Difficult oil of the Tyumen formation. Difficult oil of the Tyumen formation Yem Egovskoye field on the map

The studied Em-Yogovsky license area (LU), which is part of the Krasnoleninsky oil and gas condensate field, is administratively located in the Oktyabrsky district of the Khanty-Mansiysk Autonomous Okrug (KhMAO) of the Tyumen region. The nearest large settlement is the city of Nyagan (Figure 1).

Brief information about the geographical and economic conditions of the study area is given in Table 1.

The exploratory drilling project for the Em-Yogovskaya area was drawn up in 1970, and exploratory drilling began in 1971. Within the area, commercial oil was obtained in exploratory well 2g in 1971 from Jurassic sediments.

History of field development

deposit formation well development

In 1953, the West Siberian Aeromagnetic Expedition carried out magnetic exploration at a scale of 1:1,000,000. Based on its results, zones of predominance of positive and negative magnetic fields were identified.

In 1955, the Khanty-Mansiysk party 37/35 carried out magnetic exploration on a scale of 1:200,000, and local positive and negative magnetic anomalies were identified against the background of regional fields.

Table 1 - Geographical and economic conditions

Figure 1 - Overview map of the Krasnoleninskoye oil and gas condensate field

In 1956-1957, gravimetric parties of the Khanty-Mansiysk oil exploration expedition, based on the results of gravity exploration, compiled a tectonic zoning diagram of the foundation, and for the first time the Krasnoleninsky arch was identified.

In 1957-1961, joint ventures 14/57-58, 7/58, 3/59, 3/60, 15/60-61 TTGU expeditions carried out seismic sounding (SES) on a scale of 1:500,000. A vast area of ​​the river basin was studied. Ob, including the clarification of the tectonic structure of the Krasnoleninsk zone, a structural map of the lower platform Mesozoic was constructed.

The Em-Yogovsky local uplift was identified based on the results of seismic work sp 09/60-61 in 1961 (MOV), on a scale of 1:100,000. The Sosnovo-Mysskoye local uplift, which is part of the Em-Yogovsky license area, was identified as a result of work carried out by joint venture 19/69-70 in 1970.

In 1961-1962 sp 20/61-62 seismic exploration (SE) was carried out on a scale of 1:100,000, as a result the Em-Yogovsky uplift was detailed and prepared for drilling.

Areal seismic surveys (MAS, MOGT-20) at a scale of 1:50,000, 1:100,000 within the Em-Yogovskaya area were carried out from 1970 to 1983. Based on the results of these works, structural maps were compiled for reflecting horizons A, B, M, M1 (K) and D, local uplifts were prepared for deep drilling.

Throughout this time, regional seismic surveys were also carried out, the purpose of which was to study the topography of the foundation. As a result of the work, numerous faults, areas of local inflections and zones that are promising for searching for structural and stratigraphic traps were identified.

Since 1989, detailed seismic work MOGT-20 at a scale of 1:25,000 sp 13/89-90 PGO Tyumenneftegeofizika has been carried out on the Yem-Yogovskaya area, including using the MOGT-30 method.

In 1999, JSC Sibneftegeofizika carried out detailed seismic exploration work MOGT-20 with a density of 2-2.5 km/km2 in the northern part of the central dome of the Em-Yogovskaya area. In 2001, a reinterpretation of the work performed by MOGT-30 in 1989-91 was carried out. joint 13 on Malo Yem-Yogovskaya Square. As a result, the geological structure of pre-Jurassic formations, Jurassic and Lower Cretaceous parts of the section along reflecting horizons was clarified

A, T2, T1, T, P, B, M, M1, M11, D. The block structure of the work area has been established. Zones of development of the weathering crust and the Triassic complex were identified, the structure of deposits of the Tyumen formation was detailed, the proposed zones of development of fractured reservoirs in the deposits of the Bazhenov and Abalak formations were mapped, and the contours of the oil-bearing capacity of the Vikulovsky deposit were clarified.

