of the structure of OJSC NK Rosneft - Sakhalinmorneftegaz.

The history of the NGDU Okhaneftegaz enterprise began with the development of the Okha field in 1923. From 1923 to 1928, the Okha deposit was developed by Japan under a concession agreement. From 1928 to 1944, exploration and development of the field was carried out jointly by the Sakhalinneft Trust (formed in 1927) and the Japanese concessionaire.

In 1944, the agreement with Japan was terminated, and since that time the development of the Okhinskoye field has been continued by the Sakhalinneft association, and the Okhinsky oil field has been included in various divisions in different years:

1944-1955 - Okha oil field (in the development of the Central Okha field);

1955-1958 - the Okha enlarged oil field, which is part of the Ekhabineft Oilfield Directorate (in the development of the Central Okha, Severnaya Okha, Nekrasovka, Yuzhnaya Okha, Kolendo fields - until 1965);

1968-1971 - Oilfield Administration Okhaneft (in the development of the Central Okha, Yuzhnaya Okha, Nekrasovka fields);

1971-1979 - NGDU Kolendoneft (in the development of the Central Okha, North Okha, South Okha fields);

1979-1981 - Basic enterprise of the Sakhaneftegazdobycha Production Association, which is part of the Sakhalinmorneftegaz All-Union Industrial Association (in the development of the Central Okha, Severnaya Okha, Yuzhnaya Okha fields);

1981-1988 - NGDU Seveneftegaz (the same fields are being developed). NGDU Okhaneftegaz operates at 17 oil and gas fields located in the Okha region.

In 1988, PO Okhaneftegazdobycha and VPO Sakhalinmorneftegaz were transformed into PA Sakhalinmorneftegaz, and NGDU Severneftegaz - into NGDU Okhaneftegaz, which again includes the Kolendo field. At old oil fields, which are located on land, the introduction of hydraulic fracturing technology has begun, which makes it possible to increase well production rates.

1. Theoretical part

General information about the deposit. The Tungor field was discovered in 1958, 28 km south of the city of Okhi. In orographic terms, the anticlinal fold is located at the boundaries of two morphological zones: the eastern, uplifted, expressed in the form of the meridian ridge of the East Sakhalin ridge, and the western, represented by more gentle and low relief forms. The maximum absolute elevations in the eastern part reach 120 meters. The arch of the fold corresponds to a low relief zone with absolute marks not exceeding 30-40 m.

The district's hydrographic network is poorly developed. It should be noted that there are two local drainage basins - Tungor and Odoptu lakes, which have a tectonic nature. A number of small streams and rivers flow through the area. Their valleys are swampy, water flow is uneven. The village of Tungor is located in the immediate vicinity of the deposit, which is connected with the city of Okha by a road 28 km long.

The climate of the region is cold, winter is long, snow cover falls in November and lasts until May. Typhoons bring blizzards in winter and heavy rains in summer. The wind reaches 30m / s. Summer is short and rainy. The average annual temperature is 2.5.

Stratigraphy. The section of the deposits of the Tungorskoye field is represented by terrigenous sandy-argillaceous rocks of the Neogene age. The complex of formations uncovered by the deepest wells is divided (from bottom to top) into the Daginskaya, Okobykayskaya and Nutovskaya formations.

Daginskaya suite. The maximum penetrated thickness in well No. 25 is 1040m. The boundary between the Dagin and Okobykai formations is drawn along the top of the XXI horizon. The Daginsky deposits are subdivided into horizons XXI - XXVI.

They are composed mainly of sands and sandstones of light gray, gray, uneven-grained, silty-clayey rocks.

Mudstones are dark gray to black, fractured, comminuted, on top - sandy-silty, micaceous, contain charred plant remains. The rocks are characterized by a high content of silica.

Okobykayskaya Formation. The boundary between the deposits of the Nutovskaya and Okobykayskaya formations is conventionally drawn at the bottom of the 3rd layer. The thickness of the suite reaches 1400m. Clastic rocks are represented by sands, clays and their intermediate and cemented varieties. The upper half of the formation section is characterized by sedimentation stability, which appears when analyzing thicknesses. The ubiquitous discontinuity of strata III - XII, sharp lithological-facies substitutions complicate the local correlation of the section of individual wells, predetermine the conventionality of the contact between the Nutov and Okobykai deposits.

Sands and sandstones are gray, light gray, fine-grained, clayey-silty with pebbles and gravel. Siltstones and siltstones are light and dark gray, clayey-sandy. Clays and mudstones are dark gray, sandy, silty and fractured. The clay-sandy complex of the Lower Okobykayskaya strata includes the main oil and gas deposits.

Nutovskaya suite. It is distributed throughout the area; in the crest of the fold, the Middle Nutovsky rocks are exposed. The total capacity is over 1000m. If in the lower part of the section it is possible to trace individual sandy layers (III, II, I, M), then a continuous sandy complex with thin clay layers is exposed above. Sandy rocks are gray, light gray, friable, fine-grained and uneven-grained with scattered pebbles and gravel. Clays are dark gray, sandy-silty, silty with inclusions of charred plant remains.

Tectonics. The Tungor fold is part of the Ekhabinsky anticlinal zone located in the northeastern extreme part of the island.

Within the anticlinal zone, nine anticlinal structures have been identified, grouped into two anticlinal branches - the Okha and East Ekhabinsky.

The Tungor anticline is located at the lower end of the East Ekhabinsky zone and differs from other folds in a number of structural features. It differs from neighboring structures - Vostochno-Ekhabinskaya in the east and Ekhabinskaya, adjoining from the north, by a slight subsidence, lower contrast, and the absence of discontinuities. According to the Pliocene deposits developed on the surface, the fold is a meridian-striking brachyanticline.

Along the top of horizon XX, the fold extends in the meridional direction, its wings are almost symmetrical. The angles of incidence of rocks on the western wing vary within 8-9 degrees, on the eastern - more steep, reaching 12-14. The subsidence of rocks in the southern direction is gently sloping, at an angle of 3-4; on the northern perkline, there is a flexural thickening of isohypsum and a steeper dip of the hinge (angle of incidence 6 -7).

Oil-bearing capacity. In 1958, the borehole discoverer established the commercial oil-bearing capacity of the XX horizon. In 1961, an oil deposit of the XX horizon was discovered during testing of well No. 28. To date, the productivity of three oil horizons (XXI, XX and XX) and ten gas horizons has been proven in the Tungor field. In the section of the Tungor field, there is a wide range of productivity and observance of vertical zoning in the distribution of deposits: up the section, oil deposits are replaced by gas condensate, then purely gas. The morphology of the natural reservoirs of the Tungor field is of a vile form, respectively, the traps of oil and gas deposits will belong to the formation vaulted and most of them are partially lithologically screened.

1.3. Classification of enhanced oil recovery methods

The use of methods for maintaining reservoir pressures during the development of oil deposits (in-circuit and in-circuit waterflooding, injection of gas or air into elevated parts of the reservoir) allows the most rational use of natural reservoir energy and replenish it, significantly reduce the development time of deposits due to more intensive rates of oil withdrawal. And nevertheless, the balance of residual reserves at the fields that are in the final stage of development remains very high, in some cases amounting to 50-70%.

Currently, a large number of enhanced oil recovery methods are known and implemented. They differ in the method of influencing the productive formations, the nature of the interaction between the working agent injected into the formation and the fluid that saturates the formation, and the type of energy introduced into the formation. All methods of enhanced oil recovery can be divided into hydrodynamic, physicochemical, and thermal.

Hydrodynamic methods of enhanced oil recovery.

When applying these methods, the system of spacing of production and injection wells does not change and additional energy sources introduced into the formation from the surface to displace residual oil are not used. Hydrodynamic methods of enhanced oil recovery function within the implemented development system, more often during waterflooding of oil reservoirs, and are aimed at further intensification of natural oil recovery processes. Hydrodynamic methods include cyclic waterflooding, variable filtration flows and forced fluid withdrawal.

Cyclic waterflooding. The method is based on a periodic change in the reservoir operation mode by stopping and resuming water injection and withdrawal, due to which capillary and hydrodynamic forces are more fully used.

This facilitates the introduction of water into the reservoir zones that were not previously covered by the impact. Cyclic waterflooding is effective in fields where conventional waterflooding is used, especially in hydrophilic reservoirs, which capillary better retain the water that has invaded them. In heterogeneous formations, the efficiency of cyclic waterflooding is higher than conventional waterflooding. This is due to the fact that in the conditions of waterflooding of a heterogeneous formation, the residual oil saturation of the regions of the formation with the worst reservoir properties is significantly higher than that of the main flooded part of the formation. With an increase in pressure, the elastic forces of the formation and the fluid contribute to the introduction of water into the regions of the formation with the worst reservoir properties, while capillary forces keep the water that has penetrated into the formation with a subsequent decrease in the formation pressure.

The method of changing the direction of filtration flows. In the process of waterflooding of oil reservoirs, especially heterogeneous ones, according to traditional schemes, the pressure field and the nature of filtration flows are gradually formed in them, in which individual sections of the reservoir are not covered by the active process of oil displacement by water. To involve stagnant zones of the reservoir not covered by waterflooding in development, it is necessary to change the general hydrodynamic situation in it, which is achieved by redistributing water withdrawals and injection through the wells. As a result of changes in production (injection), the direction and magnitude of pressure gradients change, due to which the areas that were not previously covered by waterflooding are affected by higher pressure gradients, and oil from them is displaced into the flooded, flowing part of the formations, which increases oil recovery. When implementing the method, along with a change in production and injection, periodic shutdown of individual wells or groups of production and injection wells is practiced.

Ministry of Education and Science of the Russian Federation and the Republic of Tatarstan

Almetyevsk State Oil Institute

Department "Development and operation

oil and gas fields "

Report

Student Abunagimov Rustam Rinatovich group 68-15 W

Faculty of oil and gas specialties 13503.65

On educational practice, passed in JSC "Bashneft"

NGDU "Oktyabrskneft"

( enterprise, NGDU)

Place of practice OJSC "Bashneft"

NGDU "Oktyabrskneft"

Practice leader

from the Department of RIENGM Chekmaeva R.R.

(position, full name)

Almetyevsk

INTRODUCTION 3

1 Production and organizational structure of NGDU. 4

2. Geological and physical characteristics of objects. eight

3. Drilling wells. 13

4. Development of oil fields. 15

5. PPD system. 19

6. Operation of oil and injection wells. 22

7. Well survey. 25

8. Methods for increasing well productivity. 26

9. Routine and capital repairs of wells. thirty

10. Collection and preparation of oil, gas and water. 33

11. Safety, labor and environmental protection. 36

REFERENCES 39

INTRODUCTION

This practice was completed by me at the Oktyabrskneft oil and gas production department. In the course of my practice, I got acquainted with the methods of oil production, methods of enhancing oil recovery, the reservoir pressure maintenance system, as well as the well production system under the conditions of this oil and gas production department.

NGDU Oktyabrskneft is an oil and gas production company. The basis of the NGDU's activities is the extraction of oil, gas, bitumen, fresh and mineral waters, their transportation by various types of transport, in some cases, processing and sale.

NGDU Oktyabrskneft is a large subdivision of OJSC Bashneft. Due to the high degree of exploration (more than 82%) of the territory of Bashkortostan, the company continues to carry out exploration work, both in the territory of the Republic and in other regions. In 2009, the annual plan of exploration drilling of more than 10 thousand meters was completed, 10 wells were completed, industrial oil flows were obtained in 6 wells (efficiency 60%), 2 new oil fields were discovered, the increase in recoverable reserves of industrial categories was 1.3 million tons The company conducts seismic exploration, deep exploration drilling, geochemical studies and thematic works in the field of geological exploration. Oil production will increase due to the fields being developed by the company, such as Arlanskoye, Sergeevskoye, Yugomashevskoye and other fields. An increase in oil production is expected due to an increase in the volume of geological and technical measures: drilling new wells, optimizing fluid production, transferring wells to other facilities, performing hydraulic fracturing, creating new waterflooding centers, reducing idle wells and expanding the use of proven highly effective methods of increasing oil recovery.

NGDU "Oktyabrskneft" is about two dozen workshops and subdivisions of the main and auxiliary production and the sphere of social services. The department has: its own training center, the House of Technology, a subsidiary greenhouse farm, a recreation center, a dental and paramedic centers, etc.

Recently, oilmen have been working on environmental issues a lot: saline springs are being restored, rivers are being cleaned, and oiled lands are being reclaimed.

In practice, we often went to bypass wells, during which I mastered the actions of an operator for oil and gas production directly in working conditions. An important aspect of the practice was the consolidation of previously studied theoretical knowledge in practice.

1 Production and organizational structure of NGDU

NGDU "Oktyabrskneft" is located in the river. p. Serafimovskiy Tuymazinsky region, Republic of Bashkortostan. The manufactured products, according to the main activity of the enterprise, are commercial oil.

By the type of management structure, NGDU Oktyabrskneft refers to a linearly functional management structure that has minor flaws and, in general, is optimal for this enterprise. In 2009, the number of this enterprise was about 1750 people.

NGDU Oktyabrskneft is a complex system of structures and divisions that ensure uninterrupted oil production. A diagram of the structure of NGDU Oktyabrskneft is shown in Figure 1.

The management is carried out by the head of the NGDU, to whom all services, departments and workshops are subordinate. He directs all activities of the enterprise on the basis of unity. The rights and obligations of each department of the deputy chief, as well as the staff of the apparatus, are separated by special provisions.

