Communicating well capable of preventing tubular column from being squeezed flat

Abstract

The utility model discloses a communicating well preventing tubular columns from being squeezed flat, which comprises an injection-production gas well and a brine discharging well which are communicated with each other, a first tubular column of the injection-production gas well is connected with an injection-production gas pipe, a second tubular column of the brine discharging well is connected with a brine discharging pipe, and a gas conveying pipe is connected between the brine discharging pipe and the injection-production gas pipe. A first pressure detection device and a second pressure detection device are arranged on the gas conveying pipe, and a first adjusting valve is further arranged on the gas conveying pipe and located between the first pressure detection device and the second pressure detection device. Compared with the prior art, the first pressure detection device and the second pressure detection device can detect the wellhead pressure of the gas injection and production well and the brine discharge well respectively, and when the wellhead pressure difference of the two wells reaches 0.5 Mpa, the first adjusting valve is opened, so that part of produced natural gas enters the second pipe column of the brine discharge well through the gas conveying pipe; therefore, the situation that the second pipe column is hollowed out and is possibly shrunken by the stratum is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of salt cavern gas storage, in particular to a connecting well which can prevent a pipe column from being squeezed and collapsed. Background Art

[0002] The connecting wells usually have one well used as a gas injection and production well and the other well used as a brine drainage well. During gas injection, natural gas is injected from the gas injection and production well, and brine is discharged from the brine drainage well. When the brine is discharged to the bottom of the gas injection and production well, the brine drainage well is closed, and then gas is continued to be injected into the gas injection and production well. When the pressure in the well rises to the upper limit pressure of the salt cavern, the gas injection is stopped.

[0003] When producing gas, in the first stage, gas is produced from the upper limit pressure of the injection and production well to the wellhead pressure of the brine drainage well being 0. If gas production continues in the second stage, the brine level in the casing of the brine drainage well will drop, which will cause hollowing out and easily lead to the casing being squeezed by the formation. If gas production does not continue and the lower limit pressure of the gas storage has not been reached, some gas cannot be produced, reducing the economic benefits of the gas storage. Utility Model Content

[0004] The main purpose of the utility model is to provide a connecting well that prevents the pipe string from being squeezed. The first pressure detection device and the second pressure detection device can respectively detect the wellhead pressures of the gas injection and production well and the brine drainage well. When the wellhead pressure difference between the two wells reaches 0.5Mpa, the first regulating valve is opened, so that part of the produced natural gas enters the second pipe string of the brine drainage well through the gas pipeline, thereby avoiding the situation where the second pipe string may be squeezed by the formation due to being hollowed out.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A connecting well for preventing a pipe string from being squeezed, comprising a connected gas injection and production well and a brine drainage well, wherein the first pipe string of the injection and production gas well is connected to an injection and production gas pipe, the second pipe string of the brine drainage well is connected to a brine drainage pipe, a gas transmission pipe is connected between the brine drainage pipe and the injection and production gas pipe, a first pressure detection device and a second pressure detection device are provided on the gas transmission pipe, a first regulating valve is also provided on the gas transmission pipe and the first regulating valve is located between the first pressure detection device and the second pressure detection device.

[0007] Furthermore, the brine exhaust pipe is also connected to a venting device for venting the natural gas in the second pipe column.

[0008] Furthermore, the venting device comprises a venting pipe connected to the brine exhaust pipe, a flare is connected to the end of the venting pipe, and a second regulating valve is installed on the venting pipe.

[0009] Furthermore, the bottom of the torch is sealed and connected to a waste pipe, and a valve is provided on the waste pipe.

[0010] Furthermore, a third regulating valve is provided on the gas injection and production pipe, and a fourth regulating valve is provided on the brine exhaust pipe.

[0011] Furthermore, the first pressure detection device and the second pressure detection device are both pressure gauges.