In 2007-2008 in the southwestern part of the license area, CDP-30 work was carried out (Figure 2).

Figure 2 - Scheme of seismic exploration coverage of the Em-Yogovsky license area

To study the velocity characteristics of the section and clarify the stratification of the reflecting horizons identified in it, seismic logging and VSP work were carried out. In the area, such studies were carried out in wells: 30034g, 30042g, 2014, 30025g, 1g, 586g.

graduate work

1.1 Geographical location

The studied Em-Yogovsky license area (LU), which is part of the Krasnoleninsky oil and gas condensate field, is administratively located in the Oktyabrsky district of the Khanty-Mansiysk Autonomous Okrug (KhMAO) of the Tyumen region. The nearest large settlement is the city of Nyagan (Figure 1).

Brief information about the geographical and economic conditions of the study area is given in Table 1.

The exploratory drilling project for the Em-Yogovskaya area was drawn up in 1970, and exploratory drilling began in 1971. Within the area, commercial oil was obtained in exploratory well 2g in 1971 from Jurassic sediments.

Geological structure and prospects for oil and gas content of Miocene deposits of the northern side of the West Kuban trough

The research area is located in the Krasnodar region (Figure 1). In physical-geographical terms, it is confined to the Azov lowland. In terms of climate, the area belongs to the second (Azov) climatic province of the Krasnodar Territory...

Geological and geomorphological study of the area practice

Located in the center of Eurasia, in the west of the Asian part of Russia, the Tyumen region extends from the steppes of Kazakhstan to the shores of the Arctic Ocean and occupies most of the West Siberian Plain...

Hydrological regime of the Amur River

The territory considered in this work includes the Amur basin and the catchments of rivers flowing into the Sea of ​​Japan from the mouth of the Amur to the Tumaina River. The Amur is the largest river in the Far East. It is formed by the confluence of the Shilka and Argun rivers...

Development of oil fields. Krosnoleninskoye field.
Basic design solutions for the development of the Krasnoleninskoye field.
At the first stage of development of the Em-Egovskaya field, industrial oil and gas potential was associated with the weathering crust of the basement, sediments of the Tyumen and Vikulovskaya formations. The main object of exploitation was the deposits of the Tyumen formation (YUK2 - 9), the Vikulovsky formation (VK), and the weathering crust (WC), which were not considered in the first project documents due to poor knowledge.

In 1978, the Siberian Scientific Research Institute (SibNIINP) prepared a new project document for the development of the field, “Principal diagram of pilot industrial exploitation of the Krasnoleninsky oil and gas region.” At a time when the fields were poorly studied, the work presented by the Central Commission for Field Development (CDC) was not accepted. On its basis, from the position of additional study of geological production statistics of productive strata in the Em-Egovskaya area of ​​the field, pilot work was determined with the opening of 270 wells according to the areal inverted 9th development system, area 450 * 450 m (TsKR protocol No. 750 dated November 28, 1978).

During the development of exploration wells at the site, flow rates from 8 to 155 tons/day were obtained.
Subsequently, 4 project documents for the development of the field were approved (1982, 1989, 1990 - 1991 and 1996);

1. Technological scheme of pilot production of the Em - Egovskoye and Palyanovskoye fields (Minutes of the Central Committee of the Red Cross No. 9712 dated April 21, 1982);

2. Technological scheme of the pilot project Em - Egovskaya and Kamennaya areas of the Krasnoleninskoye field (drawn up in 1989) (Minutes of the Central Committee for Mineral Resources No. 9321 dated 07.11.1990);

3. Project for pilot project Em - Egovskaya and Kamennaya squares (drawn up in 1990) (Minutes of the Central Committee of the Red Cross No. 4421 dated March 31, 1991). Technological indicators of the experimental industrial development of the Em - Egovskaya and Kamennaya areas (compiled in 1991).