The first deputy chief is the chief engineer, he carries out production and technical management of the team, along with the director bears full responsibility for the efficiency of the enterprise.

The chief engineer is in charge of:

1) Production and technical department (PTO), the main task of which is to determine the rational technique and technology for oil and gas production, the introduction of new equipment and advanced technology.

2) The service of the chief mechanic (SGM) manages the mechanic-repair service of the NGDU.

3) The Service of the Chief Power Engineer (SGZ) is engaged in the organization of reliable and safe operation of heat and power plants, the introduction of new, more reliable, economical electric drives and power supply schemes.

4) Department of industrial safety and labor protection (OSB and TB) whose main task is to organize work to create safe working conditions.

The Geological Department reports to the Chief Geologist. The department is engaged in a detailed study of the field, accounting for the movement of oil and gas reserves, additional exploration of individual areas, the introduction of technological schemes and development projects, and finding ways to intensify development.

Figure 1 Organizational structure of NGDU "Oktyabrskneft"

The Economic Planning Department (PEO) is subordinate to the chief economist of the NGDU. The main task of the department is to organize the work of the department, analyze the work of the enterprise, and identify ways to increase the efficiency of production. The Department of Labor and Wages (Labor and Salary) is engaged in improving the organization of labor and production management, introducing progressive forms and systems of wages, material incentives in order to further increase labor productivity.

The Service for Logistics and Equipment Procurement (SMTO and KO) is subordinate to the Deputy Head of NGDU for General Issues. The main task is to provide the subdivisions of NGDU with all types of materials and resources.

The deputy chief for economic affairs is the chief economist, who coordinates and controls the activities of all economic services and departments.

The department of the automated control system (OASU) is intended for automated control. It interacts with enterprise management systems, served by cluster computing and information computing centers (CVC and KIVC).

Production at NGDU is subdivided into main and auxiliary. The main production includes workshops that are directly involved in the production of main products.

These include TsDNG 1, 2, 3, 4; CPPD; CPPN. These shops perform the following functions: advance oil and gas to the bottom by using reservoir energy; lifting oil to the day surface, collecting, monitoring, measuring the volume of production; complex preparation of oil in order to make it marketable.

The structure of auxiliary production includes those divisions of the enterprise that ensure the uninterrupted operation of the shops of the main production. The activities of auxiliary production include: repair of equipment, wells, devices and mechanisms; provision of production facilities with electricity, water and other necessary materials; provision of information services to the shops of the main production. All these tasks are performed by workshops included in the structure of NGDU: TsAPP; CAC; TsNIPR; CPKRS; PRCEO; transport shop.

CPF, oil preparation and pumping shop, reception of the produced three-phase liquid (oil, gas, water) from the Oilfield, preparation (separation into phases), oil and water metering, oil delivery to the pipeline management, and formation water to the reservoir pressure maintenance workshop, for use in the reservoir maintenance system. pressure.

Reservoir pressure maintenance (RPM) workshop - water injection into productive formations.

Workshop for underground and workover of wells (PRS section) carrying out routine workover of wells, performing geological technical measures to influence the bottomhole formation zone.

Well workover section (CDW) - well workover, geological technical measures aimed at intensifying oil production, increasing oil recovery, increasing the injectivity of injection wells.

Electrical equipment and power supply rolling repair shop (PRTSE and E) - providing power supply to NGDU facilities, performing scheduled preventive repairs and preventive tests of electrical equipment, equipment and electrical networks.

Production automation and steam supply workshop (CAPP) - supplies process water and heat energy (steam) to the subdivisions of NGDU and third-party consumers.

Construction and assembly shop (SMC) - arrangement of exploration, operational and commissioned wells, capital repairs of oil production facilities and social and cultural facilities, maintenance and scheduled preventive maintenance of instrumentation, automation and telemechanics at NGDU facilities.

Oilfield Research and Production Workshop (TsNIPR) - performance of hydrodynamic studies of wells and reservoirs, inspection of fresh water reservoirs, determination of air pollution in the area of ​​operation of NGDU, laboratory studies of the produced fluid, determination of the quality of treated and waste water at the UPTP, analysis of the physicochemical properties of petroleum gas ...

Workshop for anti-corrosion coatings and overhaul of pipelines and structures (DAC and KRTS). Workshop functions: internal cleaning of tanks, overhaul of tanks and heat exchangers, anticorrosive coating of tanks and tanks, dismantling of equipment and structures, laying pipelines at GPMT (flexible polymer metal pipes), monitoring the condition of welded seams, and measuring the wall thickness of pipelines, tanks, samplers and tanks (defectoscopy), repair of pumping compressor pipes, delivery of them to teams of workover and workover.

Workshop of flexible polymer-metal pipes (TsGPMT) - production of flexible polymer-metal pipes for oil collection and reservoir pressure maintenance systems, for transportation of highly watered oil and highly aggressive waste water, production of consumer goods.

The considered structure of NGDU "Oktyabrskneft" allows the enterprise to solve all the tasks assigned to it, to effectively use material and labor resources, therefore, it is advisable to dispose of its production capabilities.

2 Geological and physical characteristics of objects

The Serafimovskoye oil field is located in the northwestern part of Bashkortostan, in the Tuimazinsky region. Directly to the northwest of it is the large Tuimazinskoye oil field, and to the south the Troitskoye and Stakhanovskoye.

Within the limits of the deposit there are r.p. Serafimovsky, which was founded on December 31, 1952. It is home to the bulk of the workers leading the development and operation of this field. On the territory of the field there are asphalt roads and highways connecting the oil field facilities with the cities of Oktyabrsky and Belebey, with the railway stations of Tuimazy, Urussu, and Kandra.

The field is being developed by OOO NGDU Oktyabrskneft, located in the settlement Serafimovsky, and the drilling of wells is carried out by BurKan. The production of oil wells after primary treatment from the oil gathering park through the pumped station Subkhankulovo is pumped through the pipeline to the oil refineries in Ufa. Associated gas is consumed by the Tuimazinsky gas processing plant, partly used for local needs and transported through a gas pipeline to Ufa. Water supply is carried out from the central water conduit, which feeds water from the under-channel wells of the Usen River.

The climate of the region is continental. It is characterized by frosty winters with temperatures up to 45 0 C in January and rather hot summers with temperatures up to + 35 0 C in July. The average annual temperature is +3 0 C. The average annual precipitation is about 500 mm. Precipitation occurs mainly in the autumn and winter seasons.

From minerals, in addition to oil, there are limestones, clays, sands. These materials are used by the local population for construction and household needs. Besides, clay of special quality is used for preparation of mud for drilling wells.

Orographically, the area of ​​the deposit is a hilly plateau. The lowest elevations are confined to the river valleys, are about + 100m, the highest absolute elevations on the watersheds reach + 350m. As a rule, the southern slopes of the watersheds are steep and form promontory heights, well exposed, while the northern slopes are gentle, turf-covered and often covered with forest.

The hydrographic network of the region is well developed, but there are no large rivers. The main waterway of the region is the river. Ik. Its tributaries to the south of the deposit. are the rivers Kidash and Uyazy Tamak. The river flows within the deposit. Bishinda, which is a left tributary of the river. Ussen flowing outside the field. In the south of the deposit, groundwater outflows are observed in the form of springs.

Precambrian, Bavlinsky, Devonian, coal, Permian, Quaternary, Riphean, and Vendian deposits take part in the geological structure of the Serafimovskoye deposit.

The Serafimovskoye field is multi-layer. The main productive horizon is the sandy layer D I Pashi horizon. Commercially oil-bearing sandy formations: C- VI 1 , WITH- VI 2 , Bobrikovsky horizon, carbonaceous member of the Kizelovsky horizon of the Tournaisian stage, carbonate members of the Famennian stage, sandy layer D 3 kynovsky horizon, sandy layer D II Mullinsky horizon, sandy layers D III and D IV of the Old Oskal horizon.

The average depth of the Bobrikovian horizon is 1250 m, the Tournaisian stage is 1320 m, the Famennian stage is 1560 m, the D layer I -1690m, layer D II - 1700m, bed D III - 1715 m, layer D IV - 1730 m.

Tectonically, the Serafimovskaya Brakha anticlinal structure is located in the southeastern part of the Almetyevskaya summit of the Tatar arch and, together with the Baltaevskaya structure, makes up the Serafimovsko Baltaevsky swell. The total length of the embankment reaches 100 km, and its width ranges from 26 km in the west to 17 km in the east. In the central and northeastern parts of the Serafimovsko-Baltaevsky swell, the Serafimovskoe uplift is located, contoured in the southwestern part by the stratoizozypsum minus 1560m, and in the northeastern part by minus 1570m. The uplift measures 12X4 km and extends from southwest to northeast.

It should be noted that the arches of structures in the Carboniferous and Permian on the Leonidovskoe and Serafimovskoe uplifts coincide with its position in the Devonian sediments.

According to geophysical data, the stratum is represented mainly by three types of rocks: mudstones, siltstones and sandstones.

Devonian deposits are the main ones at the field. The most widespread in terms of area and thickness is layer D I ... Its thickness reaches 19.6 m. It is represented by quartz and fine-grained sandstone.

Horizon D II belongs to the sandstones of the Mullinovsky horizon. It is represented by interlayers of siltstones and mudstones, but mainly fine-grained, quartz sandstone prevails. Its capacity ranges from 19 - 33 meters.

Horizon D layers III represented by poorly sorted fine-grained quartz sandstones. Their capacity is very small and ranges from 1-3 meters. The deposits of this horizon are structurally lithologically small in size.

Horizon D layers IV - represented by fine-grained, in some places gravel, quartz sandstone. Their thickness is 8 meters, and in some places 8 to 12 meters. They contain 10 deposits of structural type.

The total thickness of the reservoirs of unit D is 28 - 35 m, and the oil-saturated thickness of the strata is 25.4 m.

The main characteristics of the horizons are shown in Table 1.

Table 1 Main characteristics of horizons

The formation oil of the Tournaisian stage is much different from the oils of the Devonian deposits. The saturation pressure of oil with gas is 2.66 MPa. In the Devonian deposits, this value is equal to 9 9.75 MPa, which is more than three times higher than in the Tournaisian stage. The density of oil in reservoir conditions is 886 kg / m3. More details on the properties of oil are given in tables 2 and 3.

Table 2 Physical properties of oil

Table 3 Chemical composition of oil

The properties of produced water are shown in Table 4.

Table 4 Properties of produced water

The gas composition is shown in table 5.

Table 5 Gas properties

3 Drilling of the wells.

An oil or gas field is being drilled under a development or exploration project. The geological department of the well drilling office, guided by the project, beat off the points on the ground by the topographer, which will be the wells of this field.

In order to technologically competently carry out the drilling process, it is necessary to know the basic physical and mechanical properties of rocks that affect the drilling process (elastic and plastic properties, strength, hardness, and abrasive ability). This is achieved by drilling exploratory wells from which a rock cut (core) is obtained. Samples of core and cuttings are sent to the geological department, which carries out their full examination.

Well drilling technology is a complex of sequentially performed operations aimed at achieving a specific goal. It is clear that any technological operation can be carried out only with the use of the necessary equipment. Let's consider the sequence of operations during well construction. Well construction is understood as the entire cycle of well construction from the beginning of all preparatory operations to the dismantling of equipment.

Preparatory work includes planning the area, installing foundations for an oil rig and other equipment, laying technological communications, electrical and telephone lines. The amount of preparatory work is determined by the relief, climatic and geographic zone, ecological situation.

Installation, placement of drilling rig equipment on the preparation site and its piping. Currently in the oil industry, block assembly is widely practiced, construction of large blocks assembled at factories and delivered to the installation site. This simplifies and speeds up installation. Installation of each node ends with testing it in working mode.

Well drilling is a gradual deepening into the earth's surface to the oil reservoir with strengthening of the walls of the wells. Well drilling begins with laying a hole 2..4 m deep, into which a chisel is lowered, screwed to a square suspended on a tackle system of the derrick. Drilling begins by imparting rotational motion to the square, and therefore to the bit, using the rotor. As it goes deeper into the rock, the bit together with the square is lowered with the help of a winch. The cuttings are removed by flushing fluid, which is pumped to the bit through a swivel and a hollow square.

After the well is deepened by the length of a square, it is lifted out of the well and a drill pipe is installed between it and the bit.

In the process of deepening, the destruction of the walls of the wells is possible, therefore, they must be strengthened (cased) at certain intervals. This is done using specially lowered casing pipes, and the well structure becomes stepped. At the top, drilling is carried out with a large diameter bit, then a smaller one, etc.

The number of stages is determined by the depth of the well and the characteristics of the rocks. Well design is understood as a system of casing pipes of various diameters, which are lowered into the well to various depths. For different regions, the designs of oil wells are different and are determined by the following requirements:

- counteraction to the forces of rock pressure, striving to destroy the well;

- preservation of the specified diameter of the trunk throughout its entire length;

- Isolation of horizons occurring in the well section containing agents of dissimilar chemical composition and the exclusion of their mixing;

- the ability to launch and operate various equipment;

- the possibility of prolonged contact with chemically aggressive media and resistance to high pressures and temperatures.

Gas, injection, piezometric wells are constructed at the fields, the designs of which are similar to those of oil.

The individual elements of the well structure have the following purposes:

1 The direction prevents the erosion of the upper unconsolidated rocks by the drilling fluid when drilling the well.

2 The conductor provides isolation of the aquifers used for drinking; water supply.

3 An intermediate string is run to isolate lost circulation zones, overlap productive horizons with abnormal pressures.

4 The production string provides isolation of all strata occurring in the field, running equipment and operating the well.

