RU2441144C2 - Method of oil bench development - Google Patents

Abstract

FIELD: oil-and-gas production.

SUBSTANCE: proposed method comprises well drilling, exposing oil bench and well operation. In compliance with this invention, to make design spacing pattern, one well exposes oil bench in two design points along descending and ascending bores with spacing between said points corresponding to well pattern spacing. Well is operated using a simultaneous-separate process. For this, well is equipped with two oil-well strings. Oil production rod pump is suspended on one string and another string is used for forcing water in oil bench, that is, for bench flooding.

EFFECT: saving of stock of wells and increase in oil production.

1 ex, 4 dwg

Description

The invention relates to the oil industry, and in particular to a method for developing an oil reservoir.

There is a method of developing an oil reservoir by using the technology of simultaneous-separate operation of two reservoirs. (V.I. Kudinov “Fundamentals of Oil and Gas Production”, Moscow - Izhevsk, Institute for Computer Research; Udmurd State University, 2005, 371-378 pp.)

The disadvantage of this method is the operation of one well of two layers. In this case, the impact on each layer is carried out only at one point, opened by the well. To organize a stimulation system, drilling additional wells is required.

The closest technical solution, selected as a prototype, is a method for developing a hydrocarbon deposit, when one layer is opened by one well two or more times (US Pat. No. 1798486, "Method for the development of a hydrocarbon deposit", auth. V. Minlikaev et al. , registered in the State register of inventions of the USSR, 10/08/1992).

However, the disadvantages of this method are:

1. The use of the productive interval of the first intersection of the wellbore with the reservoir only for monitoring the work.

2. Opened by the second wellbore of the oil reservoir at a predetermined point (see figure 1).

To implement a design grid of wells, it is necessary to drill exactly the same number of wells as the nodes of the design grid of wells.

Figure 2 presents the technical implementation of the "Method for the development of hydrocarbon deposits", selected as a prototype. The wellbore crosses the reservoir in two places. The wellbore is lined with a string of pipes. Casing pipes in the interval of the first intersection (downward shaft) are not perforated; in the interval of the second intersection, casing pipes have perforations.

In this connection, especially under the conditions of an economically optimal approach, the problem arises of the most rational use of the well stock for the implementation of the design grid of wells.

This problem is solved by the proposed method of developing an oil reservoir, including drilling wells, opening an oil reservoir and its operation, according to the invention, to realize a design grid of wells, one well is opened by perforating the oil reservoir at two design points along the descending and ascending shafts, and operation in the well is carried out using technologies for simultaneous and separate operation.

The proposed method of developing an oil reservoir

Figure 3 presents the General diagram of the wiring of the well and the equipment lowered into it.

When drilling a well, productive formation 4 is opened at two points 1 and 2 and cased by a string of pipes 3. The distance between points 1 along the descending well and point 2 opened along the ascending well corresponds to the grid spacing adopted in the project document for field development.

The well is equipped with two columns of tubing 5 and 6, on the tubing string 5, a sucker rod pump 7 is suspended using a retainer 8. Pump 7 is lowered below the fluid level 9 in the well. To isolate the wellbore between the two opening points 1 and 2, a packer 10 is used, and if possible 11.

Figure 4 presents the implementation of the development system using this method of developing an oil reservoir. As follows from figure 4, for the implementation of the process of developing an oil field by this method will require half the number of wells than traditional with drilling an independent grid of wells.

Concrete example

Figure 4 presents the design grid of wells, approved by the design document for the development of this formation. In this Fig. 4, pairs of formation penetration points by one well are highlighted. The well is drilled in such a way that during a downward opening of the formation, the formation is opened at one design point 1 (Fig. 3), and during further drilling of the well below the bottom of the formation, the opening is performed along an ascending path, and the formation is opened at the next design point 2 from the sole to the roof . As a result of this, a single well is opened at two design points.

After that, the well is cased with a casing and cemented 3. Perforation of the string is carried out at the intersection of the wellbore with the formation at points 1 and 2. Then, pumping equipment is lowered into the well, which allows for simultaneous and separate production and injection of water. To the point 2 down tubing 6, through which water will be pumped. The space between these tubing 6 and casing 3 is isolated by the packer 10 below the bottom of the formation at point 1, and if possible by the packer 11 below the bottom of the formation at point 2. Pump 7 is lowered below the fluid level 9 in the wellbore on tubing 5 . In the part of the wellbore there are two tubing, which are fixed by a retainer 8.

As a result, it is possible to inject water, which is injected into the formation at point 2, and to conduct formation fluid extraction from the formation at point 2. Thus, a design grid of wells is implemented with the organization of a waterflooding and production system using fewer wells.

The main essential features of the proposed method are:

1. The use in one well of the opening of the reservoir at two points corresponding to the design grid of wells.

2. The use of technology for simultaneous and separate operation on one reservoir, which allows you to drain one reservoir at two points in accordance with the design of the wells.

3. The use of technology for simultaneous and separate operation allows keeping records of production or injection at each opening point of the reservoir.

Thus, the proposed method for developing an oil reservoir allows to reduce the number of wells in the field by half, which, of course, will lead not only to a decrease in the area of land for well clusters, but also to a decrease in capital investments for well construction.

Claims (1)

A method of developing an oil reservoir, including drilling wells, opening an oil reservoir and its operation, characterized in that for the implementation of the design grid of wells, one well is opened by perforating the oil reservoir at two design points along the descending and ascending bore with a distance between these points corresponding to the step of the grid of wells , and the wells are operated using the technology of simultaneous-separate operation, for which the well is equipped with two tubing strings, one of which x suspended rod pump for oil, and another column of tubing is used to inject water into the oil reservoir - water flooding of the formation.

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