4. Addition to the TECHNICAL SCHEME of Yem - Egovskaya and Palyanovskaya squares (protocol of the Central Committee of the Russian Federation No. 22121 dated November 21, 1997). SibNIINP drew up only one project document for the development of the Abalak formation in 1997. Currently, the development of the Abalak formation is carried out on the basis of the “Addition to the TECHNICAL SCHEMA of development of 1996”. Let me give a brief description of this document.

Addition to the TECHNICAL SCHEME of the Yem-Egovskaya and Palyanovskaya areas (Abalak formation 1996).
The last project document for the formation YuK1-2 of the Em - Egovskaya area is the “Addition to the TECHNICAL SCHEMA for the development of the Em - Egovskaya and Palyanovskaya areas (Abalak formation)”, approved by the Central Committee of the Russian Federation (Minutes No. 2212 of 04/21/1996).
The need to draw up a project document is caused by the actual commissioning of a new object into industrial development - the Abalak formation, characterized by high productivity and relatively insignificant reserves (the average oil-saturated thickness of the object is 1.6 m). The deposit was put into development in 1992, through inclusion in drilled wells. object YUK1. Resources for Jurassic deposits were not submitted to the State Reserves Committee for assessment.

In the “Addendum to the TECHSCHEMA field development Em - Egovskaya and Palyanovskaya areas" calculations of technological indicators for the development of the Abalak formation were carried out according to three development options, differing in the number of wells and the volume of production drilling on the undrilled part of the area.
Taking into account the peculiarities of the geological structure of the deposit and the high zonal heterogeneity of the object, the placement of wells was carried out individually and in stages, starting with presumably more productive zones. Wells are primarily located mainly on seismic profiles and in fairly confidently traced zones of small uplifts and high-gradient slopes, so the placement of wells is uneven. Of the three options, the second development option was adopted, which provides for the following main solutions:

– allocation of one development object;
– development of the deposit in a natural mode;
– placement of wells is individual based on a complex of geophysical studies (seismic and gravity survey);
– drilling of 30 estimated wells since 1997. with core sampling and a full range of well logging, total stock of 119 wells;
– pilot waterflooding, organization of transfer of 10 wells. from prey;
– Hydraulic fracturing in low-permeability intervals.

Jurassic deposit reserves
Em-Egovskaya area, listed on the balance sheet of the Russian Federation

– design level of oil production – 405.5 thousand tons (1996);

– accumulated oil production over 10 years – 2178.8 thousand tons; over 20 years - 2491 thousand tons.

Main technological development indicators
One of the more highly productive is the YuK formation (the first) of the YuK development object, the initial geological oil reserves of which were not approved by the State Reserves Committee of the Russian Federation. As of January 1, 2002, the State Balance Sheet lists 27.4 million tons of oil classified under category C1, which is about 8.5 percent of the oil reserves of all deposits of the Jurassic horizon. Category C2 reserves for the reservoir amounted to 66.4 million tons or 19.4 percent. The distribution of initial recoverable oil reserves by reserve category for the YuK1 reservoir was: Category C1 = 6.9 million tons of oil or 5.9%, category C2 = 5.4 or 8.9%.

Table
Oil reserves as of January 1, 2002 (million tons)

On the balance sheet of the RGF Balance sheet ABC1

Since the beginning of development as of January 1, 2003, 5017.6 thousand tons of oil or 93.1% of production from the YuK reservoir have been produced from the YuK1 formation. The recovery from the initial recoverable reserves of category C1 was 72.7%. The current oil recovery factor is 0.813. Oil production in 2002 amounted to 99.7 thousand tons or 86.5% of production at the YuK facility. Liquid production – 107.2 thousand tons. Oil flow rate is 31.1 t/day, liquid flow rate is 33.4 t/day. Water cut – 7.0%. The stock of production wells is 37, the operating wells are 10. The stock of injection wells is 3, the operating wells are 3. The reservoir is being developed in a natural mode.
Test water injection was carried out in 1995 in a volume of 5.9 thousand m3, in 2001 in a volume of 61.9 thousand m3 and in 2002 - 186.6 thousand m3.

