The method of developing multilayer oil deposits

 

(57) Abstract:

The invention relates to the oil industry and can find application in the development of the multilayer oil deposits. Provides increased oil recovery from reservoirs. The inventive when designing multilayer oil deposits are oil extraction through production wells from the reservoir. Download the working agent through the injection well into the reservoir. Carry out the drilling of additional production wells to the upper productive formation. Analyze its productivity. In low productivity are drilling additional production wells in the interval between the upper and lower productive formations. Grow an additional production well in the interval of absence of oil-saturated layers. Go down the column tubing to the drilled borehole bottom. Selected formation fluids through the column tubing from the whole open interval. Determine the oil-water section in the annulus and set casing shoes tubing at the level of the oil-water partition. After the extraction of oil from the open interval Buryats additional production well on Nizhni and may find application in the development of the multilayer oil deposits.

There is a method of developing multilayer oil fields, including the allocation of production facilities, drilling of production and injection wells on a dedicated production facilities, pumping the working agent through the injection wells and oil extraction through production wells (RF Patent 2142046, CL E 21 In 43/20, published. 1999).

The method allows to extract from the reservoir oil reserves, however, a considerable part of them remains in the deposits.

Closest to the invention to the technical essence is a way of developing multilayer heterogeneous petroleum deposits, including oil extraction through production wells from the reservoir, sampling formation water from the lower reservoir through wells and injection of produced water through injection wells in the reservoir. This are drilling additional wells on the depth of the Deposit. When passing through the oil reservoir wells operate as mining. (RF patent 2061177, CL E 21 In 43/20, published. 1996 - prototype).

The disadvantage of this method is the low oil recovery reservoir.

The invention solves the problem of increasing oil deposits.

The task is solved in that the JV is in, download working agent through the injection well into the reservoir and the drilling of additional production wells through the layers, according to the invention an additional production well Buryats to the top of the reservoir, analyze its productivity and low productivity are drilling additional production wells in the interval between the upper and lower productive formations grow additional production well in the interval of absence of oil-saturated layers, the lower column tubing to the drilled borehole bottom, selected formation fluids through the column tubing from the whole open interval, determine the oil-water section in the annulus and set casing shoes tubing at the level of the oil-water partition.

After the extraction of oil from the open interval Buryats additional production well on the bottom of the reservoir and take the oil.

Features of the invention are:

1) selection of oil through the production wells from the reservoir;

2) download a working agent through the injection well into the reservoir;

3) the drilling of additional production wells through produktivnost the top of the formation;

6) when insufficient efficiency of the drilling of additional production wells in the interval between the upper and lower productive formations;

7) the service of an additional production well in the interval of absence saturated interlayers;

8) run a string of tubing to the drilled borehole bottom;

9) sampling of formation fluids through the column tubing from the whole open interval;

10) determination of oil-water section in the annulus;

11) establishment of the footing of the column tubing at the level of the oil-water partition;

12) after the extraction of oil from the open interval, drilling of additional production wells in the lower reservoir and oil extraction.

Signs 1 to 3 are common with the prototype, signs 4-11 are the salient features of the invention, the sign 12 is a particular characteristic of the invention.

The invention

When developing a multi-reservoir oil reservoir of the oil remains in the reservoir. The invention solves the problem of increasing oil deposits. The problem is solved as follows.

When designing multilayer oil sales the new well in the reservoir. This achieves the basic selection of oil from the reservoir. Buryats additional production well to the upper productive formation. Analyze its productivity and low productivity are drilling additional production wells in the interval between the upper and lower productive formations. Grow an additional production well in the interval of absence of oil-saturated layers and annulus cement. These exclude the possibility that water enters the well from the aquifer. Go down the column tubing to the drilled borehole bottom. This suggest that the well passes through many oil-saturated layers of small thickness, each of which is to allocate an object in its own development is not possible. The thickness of such layers can be a centimeter or more. At the same time, the total thickness of these layers may be closer to a thickness independent of the object of development. Selected formation fluids through the column tubing from the whole open interval. Selection of lead in total from all layers of small thickness. Determine the oil-water section in the annular space and set of bashmachnikov water and preferential water flow, and not oil. The development of open interval leads to profitability. After the extraction of oil from the open interval and irrigation wells gaboriaud additional production well to the bottom of the reservoir, grow well shank and cement annulus, perforined in the new perforation interval and take the oil.

Oil recovery is increased deposits by introducing in the development of oil-saturated layers of small thickness.

Examples of specific performance

Example 1. Develop oil reservoir Romashkinskoye field with the following characteristics: porosity - 11.9%, permeability - 0,029 μm2the saturation - 61,1%, absolute mark oil-water contact - 870 m, the average net pay thickness - 8m, initial reservoir pressure of 11 MPa, reservoir temperature - 25oWith the parameters of the reservoir oil: density of 930 kg/m3viscosity - 46 mPas, the saturation pressure of 1.8 MPa, gas content - 15.2 m3/t sulphur content is of 3.64%.

On deposits allocate bobrikovskian horizon (object design) at a depth of 1000 m and Devonian horizon (object design) at a depth of 1650 m Bobrikovsky and Devonian stacked horizons Zoni features many oil-saturated layers of small thickness, each of which is to allocate an object in its own development is not possible. The thickness of such layers can be from several millimeters or more. At the same time, the total thickness of these layers may be closer to a thickness independent of the object of development. It is noticed that such small oil-bearing interlayers are generally grouped in the lower part closer to the Devonian horizon.

Download desktop agent (produced water) through injection wells in the reservoir Bobrikovsky and Devonian horizon. Select the oil through the production wells from the same strata.

Buryats additional oil hole on bobrikovskian horizon at a depth of 1000 m Due to the low profitability of the production facility in development is not administered. Deepen the well to 630 m below the top of the object of development, but above the bottom of the object of development, which is Devon facility development at a depth of 1650 m Zone of ncollector (interval of absence of oil-saturated layers), to a depth of 1550 m grow, and annulus cement. In the interval of the proposed placement of oil-saturated layers of small thickness, the borehole from a depth of 1550 m to glum. Selected formation fluids through the tubing pipes of all open intervals of 80 m After 10 days of operation and establish in the well water partition determine the oil-water section in the annulus of the well at a depth of 1600 m Set casing shoes tubing at the level of the oil-water partition 1600 meters Operate well with a flow rate of 10 m3/day and a water content of 13%.

Example 2. Perform as example 1. After 10 years of oil extraction from an open interval and irrigation wells gaboriaud additional production well until the Devonian horizon (lower productive formation), grow well shank and cement annulus, perforined in the new perforation interval and take the oil.

The application of the proposed method will allow you to take the oil from reservoirs that were not previously covered by the impact and, thereby, to increase the recovery rate deposits.

1. The method of developing multilayer oil deposits, including oil extraction through production wells from the reservoir, the injection of working agent through the injection well into the reservoir and the drilling of additional production wells through the layers, characterized in that city and low productivity are drilling additional production wells in the interval between the upper and lower productive layers, grow an additional production well in the interval of absence of oil-saturated layers, the lower column tubing to the drilled borehole bottom, selected formation fluids through the column tubing from the whole open interval, determine the oil-water section in the annulus and set casing shoes tubing at the level of the oil-water partition.

2. The method according to p. 1, characterized in that after the extraction of oil from the open interval Buryats additional production well on the bottom of the reservoir and take the oil.

 

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