Depending on the number of casing strings, the well structure can be single-string, double-string, etc.

The bottom hole of the well, its filter, is the main element of the string, since it directly provides communication with the oil reservoir, drainage of the formation fluid within specified limits, and impact on the reservoir in order to intensify and regulate its operation.

Face designs are determined by the characteristics of the rock. So in mechanically stable rocks (sandstones) an open face can be performed. It provides full communication with the reservoir and is taken as a standard, and the indicator of the communication efficiency, the coefficient of hydrodynamic perfection, is taken as a unit. The disadvantage of this design is the impossibility of selective opening of individual interlayers, if any, therefore, open faces have received limited use.

Known bottomhole designs with separately run, prefabricated filters into a completely exposed uncased layer. The annular space between the bottom of the casing and the top of the screen is sealed. The openings in the filter are made round or slot-like, width 0.8 ... 1.5 mm, length 50 ... 80 mm. Sometimes filters are lowered in the form of two pipes, the cavity between which is filled with sorted gravel. These filters can be changed as soon as they become dirty.

The most widely used filters are those formed in the overlapping oil reservoir and cemented production casing. They simplify the technology of opening, make it possible to reliably isolate individual layers and act on them, but these filters also have a number of disadvantages.

4 Development of oil fields .

The development of an oil field is understood as the implementation of the process of moving liquid (oil, water) and gas in layers to production wells. Controlling the flow of liquid and gas is achieved by placing oil, injection and control wells in the field, the number and procedure for putting them into operation, the operating mode of the wells and the balance of reservoir energy. The development system adopted for a particular deposit predetermines technical and economic indicators - oil flow rate, its change over time, oil recovery factor, capital investments, prime cost, etc. Before drilling a deposit, the development system is designed. In a development project, on the basis of exploration and trial operation data, conditions are established under which the deposit will be exploited, i.e., its geological structure, reservoir properties of rocks (porosity, permeability, degree of heterogeneity), physical properties of fluid and gases saturating the formation (viscosity , density, solubility of gases), saturation of rocks oil, water and gas, reservoir pressure, temperature, etc. Based on these data, with the help of hydrodynamic calculations, the technical indicators of reservoir exploitation for various development system options are established and an economic assessment of the system options is made. As a result of a technical and economic comparison, the optimal development system is selected.

Oil recovery from wells is carried out either by natural flowing under the influence of reservoir energy, or by using one of several mechanized methods of liquid lifting. Usually, in the initial stage of field development, flowing production predominates, and as the flowing weakens, the well is switched to artificial lift. The mechanized methods include: gas-lift and deep pumping (using sucker-rod, submersible electric centrifugal and screw pumps).

The development of oil fields is an intensively developing area of ​​science. Its further development will be associated with the use of new technologies for extracting oil from the subsoil, new methods for recognizing the nature of the flow of in-situ processes, managing field development, using advanced methods for planning exploration and development of deposits taking into account data from related sectors of the national economy, using automated control systems for extracting minerals from the subsoil, the development of methods for detailed accounting of the structure of layers and the nature of the processes occurring in them on the basis of deterministic models.

The development of oil fields is associated with significant human intervention in nature and therefore requires unconditional compliance with established standards for the protection of subsoil and the environment.

Well drilling ends with the opening of the oil reservoir, i.e. communication of the oil reservoir with the well. This stage is very important for the following reasons. The oil and gas mixture in the formation is under high pressure, the magnitude of which may be unknown in advance. At a pressure exceeding the pressure of the liquid column filling the well, liquid may be ejected from the wellbore and open flowing will occur; the ingress of drilling fluid (in most cases, it is a clay solution) into the oil reservoir clogs its channels, impairing the flow of oil into the well.

It is possible to avoid gushing by providing for the installation of special devices at the wellhead, blocking the wellbore of preventers, or by using a high-density flushing fluid.

Prevention of the penetration of the solution into the oil reservoir is achieved by introducing various components into the solution: components similar in properties to the formation fluid, for example, oil-based emulsions.

Since, after opening the oil reservoir by drilling, the casing is lowered into the well and cemented, thereby blocking the oil reservoir, it becomes necessary to re-open the reservoir. This is achieved by shooting through the string in the formation interval with special perforators having powder-based charges. They are lowered into the borehole on a cable rope by a geophysical service.

Currently, several methods of well perforation have been mastered and are being applied.

Bullet perforation of wells is included. in the descent into the borehole on a cable rope of special devices of perforators, in the body of which powder charges with bullets are built. Receiving an electrical impulse from the surface, the charges explode, imparting high velocity and high penetrating power to the bullets. It causes destruction of the column metal and the cement ring. The number of holes in the string and their location along the thickness of the formation are calculated in advance, so sometimes a string of perforators is lowered. The pressure of the burning gases in the barrel of the chamber can reach 0.6 ... 0.8 thousand MPa, which ensures the production of perforations with a diameter of up to 20 mm and a length of 145 ... 350 mm. Bullets are made of alloy steel and are coated with copper to reduce friction when moving along the chamber or lead.

Torpedo perforation on the principle of implementation is similar to the bullet, only the weight of the charge is increased. from 4 ... 5 to 27 years and horizontal shafts are used in the perforator. The diameter of the holes is 22 mm, the depth is 100 ... 160 mm, up to four holes are made per 1 m of the layer thickness.

Cumulative perforation - the formation of holes due to the directional movement of a jet of incandescent escaping from the perforator at a speed of 6 ... 8 km / s with a pressure of 0.15 ... 0.3 million MPa. In this case, a channel is formed with a depth of 350 mm and a diameter of 8 ... 14 mm. The maximum thickness of the seam, exposed by a cumulative perforator per launch up to 30 m, torpedo up to 1 m, bullet up to 2.5 m.The amount of powder charge is up to 50 g.

Hydro-sandblasting perforation - the formation of holes in the column due to the abrasive action of the sand-liquid mixture escaping at a speed of up to 300 m / s from calibrated nozzles with a pressure of 15 ... 30 MPa.

Developed at VNII and mass-produced under the code AP 6M, the sandblasting machine has proven itself well: the depth of the pear-shaped channels it receives can reach 1.5 m.

Drilling hammer is a device for forming a filter by drilling holes. For this purpose, a drilling core barrel developed at VNIIGIS (Oktyabrsky) is used, the electric drive of which is connected to a diamond drill. The maximum radial is 60 mm, which provides, according to the results of the practice of passing the casing, the entry into the formation to a depth of no more than 20 mm. Perforation has received the name "sparing", as it excludes damage to the column and the cement ring, which are inevitable with blasting methods. Drilling perforation has a high precision in the formation of the filter in the required interval.

The development of oil wells is a set of works carried out after drilling, in order to induce the flow of oil from the formation into the well. The fact is that in the process of opening, as mentioned earlier, it is possible for drilling mud and water to enter the formation, which clogs the pores of the formation, displaces oil from the well. Therefore, spontaneous oil inflow into the well is not always possible. In such cases, they resort to an artificial inflow challenge, which consists in carrying out special works.

This method is widely used and is based on the well-known fact: a column of liquid with a high density exerts more back pressure on the formation. The desire to reduce the back pressure by displacing from the wellbore, for example, clay mud with a density of Qg = 2000 kg / m3 with fresh water with a density of Qb = 1000 kg / m3 leads to a halving of the back pressure on the formation. The method is simple, economical and effective in case of weak formation clogging.

If the replacement of the solution with water does not bring results, they resort to a further decrease in density: air compressed by a compressor is fed into the barrel. At the same time, it is possible to push the liquid column back to the tubing shoe, thus reducing the back pressure on the formation to significant values.

In some cases, it can be effective to intermittently supply air by the compressor and liquid by the pumping unit, creating successive air portions. The number of such portions of gas can be several, and they, expanding, eject liquid from the barrel.

In order to increase the efficiency of displacement along the length of the tubing string, opening valves are installed through which compressed air enters the tubing immediately upon entering the well and begins to "work" i.e. to lift fluid both in the annulus and in the tubing.

Also used is the running of the tubing of a special swab piston equipped with a check valve. Moving downward, the piston passes liquid through itself, when it rises upward, the valve closes, and the entire column of liquid above it is forced to rise together with the piston, and then be thrown out of the well. Since the column of fluid being lifted can be large (up to 1000 m), the pressure drop on the formation can be significant. So, if the well is filled with liquid to the wellhead, and the swab can be lowered to a depth of 1000 m, then the pressure will decrease by the amount of the decrease in the liquid column in the annulus, from where part of the fluid will flow from the tubing. The swabbing process can be repeated many times, which makes it possible to reduce the pressure on the formation by a very large amount.

5 PPD system

Natural modes of occurrence of oil deposits are short-lived. The process of reducing reservoir pressure accelerates as the production of fluids from the reservoir increases. And then, even with a good connection of oil deposits with the supply circuit, its active influence on the deposit, the depletion of reservoir energy inevitably begins. This is accompanied by a widespread decrease in dynamic fluid levels in the wells and, consequently, a decrease in production.

When organizing the maintenance of reservoir pressure (RPM), the most difficult of the theoretical issues and still not fully resolved is the achievement of maximum displacement of oil from the reservoir with effective control and regulation of the process.

It should be borne in mind that water and oil differ in their physicochemical characteristics: density, viscosity, surface tension coefficient, and wettability. The greater the difference between the indicators, the more difficult is the process of displacement. The mechanism of oil displacement from a porous medium cannot be represented by a simple piston displacement. Here, there is a mixing of agents, and a rupture of an oil jet, and the formation of separate, alternating flows of oil and water, and filtration through capillaries and cracks, and the formation of stagnant and dead-end zones.

The oil recovery factor of a field, to the maximum value of which the technologist should strive, depends on all of the above factors. The materials accumulated to date make it possible to assess the impact of each of them.

A significant place in the efficiency of the reservoir pressure maintenance process is occupied by the placement of wells in the field. They define the waterflooding pattern, which is subdivided into several types.

In-circuit waterflooding involves the injection of water into injection wells located outside the outer contour of oil-bearing capacity. As the oil-bearing contour moves away from the injection wells and watering of the first row of production wells, the injection front is transferred.

The criterion for the normal conduct of the process is the value of the reservoir pressure in the production zone, which should tend to increase or stabilize.

Inline waterflooding is effective when the following factors are present:

- small size of the deposit (the ratio of the area of ​​the deposit to the perimeter of the oil-bearing contour is 1.5 ... 1.75 km);

- homogeneous reservoir with good reservoir properties in thickness and area;

Injection wells are spaced from the oil-bearing contour at a distance of 300 ... 800 m, which will ensure a more uniform advance of the water front and prevent the formation of flooding tongues;

there is a good hydrodynamic connection between the withdrawal zone and the injection zone.

The disadvantages of aquifer flooding include:

1 large losses of injected water due to its leaks to the side opposite to the injection area, which leads to additional energy consumption;

2 remoteness of the injection line from the extraction zone, which requires significant energy consumption to overcome losses;

3 delayed reaction of the selection front to changes in conditions on the discharge line;

4 the need to construct a large number of injection wells; the remoteness of injection wells from the main injection targets, which increases during development, increases the cost of the system.

Intra-contour waterflooding involves the injection of water directly into the oil zone, the organization of one or several rows of injection wells in the center of the field and, due to this, the dismemberment of the reservoir into separate areas, developed independently. Cutting can be done into strips, rings, etc. The efficiency of this waterflooding method is obvious: the efficiency of the system increases by eliminating the outflow of fluid, approaching the injection front to the withdrawal front.

A variety of intra-contour waterflooding are: areal, focal, selective, block.

Areal waterflooding provides for the placement of injection wells in the field according to one of the schemes. Areal waterflooding is usually organized at a late stage of field development, when intensive waterflooding begins and other waterflooding methods do not reach the goal. Injection wells are placed on a geometric grid: five, seven or nine-spot. At the same time, for one injection well there is one production well with a five-point system, two with a seven-point system, and three with a nine-point system.

Focal waterflooding can be schematically represented in the form of one or several injection wells located in the center of the reservoir and a certain number of production wells at the periphery. This method of waterflooding is typical for small-area, localized deposits (lenses, stagnant zones).

Selective waterflooding is used to displace oil from separate, poorly drained formations that are heterogeneous along strike. For its application, information is needed on the characteristics of the section, disturbances and connections of the productive formation with others. Such data can be obtained after some time of reservoir development, therefore, selective waterflooding is used at a later stage of development.

Block flooding consists in cutting the reservoir into separate parts and delineating each of them with injection wells. Production wells are drilled inside each block, the number and arrangement of which are determined by calculations. Block flooding allows the field to be brought into development immediately, before it is fully explored and, thus, to reduce the development time. This is effective for large deposits.

The existing disadvantages of the RPM system by water injection include:

1) progressive flooding of the field with a large amount of oil that has not been recovered;

2) low washing properties of water injected into the reservoir;

3) a large number of complications caused by the return to the formation of stratal waters produced together with oil, expressed in the form of destruction of water pipelines, salinization of drinking water sources, and disturbances in the ecological balance.

Improvement of the PPD is in the following areas:

1) development of new process fluids or additives to water that improve its washing properties and are less aggressive towards equipment and nature;

2) development of reliable control over the movement of fluid in the formation;

3) development of a method for regulating filtration flows in the reservoir and excluding the formation of dead-end and undeveloped zones.

