RU2513965C1 - Multilayer oil deposit development method - Google Patents

Abstract

FIELD: oil and gas industry.SUBSTANCE: production zones are determined, producing and injection wells are drilled, oil recovery is made through producing wells and working fluid injection is made through injection wells. At that the four following zones are indentified as production zones: two terrigenous and two carbonate zones, at the end of the second stage of oil deposit development when maximum year oil production parameters start decreasing and measures are performed on year-by-year basis starting since the first year of the method implementation. During the first year two vertical producing wells and one injection well are drilled for the first zone, offshoot is made in the fourth zone from the existing piezometric well, one producing well is switched to water injection in the second zone and one piezometric well is switched to a producing well for the first zone. During the second year one well is switched to injection in the second zone, one well is equipped with installation for downhole pumping from one horizon to another within limits of the first zone, one hole is equipped with dual production unit for the first and second zones. During the third year one well is switched for injection in the first zone, one hole is equipped with dual pumping unit for the first and second zones, two holes are equipped with dual production unit: one from the first and second zones and one from the fourth and first zones; one horizontal offshoot is made at the first zone from the existing producing well, one piezometric well is started up as a producing one for the third zone. During the fourth year one vertical producing well is drilled for the fourth zone; during the fifth year one well from the third zone is witched for production at the fourth zone; during the eighth year one horizontal offshoot is made at the first zone from the existing producing well.EFFECT: improving oil recovery rate of the deposit by optimisation of its development system.2 cl, 7 dwg

Description

The invention relates to the oil industry and may find application in the development of oil fields with oil deposits in carbonate and terrigenous reservoirs.

A known method of developing a multilayer oil field, according to which the selection of oil through production wells from the lower productive horizon, the injection of a working agent into the lower production horizon, the selection of oil through production wells from the upper production horizon and compaction of the network of wells of the upper horizon. The selection of oil through production wells from the upper productive horizon is carried out until the reservoir pressure is reduced by 10-40%, while compaction of the grid of wells on injection wells operating on the lower horizon, perforation is performed in the interval of the upper horizon. A simultaneous-separate injection of the working agent into the lower and upper horizons is performed. When uploading to the upper horizon, the injection volume is set equal to the required compensation volume over the site, and the effect is monitored for reacting production wells. If there is an effect confirmed by an increase in the current bottomhole pressure at production wells of at least 10%, injection flow rate is limited to 20-80% of the initial one and the production is intensified by reacting production wells (RF Patent No. 2474676, publ. 10.02. 2013).

Closest to the proposed invention in technical essence is a method of developing a multilayer oil field in which production facilities are distinguished, a grid for the location of production and injection wells is drilled, wells are drilled, oil is extracted from production wells and the displacing agent is injected into injection wells. The life of the field’s reserves is close to the average guaranteed service life of the wells, in which, for technical reasons, no more than 20% of the production well stock is eliminated. For this purpose, a common through hole grid is drilled for a group of field deposits with an increase in the number of wells and accelerated development time. At the same time, the exploitation of the field is carried out by the entire fund of production wells by sequentially selecting products from an individual deposit or a group of reservoir deposits combined by jumpers of a non-collector with a thickness of not more than 30 m, in decreasing order of their productivity, starting with the most productive ones (RF Patent No. 2307923, publ. 10.10 .2007 - prototype).

A disadvantage of the known technical solutions is the uneven production of oil reserves in the whole field and, as a result, low oil recovery.

The proposed invention solves the problem of increasing oil recovery by optimizing the development system.

