RU2473793C1 - Oil deposit development method - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: according to the method, production wells are arranged on the deposit along triangular grid; product is extracted through production wells; working fluid is pumped through injection wells so that out-contour and contour flooding is formed. Production wells are arranged along triangular grid so that rows of wells oriented at 120° to each other are formed. Buildups of increased thickness, which are associated with paleochannel, are extracted on the deposit, in dome part of which there drilled are horizontal production wells with parallel and series location of horizontal shafts at equal distance from existing vertical production wells in the existing triangular grid. Distance between parallel horizontal shafts is maintained within 220 to 280 m, and distance between faces of horizontal wells at their series location is maintained within 220 to 360 m.

EFFECT: increasing oil recovery of the deposit owing to enlarging the coverage area of the deposit.

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Description

The invention relates to the oil industry and may find application in the development of oil deposits.

A known method of developing an oil reservoir in which injection and production wells are placed on a uniform triangular grid with the formation of areal 13-point development elements with a central injection well and concentric rows of production and injection wells. Oil is taken through six production wells of the internal concentric row. The working agent is pumped through injection wells cyclically with equal amounts in each cycle in four stages. At the first stage, the working agent is pumped through the central and three injection wells of the external concentric row, located through one at the stop of three other injection wells. At the second stage, the working agent is pumped through the central and three injection wells of the external concentric row, which were stopped when three wells were stopped, through which the working agent was pumped at the first stage. At the third stage, the working agent is pumped through the central injection well when all six wells of the external concentric row are stopped. In the fourth stage, the working agent is pumped through six wells of the external concentric row when the central injection well is shut down. The amount of injected working agent is distributed between the injection wells of the external concentric row and the central injection well in relation to the difference between the unit and the coverage factor of the area of the development element of extrusion to the coefficient of coverage of the area of the development element of extrusion (RF Patent No. 2084618, publ. July 20, 1997).

Closest to the proposed invention in technical essence is a method for developing high-viscosity oil deposits, according to which the deposits are opened with a uniform triangular grid of producing wells with the formation of areal 13-point development elements of 6 wells in each concentric row. In the central well, horizontal shafts are drilled from independent windows onto predetermined packs of layers of the development object with a length of about 1/3 of the distance between the grid wells. The selection of products and the injection of coolant are carried out cyclically with an equal amount of injected coolant in each cycle. Each cycle is carried out in three stages. At the first stage, the coolant is pumped through the central well and the producing wells of the outer ring located through one. From the remaining production wells located between them, production is selected. At the second stage, the production wells of the outer ring, through which the coolant was pumped, are transferred to the selection of products and the production wells of the outer ring, through which the products were taken, are transferred to the coolant injection. Products are taken through a central well. At the third stage, they select products from production wells through which coolant was pumped, and select products from all other production wells. The distribution of the estimated amount of coolant between the central well and the wells of the outer ring is carried out in accordance with mathematical expressions (RF Patent No. 2132942, publ. 07/10/1999 - prototype).

A common disadvantage of the known methods is the low oil recovery due to insufficient coverage of the reservoir by exposure.

The proposed invention solves the problem of increasing oil recovery by increasing exposure exposure.

The problem is solved in that in the method of developing an oil reservoir, including placing production wells on a triangular grid, selecting products through production wells and injecting a working agent through injection wells, according to the invention, the placement of wells is carried out on a triangular grid of production wells with the formation of rows of wells oriented mainly at an angle of 120 ° to each other, deposits of increased thickness are allocated to the deposits, confined to the paleo-riverbed, in the domed part of which horizontal production is drilled wells with parallel and sequential arrangement of horizontal wells at the same distance from existing vertical production wells in the existing triangular grid, the distance between parallel horizontal wells is kept in the range from 220 to 280 m, and the distance between the faces of horizontal wells with their sequential location is kept within 220 to 360 m, and the injection of the working agent through injection wells is carried out with the formation of circuit and intra-circuit flooding.

SUMMARY OF THE INVENTION

When developing an oil reservoir, a significant part of the oil reserves remains in the reservoir due to insufficient coverage of the reservoir by the impact of producing and injection wells. Existing methods solve this problem only partially. The proposed invention solves the problem of increasing oil recovery by increasing exposure exposure. The problem is solved as follows.

On oil deposits, production wells are placed along a triangular grid with the formation of rows of wells oriented mainly at an angle of 120 ° to each other. Injection wells are placed behind the circuit and inside the oil circuit. They select products through production wells and pump the working agent through injection wells. Deposits of increased thickness are allocated to the deposits, confined to the paleo-riverbed, in the dome part of which horizontal production wells are drilled with parallel and sequential arrangement of horizontal shafts at the same distance from existing vertical production wells in the existing triangular grid, the distance between parallel horizontal shafts is maintained in the range from 220 to 280 m, and the distance between the faces of horizontal wells with their sequential location is maintained in the range from 220 to 360 m.

Figure 1 shows the plan of the reservoir, in which 1 - production wells are placed on a triangular grid with the formation of rows of wells oriented at 120 ° to each other, 2 - injection wells, 3 - oil content circuit, 4 - the border of deposits of increased capacity, confined to paleo-Ruslou, 5 - horizontal wells, A - the distance between parallel horizontal shafts, B - the distance between the faces of horizontal wells with their sequential location.

As a result of such a development scheme, reservoir exposure is increased and oil recovery is increased.

Concrete example

An oil reservoir is developed with the following characteristics: oil-water contact depth - 1234 m, reservoir thickness from 2.4 to 51.2 m, oil saturation zone thickness - from 3.1 to 45.2 m, residual oil saturation zone thickness - from 2 to 17 , 4 m, reservoir pressure - 125 atm, reservoir temperature - 21 ° C, porosity - 0.26, permeability - 0.826 μm ² , oil saturation - 0.93, oil viscosity - 56.62 MPa · s, oil density - 889 kg / m ³ .

58 oil wells are placed on oil deposits along a triangular grid with a distance between the wells of 300 m and with the formation of rows of wells oriented mainly at an angle of 120 ° to each other (figure 1). 18 injection wells are placed behind the circuit and inside the oil circuit. They select products through production wells and pump the working agent through injection wells. Deposits with a thickness ranging from 2.4 to 30 m, confined to the paleo bed, are distinguished into deposits. In the domed part of the sediments, 6 horizontal production wells are drilled with a parallel arrangement of horizontal shafts of 3 shafts and a sequential arrangement of 2 rows at a distance from existing vertical production wells ranging from 75 to 100 m in the existing triangular grid. The distance between parallel horizontal trunks “A” is maintained in the range from 220 to 280 m, and the distance between the faces of horizontal wells “B” with their sequential location is maintained in the range from 220 to 360 m.

As a result of development according to the proposed technology, the reservoir coverage is increased by the impact, and the oil recovery of the reservoir reaches 39%. As calculations show, the application of the proposal for the prototype ensures the achievement of oil recovery of only 33%.

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

Claims (1)

A method of developing an oil field, including placing production wells on a triangular grid, selecting products through production wells, injecting a working agent through injection wells with the formation of side and side water flooding, characterized in that the placement of wells is carried out along a triangular grid of production wells with the formation of rows of oriented wells at 120 ° to each other, deposits of increased thickness are allocated to the deposits, confined to the paleo-riverbed, in the domed part of which they drill horizontally f production wells with parallel and sequential arrangement of horizontal wells at the same distance from existing vertical production wells in the existing triangular grid, the distance between parallel horizontal wells is kept within 220 to 280 m, and the distance between the faces of horizontal wells with their sequential location is kept within from 220 to 360 m.

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