The reservoir pressure maintenance is designed at the beginning of the development of most oil fields.

Currently, several types of water are used for RPM purposes, which are determined by local conditions. This is fresh water extracted from special artesian or under-channel wells, water from rivers or other open water sources, water from aquifers found in the geological section of a field, formation water separated from oil as a result of its preparation.

All these waters differ from each other in their physicochemical properties and, therefore, in the effectiveness of stimulating the formation not only to increase pressure, but also to increase oil recovery.

Formation water in the process of separation from oil is mixed with fresh water, with demulsifiers, as well as with process water of oil treatment units. It is this water, called waste water, that is pumped into the reservoir. A characteristic feature of waste water is the content of oil products (up to 100 g / l), hydrocarbon gases up to 110 l / m3, suspended particles - up to 100 mg / l.

Such water cannot be injected into the reservoir without cleaning up to the required standards, which are established based on the results of the pilot injection. At present, in order to reduce the consumption of fresh water and utilize the produced stratal water, wastewater treatment is widely used for reservoir pressure maintenance purposes.

The most common cleaning method is gravity separation of components in tanks. In this case, a closed scheme is applied. Waste water with a content of oil products up to 500 thousand mg / l and mechanical impurities up to 1000 mg / l enters the sedimentation tanks from above. The oil layer at the top serves as a kind of filter and improves the quality of water purification from oil. Mechanical impurities settle down and, as they accumulate, are removed from the reservoir.

From the reservoir, water enters the pressure filter. Then a corrosion inhibitor is fed into the pipeline, and the water is pumped out by pumps to the pump station.

For accumulation and settling of water, vertical steel tanks are used. Anti-corrosion coatings are applied to their inner surface in order to protect them from the effects of formation waters.

6 Operation of oil and injection wells

The most widespread technological complex during field operation at the enterprise LLC NGDU "Oktyabrskneft" is oil production by sucker rod pumps. Forced lifting of oil from wells using sucker rod pumping units is the longest in the life of the field.

Modern sucker-rod pumping units can produce oil from one or two wells with a depth of up to 3500 m with a liquid flow rate from several cubic meters to several hundred cubic meters per day. At the Serafimovskoye field, 172 wells are equipped with sucker-rod pumping units, which is 94% of the total stock of producing wells.

The USHGN is a single-acting piston pump, the rod of which is connected by a column of rods with a ground drive - a rocker unit.

The latter includes a crank mechanism that converts the rotational motion of the prime mover into reciprocating motion and imparts it to the rod string and the pump plunger. The underground equipment consists of: tubing, pump, rods, devices for dealing with complications. Ground equipment includes a drive (rocker), wellhead equipment, working monifold.

The installation works as follows. When the plunger moves up, the pressure in the pump cylinder decreases and the lower (suction) valve rises, opening the access of liquid (suction process). At the same time, the liquid column located above the plunger presses the upper (delivery) valve to the seat, rises up and is thrown out of the tubing into the working monifold. When the plunger moves down, the upper valve opens, the lower valve is closed by fluid pressure, and the liquid in the cylinder flows through the hollow plunger into the tubing.

In LLC NGDU Oktyabrskneft, surface equipment of wells is represented mainly by pumping units of a normal row type SKN5 31%, SKD8 15%, 7SK8 29%

Electric centrifugal pump installations (ESP) are also used at the field. As a drive of the ESP, a submersible electric motor is used, which is lowered into the well together with a pump to a given depth.

By design, ESPs are subdivided into three groups:

a) pumps of version 1 are intended for the operation of oil and water-cut wells with a solids content of up to 0.1 g / l;

b) pumps of version 2 (wear-resistant version) are intended for operation of heavily watered wells with a solids content of up to 0.5 g / l;

c) pumps of version 3 are designed for pumping liquid with a pH value of 5-8.5 and a content of up to 1.25 g / l of hydrogen sulfide.

Underground equipment includes:

a) an electric centrifugal pump, which is the main unit of the installation (ESP);

b) a submersible electric motor (SEM), which drives the pump;

c) a hydraulic protection system that protects the submersible from the ingress of formation fluid into it and consists of a protector and a compensator;

d) a current-carrying cable serving to supply electricity to the submersible motor;

e) tubing (tubing), which is a channel through which the produced fluid flows from the pump to the day surface.

Ground equipment includes:

a) wellhead equipment, which serves to direct and control the incoming fluid from the well and to seal the wellhead and cable;

b) a submersible motor control station that launches, monitors and controls the operation of the ESP;

c) a transformer designed to regulate the magnitude of the voltage supplied to the SEM;

d) a suspension roller, which serves to suspend and direct the cable into the well during running and lifting operations.

ESP is the main unit of the installation. Unlike piston pumps, which impart the pressure of the pumped liquid through the reciprocating movements of the piston, in centrifugal pumps the pumped liquid receives pressure on the blades of a rapidly rotating impeller. In this case, the kinetic energy of the moving fluid is converted into potential pressure energy.

Before installing the ESP, it is necessary to prepare the well for its operation. To do this, it is washed, that is, the bottom is cleaned of sand plugs and possible foreign objects. Then, a special template is lowered and raised into the casing string from the wellhead to a depth exceeding the unit lowering depth by 100 - 150 m, the diameter of which is slightly larger than the maximum diameter of the submersible unit. At the same time, the tower or mast is carefully centered relative to the wellhead.

For the most part, injection wells do not differ in design from production wells. Moreover, a certain number of production wells that find themselves in the zone of the water-bearing contour or behind it are transferred to the category of injection wells. In case of intra-contour and areal flooding, the transfer of production wells to water injection is considered normal.

The existing designs of injection wells provide for water injection through the tubing, which is run with a packer and an anchor. Above the packer space should be filled with a liquid neutral to metal.

The bottomhole must have a filter of sufficient thickness, ensuring the injection of the planned volume of water, with a depth of at least 20 m for the accumulation of mechanical impurities. It is advisable to use insert filters, which can be periodically raised from the wells and cleaned.

The wellhead fittings of the injection well are designed to supply and control the volume of water into the well, to carry out various technological operations of flushing, development, treatments, etc.

The armature consists of a casing flange, a cross used for communication with the annular space, a coil on which the tubing is suspended, a tee for supplying the injected fluid to the well. The purpose and design of the packer and anchor do not fundamentally differ from those used for flowing wells.

7 Well survey

During the operation of wells, they are investigated in order to monitor the technical condition of the production string, the operation of equipment, check the compliance of the parameters of the wells with the established technological regime, and obtain information necessary to optimize these regimes.

When examining wells:

a) the technical condition of the well and installed equipment is checked (tightness of cement stone, casing and tubing, condition of the bottomhole formation zone, contamination of the wellbore, pump flow, operation of valves and other devices installed at depth);

b) the reliability and performance of the equipment units is assessed, and the overhaul period of the equipment and wells is determined;

c) receive the information necessary for planning various types of workover and other work in wells, as well as for establishing the technological efficiency of these works.

To solve the above problems, a complex of various types of research and measurements is used (measurement of oil production, water cut, gas factor, in-depth measurements of temperatures and pressure, depth measurements, dynamometry, recording the costs of a working agent, accounting for equipment failures and repairs, analysis of well production samples, etc. .).

The types, volume and frequency of studies and measurements in order to control the operation of equipment for all methods of well operation are established by the department together with research organizations and geophysical enterprises.

Studies to monitor the operation of production wells must be carried out in full compliance with safety rules in the oil and gas industry, in compliance with the requirements for the protection of subsoil and the environment.

The basis of the study of the sucker rod pumping unit is dynamometry - a method of operational control over the operation of underground equipment and the basis for establishing the correct technological mode of operation of the pumping unit.

The essence of the method is that the load on the stuffing box rod is determined without lifting the pump to the surface using a dynamograph. On paper, in the form of a diagram, the loads are recorded during the up and down strokes, depending on the movement of the stem.

To determine the distance from the mouth to the dynamic level, sound metering methods are used. The most common are various echometric installations for wells with a pressure of 0.1 MPa. The principle of operation of these installations is that an acoustic pulse is sent into the annulus from a powder crackle. This impulse, reflected from the level of the liquid, returns to the mouth, acting on the thermophone, and, after being converted and amplified into an electrical one, is recorded by a pen on a moving paper tape.

Wave metering is performed using an echo sounder, which allows you to determine the dynamic level in wells up to 4000 m deep at an annular pressure of up to 7.5 MPa. Downhole and along the wellbore, pressure and temperature are measured using depth thermometers, which are combined in one device.

8 Methods for increasing well productivity

In oil and gas wells, the flow rate and productivity of the wells decrease over time. This is a natural process, since there is a gradual decrease in reservoir pressure, the energy of the reservoir, which is required to lift liquid and gas to the surface, decreases.

Well productivity also decreases as a result of the deterioration of the permeability of the rocks, the productive formation due to the clogging of its pores in the bottomhole zone with resinous, paraffinic deposits, mechanical particles of formation removal.

To stabilize the level of oil and gas production, various methods of influencing the bottomhole formation zone are used, which make it possible to increase oil recovery and not reduce well productivity. Methods for increasing the productivity of wells when influencing the bottomhole formation zone are divided into chemical, mechanical, thermal and complex.

Of decisive importance when choosing a treatment method in each specific case is the required depth of treatment of a productive formation to restore or improve permeability. Therefore, according to the depth of impact on the porous medium, the methods of well stimulation can be divided into two large categories: methods with a small radius of influence and methods with a large radius of influence. The main ways to improve the connectivity of the formation with a well with a small impact radius:

a) The use of explosives. These include bullet, cumulative perforation, various torpedo options.

If there is insufficient connectivity between the formation and the wellbore, conventional perforation with a bullet perforator can be repeated. To increase its efficiency, the well is filled not with clay solution or water, but with fluids that do not pollute the newly created perforations.

With hard and dense rocks, it is possible to torpedo the productive formation with an explosive lowered into the interval of the formation in the liners, and an electric fuse, which is blown up with a cable from the wellhead. The liners are made from asbestos metal or plastics. The most commonly used explosives are nitroglycerin, TNT dynamite, etc. An explosion can create caverns and cracks in a pay stratum. Thus, at the same time as improving the connectivity of the formation with the well, the permeability of the formation in the zone with a large radius also increases (the creation of micro and macro cracks, which can spread over tens of meters).

Directional torpedoing can be accomplished by using an appropriate external charge form and inserts in the blast path. Depending on the need, torpedoes of lateral scattered action, lateral concentrated and vertical action can be used.

Perforators with explosive projectiles create round holes in the column and with the cement ring, penetrating into the rock, and, exploding, form caverns and cracks. A shaped-charge perforator consists of a device, the cells of which contain charges of shaped-charge action. Each cell on the opposite side of the fuse is equipped with a recess of the corresponding profile. Thus, the gaseous products of the explosion are directed along the axis of the charge in the form of a powerful jet, which creates a channel in the column, cement and rock in the corresponding direction.

b) Cleaning the wellbore and perforation zone with surfactants or acid baths. The liquids used in this case consist either of a solution of 1 5% surfactants dissolved (or dispersed) in water, or from a solution with a content of 15% HCI , To which is added 0.5 to 2% of a corrosion inhibitor and sometimes 1 to 4% of hydrofluoric acid. In some cases, mixed compositions of acids and surfactants are used. Typically, the well is flushed with one of the above-mentioned solutions, then a working fluid is included in the formation in a volume of 0.3 0.7 m 3 for each meter of the perforation interval. For acid compositions, an exposure of 1-6 hours is given, for a surfactant without acid, the exposure is 24 hours, then the spent solution is removed and the well is put into operation or the formation is started using a method with a large radius of influence.

The use of surface-active solutions for flushing the well or pumping into the formation at a shallow depth ensures despergation and removal of solid particles and drilling mud filtrate from the wellbore and from the formation, as well as oil-water emulsion.

Acid baths are cleaned of clay solution in new wells (or those that have been overhauled), and also eliminate salt deposits from formation water accumulated during operation.

c) Increase in temperature in the wellbore in the interval of the productive formation. Thermal methods. To increase the temperature, you can use the circulation of hot liquid in the well, thermochemical processes, electric heaters. The duration of heating the perforated zone of the well is usually 5-50 hours. In this case, the liquefaction of deposits of solid hydrocarbons (paraffin, resins, asphaltenes, etc.), which are then removed when the well is put into operation. The circulation of flammable liquids in the well is easily realized, but at depths of more than 1000-2000 m. it is not very effective due to large heat losses from the well into the sediments of the exposed geological discharge.

Electric heaters use a system of electrical resistances mounted in a pipe, which is installed at the end of the tubing string. Electric power is supplied from the surface via a cable. There are also heaters based on the use of high frequency tones. Electric heaters can be located at the bottom of the well and during its operation. In this case, starting and stopping the heaters are carried out by turning the power supply on and off.

Gas burners consist of a tubular chamber, lowered into a well, with two concentric tubing strings. Combustible gases are injected through pipes of small diameter, primary air through the annular space, and secondary air through the column. Combustion is initiated by supplying electrical energy through a cable from the surface. Another cable with a thermocouple measures the temperature from the outside, which should not exceed 300 400 0 С, so as not to damage the well string. The temperature is maintained at the desired level by appropriately adjusting the gas and air discharge volumes.

Thermochemical treatment is based on the release of heat at the bottom of the well due to a chemical process, which straightens out heavy hydrocarbons that have fallen out in the perforation zone of the well, with the aim of their subsequent removal. To do this, use the reaction of a 15% solution HCI with caustic soda ( Na OH), aluminum and magnesium.

