SU1553655A1 - Method of producing gas from water-bearing formation - Google Patents

Abstract

This invention relates to the gas industry. The purpose of the invention is to increase the efficiency of the gas recovery of the aquifer when pumping the production of the well through a submersible pump. The degassing of the reservoir water is carried out by diluting the pressure and lifting it through the tubing string (CNPC), the pressure being diluted by raising the reservoir water to the wellhead, and then disconnecting the submersible pump and draining the reservoir water to the well. the dynamic level, then a sequential and separate selection of gas and degassed liquid is performed, after which the cycle is repeated. A submersible pump is lowered into the well, a deep-well pump is tied around the wellhead, with a gas line with a shut-off valve and a water line 6 with a shut-off valve, and a deep-well pump is put into operation. After pumping from the well to the mouth of the volume of formation water turn off the deep pump. The reservoir water through the submersible pump goes into the absorbing reservoir and creates a pressure depression, which contributes to the intensive evolution of gas. Upon reaching the dynamic water level, a deep-well pump is put into operation in the CCTF.

Description

to work the deep well pump. After pumping from the well to the mouth of the volume of formation water turn off the deep pump. Reservoir water through a submersible pump goes into absorbing

the reservoir and creates a vacuum pressure, which contributes to the intensive evolution of gas. Upon reaching the dynamic water level, a deep-well pump is put into operation in the CCTF.

The invention relates to the gas industry and can be used to extract gas from aquifers.

The aim of the invention is to increase the efficiency of the gas recovery of the aquifer when pumping the production of a well through a submersible pump.

The drawing shows an installation for implementing the method.

The essence of the method of extracting gas from an aquifer is that the degassing of the reservoir water is carried out by diluting the pressure and raising it through a column of pump-compressor pipes (PCS), the negative pressure being produced by raising the reservoir water to the wellhead and then disconnecting the deep well. pumping and draining the produced water into the absorbing reservoir until it reaches a dynamic level in the well, then a sequential and separate selection of gas and degassed liquid is performed, after which the cycle is repeated.

The method is carried out as follows.

The well 1 is lowered onto the string 1 of the tubing 2 deep well pump 3, the wellhead is tied up with a gas line C with a shut-off valve 5 and a water line 6 with a shut-off valve 7.

Then let the in-depth pump 3 into operation with the valve 7 open (valve 5 is closed). After pumping from the well 1 the volume of produced water to the mouth equal to the internal volume of the tubing string, the submersible pump is switched off with simultaneous shut-off of the valve 7.

.Under the overpressure, water from the tubing 2 through the in-depth pump 3 is drained off, is absorbed by the formation. The low pressure tubing 2 created at the top of the column (when valves 5 and 7 overlap) promotes the intensive release of dissolved gas from water.

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After reaching a dynamic water level in the tubing string (close to the static level), the valve 5 of the gas line k is opened and the submersible pump 3 is put into operation. When raising the fresh water, the valve 5 is closed to the wellhead and the valve 7 is opened again to remove a portion of degassed produced water .

The order of switching on and off of valves 5 and 7 is determined by means of a pressure gauge 8 and a contact device 9.

A gas line 4 is connected to the line TO of the annular space, on which a shut-off valve 11 is installed, which is controlled to operate at a certain pressure. The valve 11 is adjusted to such a pressure that in the annulus water is not pushed aside to the depth of the installation of a submersible pump.

For example, the dynamic level in piezometric wells is 300-350 mm, the gas saturation of formation water is 2 m / m3 at a current reservoir pressure of 90-100 atm.

With a descent into the 219 mm production string of 168 mm pump-compressor pipes with a submersible pump in the tubing string, it is possible to degass the produced water in the interval of 0-300 m. The inner volume of the tubing string in this interval is 5.3 m3. The pumping out of the formation water and its degassing after the creation of a negative pressure will occur within 5 minutes with the creation of an overpressure in the tubing string over 2 atm. Thus, within one hour you can get about 120 m3 of gas.

In an aquifer with a capacity of about 300 m with a drainage radius of 5 km, 10,515 million m3 of gas is contained with a porosity of 0.3.

Extraction of large volumes of water from the watering production wells reduces the degree of gas localization and pinching in the reservoirs,

especially represented by heterogeneous strata. Additional extraction of dissolved natural gas reduces the cost of selecting large volumes of produced water.

Thus, in the process of applying the proposed method, the operating costs for gas production are reduced and the gas recovery coefficient of deposits increases.

The recovered degassed formation water can be used at most fields to maintain reservoir pressure during the development of oil deposits.

After the extraction of all free gas or oil from gas-oil-saturated reservoirs, the ground field equipment and all the wells in the field can be used to extract the dissolved gas from the flooded production using the proposed method.

seams that allow gas production.

support

Claims (1)

Invention Formula A method of extracting gas from an aquifer, including degassing the produced water by diluting the pressure and raising it through the tubing string, characterized in that, in order to increase the efficiency of gas recovery of the aquifer when pumping the well’s production using a deep well pump, the vacuum is produced by lifting formation water to the wellhead, followed by shutting down the submersible pump and draining the reservoir water into the absorbing reservoir until it reaches a dynamic level in the well, then produces T sequential and separate sampling of gas and degassed liquid, after which the cycle is repeated.