RU2149987C1 - Method of oil pool development - Google Patents

Abstract

FIELD: oil-producing industry; applicable in development of oil pools complicated with low-amplitude formation doming. SUBSTANCE: in development of oil pool, production is withdrawn from producing wells and working agent is injected by cycles through injection wells. Determined for producing well are all the nearest acting injection wells. Subject to determination are period from beginning of operation of each nearest acting injection well up to attaining of maximum formation pressure and period from shutdown to attaining of minimum formation pressure in producing well. Operation of all nearest acting injection wells is coordinated by attaining of maximum and minimum formation pressure in respective producing well. During the period of maximum formation pressure in producing well, well production rate is intensified, and during minimum formation pressure, water inflow shutoff operation are effected in producing well. EFFECT: higher oil recovery from pool. 1 ex

Description

 The invention relates to the oil industry and may find application in the development of an oil reservoir complicated by low-amplitude formation uplifts.

 A known method for the development of oil deposits, including the injection of a working agent through injection wells and the selection of oil through production wells [1].

 The known method does not allow to develop 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 products through production wells and the cyclic injection of a working agent through injection wells [2].

 The known method allows to increase oil production, however, a significant part of the oil reserves remains in 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 the selection of products through production wells and cyclic pumping of a working agent through injection wells, according to the invention, for the production well, all the closest acting injection wells are determined, the period from the start of operation of each closest acting injection well to achieving maximum reservoir pressure and the period from shutdown to achieving minimum reservoir pressure in the producing well, agree by affecting the operation of all the nearest injection wells to achieve maximum and minimum reservoir pressure in the production well within the maximum reservoir pressure in the production well carry out work on the intensification flow rate, and during the minimum reservoir pressure in the production well carry out work on the water inflow isolation.

The essential features of the invention are:
1. selection of products through production wells;
2. cyclic injection of the working agent through injection wells;
3. for the producing well, the determination of all the closest acting injection wells;
4. determination of the period from the start of operation of each nearest acting injection well to the achievement of maximum reservoir pressure;
5. and the period from shutdown to reaching the minimum reservoir pressure in the producing well;
6. coordination of the work of all the nearest acting injection wells to achieve maximum and minimum reservoir pressure in the producing well;
7. during the period of maximum reservoir pressure in the producing well, work to intensify the flow rate;
8. during the period of minimal reservoir movement in the producing well, carrying out work to isolate the influx of water.

 Signs 1, 2 are common with the prototype, signs 3 to 8 are the essential distinguishing features of the invention.

SUMMARY 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 the oil reservoir, complicated by low-amplitude reservoir uplifts. 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 field, products are selected through production wells and cyclic injection of the working agent through injection wells. During cyclic injection of the working agent through injection wells during the injection period, the reservoir pressure increases, and when the injection wells stop, the reservoir pressure decreases. Hydrodynamic studies for the production well determine all the closest acting injection wells, determine the period from the start of operation of each closest acting injection well to the maximum reservoir pressure and the period from shutdown to the minimum reservoir pressure in the producing well. Since the productive formations are heterogeneous and the distance from the injection wells to the production can be different, then to achieve the maximum and minimum reservoir pressure in the production well, the work of all the closest acting injection wells is coordinated. During the period of maximum reservoir pressure in the producing well, work is carried out to intensify the flow rate. Intensification work is associated with the release of the bottom-hole zone of the producing well from the clogging elements. In this case, the removal of the clogging elements is carried out from the bottomhole zone into the well. Such removal is most effective at maximum pressure in the bottomhole zone, with a maximum pressure drop in the bottomhole zone and in the well.

 During the period of minimum reservoir pressure in the producing well, work is carried out to isolate the influx of water. In this case, the insulating work is accompanied by crushing into the bottomhole zone of insulating materials to a considerable depth. Most easily, such work is carried out with minimal back pressure from the bottom-hole zone, i.e. at the time of minimum reservoir pressure in the bottomhole zone.

 As a working agent, use fresh water, mineralized water.

 The combined use of the above actions allows to increase the productivity of producing wells, to reduce the water cut of produced products and ultimately to increase oil recovery.

Concrete example
Example 1. An oil reservoir of the Romashkinskoye field is developed with the following characteristics: porosity - 18.4%, average permeability - 0.646 μm ² , oil saturation - 61.1%, absolute mark of water-oil contact - 1530 m, average oil-saturated thickness - 4 m, initial reservoir pressure - 16 MPa, reservoir temperature - 29 ^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, content sulfur - 3.64%.

 Wells are placed in the deposits and products are selected through production wells and cyclic injection of the working agent through injection wells.

 At the development site for the producing well, it is determined that four of the closest injection wells are acting on it. The period from the start of operation of each nearest acting injection well to the achievement of the maximum reservoir pressure and the period from the shutdown to the achievement of the minimum reservoir pressure in the production well are determined. These periods range from 1.5 to 2.5 days. Coordinate the work of all the nearest acting injection wells to achieve maximum and minimum reservoir pressure in the producing well. For this, injection cycles are prescribed for at least 5 days, and the beginning of the injection cycles of all wells is combined in time. During the period of maximum reservoir pressure in the producing well on the third day from the beginning of the injection cycle, work is carried out to intensify the flow rate - hydrochloric acid treatments of the bottom-hole zone with a depressive effect on the bottom-hole zone. During the period of minimum reservoir pressure in the producing well on the third day from the start of the shutdown cycle of injection wells, work is carried out to isolate the influx of water by injecting an aqueous solution of polyacrylamide with a hardener into the bottomhole zone of the producing well.

 As a result, oil recovery at the development site increased by 3%.

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

Sources of information taken into account
1. I. M. Muravyov et al. Development and operation of oil and gas fields. M .: Nedra, 1970, p. 102-103.

 2. R. S. Khisamov. Features of the geological structure and development of multilayer oil fields. Kazan, Publishing house "Monitoring", 1996, p. 216-218 is a prototype.

Claims (1)

 A method of developing an oil reservoir, including product selection through production wells and cyclic injection of a working agent through injection wells, characterized in that for the production well, all the closest acting injection wells are determined, the period from the start of operation of each nearest acting injection well to the maximum reservoir pressure is determined and the period from shutdown to the minimum reservoir pressure in the production well, coordinate the work of all the closest operating injection wells, upon reaching the maximum and minimum reservoir pressure in the producing well, during the period of maximum reservoir pressure in the producing well, production is intensified, and during the period of minimum reservoir pressure in the producing well, water inflow isolation is carried out.