As a result of the reaction of 1 kg of sodium hydroxide with hydrochloric acid, 2868 kJ of heat is released. A large amount of heat is obtained during the reaction HCI with aluminum (which generates 18924 kJ per kg Al ). However, this produces flakes of aluminum hydroxide. Al ( OH ) 3, which are capable of plugging pores and flow channels in the reservoir. The most effective use of magnesium, which, when reacted with HCI releases 19259 kJ, and magnesium chloride MgCi 2 dissolves well in water.

The main ways to improve the connectivity of a productive formation with a well with a large impact radius:

a) Acid treatment of the bottomhole zone of the productive formation. These methods are mainly used in sands with a carbonate content of more than 20% or with a cementitious material consisting of calcium or magnesium carbonates.

The main acid used is H WITH I ... It effectively acts on calcium or magnesium carbonate to form soluble and easily removable chlorides. Hydrochloric acid is cheap and not in short supply. Other acids are also used: acetic, formic, etc. Various additives are also introduced into acid solutions: corrosion inhibitors, additives for reducing surface tension, slowing down the reaction, dispersing, etc.

When an acid solution is injected into the reservoir at injection pressures lower than the fracture pressure, the pores in the bottomhole formation zone or cracks and microcracks in the reservoir rock are cleaned and expanded, thus restoring the impaired permeability of the treated zone, and in some cases even increasing its initial value ...

The work technology is as follows: the well is cleaned and filled with oil or water (salt or fresh) with an additive of 0.1 0.3% surfactant. An acidic solution is prepared on the surface with the addition of the necessary components, the sequence of the introduction of which is established mainly according to laboratory research data. An acidic solution is pumped into the tubing with an open valve on the annulus of the well. When it reaches the perforation interval of the well, the valve is closed and the acid solution is pumped through the pipes until it penetrates into the reservoir, and at the last stage the solution is forced through with oil or water with an additive of 0.1–0.3% surfactant. Withstand 1 6 hours (but not more) for the acid reaction, then the solution is removed. The well is put into operation. At the same time, the change in production rate is closely monitored to determine the effect of the treatment performed.

There are various technological options for acidizing, such as: simple, selective, repeated, alternating, with vibration, etc.

b) Hydraulic fracturing of the productive formation in the bottomhole zone of the well. This method is used in formations represented by hard, dense rocks with low permeability (sandstones, limestones, dolomites, etc. The fracture pressure is reached by pumping liquid under high pressure into the well. In this case, existing cracks and microcracks are opened or new ones are created, which can significantly improve the hydrodynamic connection between the formation and the well.

c) Underground nuclear explosions. Explosions have been experimentally investigated with positive results in hard, tight formations with low permeability. As a result of a nuclear explosion, a cavity is formed around the charge well in the productive formation, filled with destroyed rock, then a crushing zone and behind it a zone with a system of cracks and microcracks. This method is of interest, especially for gas wells, the flow rate of which can thus be increased by several tens of times.

d) Thermal methods. They are based on the increase in temperature in the formation around the well and are used in pay deposits saturated with highly viscous oils with a high paraffin content. These methods are similar to the methods of increasing the temperature in the wellbore, but require more heat to warm up the formation within a radius of 2-15 m. a reservoir of limited volumes of steam (cyclic steam injection) or a circular front of underground combustion around a production well, determined by the calculated radius to which it is necessary to heat the reservoir. In addition, in recent years, various new technologies have been developed for influencing the bottomhole formation zone, based on the use of modern reagents and chemical industry wastes.

9 Routine and workover of wells

There are two types of well workover - surface and underground. Ground repair is associated with the restoration of the operability of the equipment located at the wellhead of pipelines, pumping units, valves, electrical equipment, etc.

Underground repair includes work aimed at eliminating malfunctions in equipment run into the well, as well as restoring or increasing the flow rate of the well. Underground repairs are associated with lifting equipment from a well.

According to the complexity of the operations performed, underground repairs are divided into current and capital repairs.

Under the current workover of a well is understood a set of technological and technical measures aimed at restoring its productivity, and limited by impact on the bottomhole formation zone and equipment located in the well.

Routine repair includes the following works: replacement of failed equipment, cleaning the bottom and the wellbore, restoring the reservoir productivity due to separate methods of stimulation (heating, flushing, injection of chemicals).

Current repairs can be planned preventive and carried out for the purpose of preventive inspection, identification and elimination of individual disturbances in the well operation, which have not yet announced themselves.

The second type of current repair - recovery, carried out in order to eliminate the failure - is, in fact, emergency repair. In practice, such repairs prevail due to various reasons, but mainly due to imperfect technologies and low reliability of the equipment used.

The indicators characterizing the operation of a well in time are the operating factor (KE) and the overhaul period (MCI). CE is the ratio of the time worked by the well, for example, per year (TOTR), to the calendar period (TCAL). MCI is the average time between two repairs for the selected period, or the ratio of the total TOTR hours worked per year to the number of repairs P during the same period.

CE = TOTR / TKAL;

MRP = TOTR / R;

The ways to increase the CE and MFR are to reduce the number of workovers, the duration of one workover, and an increase in the well staying time.

Currently, more than 90% of all workovers are performed on wells with sucker-rod pumps and less than 5% with ESPs.

During the current repair, the following operations are carried out

1. Transport - delivery of equipment to the well;

2. Preparatory - preparation for repair;

3. Lowering - lifting and lowering of oil equipment;

4. Operations for cleaning the well, replacing equipment, eliminating minor accidents;

5. Final - dismantling the equipment and preparing it for transportation.

If we evaluate the time spent on these operations, then we can see that the main loss of time is spent on transport operations (they take up to 50% of the time), therefore, the main efforts of designers should be directed towards reducing the time for transport - by creating assembly-capable machines and units , round-trip operations - due to the creation of reliable automatic machines for screwing and unscrewing pipes and rods.

Since routine maintenance of a well requires access to its wellbore, i.e. associated with depressurization, therefore, it is necessary to exclude cases of possible gushing at the beginning or at the end of work. This is achieved in two ways: the first and widely used - "killing" the well, i.e. injection into the formation and the well of a liquid with a density that ensures the creation of pressure P zab at the bottom of the well. exceeding the reservoir. The second is the use of various devices - cut-off devices that shut off the bottom of the well when lifting the tubing.

Run-and-hop operations (TROs) occupy the main share in the total balance of time spent on well workover. They are inevitable during any work on running and replacing equipment, impact on the bottom hole, flushing strings, etc. The technological process of tripping consists of alternately screwing (or unscrewing) the tubing, which is a means of suspending equipment, a channel for lifting the produced fluid and supplying process fluids to the well, and in some cases, a tool for fishing, cleaning and other works. This variety of functions has made tubing an indispensable component of well equipment for any method of operation without exception.

Tubing operations are monotonous, labor intensive and can be easily mechanized. In addition to the preparatory and final operations, which have their own specifics for various modes of operation, the entire process of tripping with tubing is the same for all types of maintenance. Descent and lifting operations with the rods are performed in the same way as with pipes, and the unscrewing (screwing) of the rods is performed with a mechanical rod wrench.In case of jamming of the plunger in the pump cylinder or rods in the tubing (waxing), as well as when they break, it becomes necessary to simultaneously lift the pipes and rods. The process is carried out by alternately unscrewing the pipe and rod.

Well workover combines all types of work that require a long time, great physical effort, and the involvement of numerous multifunctional equipment. These are works related to the elimination of complex accidents, both with equipment lowered into the well, and with the well itself, work on transferring a well from one operation object to another, work to limit or eliminate water inflow, increase the thickness of the exploited material, impact on the formation, sidetracking of a new trunk and others.

Taking into account the specifics of the work, specialized workshops for workover of wells are being created in the oil and gas production departments. The well included in the overhaul remains in the operating stock, but is excluded from the operating stock.

10 Collection and preparation of oil, gas and water

Production from oil and gas wells is not, respectively, pure oil and gas. Formation water, associated (oil) gas, solid particles of mechanical impurities come from wells together with oil.

Produced water is a highly mineralized medium with a salt content of up to 300 g / l. The content of formation water in oil can reach 80%. Mineral water causes increased corrosive destruction of pipes, reservoirs, wear of pipelines and equipment. Associated (petroleum) gas is used as raw material and fuel.

It is technically and economically feasible to subject oil to a special preparation before being fed into the main oil pipeline in order to desalt it, dehydrate it, degass it, and remove solid particles.

In oil fields, a centralized scheme for collecting and treating oil is most often used (Fig. 2). The collection of products is carried out from a group of wells to automated group metering units (AGZU). From each well through an individual pipeline, oil is supplied to the AGSU along with gas and formation water. The AGZU records the exact amount of oil coming from each well, as well as primary separation for partial separation of formation water, oil gas and mechanical impurities with the direction of the separated gas through a gas pipeline to a gas processing plant (gas processing plant). Partially dewatered and partially degassed oil flows through a collection header to a central collection point (CPF). Usually, one CPF is arranged at one oil field.

Oil and water treatment plants are concentrated at the CPF. All technological operations for oil preparation are carried out at the oil treatment plant. The set of this equipment is called the UKPN complex oil treatment unit. .

Figure 2. - Scheme of collection and preparation of well production in the oil field:

1 oil well;

2 automated group metering units (AGZU);

3 booster pump station (BPS);

4 formation water treatment unit;

5 oil treatment unit;

6 gas compressor station;

7 7central collection point for oil, gas and water;

8 reservoir Park

Dehydrated, demineralized and degassed oil, after the completion of the final control, enters the tanks of commercial oil and then to the head pumping station of the main oil pipeline.

Oil dehydration is hindered by the fact that oil and water form stable water-in-oil emulsions. In this case, water is dispersed in the oil medium into tiny droplets, forming a stable emulsion. Therefore, for dehydration and desalination of oil, it is necessary to separate these tiny water droplets from it and remove water from the oil. For dehydration and desalting of oil, the following technological processes are used:

- gravity sediment of oil,

- hot oil sludge,

- thermochemical methods,

- electrical desalination and electrical dehydration of oil.

The process of gravity settling is the simplest in terms of technology. In this case, the tanks are filled with oil and kept for a certain time (48 hours or more). During exposure, the processes of coagulation of water droplets occur, and larger and heavier water droplets under the action of gravity (gravity) settle to the bottom and accumulate in the form of a layer of produced water.

However, the gravitational process of cold oil sludge is an ineffective and insufficiently effective method of oil dehydration. The hot sludge of watered oil is more efficient, when, due to the preheating of oil to a temperature of 50–70 ° C, the processes of coagulation of water droplets are greatly facilitated and the dehydration of oil during sludge is accelerated. The disadvantage of gravity dewatering methods is its low efficiency.

More effective methods are chemical, thermochemical, as well as electrical dehydration and demineralization. In chemical methods, special substances called demulsifiers are introduced into the watered oil. Surfactants are used as demulsifiers. They are added to the composition of oil in small quantities from 5 10 to 50 60 g per 1 ton of oil. The best results are shown by the so-called nonionic surfactants, which do not decompose into anions and cations in oil.

Demulsifiers are adsorbed at the oil-water interface and displace or replace surface-active natural emulsifiers contained in the liquid. Moreover, the film formed on the surface of water droplets is fragile, which marks the merging of small droplets into large ones, i.e. coalescence process. Large droplets of moisture easily settle to the bottom of the tank. The efficiency and rate of chemical dehydration is significantly increased by heating the oil, i.e. with thermochemical methods, by reducing the viscosity of oil during heating and facilitating the process of coalescence of water droplets.

Removal of the residual water content is achieved using electrical methods of dehydration and desalination. Electrical dehydration and electrical desalination of oil are associated with passing oil through special electrical dehydrators, where oil passes between electrodes, creating a high voltage electric field (20-30 kV). To increase the rate of electrical dehydration, the oil is preheated to a temperature of 50–70 ° C. During storage of such oil in tanks, during its transportation through pipelines and in tanks by rail, a significant part of hydrocarbons is lost due to evaporation. Light hydrocarbons are valuable raw materials and fuels (light gasolines). Therefore, before supplying oil, light low-boiling hydrocarbons are extracted from it. This technological operation is called oil stabilization. To stabilize the oil, it is subjected to rectification or hot separation. The simplest and most widely used in the field preparation of oil is hot separation, performed on a special stabilization unit. In hot separation, oil is preheated in special heaters and fed to a separator, usually horizontal. In the separator, oil is heated to 40 to 80 ° C and light hydrocarbons are actively evaporated from it, which are sucked off by the compressor and sent through the refrigeration unit to the collecting gas pipeline.

Together with purified formation water, fresh water is pumped into productive formations to maintain formation pressure, obtained from two sources: underground (artesian wells) and open water bodies (rivers). The groundwater produced from artesian wells is characterized by a high degree of purity and, in many cases, does not require deep purification before injection into reservoirs. At the same time, the water of open reservoirs is significantly polluted with clay particles, iron compounds, microorganisms and requires additional purification. Currently, two types of water intake from open reservoirs are used: under-channel and open. With the under-channel method, water is taken below the bottom of the river "under the channel". To do this, wells with a depth of 20-30 m and a diameter of 300 mm are drilled in the river floodplain. These wells necessarily pass through a layer of sandy soil. The well is reinforced with casing pipes with holes on the spokes and water intake pipes with a diameter of 200 mm are lowered into them. In each case, two communicating vessels "river-well" are obtained, separated by a natural filter (a layer of sandy soil). Water from the river flows through the sand and accumulates in a well. The inflow of water from the well is forced by a vacuum pump or a water-lifting pump and is fed to a cluster pumping station (SPS). With the open method, water is pumped out of the river with the help of pumps and fed to a water treatment plant, where it goes through a cleaning cycle and enters a settling tank. In the sump, with the help of coalescer reagents, particles of mechanical impurities and iron compounds are removed into the sediment. The final water purification takes place in filters, where clean sand or fine coal is used as filtering materials.