Comparison of projected and actual levels of oil production in the Abalak formation
State of the well stock
The balance stock of wells in the YuK1 formation is 94 units, of which 87 are in the production stock, incl. – 10 – active, 27 – inactive, 46 – in conservation, 4 – in the piezometer; in the injection stock - 5, incl. 3 – active, 2 – in conservation; 2 – others.
As of January 1, 2003, there were 77 production wells inactive, mothballed, and piezometered, of which 49 were in production (Fig. 3.2.1, Fig. 3.2.2).
Cumulative oil production per well in this category is 66 thousand tons. The accumulated recovery of the idle fund is equal to 3234.4 thousand tons or 64.5% of the accumulated oil production in the reservoir.

Most of the idle stock is characterized by low water cut (93.9% of the shut-in well stock worked with a water cut from 0 to 20%), 4.1% of the shut-in well stock worked with a water cut from 20 to 50%, 2% of the shut-in well stock worked with a water cut from 50 to 90%.
The existing well stock of the facility is characterized as high oil production and low water cut.
The average oil flow rate of the existing wells is 31.1 tons/day, water cut is 7%.

Characteristics of the idle production well stock

The average fluid flow rate from existing wells is 33.4 t/day.
The distribution of wells by fluid flow rate is as follows (Figure 3.2.4):
— from 5 to 10 t/day – 30% of the fund (3 wells);
- from 10 to 20 t/day - no;
— from 20 to 50 t/day – 50% of the stock (5 wells);
— from 50 to 100 t/day – 10% of the fund (1 well);
— from 100 to 150 t/day – 10% of the fund (1 well).

Distribution of wells by water cut:
- less than 2% - 10% of the fund (1 well);
- from 2% to 20% - 90% of the fund (9 squares).
The coefficient of utilization of the production fund is 0.27, and that of the injection fund is 1.0.

Application of PNP methods
Geological and technological measures for the YuK1 formation, carried out in 2002, ensured an increase in oil production in the amount of 17.1 thousand tons (17.1% of annual production) due to:
— optimization of the operation of downhole equipment (5 wells – operations) – 14.8 thousand tons;
- other geological and technical measures (1 well - operation) -2.3 thousand tons.

Decline oil production in 2003 is explained by the lack of geological and technical measures. As a result, the average oil flow rate of producing wells will be 30.2 tons/day, instead of 31.1 tons/day in 2002; the planned liquid flow rate is 35.5 t/day (in 2002 – 33.4 t/day).
The stock of producing wells will be 37 units, the operating stock of producing wells at the end of the year will be 10. The stock of wells will not change relative to 2002. The average annual water cut will be 10% (in 2002 – 7.0%).
Energy state deposits
For the YuK1 formation, the reservoir pressure in the production zone is 12.6 MPa. Compared to the initial one (26.7 MPa), the pressure decreased by 13.8 MPa. The YuK1 formation is being developed in a natural mode, in accordance with the decision of the project document approved by the Central Development Committee. Wells operating the YuK1 facility, in which there is a significant decrease in reservoir pressure, are mothballed. The facility requires experimental industrial work to find a technology for restoring and maintaining reservoir pressure.
Since the beginning of development, 61,876 thousand tons of water have been pumped into the formations, fluid withdrawal has been compensated by 2.85%, the current compensation is 103.7%. Development of oil fields.

Administratively, Em-Yogovskaya Square is located on the territory of the Oktyabrsky District of the Khanty-Mansiysk Autonomous Okrug of the Tyumen Region.

