RU2399757C1 - Development method of gas well with packer in conditions of abnormally low formation pressures - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention refers to development of gas wells with packer in conditions of abnormally low formation pressures - ALFP. Development method of gas well with packer in ALFP conditions involves gas supply from operation wells to booster compression station - BCS, where gas is compressed to the pressure of 5.0-5.5 MPa. After BCS the gas is supplied to gas processing facility - GPF, where gas is cleaned from mechanical impurities and water, and gas is supplied under pressure of 3.0-4.0 MPa to cluster site of the developed well and then to booster station to which process water is pumped at the same time. The obtained liquid-gas mixture is compressed to the value of 7.0-10.0 MPa; after that gas-liquid mixture is supplied to separator where gas-liquid mixture is separated into high pressure gas and liquid. Liquid is supplied to pump station, and high pressure gas is supplied to ejector to which there also supplied is foam-forming liquid - FFL. Aerated foam-forming liquid - AFFL obtained on ejector is supplied to flexible pipe - FP of coil tubing unit which is lowered to tube space of the well with stops in every 50-100 m. At each FP burial step the supply of FFL to ejector is stopped, and high pressure gas is supplied to FP by passing the ejector, forcing away damping liquid and AFFL to day surface and by performing well ventilation till gas influx is obtained from productive formation. After gas influx is obtained, the well is developed till it is brought to process mode; after that FP is removed from well, and well is brought into operation.

EFFECT: reducing the time required for well development and providing influx from formation of gas well with packer in ALFP conditions with abnormal coefficient lower than 0,2.

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Description

The invention relates to the oil and gas industry, in particular to the development of packaged gas wells under conditions of abnormally low formation pressure - AAP, especially in conditions of low formation pressure with an anomaly coefficient below 0.2.

A known method of well development, including replacing the kill fluid with a lightweight fluid, calling up the inflow, running the well for a flare [RF Patent No. 2109934].

The disadvantage of this method is the low efficiency of the call inflow from the wells in the conditions of the API and the impossibility of calling it with an anomaly coefficient below 0.2.

A well-known method of well development, including replacing the kill fluid with lightweight fluid, supplying high pressure gas to a flexible pipe — GT of a coiled tubing installation, inflow challenge, drilling a well for a flare [RF Patent No. 2235868].

The disadvantage of this method is the low efficiency of the call inflow from the wells in the conditions of the API and the impossibility of calling it with an anomaly coefficient below 0.2.

The challenge facing the creation of the invention is to increase the reliability and efficiency of the development of packaged gas wells in the conditions of the oil production with an anomaly coefficient below 0.2.

Achievable technical result, which is obtained as a result of the creation of the invention, consists in providing the ability to call the inflow from the reservoir of a packaged gas well in the conditions of the AAP with an anomaly coefficient below 0.2 and in reducing the time of its development.

The task and technical result are achieved by the fact that during the development of a packaged gas well under the conditions of oil production, gas from production wells is fed to a booster compressor station - DKS, where gas is compressed to a pressure of 5.0-5.5 MPa, after the DKS gas is supplied to the complex gas preparation - UKPG, where the gas is cleaned of mechanical impurities and water, and under a pressure of 3.0-4.0 MPa, gas is supplied to the well pad of the well being developed and then to the booster installation, into which technical water obtained from the gas-liquid is simultaneously pumped the remaining mixture is compressed to a value of 7.0-10.0 MPa, after which the gas-liquid mixture is sent to a separator, where the gas-liquid mixture is separated into high-pressure gas and liquid, the liquid is sent to the pump unit, and the high-pressure gas is fed to the ejector, to which at the same time, a foaming fluid is supplied - POR, an aerated foaming fluid obtained on an ejector - AOF is fed to the coiled tubing unit GT, which is lowered into the borehole space with stops every 50-100 m, at each stage the deepening of the GT, the flow of coolant to the ejector is stopped, and the high-pressure gas is supplied to the GT, bypassing the ejector, squeezing the kill fluid and ALS onto the day surface and purging the well to receive gas flow from the reservoir, after receiving the gas flow, the well is worked out until it is brought to technological mode, after which the GT is removed from the well, and the well is put into operation.

The drawing shows a diagram for implementing this method.

The method is implemented as follows.

A low-pressure gas of 0.8-1.2 MPa in size from a production well 1 is fed through a pipeline 2 to a booster compressor station, where it is compressed to a pressure of 5.0-5.5 MPa. After the BCS, gas is supplied to the gas treatment unit, where the gas is cleaned of mechanical impurities and drained of water, and under a pressure of 3.0-4.0 MPa, gas is supplied through pipeline 3 to the well pad of the well being developed and then to booster unit 4, simultaneously from pumping unit 5 through the pipeline 6 serves industrial water, in winter time - methanol water or an aqueous solution of potassium, calcium or sodium chlorides. In the booster installation 4, gas and process water are mixed to form a gas-liquid mixture, the gas-liquid mixture is compressed to a pressure of 7.0-10.0 MPa, which exceeds the current reservoir pressure, the high-pressure gas-liquid mixture is fed via line 7 to the separator 8. Here, the gas-liquid mixture is separated on liquid and gas media. The liquid from the separator 8 through the pipeline 9 is again sent to the pump unit 5 for reuse, and the high pressure gas of 7.0-10.0 MPa is fed through the pipeline 10 to the ejector 11. At the same time, the ejector 11 from the pumping unit 12 is fed through the pipeline 13 Pozh, in winter - non-freezing foaming liquid - NPOZH. You can use process water with OP-10 or process water with sulfanol as a lifeguard agent. An aqueous solution of calcium chloride or another salt with OP-10 or with sulfanol can be used as an NPOS. Then, the APOZ obtained on the ejector is fed through pipeline 14 to GT 15 of the coiled tubing installation 16 and then to the annular gap 17 between GT 15 and the lift column 18 of the well being developed 19. GT 15 is lowered into the lift column 18 in steps with stops of 50-100 m at each stage , with the simultaneous supply of AOF through it, which displaces the kill fluid located in the well being developed 19, through the annular gap 17 along the flow line 20 and the pipe 21 into the reservoir 22 for collecting the kill fluid. When the well is deepened by 50-100 m, the supply of coolant to the ejector 11 is stopped, and the high-pressure gas is supplied to the gas turbine 15 bypass 23, bypassing the ejector 11, squeezing the ALS to the surface and purging the well through flow line 20 to the flare line 24. This the alternation of the injection of ALS and high pressure gas is carried out at each stage until an inflow from the reservoir is obtained 25.

The gas supply to the booster unit 4 from the booster compressor station, and not from the neighboring production well 1, must be carried out to create the required performance of the booster unit 4, which is required during the development of the well 19, which the neighboring production well 1 due to low reservoir pressure equal to 0.8-1, 0 MPa, cannot provide.

The displacement of the kill fluid through the annular gap 17 is carried out due to the presence of a packer 26 in the composition of the lift column 18, which hermetically separates the annulus 27 between the lift 18 and production 28 columns of the well being developed 19. The ALF displacement by high-pressure gas contributes to additional aeration of the ALF, reducing its density and reduce back pressure on the reservoir 25, a smoother and faster call of inflow from the reservoir 25.

After receiving an inflow of gas from the reservoir 25, the well being developed 19 is worked out through a flare line 24 until it is put into operation. After that, GT 15 is removed from the well being developed 19, and the well itself is put into operation.

In the absence of removal of the kill fluid to the day surface, which is possible when it is absorbed by the reservoir 25, GT 15 is lifted and continues to supply high pressure gas to the well being developed 19. Lift GT 15 is carried out until the recovery of the fluid killing from the well being developed 19 to the day surface is restored.

Due to the low reservoir pressures, it is not allowed to force the kill fluid into the reservoir 25.

Due to the low ambient temperatures in winter and the presence of 19 permafrost rocks in the estuarine zone of the well being developed in the development process, a steam heating unit 29 is used to heat process water and fluids, as well as ground and wellhead equipment.

An example of the implementation of the proposed method at well No. 149 of the Vyngapurovsky field.

Gas from a production well with a pressure of 0.8 MPa was supplied to the BCS, where it was compressed to a pressure of 5.0 MPa. After that, the gas was supplied to the gas treatment plant, where it was dried from the liquid and purified from mechanical impurities. After that, gas under a pressure of 3.5 MPa, the maximum permissible pressure of this pipeline, was supplied through the pipeline to the cluster pad and then to the booster installation, while technical water was supplied through the pipeline from the pump installation to it. In the booster installation, gas and process water were mixed, a gas-liquid mixture was formed, the gas-liquid mixture was compressed to a pressure of 7.0 MPa, exceeding the current reservoir pressure in the well being developed. The high-pressure gas-liquid mixture was fed to a separator. Here, the gas-liquid mixture was separated into liquid and gas media. The liquid from the separator was again sent through the tank to the pump unit, and high-pressure gas of 7.0 MPa was fed to the ejector. At the same time, coolant was applied to the ejector. Then, the ALF obtained on the ejector during mixing of high-pressure gas and RLF was fed into the hydraulic core of the coiled tubing unit and then into the annular gap located between the hydraulic core and the lift column of the well being developed. Such circulation was carried out due to the presence of a packer in the well, tightly blocking the annular space of the well between the elevator and production columns. GTs were lowered into the inner cavity of the lift string, into the borehole space, stepwise with stops every 50 m. During the course of the GT descent, the ALF flowing into the well displaced the killing fluid in the well to the surface to collect the killing fluid. After every 50 m, the well was purged, stopping the supply of coolant to the ejector and supplying high pressure gas to the well, bypassing the ejector. When the gas reached the shoe of the elevator string, a valve was opened connecting the pipe space of the well being developed with the flare line, and continued to supply high pressure gas to the gas turbine and further into the annular space until the development of the mastered well began. Then the well was drilled into the flare through the pipe space of the lift column and flare line until a steady flow was obtained, bringing the well to the technological mode of operation. After that, the GT was removed from the well and the well was put into operation.

The proposed method provides reliable development of a packaged gas well in the conditions of the oil production with an anomaly coefficient below 0.2. It reduces the duration and cost of work, provides fire and anti-fouling process safety.

Due to the step-by-step displacement of the killing fluid and the ALS from the well, the conditions of their extrusion into the reservoir are eliminated, the filtration-capacitive properties of the reservoir are preserved, which is extremely important in the case of an API.

Due to the step-by-step purging of the well, a smoother, more “gentle” and easier call of gas inflow from the formation is carried out.

Claims (1)

A method of developing a packaged gas well under conditions of abnormally low reservoir pressure is an AAP, in which gas from production wells is fed to a booster compressor station - DKS, where gas is compressed to a pressure of 5.0-5.5 MPa, after the DKS, gas is supplied to a complex installation gas preparation - UKPG, where the gas is cleaned of mechanical impurities and water, and under a pressure of 3.0-4.0 MPa, gas is supplied to the well pad of the well being developed and then to the booster installation, into which technical water, the obtained gas-liquid mixture, is simultaneously pumped they are compressed to a value of 7.0-10.0 MPa, after which the gas-liquid mixture is sent to a separator, where the gas-liquid mixture is divided into high-pressure gas and liquid, the liquid is sent to the pump unit, and the high-pressure gas is fed to the ejector, which is simultaneously fed foaming fluid - ALF, aerated foaming fluid obtained on an ejector - APOF is fed into a flexible pipe - HT of a coiled tubing installation, which is lowered into the borehole space with stops every 50-100 m, at each stupa neither the deepening of the GT, the flow of coolant to the ejector is stopped, and the high-pressure gas is supplied to the GT, bypassing the ejector, squeezing out the kill fluid and ALS onto the surface and purging the well until a gas inflow from the reservoir is produced, after receiving the gas inflow, the well is worked out until it is withdrawn to the technological mode, after which the GT is removed from the well, and the well is put into operation.

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