[0012] Compared with the prior art, the utility model has the following beneficial effects:

[0013] The first pressure detection device and the second pressure detection device of the utility model can respectively detect the wellhead pressures of the gas injection and production well and the brine drainage well. When the wellhead pressure difference between the two wells reaches 0.5Mpa, the first regulating valve is opened, so that part of the produced natural gas enters the second pipe column of the brine drainage well through the gas pipeline, thereby avoiding the situation where the second pipe column may be squeezed by the formation due to being hollowed out.

[0014] After the second regulating valve of the utility model is opened, the natural gas in the second pipe column can enter the flare through the venting pipeline, and the flare can fully burn the entering natural gas to prevent the natural gas from being directly discharged into the air. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The utility model is an overall schematic diagram of a connecting well for preventing a pipe column from being squeezed and collapsed.

[0016] Figure 2 The utility model is a schematic diagram of the connection of a flare, a drainage pipe and a valve of a connecting well for preventing a pipe column from being squeezed.

[0017] In the figure: 1. injection and production gas well; 2. brine drainage well; 3. first tubular column; 4. second tubular column; 5. injection and production gas pipe; 6. first pressure detection device; 7. first regulating valve; 8. second pressure detection device; 9. brine drainage pipe; 10. fourth regulating valve; 11. third regulating valve; 12. venting pipeline; 13. second regulating valve; 14. flare; 1401. drainage pipe; 1402. valve; 15. gas pipeline. DETAILED DESCRIPTION

[0018] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.

[0019] like Figure 1-2As shown, a connecting well for preventing a pipe string from being squeezed comprises a connected gas injection and production well 1 and a brine drainage well 2, wherein the first pipe string 3 of the gas injection and production well 1 is connected to an injection and production gas pipe 5, and the second pipe string 4 of the brine drainage well 2 is connected to a brine drainage pipe 9, and a gas transmission pipe 15 is connected between the brine drainage pipe 9 and the gas injection and production pipe 5, and a first pressure detection device 6 and a second pressure detection device 8 are provided on the gas transmission pipe 15, and a first regulating valve 7 is also provided on the gas transmission pipe 15 and the first regulating valve 7 is located between the first pressure detection device 6 and the second pressure detection device 8, wherein the first pressure detection device 6 and the second pressure detection device 8 are both pressure gauges.

[0020] In this embodiment, natural gas is first injected into the gas injection and production well 1 through the gas injection and production pipe 5, so that brine is discharged through the brine discharge pipe 9 of the brine discharge well 2. When the brine is discharged to the bottom of the gas injection and production well 1, the brine discharge well 2 is closed to stop the brine discharge, and gas injection is continued until the pressure in the well reaches the upper limit and then the gas injection is stopped;

[0021] When producing gas, the injection and production gas pipe 5 is opened to allow the natural gas in the injection and production gas well 1 to be discharged through the injection and production gas pipe 5 until the wellhead pressure of the brine drainage well 2 is zero, and then continue to produce gas. During this process, the wellhead pressure of the brine drainage well 2 will gradually decrease. The first pressure detection device 6 and the second pressure detection device 8 can respectively detect the wellhead pressures of the injection and production gas well 1 and the brine drainage well 2. When the wellhead pressure difference between the two wells reaches 0.5Mpa, the first regulating valve 7 is opened, so that part of the produced natural gas enters the second pipe column 4 of the brine drainage well 2 through the gas pipeline 15, thereby avoiding the situation where the second pipe column 4 may be squeezed by the formation due to being hollowed out.

[0022] Among them, Figure 2 As shown, the brine discharge pipe 9 is also connected to a venting device for venting the natural gas in the second pipe column 4, and the venting device includes a venting pipeline 12 connected to the brine discharge pipe 9, a flare 14 is connected to the end of the venting pipeline 12, and a second regulating valve 13 is installed on the venting pipeline 12;

[0023] When the brine is discharged again, the natural gas in the second pipe column 4 should be emptied first. First, the second regulating valve 13 is opened to allow the natural gas in the second pipe column 4 to enter the flare 14 through the venting pipe 12, and the flare 14 can fully burn the incoming natural gas to avoid direct discharge of the natural gas into the air.