11 Safety, labor and environmental protection

Oil product supply enterprises carry out operations for the storage, supply and reception of oil products, many of which are toxic, evaporate well, can be electrified, fire and explosive. When working at the enterprises of the industry, the following main dangers are possible: the occurrence of fire and explosion when the process equipment or pipelines are depressurized, as well as when the rules for their safe operation and repair are violated; poisoning of workers due to the toxicity of many petroleum products and their vapors, especially leaded gasoline; injury to workers by rotating and moving parts of pumps, compressors and other mechanisms in the absence or malfunction of the fence; electric shock in case of violation of insulation of live parts of electrical equipment, grounding failure, non-use of personal protective equipment; increased or decreased surface temperature of equipment or air in the working area; increased vibration level; insufficient illumination of the working area; the possibility of falling when servicing equipment located at a height. When servicing the equipment and carrying out its repair, it is prohibited: the use of open fire for heating oil products, heating fittings, etc .; operation of faulty equipment; operation and repair of equipment, pipelines and fittings in violation of safety regulations, in the presence of leaks of oil products through leaks in joints and seals or as a result of metal wear; the use of any levers (crowbars, pipes, etc.) for opening and closing valves; repair of electrical equipment not disconnected from the mains; cleaning equipment and machine parts with flammable flammable liquids; work without appropriate personal protective equipment and overalls. If oil products are spilled, the area of ​​the spill should be covered with sand and then removed to a safe place. If necessary, remove soil contaminated with oil products. In the premises where the spill occurred, degassing is carried out with dichloramine (3% solution in water) or bleach in the form of gruel (one part of dry bleach for two to five parts of water). Degas with dry bleach to avoid ignition. Smoking on the territory and in the production premises of the enterprise is prohibited with the exception of specially designated places (in agreement with the fire brigade), where the signs "Smoking area" are posted. Entrances to fire hydrants and other sources of water supply must always be free for the unhindered passage of fire trucks.

In winter, it is necessary to: clean from snow and ice, sprinkle with sand to prevent slipping: floorings, stairs, crossings, sidewalks, footpaths and roads; promptly remove icicles and ice crusts formed on equipment, roofs of buildings, metal structures.

At first, the person did not think about what is fraught with intensive oil and gas production. The main thing was to pump them out as much as possible. And so they did. At first it seemed that oil only brings benefits to people, but gradually it became clear that its use has a downside. Oil pollution creates a new ecological situation, which leads to a profound change or their complete transformation of natural resources and their microflora. Soil pollution with oil leads to a sharp increase in the value of the carbon-nitrogen ratio. This ratio worsens the nitrogen regime of soils and disrupts the root nutrition of plants. The soil is self-cleaning very slowly by biodegradation of oil. Because of this, some organizations have to re-cultivate soil after pollution.

One of the most promising ways of protecting the environment from pollution is the creation of a comprehensive automation of the processes of oil production, transportation and storage. Previously, for example, the fields did not know how to transport oil and associated gas together through the same pipeline system. For this purpose, special oil and gas communications were built with a large number of facilities scattered over vast territories. The fields consisted of hundreds of objects, and in each oil region they were built in its own way, this did not allow them to be connected with a single telecontrol system. Naturally, with this technology of extraction and transport, a lot of product was lost due to evaporation and leakage. Using the energy of the subsoil and deep pumps, the specialists managed to ensure the supply of oil from the well to the central oil gathering points without intermediate technological operations. The number of commercial facilities decreased 12-15 times.

In areas of development, especially during the construction of pipelines, temporary roads, power lines, sites for future settlements, the natural balance of all ecosystems is disturbed. Such changes are affecting the environment.

The main sources of pollution of ground and underground waters in oil production areas are the discharge of industrial waste water into surface water bodies and drains. Pollution also occurs: during spills of industrial wastewater; in case of water pipe breaks; when surface runoff from oil fields gets into surface waters; with peritoks of highly mineralized waters of deep horizons into freshwater horizons, due to leakage in injection and production wells.

In the oil industry, various chemicals are widely used in various technological processes. All reagents, if released into the environment, have a negative impact. The main causes of environmental pollution when injecting various chemicals into the reservoir are the following factors: leakage of systems and equipment and violation of safety measures during technological operations.

In environmental activities at the enterprise, in addition to traditional areas of environmental monitoring, rational use of water and reclaimed land resources, air protection, overhaul and replacement of emergency sections of oil-gathering networks, water pipelines, tanks, the latest technologies for environmental protection are being actively introduced.

BIBLIOGRAPHY

1. Akulshin A. I. Operation of oil and gas fields M., Nedra, 1989.

2. Gimatutdinova Sh.K. Reference book on oil production. M., Nedra, 1974.

3.Istomin A.Z., Yurchuk A.M. Calculations in oil production. M.,: Nedra, 1979.

4. Instructions on labor protection for workers of the oil and gas production department. Ufa, 1998.

5.Mishchenko I. T. Calculations in oil production. M., Nedra, 1989.

6. Muravyov V. M. Operation of oil and gas wells. M., Nedra, 1978.

7. Safety rules in the oil and gas industry. M., Nedra, 1974

8. Production material of OOO NGDU Oktyabrskneft. 2009 2010.

9. Reference book on oilfield equipment. M., Nedra, 1979.

10. Shmatov V.F. , Malyshev Yu.M. Economics, organization and planning of production at the enterprises of the oil and gas industry M., Nedra, 1990.

Federal Agency for Education

State educational institution of higher professional

Education

"UFA STATE OIL TECHNICAL

UNIVERSITY "

Department of "Oil and Gas Field Equipment"

training practice

Student of group MPZ - 02 - 01 A.Ya. Islamgulov

Practice leader from R.R. Safiullin

department Ph.D. assistant professor

General characteristics of the enterprise

The Aksakovneft oilfield production department was formed in 1955 in connection with the discovery of well No. 3 of the Shkapovskoye oil field by the drilled crew of foreman I.Z. Poyarkov on November 23 (Figure 1).

Figure 1 - Well No. 3

From the very beginning of its activity, NPU "Aksakovneft" belonged to the "Bashneft" trust located in Ufa, which was reorganized into the joint-stock oil company "Bashneft",

There are 15 deposits on the balance sheet of NGDU. Recoverable residual reserves as of 01.01.2004 amount to 22.358 million tons (excluding the increase in reserves in 2004). With the current volumes of oil production, the provision of reserves is 21 years. Currently, exploratory drilling is being carried out at 2 areas: Afanasyevskaya and Lisovskaya.

The fields of OOO NGDU Aksakovneft are shown in Figure 2.

Since the beginning of development, 229,937 tons of oil have been produced. The plan for oil production in 2004 is being fulfilled by 100.2%, 2 thousand tons of oil have been produced in excess of the plan.

Figure 2 - Overview map of deposits

21 new wells were put into operation, with the planned 20. Oil produced from new wells is 31,768 tons with the plan of 27,000 tons, the production rate of new wells is 9.5 tons / day, while the plan is 7.8 tons / day.

6 new injection wells were put into operation, compared to the planned 6.

Out of inactivity, 26 wells were commissioned against the plan of 26.

The well completion period at the standard of 17 days was 7.7 days.

Collected 39754 thousand m3 of associated gas, including 422 thousand m3 in excess of the plan. The level of utilization of associated petroleum gas resources is 96.3%, while the plan is 95.1%.

The main attention is paid to the introduction of new equipment and advanced technologies, increasing oil recovery and the efficiency of geological and technical measures (Figure 3).

Due to new technologies for enhanced oil recovery, 348 tons were produced. Over the past period of the year, a large amount of work was carried out to perform geological and technical measures. So, with the plan of 467, 467 events were carried out. The efficiency is 113.8 thousand tons.

Specific efficiency with the plan of 243.3 t / meter. will amount to 243.7 t / measure.

Figure 3 - Technology for increasing the injectivity of an injection well using the technology using a coiled tubing unit.

One of the stages of the reorganization of ANK Bashneft was the joining in July of last year of the team of the Shkapovsky gas processing plant to OOO NGDU Aksakovneft. In 2004, 39 million 208 thousand cubic meters of associated petroleum gas were processed against the plan of 34 million 712 thousand cubic meters, the overfulfillment amounted to 4496 thousand cubic meters or + 13% to the plan.

LLC NGDU Aksakovneft is an enterprise with highly developed equipment and technology for oil production and regional infrastructure located in the southwestern part of the Republic of Bashkortostan at the address Priyutovo, st. Vokzalnaya 13. This is a modern highly developed enterprise - a subdivision of the Bashneft association with advanced equipment and technology for oil production and treatment.

The main goal is to make a profit and meet social needs for goods and services produced by him. The main activities are:

Oil and gas production and preparation;

Arrangement, overhaul and workover of wells:

Repair and construction of highways;

Provision of paid services to the population;

Production of consumer goods;

Arrangement, operation and repair of oilfield facilities and social facilities;

Transport services, services of special equipment;

Production and sale of steam and water;

Training and professional development of personnel;

Carrying out a single economic, pricing, technical and environmental policy with the Company;

The Company carries out its activities on the basis of the current legislation of the Russian Federation and the Republic of Bashkortostan, the Charter, decisions of the Company's governing bodies and concluded agreements.

The authorized capital of the Company, its movement is reflected in the balance sheet of the Office of JSOC Bashneft.

MINISTRY OF EDUCATION AND SCIENCE

RUSSIAN FEDERATION

FEDERAL EDUCATION AGENCY

GOUVPO "UDMURTSK STATE UNIVERSITY"
OIL FACULTY

Department "Development and operation of oil and gas fields"

on the second production practice
Content
1. Introduction ………………………………………………………………… .3

2. Characteristics of the deposit …………………………………………… 4

3. Development objects and their characteristics ………………………………… 5

4. Reservoir properties of productive formations ………………………… 11

5. Physical properties of formation fluid (oil, gas, water) ………… 12

6. Indicators of reservoir development (productive formation) ………………… 17

7. Installation diagram of a borehole sucker rod pump (USSHN) ………… .... 18

8. Downhole sucker rod pumps, their elements …………………………… 19

9. Threaded connections for tubing and

sucker rods ……………………………………………………… ... 22

10. Installation diagram of an electric centrifugal pump (ESP) ……………… 25

11. Technological mode of operation of the USSHN at constant

12. Technological mode of operation of the USSHN at periodic

pumping liquid ... ............................................... ....................................... 27

13. Technological mode of operation of the ESP ………………………………… .28

14. Devices for researching the operation of borehole pumps ..................... 29

15. Results of the study of the operation of the USSHN ……………………………… ..37

16. Design of gas-sand anchors ……………………………………… .38

17. Devices for combating wax deposits in

underground equipment ……………………………………………… .39

18. Diagram of a group metering unit ............................................................................. 40

19. Booster pump station diagram ……………………………………………………………… .41

20. Automation of operation of borehole pumping units ......................................... ... 42

21. Functional responsibilities of the operator for oil and gas production …… .43

22. Ensuring labor protection requirements during maintenance

producing wells ………………………………………………… ... 44

23. Reporting documentation in the oil production team …………………… .47

24. The structure of the oil and gas production enterprise ……………………… ... 49

25. Requirements for environmental protection during oil production ………… .50

26. Technical and economic performance indicators of NGDU ……………… 51

List of used literature ………………………………………… ... 53

1. INTRODUCTION

I had an internship at OAO Udmurtneft in the Votkinsk oil and gas production department at the Mishkinskoye field in an oil and gas production team. He held the position of a 4-grade oil and gas production operator.

I was assigned to a 5th grade d / n operator, under whose guidance I did my internship. During my practice, I went through briefings on technical safety and electrical safety, went on detours, where I watched the work of the IC and GZU, worked on a computer, where I made an electronic version of various schemes.

I have good impressions from the practice. Firstly, the foreman made sure that I received as much information as possible about the duties of an operator for oil and gas production: he gave instructions to the operator assigned to me, after 3 weeks of practice, he conducted an exam on the knowledge I had acquired. Secondly, the desire of the operators themselves to talk about their work.

Almost every day I was at various jobs. I was not disappointed in my chosen profession and I am glad that I study in this particular specialty.

^ 2. CHARACTERISTICS OF THE DEPOSIT

The Mishkinskoye oil field was discovered in 1966 and is located on the border of the Votkinsky and Sharkansky districts north of the city of Votkinsk.

The deposit area is located in the Kama river basin and occupies the watersheds of the Votka and Siva rivers. The absolute elevations of the relief vary from 140 - 180 m in the south, to 180 - 250 m in the north. The area of ​​the Mishkinskoye field is 70% occupied by coniferous forests, the rest is occupied by agricultural land.

The climate of the region is temperate continental, with long winters. The average annual temperature is + 2С, frosts in January - February sometimes reach -40С. The average depth of soil freezing is 1.2 m, the thickness of the snow cover is 60 - 80 cm.

