The way of the development of carbonate deposits of oil through periodic recovery reservoir pressure to the initial

 

(57) Abstract:

The invention relates to the oil industry and can find application in the development of deposits with weak hydrodynamic connection between the wells and the low mobility of the oil. Provides enhanced oil recovery reservoir. The inventive in the development of oil deposits with weak hydrodynamic connection between the wells and the low mobility of the oil is taken oil through production wells at the idle injection wells before reaching the reservoir pressure of the order of 0.05 to 0.25 from the initial reservoir pressure. Stop producing wells and initiate injection wells. Download the working agent through the injection well to the recovery reservoir pressure to the initial level. Further development of the deposits are in constant operation of injection wells and periodic operation of producing wells. Bottom-hole pressure in the injection wells support equal 65-75% of the saturation pressure.

The invention relates to the oil industry and can find application in the development of deposits with weak hydrodynamic connection between the wells and the low mobility of oil.

The known method does not allow to develop oil reservoir with high recovery.

Closest to the invention to the technical essence is the way of the development of oil deposits, including oil extraction through production wells to reduce the reservoir pressure below the saturation pressure and to achieve the formation pressure at which the flow rate begins to decrease and the gas released from the oil begins to break through into the producing wells, injection before injection through injection wells in the amount of 2-10% of the pore volume of the reservoir rim water containing a water-soluble surfactant concentration of 0.01-5% by weight, water deposits, and subsequent development of deposits in R The known method provides a significant reduction in reservoir pressure, that allows you to develop the basic reserves of deposits, but deposits of oil recovery is low.

In the proposed invention solves the problem of increasing oil deposits.

The task is solved in that in the method of development of oil deposits, including oil extraction through production wells to reduce the reservoir pressure below the saturation pressure and the injection of working agent through the injection wells, according to the invention on deposits with weak hydrodynamics communication between the wells and the low mobility of the oil is taken oil through production wells at the idle injection wells before reaching the reservoir pressure of the order of 0.05 to 0.25 from the initial reservoir pressure, stop producing wells and initiate injection wells, pump the working substance through the injection well to the recovery reservoir pressure to the initial level, further development of the deposits are in constant operation of injection wells and periodic operation of producing wells.

Features of the invention are:

1. the selection of oil through the production wells to reduce the reservoir pressure below the saturation pressure;

2. download working agent cher the Oia about 0,05-0,25 from the initial reservoir pressure;

4. same with non-injection wells;

5. stop producing wells;

6. the start-up injection wells;

7. download working agent through the injection well to the recovery reservoir pressure to the initial level;

8. further development of deposits of continuous operation of injection wells and periodic operation of producing wells;

Signs 1, 2 are shared with the prototype, signs 3-8 are the salient features of the invention.

The essence of the invention.

In the development of oil deposits of part of the reserves of the deposits not covered by the impact. Because different zone deposits have different permeability, porosity, etc., i.e., the reservoir is heterogeneous, production of reserves from reservoirs is uneven. Covers the development of mainly high-permeability zones of the reservoir. In the proposed invention solves the problem of increasing oil recovery from an inhomogeneous multilayer deposits due to more complete coverage of deposits of influence, involvement in the development of previously broken bypassed zones. The problem is solved by the following set of operations.

In the development of oil deposits are otbiraetsya. Bring the pressure up to a pressure of about 0,05-0,25 from the initial reservoir pressure. At idle injection wells in deposits of missing a directed flow of the working agent, in normal conditions, passing through the most permeable zones. In the absence of such a stream of oil comes to producing wells from all areas of deposits, including from the tight. This increases the recovery of oil deposits on the first stage of development. Then stop producing wells and initiate injection wells, pump the working substance through the injection well to the recovery reservoir pressure to the initial level. Practice shows that the repetition of the first stage of reducing the reservoir pressure after it is restored to the original level of practically does not increase oil recovery from reservoirs, while the loss rate of development of deposits become very significant. Therefore, further development of the deposits are in constant operation of injection wells and periodic (cyclic) operation of producing wells. In the oil recovery increased deposits.

An example of a specific implementation.

Develop oil hall 18°C, the saturation pressure of 2.5-3.0 MPa, the reservoir layer, the thickness of layer 4-7 m header - carbonate, porous fractured, the porosity of 15.6%, the saturation of 76.8, permeability 10-50 MD. Oil at reservoir conditions has a viscosity of 45 MPaC and a density of 0.88 g/cm3.

The deposits develop on a triangular grid with a spacing of wells 300 meters Number of production wells is 437, injection - 107.

The Deposit is weak hydrodynamic connection between the wells (water permeability of 0.5-1 dcm/SDR, the complex parameter to 10-8cm2/s) and low mobility of oil (kinematic viscosity of more than 100 cSt, the content of resins and asphaltenes 6-22°). Under these conditions, the initial periodic hydrodynamic effects on the accumulation impractical. At the first stage are oil extraction through production wells at the idle injection wells. Bring the pressure up to the pressure on Deposit in the range of 0,5-1,7 MPa, which is approximately 0,05-0,25 from the initial reservoir pressure. With this mode selected from a Deposit of 25% of the recoverable oil reserves. Then stop producing wells and vosstanovleniya reservoir pressure to the initial level. Further development of the deposits are in constant operation of injection wells and periodic (cyclic) operation of producing wells: 15 days. - work 15 days. - stop. In the oil recovery increased deposits by 3%.

The application of the proposed method will improve the recovery of oil deposits.

The way of the development of carbonate deposits of oil through periodic recovery reservoir pressure before starting, including the selection of oil through the production wells to reduce the reservoir pressure below the saturation pressure and the injection of working agent through the injection wells, deposits with weak hydrodynamic connection between the wells and the low mobility of the oil is taken oil through production wells at the idle injection wells before reaching the reservoir pressure of the order of 0,05-0,25 initial reservoir pressure, stop producing wells and initiate injection wells, pump the working substance through the injection well to the recovery reservoir pressure to the initial level, further development of the deposits are in constant operation of injection wells and periodic operation of producing wells.

 

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5 cl, 3 dwg

FIELD: oil extractive industry.

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EFFECT: higher efficiency.

1 ex

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EFFECT: higher efficiency.

2 cl, 2 dwg

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EFFECT: possibility to retain oil relative permeability of oil-saturated formation area.

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EFFECT: improved oil recovery.

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FIELD: oil industry.

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EFFECT: higher oil yield.

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EFFECT: increased efficiency, oil recovery and production well injectivity, as well as increased sweep efficiency and oil recovery ratio.

1 dwg

FIELD: oil production industry, particularly oil deposit development.

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EFFECT: increased operational reliability.

1 ex, 3 dwg

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