[0024] Among them, Figure 2 As shown, the bottom of the flare 14 is sealed and connected to a waste pipe 1401, and a valve 1402 is provided on the waste pipe 1401. In the process of discharging natural gas into the flare 14, brine will enter the flare 14 at the end. At this time, the brine will fall to the bottom of the flare 14, so when the valve 1402 is opened, the brine at the bottom of the flare 14 can be discharged.

[0025] Among them, a third regulating valve 11 is provided on the injection and production gas pipe 5, and a fourth regulating valve 10 is provided on the brine exhaust pipe 9. The third regulating valve 11 is used to control the opening and closing of the injection and production gas pipe 5, and the fourth regulating valve 10 is used to control the opening and closing of the brine exhaust pipe 9.

[0026] Working principle: First, natural gas is injected into the injection and production gas well 1 through the injection and production gas pipe 5, so that brine is discharged through the brine discharge pipe 9 of the brine discharge well 2. When the brine is discharged to the bottom of the injection and production gas well 1, the brine discharge well 2 is closed to stop the brine discharge, and the gas injection is continued until the pressure in the well reaches the upper limit and then the gas injection is stopped. When gas is produced, the injection and production gas pipe 5 is opened to discharge the natural gas in the injection and production gas well 1 through the injection and production gas pipe 5 until the wellhead pressure of the brine discharge well 2 is zero, and then the gas production is continued. In this process, the wellhead pressure of the brine discharge well 2 will gradually decrease, and the first pressure detection device 6 and the second pressure detection device 8 can respectively detect When the wellhead pressure difference between the gas injection and production well 1 and the brine drainage well 2 reaches 0.5Mpa, the first regulating valve 7 is opened, so that part of the produced natural gas enters the second pipe column 4 of the brine drainage well 2 through the gas pipeline 15, thereby avoiding the second pipe column 4 from being squeezed by the formation due to being hollowed out. When gas is injected and brine is drained again, the natural gas in the second pipe column 4 should be drained first. First, the second regulating valve 13 is opened, so that the natural gas in the second pipe column 4 can enter the flare 14 through the venting pipe 12, and the flare 14 can fully burn the incoming natural gas to avoid the natural gas being directly discharged into the air.

[0027] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A connecting well for preventing a pipe string from being squeezed, comprising a connected gas injection and production well (1) and a brine drainage well (2), wherein a first pipe string (3) of the gas injection and production well (1) is connected to a gas injection and production pipe (5), and a second pipe string (4) of the brine drainage well (2) is connected to a brine drainage pipe (9), characterized in that: A gas transmission pipe (15) is connected between the brine exhaust pipe (9) and the injection and production gas pipe (5), and a first pressure detection device (6) and a second pressure detection device (8) are provided on the gas transmission pipe (15). A first regulating valve (7) is also provided on the gas transmission pipe (15), and the first regulating valve (7) is located between the first pressure detection device (6) and the second pressure detection device (8).

2. A connecting well for preventing a pipe column from being squeezed and collapsed according to claim 1, characterized in that: The brine discharge pipe (9) is also connected to a venting device for venting the natural gas in the second pipe column (4).

3. A connecting well for preventing a pipe column from being squeezed and collapsed according to claim 2, characterized in that: The venting device comprises a venting pipe (12) connected to the brine exhaust pipe (9), a flare (14) is connected to the end of the venting pipe (12), and a second regulating valve (13) is installed on the venting pipe (12).

4. A connecting well for preventing a pipe column from being squeezed and collapsed according to claim 3, characterized in that: The bottom of the torch (14) is sealed and connected to a waste discharge pipe (1401), and a valve (1402) is provided on the waste discharge pipe (1401).

5. A connecting well for preventing a pipe column from being squeezed and collapsed according to claim 1, characterized in that: The gas injection and production pipe (5) is provided with a third regulating valve (11), and the brine exhaust pipe (9) is provided with a fourth regulating valve (10).

6. A connecting well for preventing a pipe column from being squeezed and collapsed according to claim 1, characterized in that: The first pressure detection device (6) and the second pressure detection device (8) are both pressure gauges.

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