The deposit is located on the left bank of the Ob River, which, bending around its area with a knee-shaped channel, flows in the northern, northwestern directions. It should be immediately noted that this left-bank section is flat; there is an extensive floodplain area, the width of which is 15-20 km (in the area of ​​the deposit). The floodplain is adjacent to the deposit in the area where the Palyanovskaya area is located. In connection with the noted factor, the field area can be divided into two areas in geomorphological terms. Palyanovskaya area (eastern section) has absolute relief elevations from + 25 to 40 m, Em-Yogovskaya area (western section) is more elevated, there is a greater fluctuation in absolute relief elevations from + 40 to 170 m.

In general, the territory of the deposit is a hilly and ridged plain with deep valley-gully erosion systems. There is a general uplift of the relief forms of the area in a westerly direction.

The hydrographic network of the field territory is represented by a significant number of rivers and small streams. In the southern part (almost along its southern border) of the field, the Tal River flows in a wide direction with numerous channels, the largest of which, the left-bank tributary Talovy, is one of the sources of the river and originates from the field area, flowing in a southerly direction. In the area of ​​well 15, the Tal River flows into the Em-Egan River.

The Em-Egan River flows directly through the territory of the field (Em-Egovskaya area), flows in a latitudinal, south-eastern direction and with its tributaries covers almost the entire area of ​​the Em-Egovsky site. The largest of the tributaries, the Maly Em-Egan River, is the main source of the river.

The Potymets River flows and originates in the northern part of Em-Egovskaya Square. It also flows in a latitudinal direction, but in the area of ​​wells 14 and 162, it abruptly changes its flow to the north, and there it flows into the Khugot River.

As already noted, in the eastern part of the area flows the Ob River with numerous tributaries and channels, of which the largest channel, Endyrskaya, flows almost along the eastern border of the field in a northern direction.

Lakes are developed throughout the area; they are confined mainly to floodplain and wetland areas. Of the largest, we can note such as Kholodnoye (2 * 1 km), located in the central part of the field. Lake Bolshoye Em-Ekhovskoe (4*4 km.) and Maloe Em-Ekhovskoe (2.5*3 km.), located in the southern part of the area under consideration. Somewhat east of them is Lake Bolshoi Sor.

Wetlands are developed mainly in the upper reaches of rivers and in the floodplain part of the left bank of the Ob River. The swamps are impassable and difficult to pass. As a rule, they abound with a significant number of small and insignificant lakes.

The distance from the eastern borders of the area to the Ob River is 15-20 km.

The Em-Egovskoye field is located in a forest zone, within which the vegetation is represented mainly by pine and cedar-fir forest.

Mixed forest predominates in wetlands. Coniferous tree species are developed within the swamps and floodplain areas of the Ob River, on elevated areas of the terrain, hills, which are called “Urochishchi”.

The climate of the area is sharply continental with long, cold winters and short, fairly warm summers. The average annual temperature is minus 1.8 0C. The average temperature of the coldest month, January, is minus 25 0C (with a minimum drop to – 35 0C – 40 0C), and the average temperature in July is + 15 0C (with a maximum of up to + 30 0C).

The average annual precipitation ranges from 450 to 500 mm. Of which most occur in the spring-autumn periods. The thickness of the snow cover is on average 0.8-1.0 m, reaching 1.5 m in low areas.

Freeze-up on the rivers begins in October, and their opening occurs at the end of April, at the beginning of May.

The area in question is practically uninhabited. There are no populated areas directly on the field area. The nearest settlement, located in the southeastern part, is the village of Palyanovo, located at the mouth of the Endyr River, on the southern shore of Lake Bolshoi Sor.

In the northern part of the deposit (10-15 km, north of its borders) the villages of Sosnovy and Listvenny are located. Larger settlements are located on the Ob River - Krasnoleninsky, Urmanny, Keushki, Sosnovo and others.

The soils in the work area are podzolic-alluvial gley, and peat soils are developed in the wetlands. Various types of alluvium and sand-gravel mixtures are developed in river valleys and floodplain terraces.

In the Khanty-Mansi Autonomous Okrug, in the vicinity of the city of Nyagan, speaking in the language of oil workers, there is the most promising section of the Tyumen formation - the Yem-Egovskaya area. Almost half of all reserves of the Tyumen formation are concentrated here - this is 170 million tons of hydrocarbons. The deposit has been developed since the 80s of the 20th century, but only negligible amounts of black gold have been recovered from these deposits - only 5.5 million tons.

Hard-to-recover reserves of the Tyumen formation

Undeveloped reserves of the Tyumen formation are classified as TRIZ - hard-to-recover reserves. Such reserves are concentrated in difficult geological conditions and are characterized by very low permeability and productivity.

Until today, all activity was aimed at developing traditional, so-called “light reserves” - this is oil that literally lay “on the surface”. Traditional technologies have proven to be ineffective, but new methods and incentives for their development make it possible to approach hard-to-recover reserves.

To extract TRIZ, wells are drilled horizontally. First, the drilling tool goes underground to a depth of more than 2,000 kilometers, and then begins to move parallel to the horizon or at a slight angle of inclination.

The Em-Egovskaya area was chosen for testing technologies and preparing for further drilling, since here the most successful structure of reserves and the use of this technology is possible with maximum efficiency.

New technologies, of course, require the use of different techniques, equipment, materials and high costs. The amendment to the tax code on the application of differentiated coefficients to the production tax, that is, benefits, became a powerful incentive for the development of TRIZ. The intensification of work at TRIZ made it possible to extract an additional 370 thousand tons of oil, and in the future the number will reach millions of tons.

40% TRIZ

In total, hundreds of millions of tons of oil remain in reserve at the Krasnoleninskoye field. Not only in the Yem-Egovsky area, but also in the Talinsky and Kamenny areas - these are those sections of the Tyumen Formation where 40% of the reserves are classified as hard-to-recover.

116 cluster (literal name) – many wells from one site. There are 16 of them here and they all already work using TRIZ technology. Average initial debit, i.e. the average amount of oil produced per day from one such well is 60 tons. Before the advent of new technologies, oil production was several times lower.

Well pad 177-A will go down in the history not only of Nyagan oil workers, but also in the history of the entire oil industry of the country. Here, for the first time, horizontal drilling technology was used and hard-to-recover oil reserves were extracted for the first time.

Bush 240 is still at the very beginning of development. Geologists have already decided that all of it will be developed with horizontal wells with multi-stage hydraulic fracturing. The first well is currently being drilled, which will take 40 days. This is longer than expected, since this is the first well, oil companies need to study the formation section.

One cluster can be developed for years: while one well is working, others can only plan.

The length of horizontal wells in the Em-Egovsky area varies from 400 to 1000 meters. Such a well makes it possible to cover the entire large oil-bearing section and integrate all those dissected and discontinuous layers into the overall effective development.

After a well is drilled, oil does not begin to gush out like a fountain, as it might seem, it needs to be helped to “come out” of the depths. To do this, multi-stage hydraulic fracturing or multi-stage hydraulic fracturing technology is used in horizontal sections of wells.

Pipes are lowered into the well, through which up to 100 tons of a special mixture of proppant and gel are pumped in a few minutes under a pressure of approximately 300 atm. A rupture occurs in the productive formation, and a network of tiny cracks, just a few millimeters wide, is formed, through which oil and gas enter the well.

The hydraulic fracturing mixture consists of proppant, gel, water and chemical binders. The proppant consists of tiny granules that clog the crack and prevent it from narrowing, but at the same time allow oil to pass through perfectly. This mixture is pumped into the well to a depth of 2-3 km. From now on, all wells at Em-Eg will be developed using multi-stage hydraulic fracturing technology.

Due to a lack of technology, hard-to-recover reserves have been relegated to the background for a long time. Today this is a second wind for deposits such as Em-Ega. Oil will be produced here for several more decades.