The problem is solved in that in the method of developing a multilayer oil field, including the allocation of production facilities, the location of production and injection wells, oil production through production wells and pumping a working agent through injection wells, according to the invention, four objects are distinguished as production objects: two terrigenous and two carbonate, at the end of the second stage of field development, at the beginning of the decrease in the maximum annual oil production at the field, measures are taken from year to year, counting from the first year the method was launched, in the first year two vertical production wells and one injection well are drilled to the first object, one sidetrack is drilled at the fourth object from the existing piezometric well, one production well is transferred for water injection to the second to the facility, one piezometric well is introduced as the producing well for the first facility, in the second year, one well for the second facility is transferred for injection, one well is equipped with an external installation three-well pumping from one horizon to another within the first facility, one well is equipped with a unit for simultaneous and separate production from the first and second facilities, in the third year one well is transferred for injection at the first facility, one well is equipped with a unit for simultaneous-separate injection at the first and the second objects, two wells are equipped with a unit for simultaneous and separate production: one from the first and second objects and one from the fourth and first objects, one side horizontal is posted well at the first object from the existing production well, one piezometric well is injected as the production well in the third object, in the fourth year one vertical production well is drilled in the fourth object, in the fifth year, one well is transferred from the third object to the fourth for production, in the eighth year carry out the posting of one lateral horizontal wellbore at the first object from an existing production well.

Additionally, a set of methods for increasing oil recovery (EOR) is carried out: to limit water inflow by plugging water-saturated interlayers, high-strength VPSD polymer systems are injected, to increase the production of flooded heterogeneous permeability productive formations, a viscoelastic colloidal system based on liquid glass VUKSZhS is injected, for a deep complex application composition SNPCH-9030, to limit the influx of water, is treated with reagent SNPCH-9633, to stimulate the selection of products cations are treated with a slow-acting acid composition of KSMD, compositions based on KFS synthetic resin are injected to limit water inflow, a thermo-implosion method for treating the bottom-hole formation zone using a UTI-1 thermo-implosion device equipped with a STGG-80 thermal gas generator is used to increase well productivity.

SUMMARY OF THE INVENTION

The oil recovery of the oil field is mainly influenced by the created development system. Existing technical solutions of the development system for the conditions under consideration do not fully allow the selection of oil from the deposits of field objects. The proposed invention solves the problem of increasing oil recovery.

The problem is solved as follows.

During the development of a multilayer oil field, production facilities are distinguished, production and injection wells are located, oil is produced through production wells, and a working agent is pumped through injection wells. Four production facilities are distinguished as production facilities: two terrigenous and two carbonate. At the end of the second stage of field development, at the beginning of the decrease in the maximum annual indicators of oil production at the field, measures are taken over the years, counting from the first year of the beginning of the implementation of the method, in the first year, two vertical production wells and one injection well are drilled to the first object, one sidetrack is posted to the fourth object from the existing piezometric well, one production well is transferred under water injection for the second object, one piezometric with the well at the first facility, in the second year one well is transferred for injection at the second facility, one well is equipped with a unit for downhole pumping from one horizon to another within the first facility, one well is equipped with a unit for simultaneous and separate production from the first and second facilities, the third year, one well is transferred for injection at the first facility, one well is equipped with a unit for simultaneous and separate injection at the first and second facilities, two wells are equipped with a facility for simultaneous -separate production: one from the first and second objects and one from the fourth and first objects, one horizontal lateral well is drilled at the first object from an existing production well, one piezometric well is injected into the third object as a production well, and one vertical production well is drilled for the fourth year the well to the fourth facility, in the fifth year one well is transferred from the third facility to the fourth for production, in the eighth year one horizontal lateral well is posted to the first facility ie from an existing production well.

Additionally, a set of oil recovery enhancement methods is carried out: to limit water inflow by plugging water-saturated interlayers, high-strength VPSD polymer systems are injected, to increase the production of flooded heterogeneous permeability productive formations, a viscoelastic colloidal system based on liquid glass VUKSZHS is pumped, for deep complex processing of bottom-hole formation 9030, to limit the influx of water is treated with reagent SNPCH-9633, to stimulate the selection of products they are treated with a slow-acting acidic composition of KSMD, compositions based on KFS synthetic resin are injected to limit water inflow, a thermoimplosion method for treating bottom-hole formation zones is used to increase well productivity using a UTI-1 thermoimplosion device equipped with a STGG-80 thermogas generator.

