RU2108450C1 - Method for development of oil deposit - Google Patents

Abstract

FIELD: oil production industry. SUBSTANCE: according to method, oil is recovered through producing wells. Working agent is injected through injection wells. Determined are coefficients of productivity of producing wells. Undertaken are intensifying operations in producing wells with lower coefficient of productivity. To be achieved is levelling of coefficients of productivity. Preset throughout deposit is equal pressure difference between zones of injection wells and zones of nearest producing wells. EFFECT: higher efficiency.

Description

 The invention relates to the oil industry and may find application in the development of an oil reservoir with a low permeability reservoir.

 A known method for the development of oil deposits, including the selection of oil through production wells [1].

 The known method is applicable at the initial stage of reservoir development and does not allow the development of an oil reservoir with the achievement of high oil recovery.

 Closest to the invention in technical essence is a method of developing an oil reservoir, including the selection of oil through production wells and the injection of a working agent through injection wells [2].

 The known method allows you to select the main oil reserves from the reservoir, however, some of the reserves remain in the reservoir, especially in reservoirs with low permeability reservoirs, which reduces the oil recovery of the reservoir.

 The proposed invention solves the problem of increasing oil recovery deposits.

 The problem is solved in that in the method of developing an oil reservoir, including oil extraction through production wells and pumping a working agent through injection wells, according to the invention, productivity coefficients of production wells are determined, intensification work is carried out on production wells with a low productivity coefficient, achieving equalization of productivity coefficients, after which sets the same pressure difference between the zones of injection wells and the zones of the nearest producing wells Azhinov.

The essential features of the invention are:
1. The selection of oil through production wells.

 2. Injection through injection wells of the working agent.

 3. Determination of productivity coefficients of producing wells.

 4. Carrying out intensification work on producing wells with a low productivity coefficient, achieving equalization of productivity coefficients.

 5. Set the same pressure difference across the zones between the zones of the injection wells and the zones of the nearest producing wells.

 Signs 1-2 are common with the prototype, signs 3-5 are the salient features of the invention.

 Known methods for developing oil deposits make it possible to select the main oil reserves from the reservoir, however, some of the reserves remain in the reservoir, especially in reservoirs with low permeability reservoirs, which reduces the oil recovery of the reservoir. The proposed invention solves the problem of increasing oil recovery deposits. The problem is solved by the following set of operations.

 When developing an oil reservoir at a late stage, oil is taken through production wells and injected through the injection wells of the working agent. In production wells, productivity factors are determined.

The productivity coefficient for wells is determined by the indicator curve or the pressure drop curve over time
K = Q / (P _PL - P _Zab ),
where K is the coefficient of productivity, m ³ / day • MPa;
Q - fluid flow rate or injectivity of the well, m ³ / day;
P _PL - reservoir pressure, MPa;
P _zab - bottomhole pressure, MPa.

 When injecting a working agent, production wells with a maximum productivity coefficient will experience the maximum impact.

 The productivity coefficients of producing wells are determined. On wells with low productivity coefficients, intensification work is carried out: acid treatments, mud dressing, flushing with surfactant solutions, hydraulic fracturing, drilling of new horizontal and inclined tables from existing wells, etc. Approaching the values of productivity coefficients in wells, approaching the maximum values. Development is continued, maintaining a close pressure difference between the injection well zone and the closest producing well zone, i.e. maintain the same difference between bottomhole pressures in injection and production wells.

 Mineralized water from the lower horizon is used as a working agent.

Example 1. An oil deposit of the Romashkinskoye field is developed with the following characteristics: porosity 11.9%, permeability 0.029 μm ² , oil saturation 61.1%, absolute mark of water-oil contact 870 m, average oil-saturated thickness 4 m, initial reservoir pressure 11 MPa, reservoir temperature 25 ^o C; reservoir oil parameters: density 930 kg / m ³ , viscosity 46 MPa • s, saturation pressure 1.8 MPa, gas content 15.2 m ³ / t, sulfur content 3.64%.

An oil reservoir is developed by taking oil through 15 producing wells and pumping a working agent — highly mineralized water with a density of 1180-1200 kg / m ³ from the lower horizon, through 15 injection wells.

The productivity coefficients of producing wells are determined, which are values from 0.1 to 0.7 m ³ / day • MPa. On wells with low productivity coefficients, intensification work is carried out: acid treatments, mud dressing, flushing with surfactant solutions, hydraulic fracturing, drilling of new horizontal and inclined tables from existing wells, etc. The convergence of the values of productivity coefficients in production wells to a value of 0.7 m ³ / day • MPa is achieved. The development is continued, maintaining a close pressure difference between the injection wells and production wells in the reservoir, in particular, the pressure difference in the reservoir is 30 MPa, i.e. bottomhole pressures in injection wells 36 MPa, in producing wells 6 MPa.

 As a result of the development, the oil recovery of the deposit increased by 11%, the oil recovery coefficient was 0.56.

 The application of the proposed method will improve oil recovery of oil deposits with low permeability reservoirs.

Claims (1)

 A method for developing an oil deposit, including oil extraction through production wells and pumping a working agent through injection wells, characterized in that the production factors of production wells are determined, intensification work is carried out at production wells with a low productivity coefficient, achieving equalization of production coefficients, and then established by the deposits the same pressure difference between the zones of the injection wells and the zones of the nearest adding wells.