The water intake for reservoir pressure maintenance is located on the Siva River. Power supply source - substation 220/110/35/6 kV "Siva". Oil treatment is carried out at the Mishkinsky CKPN located on the territory of the field.

The Mishkin structure is complicated by two domes: the western one - Votkinskiy and the eastern one - Cherepanovskiy.
^ 3. OBJECTS OF DEVELOPMENT AND THEIR CHARACTERISTICS

At the Mishkinskoye field, oil shows were recorded in the rocks of the Tournaisian stage and the Yasnaya Polyana over-horizon (layers Tl-0, Tl-I, Tl-II, Bb-I, Bb-II, Bb-III), the Lower Carboniferous, in the Bashkirian stage and the Vereiskiy horizon (layers B-II, B-III) of the Moscow Stage of the Middle Carboniferous.

The oil and gas content of the section was studied using core samples, lateral soil samples, analysis of data from field geophysical studies, gas logging and the results of well testing for inflow.

Tournaisian tier

In the Tournaisian sediments, three oil deposits were discovered, confined to three structures: the Western and Eastern domes of the Votkinsk and Cherepanovsk uplifts. An industrial-oil-bearing layer of porous-cavernous limestones in the roof of the Cheretsky horizon with a thickness of up to 36 m. The highest part of the oil reservoir was found at the Votkinsk uplift, in well No. 180 at an elevation of 1334 m. A small deposit was found in the area of ​​184 wells with the highest elevation of 1,357 m. ...

The slope of the OWC surface is noted (from well no. 189 to well no. 183) of the West Votkinsk dome within 2 - 2.5 m. Therefore, the OWC was adopted at an elevation of 1356 - 1354 m. The height of the oil deposit on the West Votkinsk dome is 32 m its dimensions are about 8x5 km.

On the Vostochno-Votkinskiy dome, the average position of the OWC is conventionally taken at around 1358 m. The height of the deposit on this dome in the area of ​​well No. 184 is about 5 m, its dimensions are 3x1.5 km.

On the Cherepanovskoe uplift, the OWC is conventionally taken at 1370 m. The height of the oil deposit of this uplift is 4.5 m, its dimensions are about 4.5x2 km. The presence of dense interlayers traced over a large area and sampling of near-dome wells 211, 190, 191 prove the layered-massive structure of the earth.

Oil shows of the Kizilovsky horizon were found in its lower part in a layer of finely porous limestones. Testing results indicate poor reservoir properties of the Kizilovsky horizon.

The OWC of the kizilov deposit is conventionally taken at the level of 1330.4 - 1330 m.

Yasnaya Polyanskiy superhorizon

In the Yasnaya Polyana above-horizon, oil shows are confined to layers of porous sandstones and siltstones of the Tula and Bobrikov horizons.

There are three porous layers in the Bobrikovskiy horizon. Commercial oil flow from the Bb-III reservoir was obtained in well No. 211 and oil and water from well No. 190.

The Bb-II reservoir was traced in all wells, which penetrated the Lower Carboniferous and only in well No. 191 was replaced by impermeable rocks.

The thickness of the Bb-II reservoir varies from 0 to 2 m, and the Bb-I from 0.8 to 2.5 m. From the Bb-I reservoir, commercial oil flows were obtained in well No. 189 together with other reservoirs.

In the Tula horizon, commercial oil-bearing capacity is established in three layers Tl-0, Tl-I, Tl-II. In the Yasnaya Polyana over-horizon, oil deposits are confined to the structures: the West and East Votkinsk domes and the Cherepetsk uplift. The insignificant thickness of impermeable layers separating the oil-bearing layers of the Yasnaya Polyana over-horizon, and often the connections of permeable layers with each other and their lithological variability, suggest a layered type of deposits with a single OWC for all layers of the Votkinsk uplift and separately for the Cherepanovskiy layers.

The OWC of the Cherepanovskiy uplift for the Tula formations Tl-I, Tl-II, Tl-0 is taken at the bottom of the Tl-II formation, which gave anhydrous oil in well No. 187 at an elevation of 1327.5 m.

Bashkirian stage

Oil shows in deposits of the Bashkirian stage were found in all wells that opened oil deposits and were characterized by core. Moreover, oil shows are located in the upper, denser part of the section. The thickness of the effective interlayers varies within a wide range from 0.4 to 12.2 m. In some wells, when testing inflows, they were not obtained or were obtained after hydrochloric acid treatment of the bottom. Significant fluctuations in the values ​​of the inflows suggest a complex structure of the reservoir both in size and in area. The presence of significant production rates probably indicates the presence of large vugs or fractures in the reservoir. The highest part of the oil from the Votkinsk uplift was found in well No. 211 at an elevation of 1006.6 m. The height of the deposit is about 38 meters, the size of the deposit is within 16x8 km. OWC is conventionally taken at 1044 m.

Z The oil alez of the Cherepanovskoye uplift has been insufficiently studied. It is separated from the deposit of the Votkinsk uplift by a zone of deterioration of the reservoir properties of carbonate rocks. The OWC of the Cherepanovskoye uplift was adopted at an elevation of 1044 m.

Verey horizon

In the Verey horizon, there are mainly two oil strata, separated by layers of mudstones and clayey limestones. The thickness of effective oil-saturated limestones B-III ranges from 0.6 to 6.8 m (well No. 201). The lowest mark from which anhydrous oil was obtained is 1042.8 meters (well No. 214). The highest mark of the B-III reservoir is 990 m. The OWC is taken at 1042 m. The height of the reservoir within the accepted OWC - 1042 meters is about 52 m. Its dimensions within the outer contour are about 25x12 km. The thickness of the effective part of the reservoir ranges from 1.2 to 6.4 m.

The highest part of the B-II reservoir was penetrated in well No. 211. OWC was taken at 1040 m. The height of the deposit within the accepted OWC is 104 m and is equal to about 50 m. The size of the deposit within the outer contour of oil-bearing capacity is about 25x12 km. Oil deposits of formations B-II and B-III of reservoir type.

The effective part of the B-I formation is not traced in all wells. Testing results indicate low reservoir permeability, and the complex location of porous differences in the field area complicates the assessment of the possible oil prospects of the B-I reservoir.

^ 4. COLLECTOR PROPERTIES OF PRODUCTIVE FORMATIONS
Tournaisian tier

The Tournaisian stage is represented by carbonate rocks - limestones of the Cherepetian and Kizilovsky horizons. The wells contain from 1 (well No. 212) to 29 (well No. 187) porous interlayers. The thickness of the distinguished porous varieties varies from 0.2 to 25.2 m. The total thickness of the reservoirs of the Cheretsky horizon in the studied part ranges from 10.8 (well No. 207) to 39.2 m (well No. 193). In almost all wells in the top of the Tournaisian stage, interlayers are distinguished, as a rule, this is a single layer with a thickness of about 2 m, but in some wells (195, 196), a larger number of thin porous interlayers appear, the number of which reaches 8. The total thickness of the Kizelovsky reservoir increases in this case up to 6.8 m.
Yasnaya Polyanskiy superhorizon

Deposits of the Yasnaya Polyana superhorizon are represented by alternating sandstones, siltstones, and clays of the Bobrikov and Tula horizons. In the Bobrikovsky horizon, sandstone beds Bb-II and Bb-I are distinguished, and in the Tula horizon Tl-0, Tl-I, Tl-II. These strata can be traced throughout the entire area of ​​the Mishkinskoye field. The total reservoir thickness of the Bobrikovsky and Tula horizons ranges from 7.4 m (well No. 188) to 24.8 m (well No. 199).
Bashkirian stage

It is represented by an alternation of dense and porous-permeable limestones. Limestones are not clayey. The reduced relative parameter Jnj varies from 0.88 in dense interlayers to 0.12 - 0.14 in highly porous varieties. Such a change in Jnj indicates a significant cavernousness of limestones. The number of porous interlayers in wells by area varies from 5 (well No. 255) to 33 (well No. 189). The thickness of the distinguished porous varieties ranges from 0.2 to 21.0 m. The total thickness of the Bashkirian reservoirs ranges from 6.8 m (well 205) to 45.5 m (well 201).
Verey horizon

Verey deposits are represented by alternating siltstones and carbonate rocks. The productive formation is confined to porous and permeable carbonate deposits. There are two layers B-III and B-II.

The total reservoir thickness of the Vereiskiy horizon varies from 4.0 (well No. 198) to 16.0 m (well No. 201). The thickness of a separate permeable layer varies over the area from 0.4 to 6.4 m.
Summary data on reservoir properties of productive formations

^ 5. PHYSICAL PROPERTIES OF FORMATION FLUID

(OIL, GAS, WATER)
OIL
Verey horizon

From the analysis of depth samples, it follows that the oils of the Vereya horizon are heavy, highly viscous, the value of the oil density in reservoir conditions is in the range of 0.8717 - 0.8874 g / cm 3 and on average is 0.8798 g / cm 3. The viscosity of oil in reservoir conditions ranges from 12.65 to 26.4 SP, and 18.4 SP was taken in the calculations.

The average value of the saturation pressure is assumed to be 89.9 atm. The oil of the Vereya horizon is poorly saturated with gas, the gas-oil ratio is 18.8 m 3 / t.

According to the results of the analysis of surface samples of oil, it was established: the density of oil is 0.8963 g / cm 3; the oil samples of the Vereiskiy horizon contain 3.07% of sulfur, the amount of silikogel resins ranges from 13.8 to 21% and averages 15.6%. The asphaltene content is in the range of 1.7 - 8.5% (average value 4.6%), and the paraffin content 2.64 - 4.8% (average value 3.6%).
Bashkirian stage

The analysis data show that the oil of the Bashkirian stage is lighter than the oils of other layers of the Mishkinskoye field, the oil density in reservoir conditions is 0.8641 g / cm 3. The viscosity of the oil is lower than in the Vereya horizon and is determined at 10.3 cp. The saturation pressure for the Bashkirian stage should be taken equal to 107 atm. The gas-oil ratio for the reservoir is 24.7 m 3 / t. The analysis results show that the average oil density is 0.8920 g / cm 3. The sulfur content in oil of the Bashkirian stage varies from 22.4 to 3.63% and is on average 13.01%. The amount of silicogel resins ranges from 11.6% to 18.7% and averages 14.47%. The asphaltene content is in the range 3.6 - 6.4% (average 4.51%), and the paraffin content 2.7 - 4.8% (average 3.97%).
Yasnaya Polyanskiy superhorizon

The oil of the Tula horizon is heavy, specific gravity 0.9 g / cm 3, high-viscosity 34.2 cp. The gas factor is 12.2 m 3 / t, the oil saturation pressure with gas is 101.5 atm., Which is due to the high nitrogen content in the gas up to 63.8 percent by volume.

Surface oil samples from the Yasnaya Polyana superhorizon were taken from 8 wells. The density of oil according to the results of the analysis of surface samples is 0.9045 g / cm 3. Sulfur content  3.35%, asphaltene content  5.5%, paraffin content  4.51%.
Tournaisian tier

Oil viscosity in reservoir conditions was 73.2 cp. The density of oil is 0.9139 g / cm 3. Gas factor 7.0 m 3 / t. volume factor 1.01. Surface oil samples of the Tournaisian stage were taken from 8 wells. The average density of oil is 0.9224 g / cm 3. The increased content of silikogel resins 17.4 - 36.6% (average 22.6%). The content of asphaltenes and paraffin is on average 4.39% and 3.47%, respectively.
^ ASSOCIATED GAS

The associated gas contains an increased amount of nitrogen. For the Tournaisian stage, its average value is 93.54%, for the Yasnaya Polyana superhorizon - 67.2%, for the Bashkirian stage - 44.4%, for the Vereian horizon - 37.7%. Such a nitrogen content, as well as low gas factors, make it possible to use associated gas as a fuel, only for the needs of industrial enterprises.

In terms of the helium content in the loop gas of the Yasnaya Polyanskiy (0.042%) above the horizon and the Cheretskiy stage (0.071%), it is of industrial interest, but due to low gas factors, i.e. small production of helium, the profitability of its production is questioned. The content of helium in the associated gas of the Vereian horizon and the Bashkirian stage is, respectively, 0.0265% and 0.006%.
^ FORMATION WATER
Verey horizon

The water abundance of the layers in the upper part of the Vereisky horizon has practically not been studied. Reservoir brines have a density of 1.181 g / cm 3, the first salinity is 70, they contain B - 781 mg / l, J - 14 mg / l and В 2 О 2 - 69.4 mg / l. The composition of water-dissolved gas is sharply dominated by nitrogen - 81%, methane - 13%, ethane - 3.0%, heavier - 0.3%.
Bashkirian stage

The waters of the Bashkirian deposits have a similar ion-salt composition and slightly lower mineralization and metamorphization than the waters of the higher and lower complexes. Mineralization of waters of Bashkir deposits does not exceed 250-260 mg / l., Cl - Na / Mg does not exceed 3.7; SO 4 / Cl does not exceed 0.28; the content of mg / l bromine 587 - 606; J ÷ 10.6-12.7; B 2 O 3 28-39; potassium - 1100; strontium - 400; lithium - 4.0.
Yasnopolyansky above the horizon

They are characterized by high mineralization, metamorphization, absence of asphaltenes, high contents of bromine and iodine, not exceeding 50 mg / l. The insignificant content of sulfates serves as a correlative to distinguish the waters of the Yasnaya Polyana complex from the waters of the higher and lower complexes.

