RU2331760C1 - Oil reservoir development method - Google Patents

Abstract

FIELD: petroleum industry.

SUBSTANCE: invention is referred to petroleum industry and can be applied for development of oil reservoir developed by depletion. Invention ensures higher efficiency of the method due to recovery of oil remaining reserves in the reservoir. The method includes oil recovery by depletion via producing horizontally branched wells, oil being recovered by cyclic operation of all producing wells. When wells are started up, oil is recovered until current reservoir pressure is drawdown to 60-80% of initial reservoir pressure. Wells are shutdown until current reservoir pressure is restored to the value of 70-90% of initial reservoir pressure. If during reservoir development process any of the producing wells fail to restore current reservoir pressure to 70% of initial reservoir pressure, the said producing wells shall be converted to injecting wells with continuous pumping. Oil is recovered from remaining producing wells in the same process.

EFFECT: higher efficiency of oil well production.

1 ex, 2 dwg

Description

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

A known method of developing fluid deposits (patent RU No. 2199002, IPC 7 ЕВВ 43/16, published in Bulletin No. 5 of 02/20/2003), including laying the mouths of production and injection wells in the form of a bush or battery, drilling in a mountain array rocks and fixing the trunks of vertical, deviated and / or curvilinear wells, opening the reservoir at specified points and developing wells of each bush or battery, which are placed in the central part of the field or the block being developed so that their routes pass in the acceptable zone, out of danger ty shear disturbance of casing strings, horizontal displacements of the rock mass, deforming during fluid extraction.

The disadvantage of this method is that it does not allow to develop a reservoir with the achievement of high oil recovery.

Closest to the technical nature of the present invention is a method of developing an oil reservoir (patent RU No. 2287675, IPC 7 ЕВВ 43/16, published in Bulletin No. 32 of November 20, 2006), including the selection of oil through horizontal production wells on natural mode, while the production of wells using branched in a horizontal plane, curvilinear horizontal wells, the oil is taken by cyclic shutdown and the inclusion of all production wells, when you turn on the wells, the oil is taken to reduce the current reservoir pressure up to 60-80% of the initial, and well shutdown is carried out until the restoration of the current reservoir pressure to 70-90% of the initial.

The disadvantage of this method is the insufficient production of residual oil reserves in the reservoir, due to the fact that over time, that is, during the development of the oil reservoir, the producing wells will not restore the current reservoir pressure to 70%, and therefore the effectiveness of this method is reduced.

The objective of the invention is to increase the efficiency of the method by generating residual oil reserves in the reservoir.

This problem is solved by the method of developing an oil deposit, including the selection of oil through production of branched horizontally curved wells in natural mode, while the selection of oil is carried out by cyclic shutdown and the inclusion of all production wells, when the wells are turned on, the selection of oil is carried out until the current reservoir pressure drops to 60- 80% of the initial, and well shutdown is carried out until the current reservoir pressure is restored to 70-90% of the initial.

What is new is that in the process of developing an oil reservoir, production wells that do not restore the current reservoir pressure to 70% of the initial one are successively transferred to injection wells with a constant injection mode, and oil is taken from the remaining production wells in the previous mode.

Figure 1 shows the plan of the oil reservoir at the initial stage of development.

Figure 2 shows the plan of the oil deposits in the process of developing residual reserves.

Consider an example of developing an oil reservoir using three production wells.

The selection of oil from the oil reservoir (see figure 1) are producing branched in the horizontal plane curved horizontal wells 1 ′; one''; 1 ′ ′ ′ within the oil contour 2. Oil selection is carried out by a cyclic shutdown and the inclusion of production wells 1 ′; one''; 1 ′ ′ ′, and when wells are turned on, the selection is carried out until the current reservoir pressure is reduced to 60-80% of the initial one, which is, for example, 10 MPa. The stop of production wells 1 ′; one''; 1 ′ ′ ′ is carried out until the current reservoir pressure is restored to 70-90% of the initial.

The cyclic selection of oil from an oil reservoir using producing 1 branched horizontal wells branched in the horizontal plane; one''; 1 ″ ″ are maintained until the current reservoir pressure of up to 70% of the initial pressure is restored in any of these production wells, for example, in 1 ″ production well, after which production 1 ″ is transferred to injection well 3 ( see Fig. 2) with a constant mode of fluid injection, and the selection of residual oil reserves in the deposits is performed using the remaining producing branched in the horizontal plane curved horizontal wells 1 ′ and 1 ″ ″ in the previous mode (cyclic oil withdrawal from the reservoir).

Thus, as each of the remaining producing wells 1 ′ and 1 ″ ″ will not restore the current reservoir pressure to 70% of the initial one, they will be transferred to injection wells until the residual oil reserves are depleted.

The proposed method is quite effective because it allows the production of residual oil reserves in the reservoir.

Claims (1)

The method of developing an oil reservoir, including the selection of oil through production of branched horizontally branched wells in natural mode, while the selection of oil is carried out by cyclic shutdown and the inclusion of all production wells, when the wells are turned on, the selection of oil is carried out until the current reservoir pressure drops to 60-80% of initial, and well shutdown is carried out until the current reservoir pressure is restored to 70-90% of the initial, characterized in that during the development of the oil reservoir, production wells do not recover which set the current reservoir pressure to 70% of the initial one, are successively transferred to injection with a constant injection mode, and oil is taken from the remaining production wells in the previous mode.

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