In Fig. 1, maps with events on the Kynovsky object are shown, in Fig. 2 - on the Tournaisian-Zavolzhsky object, on Figs. 3, 4, 5 - along the Tula horizon, in Figs. 6, 7 - along the Bobrikov horizon.

The method is implemented as follows.

The field is being developed while maintaining reservoir pressure, development is at 2 stages. The field is drilled with a rare grid of wells. Four development objects are distinguished from bottom to top, and they are developed in the same order. The lower object is located at maximum depth, confined to the Devonian system, then there are two objects at medium depth, confined to the Devonian and / or carbon, and the upper object is located at a minimum depth, refers to the coal system (carbon). Drilled vertical wells reveal all four objects, if they coincide in plan, and horizontal ones, on which overlying objects are drilled, as well if they coincide in plan. Impermeable rocks exist between objects.

After the start of the fall in annual oil production, a set of technologies is aimed at optimizing the existing development system. The first year is considered the year the process began. Yearly activities include the following:

- in the first year, two vertical production wells and one injection well are drilled to the Tula-Bobrikovsky site, one sidetracking is carried out at the Kynovsky site from the existing piezometric well, one production well is transferred to the Tournaisian-Zavolzhsky site for water injection, and one piezometric is introduced as production a well along the Tula-Beaver site;

- in the second year, one well is transferred for injection at the Tournaisian-Zavolzhsky site, one well is equipped with a unit for downhole pumping from the Bobrikovsky horizon to Tula, one well is equipped with a unit for simultaneous and separate production from the Turneysky and Tula-Bobrikovsky sites;

- for the third year, one well is transferred for injection at the Tula-Bobrikovsky site, one well is equipped with a unit for simultaneous and separate injection at the Tournaisian and Tula-Bobrikovsky sites, two wells are equipped with a unit for simultaneous-separate production: one from the Turney and Tula-Bobrikovsky sites and one from the Kynovsky and Tula-Bobrikovsky objects, carry out the posting of one lateral horizontal wellbore at the Tula-Bobrikovsky object from the existing production well, enter as production one a piezometric well along the Evan-Lebanese facility;

- in the fourth year, one vertical production well is drilled at the Kynovsky site;

- in the fifth year, one well is transferred from the Yevlan-Levensky facility to Kynovsky for production;

- for the eighth year, one lateral horizontal well is drilled at the Tula-Bobrikov site from an existing production well.

Additionally, a set of oil recovery enhancement methods is carried out: to limit water inflow by plugging water-saturated interlayers, high-strength VPSD polymer systems are injected, to increase the production of flooded heterogeneous permeability productive formations, a viscoelastic colloidal system based on liquid glass VUKSZHS is pumped, for deep complex processing of bottom-hole formation 9030, to limit the influx of water is treated with reagent SNPCH-9633, to stimulate the selection of products they are treated with a slow-acting acidic composition of KSMD, compositions based on KFS synthetic resin are injected to limit water inflow, a thermoimplosion method for treating bottom-hole formation zones is used to increase well productivity using a UTI-1 thermoimplosion device equipped with a STGG-80 thermogas generator.

The result of the implementation of this method is to increase the degree of oil recovery.

An example of a specific implementation of the method

Four independent development objects are distinguished at the Bastrykskoye field from bottom to top: Kynovsky (absolute elevation of the formation roof is -1526.8 m), Evlan-Levensky (-1440.6 m), Tournaisian-Zavolzhsky (-945.7 m) and Tula-Bobrikovsky ( -927.0 m). Impermeable rocks exist between objects. Drilled vertical wells reveal all four objects, and horizontal - the one on which overlying objects are drilled. Such a separation of production facilities allows for effective control over the regulation and development of oil reserves from each facility and to achieve the most cost-effective oil recovery ratios. To comply with the basic principles of rational development of the field, it is planned to develop oil reserves from the underlying reservoirs with a gradual transition to overlying horizons.

In total, by the time the implementation of the proposed method began, 4,107.2 thousand tons were produced. oil and 7805.9 thousand tons liquids. The current oil recovery factor is 0.289. The field is at 2 stages of development. The development of the field is carried out with the maintenance of reservoir pressure. Injection is carried out in 19 injection wells. From the beginning of development, 5787.1 thousand m ^{3 of} water were pumped. Compensation for fluid withdrawal by injection from the beginning of development 74.4%. The drilled well stock in the field amounted to 112, of which 72 wells were located at the Tula-Bobrikovsky site, 30 at the Tournaisian stage, 9 at the Kynovsky horizon, 1 at the Yevlan-Levensky. The production fund includes 73 wells, of which 68 are active, 5 are inactive, and 4 wells are in the piezometric fund. 15 wells were abandoned after drilling for geological reasons.

Kynovsky object. To develop the remaining oil reserves, in addition to the existing fund, sidetracking is performed from well No. 1593 (Fig. 1) in the 1st year of the beginning of the implementation of the development method; in the 4th year one vertical production well No. 7 was drilled; in the 5th year - the return of one well No. 482 from the Evlan-Levensky oil production facility. Additionally, the application of EOR is envisaged: to limit water inflow by plugging water-saturated interlayers, high-strength VPSD polymer systems are injected, compositions based on KFS synthetic resin are injected to limit water inflow, a thermal implosion method for treating the bottom-hole formation zone using a thermal implant UTI-1 is used, equipped with a thermogas generator STGG-80. Additional oil production due to EOR is 5.2 thousand tons. Over the entire development period, the accumulated oil production is 226 thousand tons, including for the period after the implementation of the proposed method 70.7 thousand tons, the final recovery factor of 0.455.

Evlanovo-Lebanese object. To develop the remaining oil reserves in the 1st year, a well No. 482 is introduced for production (Fig. 1) from the piezometric fund of the Kynovsky facility. The deposit of the Evan-Lebanese expanse coincides in plan with the Kyn deposit. In addition, EOR is used: to limit water inflow by tamponing water-saturated interlayers, high-strength VPSD polymer systems are pumped. Additional oil production due to EOR is 0.4 thousand tons. Cumulative oil production over the entire development period of 131 thousand tons, including for the period after the implementation of the proposed method, 2.0 thousand tons, the final recovery factor of 0.500.

Tournaisian-Zavolzhsky object. In order to develop the remaining oil reserves, in addition to the existing fund, a system for maintaining reservoir pressure (RPM) is organized. To do this, in the 1st year, 1 well No. 1626g is transferred (FIG. 2) from the mining fund of the Tula-Bobrikovsky facility for injection; in the 2nd year, 1 well No. 455 (Fig. 2) is transferred to the RPM from the mining ones at the Tournaisian facility; in the 3rd year - 1 well No. 1550 (Figs. 2, 3, 7) from the mining fund of the Tula-Bobrikovsky facility for injection with equipment of refinery with the Tula-Bobrikovsky facility. In the 2nd and 3rd years, the wells No. 1577 (Figs. 2, 7), 1598 with the Tula-Bobrikovsky object were attached through the ORD equipment. In addition, EORs are used: to limit water inflow by plugging water-saturated interlayers, high-strength VPSD polymer systems are pumped; Additional oil production due to EOR is 15.4 thousand tons. Over the entire development period, the cumulative oil withdrawal is 2228 thousand tons, including for the period after the implementation of the proposed method 656.8 thousand tons, the final recovery factor of 0.390.

Tula-Bobrikovsky object. In order to develop the remaining oil reserves, in addition to the existing fund, three wells were drilled in the 1st year, including two producing wells No. 1654, 1655 (FIGS. 5, 6) along the Tula horizon, one injection No. 1653 (FIG. 5) along the Tula horizon with development for oil. Sidetracking is carried out for the 3rd year in well No. 1602 (Fig. 4) along the Tula horizon and the 8th year in well No. 1593 (Fig. 7) along the Bobrikov horizon. Transfer for water injection is carried out for the 2nd year of well No. 1651 (Figs. 5, 6) along the Tula horizon and selection according to Bobrikovsky through VSP; for the 3rd year, well No. 1596 (Fig. 3) is transferred along the Tula horizon from existing producers under PPD. In the well No. 1615 (Fig. 4), for the 3rd year, the equipment of the TDS horizon with the Kynovsky horizon is being introduced. Well No. 1641 (FIGS. 5, 6) is introduced into production from the piezometric fund in the 1st year along the Tula and Bobrikov horizons simultaneously. Additionally, EORs are used: to limit water inflow by plugging water-saturated interlayers, high-strength VPSD polymer systems are injected, to increase the production of flooded heterogeneous permeability of productive formations, a viscoelastic colloidal system based on liquid glass VUKSZHS is injected, for deep complex treatment of the bottomhole zone 30, use 30 restrictions on the flow of water are treated with reagent SNPCH-9633. Estimated additional oil production due to EOR is 30.8 thousand tons. Over the entire development period, the cumulative oil withdrawal is 4055 thousand tons, including for the period after the implementation of the proposed method 1588.4 thousand tons, the final recovery factor of 0.521.

On the whole, over the entire development period, the accumulated oil withdrawal is 6640 thousand tons, including for the period after the implementation of the proposed method 2317.9 thousand tons, the final recovery factor of 0.466.

The application of the proposed method will solve the problem of increasing the coverage of the formation by exposure and, accordingly, increasing the oil recovery of the productive formation.

Claims (2)

1. A method of developing a multilayer oil field, including the allocation of production facilities, the placement of production and injection wells, oil production through production wells and the injection of a working agent through injection wells, characterized in that four objects are distinguished as production objects, two terrigenous and two carbonate, at the end of the second stage of field development, at the beginning of the decrease in the maximum annual indicators of oil production at the field, measures are taken for years reading from the first year of the beginning of the implementation of the method, in the first year, two vertical production wells and one injection well are drilled to the first object, one sidetracking is carried out at the fourth object from the existing piezometric well, one production well is transferred for water injection to the second object, introduced as producing one piezometric well in the first facility, in the second year one well in the second facility is transferred for injection, one well is equipped with an installation for downhole pumping one horizon to another within the first facility, one well is equipped with a unit for simultaneous and separate production from the first and second facilities, in the third year one well is transferred for injection at the first facility, one well is equipped with a unit for simultaneous and separate injection at the first and second facilities , two wells are equipped with a unit for simultaneous and separate production: one from the first and second objects and one from the fourth and first objects, one horizontal sidetracking is carried out at the first volume an object from an existing production well, one piezometric well is injected as a production well in the third facility, in the fourth year one vertical production well is drilled in the fourth facility, in the fifth year one well is transferred from the third facility to the fourth for production, in the eighth year one side well is drilled horizontal wellbore at the first facility from an existing production well. 2. The method according to claim 1, characterized in that they additionally carry out a set of methods for increasing oil recovery: to limit water inflow by plugging water-saturated interlayers, high-strength VPSD polymer systems are pumped, to increase the production of flooded heterogeneous permeability productive formations, a viscoelastic colloidal system based on liquid glass is pumped VUKSZHS, for a deep complex treatment of the bottom-hole zone, the composition SNPCH-9030 is used, to limit the influx of water, they are treated with the reagent SNPCH -9633, to stimulate the selection of products, they are treated with a slow-acting acidic composition of KSMD, compositions based on KFS synthetic resin are pumped to limit water inflow, to increase the productivity of wells, a thermoimplosion method for treating the bottom-hole formation zone is applied using a UTI-1 thermoimplosion device equipped with a STGG-80 thermogas generator .

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