The average gas saturation of the formation waters of the Yasnaya Polyana sediments is 0.32 - 0.33 g / l. The composition of the gas is nitrogen, the content of hydrocarbons is about 3 - 3.5%, argon - 0.466%, helium - 0.069%. Contact degassing gas consists of nitrogen 63.8%, methane 7.1%, ethane 7.9%, propane 12.1%.
Tournaisian tier

Mineralization of waters of the Tournaisian stage is 279.2 g / l; S - 68; SO 4 / Cl - 100-0.32; B - 728 mg / l; J - 13 mg / l; В 2 О 3 - 169 mg / l. The water of the Tournaisian sediments differs sharply from the waters of the Yasnaya Polyana sediments, which indicates the isolation of the aquifers of the horizon.

The waters of the Tournaisian stage are highly mineralized. They are characterized by high calcium content of 19%, the equivalent Cl-Na / Mg ratio is higher than 3; SO 4 / Cl - 100-0.12 * 0.25. Bromine content 552-706 mg / l; iodine 11-14 mg / l; NH 4 79-89 mg / l; В 2 О 3 39-84 mg / l; potassium 1100 mg / l; strontium 4300 mg / l;
Physical and chemical properties of oil in reservoir conditions

Physical and chemical properties of gas

Physicochemical properties of formation waters

^ 6. INDICATORS OF DEPOSIT DEVELOPMENT

(productive formation)

This "Technological scheme for the development of the Zapadno-Chigorinskoye field" substantiates the optimal option for further development of the field.
The work was carried out in accordance with the terms of reference of OJSC “Surgutneftegas” and approved regulatory documents.

Introduction

2. Analysis of the structure of the well stock.
3. Geological characteristics of the deposit.
4. Geological and technological model of the field.
5. Geological and field substantiation of development options.
6. Technological indicators of development options.
7. Reserves of oil and dissolved gas.
8.Safety for oil and gas operators.
9. Technological mode of operation for production wells.
10. Oil production by electric submersible installations.
11. Oil production using borehole sucker rod pumps.

Files: 1 file

FEDERAL EDUCATION AGENCY

State educational institution of higher professional education

"Tyumen State Oil and Gas University"

Department of Development and Operation of Oil Fields

on the first production practice

from "" 20 to "" 200

at the enterprise

Student

groups НР-09-1 specialties

"Development and operation of oil and

gas fields ",

specialization: "Development of oil fields"

From the enterprise

(position) F.I.O.

Protection rating:

Kogalym, 2012

Introduction

1. General information about the deposit.

2. Analysis of the structure of the well stock.

3. Geological characteristics of the deposit.

4. Geological and technological model of the field.

5. Geological and field substantiation of development options.

6. Technological indicators of development options.

7. Reserves of oil and dissolved gas.

8. Safety precautions for oil and gas production operators.

9. Technological mode of operation for production wells.

10. Oil production by electric submersible installations.

11. Oil production using borehole sucker rod pumps.

INTRODUCTION

Administratively, the Zapadno-Chigorinskoye field is located in the Surgut region of the Khanty-Mansiysk Autonomous Okrug of the Tyumen Region.

The field is located on the territory of three license areas, the subsoil user of which is OJSC “Surgutneftegas”:

• Chigorinsky license area (license KhMN No. 00684, issued on 03.12.1997, expiration date
  license validity 31.12.2040),
• Ai-Pimskiy license area (license KhMN No. 00560, issued on 09/29/1993, expiration date
  license validity 31.12.2055),
• Zapadno-Ai-Pimsky license area (license KhMN No. 00812, issued on 04.06.1998, term
  expiration of the license on 31.12.2055),

Distance to the nearest settlement - settlement. Nizhnesortymsky - 60 km. Distance to the city of Surgut - 263 km.

The field was discovered in 1998 and put into pilot production in 2003 on the basis of the "Technological Scheme for Pilot Development" drawn up by TO "SurgutNIPIneft" (protocol of the TKR KhMAO No. 259 dated 06.12.2001).

Due to the higher rates of field development in the first two years of operation (2003-2004), the actual volumes of oil production exceeded the design levels. In order to adjust the technological indicators of development in 2005, TO "SurgutNIPIneft" compiled an "Analysis of the development of the West Chigorinskoye field" (protocol TO CKR Rosnedra for Khanty-Mansi Autonomous Okrug No. 630 dated 04/27/2005).

This project document "Technological scheme for the development of the Zapadno-Chigorinskoye field" was drawn up in 2006 in accordance with the decision of the Maintenance Center of the Central Commission for the Development of Rosnedra for the Khanty-Mansi Autonomous Okrug (Minutes No. 630 dated 04/27/2005).

During the period of pilot development of the Zapadno-Chigorinskoye field:

Clarified geological structure and reservoir properties
the main operational facility of the NPP and,

• oil reserves were calculated and approved by the State Reserves Committee of Rosnedra (Minutes No.
  03.11.2006),
• the efficiency of the implemented development system is estimated.

This "Technological scheme for the development of the Zapadno-Chigorinskoye field" substantiates the optimal option for further development of the field.

The work was carried out in accordance with the terms of reference of OJSC “Surgutneftegas” and approved regulatory documents.

1. GENERAL INFORMATION ABOUT THE DEPOSIT

Administrative and geographical location. The Zapadno-Chigorinskoye field is allocated on the territory of three license areas: Ai-Pimsky license area (northeastern part of the field), West Ai-Pimsky license area (central part) and Chigorinsky license area (southeastern part, Fig. 1.1).

Administratively, the deposit is located in the Surgut District of the Khanty-Mansiysk Autonomous District of the Tyumen Region. The nearest settlement is the settlement of Nizhnesortymskiy, located 60 km north-east of the field. The center of the Surgut region is the city of Surgut, located 263 km south-east of the field. In physical and geographical terms, it is confined to the Surgut bog province of the West Siberian physical and geographical country. The field is located in the area of ​​operations of OJSC "Surgutneftegas", NGDU "Nizhnesortymsk-neft".

The climate is continental. Winter is long, severe and snowy. The average temperature of the coldest month, January is -21.4 ° С. The thickness of the snow cover is up to 60-75 cm. The duration of the period with persistent frosts is 164 days. Summer is short (50-60 days), moderately warm and cloudy, with frequent frosts. The average temperature of the warmest month (July) is + 16.8 ° С, with an absolute maximum of + 34 ° С. In general, the climate of the region is typical for the taiga zone.

Hydrography. The field is located in the interfluve of the rivers Nimatuma, Yumayakha, Totymayun. By the nature of the water regime, the rivers belong to the type of rivers with spring-summer floods and floods in the warm season. The main phase of the water regime is the flood, which, in some years, accounts for up to 90% of the annual runoff. It starts in the third decade of April and ends in June. Significant areas are swampy (60.1%). The overlapping of the territory of the work area is 17.2%. Along with small lakes, there are also large lakes on the territory of the deposit: Vochikilor, Vontirya-vinlor, Evyngyekhanlor, Num-Vochkultunglor, Vochkultunglor, Otinepatylor.

Soils. The automorphic surfaces are dominated by ferruginous illuvial and humus illuvial podzols. Among the boggy types of soils, there are peaty, peat-gley and peaty on high-moor peatlands, as well as peaty-humus-gley soils. The floodplains of the rivers are dominated by floodplain peaty-humus-gley and floodplain weakly podzolized soils.

Vegetation. According to the geobotanical zoning of Western Siberia (Ilyina and Makhno, 1976), the deposit territory is located in the northern taiga subzone.

The landscape structure of the territory is dominated by bogs of various types (60.1% of the area), mainly ridge-hollow and lake-ridge-hollow, as well as flat-hilly bogs. Pine and pine-birch forests are confined to near-valley areas (forest cover - 17.3%). In the floodplains and river valleys, pine-birch and cedar-pine forests prevail (about 5.4%).

Animal world. According to the zoogeographic zoning of the Tyumen region (Gashev, 2000), the Zapadno-Chigorinskoye field is located within the Surgut zoogeographic province. The fauna is represented by the fauna of lacustrine-bog biotopes (muskrat, white hare, waterfowl: diving and river ducks), in forest biotopes there are representatives of upland game (black grouse, wood grouse, hazel grouse), as well as squirrels, chipmunks.

Land use and specially protected areas. On the territory of the Zapadno-Chigorinskoye field, there are territories with a special status of nature management - water protection zones, cedar plantations, ancestral lands (Fig. 1.1).

Water protection zones are allocated along rivers and around lakes with a width of 100 to 500 m, occupy 5132 hectares (about 45% of the field area). Separate massifs along the river beds are cedar plantations - 172 hectares (1.5%).

By the Decree of the Head of the Administration of the Surgut region No. 124 of 30.11.1994 and the Decision of the district commission in the Sytominsk rural administration of the Surgut region, the ancestral land No. 12C was allocated on the territory of the deposit, where 4 families (12 people) from among the indigenous peoples carry out economic activities North - Khanty (families of Lozyamov K.Ya., Lozyamov S.Ya., Lozyamova R.Ya., Lozyamova L.I.). Economic agreements have been concluded between OJSC “Surgutneftegas” and the heads of the ancestral lands, providing for a set of social and economic measures.

Economic activity in water protection zones is determined by the Decree of the Government of the Russian Federation No. 1404 of 23.11.1996 "Regulations on water protection zones of water bodies and their coastal protection zones", RD 5753490-028-2002 "Regulations on environmental protection in the design and production of work single prospecting and exploration wells of OJSC “Surgutneftegas” located in the water protection zones of water bodies of the Khanty-Mansiysk Autonomous Okrug ”; cedar stands - by the Forest Code of the Russian Federation No. 22-FZ dated 01.29.1997; ancestral lands - by the Resolution of the Head of the Administration of the Surgut region No. 124 from ZOL 1.1994.

Industrial infrastructure. Zapadno-Chigorinskoye oil field is located in the area of ​​operation of Nizhneseortymskneft NGDU, which has a developed industrial infrastructure: oil collection and preparation point, booster pumping stations, a system of pressure and interfield oil pipelines, gas pipelines, a network of highways, a power supply system, and production service bases.

By the time the work was completed, the following were built at the field: 11 well pads; oil and gas gathering system with a length of 26.1 km:

• one booster pumping station with a design capacity of 10.0 thousand m / day, from the mouth
  new preliminary discharge of formation water, with a capacity of 10.0 thousand m3 / day.
  Capacity utilization as of 01.01.2006 was 12%;
• oil pipeline for external transportation of oil from the West Chigorinskoye field
  to the point of insertion into the oil pipeline from the Bittemskoye field, 15.0 km long;

cluster pumping station with a capacity of 7.2 thousand m 3 / day. Capacity utilization as of 01.01.2006 amounted to 44%;

Four water wells were drilled in the SPS area in the Cenomanian mountain
umbrella equipped with high-pressure submersible pumping units, through
in which water is injected;

High-pressure water pipe system 18.55 km long;
transformer substation PS 35/6;

• high-voltage line VL-35kV from PS110 of the Bittemskoye field to the West
  no-Chigorinskoye field, 15.8 km long;
• motor road with asphalt concrete pavement from BPS West
  Chigorinskoye field before tie-in to the corridor from Bittemskoye field "about
  13.5 km long;

Approaches to the bushes with a length of 26.15 km.

The gas gathering system at the field is not well developed. A gas turbine power plant was built at the Bittemskoye field located within 20 km. The gas utilization rate as of 01.01.2006 was 2.76%.

The closest oil treatment facility is the Alekhinsky CPF, located 95.8 km from the field. Oil delivery to the Transneft system is carried out at the Zapadny Surgut PS.

Electricity is supplied from the Tyumenenergo system. The main source of power supply for the Zapadno-Chigorinskoye field is the 35/6 kV Bit-temskaya substation (2x25 MB A).

Power supply to the on-site facilities of the Zapadno-Chigorinskoye field is carried out from SS 35/6 kV (2x6.3 MB A) No. 252, located in the area of ​​the booster pump station technological site.

During the development of the field, materials and equipment are supplied from the city of Surgut, which has a large railway junction, river port and airport, capable of receiving passenger and heavy transport aircraft.

The nearest village Nizhne-Sortymsky is provided with qualified labor resources. At NGDU "Nizhnesortymskneft" a system of repair departments and services is developed.

2. ANALYSIS OF THE STRUCTURE OF THE WELLS FUND.

As of 01.01.2006, the balance of the enterprise has 147 wells, including production wells - 109, injection - 33, control - 1, water intake - 4. The characteristics of the well stock are given in table. 2.1

At the AC12 facility, there are 129 production and injection wells, including 96 production and 33 injection wells (of which 12 are being developed for oil).

There are 13 abandoned exploration wells in the AS11 and YUSo reservoirs.

The graphical appendices show maps of the current state of development of the AC12 object. For the object as a whole, the productivity of the wells indicated on the map corresponds to the reports of the NGDU, the maps of each of the layers show the estimated productivity obtained as a result of model calculations.

The state of the fund is satisfactory. There are 2 wells in the idle well stock (2% of the well stock).

In December 2005, 100 production wells were in operation with an average oil flow rate of 13.9 t / day, an average bottomhole pressure of 12.8 MPa. There are 21 operating injection wells. The average injectivity of injection wells is 152 m 3 / day, with an average wellhead pressure of 14.9 MPa.

The range of oil production rates (from 0.1 to 63.1 t / day) for the initial stage of development is very large. To identify the main reasons for the unequal productivity of wells, a multivariate analysis of geological and field information was carried out, the most informative dependencies are shown in Fig. 4.3.1. From the given data it follows: