Water-sealed tank for recovering low-pressure natural gas

Abstract

The utility model provides a water-sealed tank for recycling low-pressure natural gas, which belongs to the technical field of petrochemical engineering and comprises a tank body, partition plates are mounted in the tank body, a gas channel is arranged between the upper portions of the partition plates and the tank body, a gas inlet pipe and a gas outlet pipe are arranged on the tank body, and the partition plates comprise perforated partition plates and non-perforated partition plates. The nonporous partition plate divides the tank body into a liquid cavity and a gas cavity, and the porous partition plate is located in the liquid cavity; the air inlet pipes extend into the tank body and comprise the first air inlet pipe and the second air inlet pipe. The design of the first gas inlet pipe can ensure that the recovered back pressure is relatively stable, so that the first gas inlet pipe conveys and recovers relatively stable low-pressure natural gas; due to the design of the second gas inlet pipe, the influence of slug flow on low-pressure natural gas recovery back pressure can be eliminated, the second gas inlet pipe conveys unstable low-pressure natural gas to the water seal liquid level to be released, continuous recovery of the low-pressure natural gas is guaranteed, and the continuity of low-pressure natural gas recovery is greatly improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of petrochemical industry, in particular to a water seal tank for recovering low-pressure natural gas. Background Art

[0002] During the oil extraction process, low-pressure natural gas (low-pressure natural gas usually refers to natural gas with a pressure of less than 100kPa during transportation) cannot be recycled because the extraction process is affected by fluctuations in oil well production, the use of cover gas in the production water treatment system, and casing exhaust. It can only be processed through the existing flare venting system, which wastes energy and increases carbon emissions.

[0003] Since the recovery of low-pressure natural gas has high economic value and social benefits, at present, the process scheme of "water seal tank + quick opening valve + bursting needle valve + compressor" is adopted to transform and upgrade the existing flare venting system to realize the recovery and utilization of low-pressure vented natural gas.

[0004] However, due to the periodic gas lock of oil wells and the unstable gas production of some oil wells, slug flow (a gas-liquid two-phase flow state in which a gas column and a liquid column alternate in the pipeline) will occur in the production process, making the low-pressure venting of natural gas unstable and conventional water seal tanks unable to achieve stable back pressure.

[0005] Therefore, designing a water seal tank suitable for recovering unstable low-pressure natural gas has become a technical problem that needs to be solved urgently by those skilled in the art. Utility Model Content

[0006] The problem to be solved by the utility model is to provide a water seal tank for recovering low-pressure natural gas.

[0007] In order to solve the above technical problems, the technical solution adopted by the utility model is: a water-sealed tank for recovering low-pressure natural gas, comprising a tank body, a partition is installed inside the tank body, a gas channel is formed between the partition and the tank body, an air inlet pipe and an air outlet pipe are arranged on the tank body, the partition comprises a perforated partition and a non-perforated partition, the perforated partition and the non-perforated partition are arranged at intervals, the non-perforated partition divides the tank body into a liquid cavity and a gas cavity, the perforated partition is located in the liquid cavity, and is used to ensure the connectivity of the liquid cavities on both sides thereof, and at the same time ensure that the water seal liquid level is relatively stable; the air inlet pipe is arranged in the tank body, and the air inlet pipe comprises a first air inlet pipe and a second air inlet pipe, the second air inlet pipe is located between the perforated partition and the non-perforated partition, and the first air inlet pipe is located on the side of the perforated partition away from the second air inlet pipe.

[0008] Furthermore, the insertion depth of the bottom end of the first air inlet pipe is greater than the insertion depth of the bottom end of the second air inlet pipe.

[0009] Furthermore, the diameter of the first air intake pipe is greater than the diameter of the second air intake pipe, and the bottom end pipe opening of the first air intake pipe and the bottom end pipe opening of the second air intake pipe are arranged obliquely.

[0010] Furthermore, drainage pipes are provided at the bottom of the liquid cavity and the gas cavity. When the water seal liquid level exceeds the non-porous partition plate and overflows into the gas cavity, the overflowed water seal liquid will be discharged from the drainage pipe.

[0011] Furthermore, the perforated partition plate is provided with a plurality of through holes.

[0012] Furthermore, the gas outlet pipe is installed on the tank body above the gas cavity.

[0013] Due to the adoption of the above technical solution, the utility model has the following beneficial effects:

[0014] The air intake pipe of the utility model includes a first air intake pipe and a second air intake pipe, the bottom end of the first air intake pipe extends to the front end of the perforated baffle, and the bottom end of the second air intake pipe extends to the rear end of the perforated baffle, and the insertion depth of the bottom end pipe opening of the first air intake pipe is greater than the insertion depth of the bottom end pipe opening of the second air intake pipe, that is, the bottom end pipe opening of the first air intake pipe is close to the bottom of the tank body, and the bottom end pipe opening of the second air intake pipe is close to the water seal liquid surface. The design of the first air intake pipe can ensure that the recovery back pressure is relatively stable, so that the first air intake pipe can transport and recover relatively stable low-pressure natural gas; the design of the second air intake pipe can avoid the problem of excessive inlet pressure or insufficient pressure caused by slug flow, and can eliminate the influence of slug flow on the recovery back pressure of low-pressure natural gas. The second air intake pipe transports unstable low-pressure natural gas to the water seal liquid surface for release, and then smoothly recovers it through the air outlet pipe, ensuring the continuous recovery of low-pressure natural gas, which greatly improves the continuity of low-pressure natural gas recovery.

[0015] The partition of the utility model comprises a partition with holes and a partition without holes. The partition without holes is used to separate the tank body into a liquid cavity and a gas cavity; the partition with holes is used to ensure the connectivity of the liquid cavities on both sides thereof and to ensure that the water seal liquid level is relatively stable, safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be described in detail below with reference to the accompanying drawings and in combination with examples, and the advantages and implementation methods of the present invention will become more obvious. The contents shown in the accompanying drawings are only used to explain the present invention and do not constitute any limitation to the present invention. In the accompanying drawings:

[0017] Figure 1 It is a structural schematic diagram of the utility model.

[0018] Figure 2 It is a structural schematic diagram of a perforated partition board of the utility model.

[0019] In the figure:

[0020] 1. Tank body; 2. Perforated partition; 3. Non-perforated partition; 4. Liquid chamber; 5. Gas chamber; 6. Drain pipe; 7. Air outlet pipe; 8. First air inlet pipe; 9. Second air inlet pipe; 10. End cap; 11. Support; 12. Through hole. DETAILED DESCRIPTION

[0021] like Figure 1 and Figure 2 As shown, the utility model is a water-sealed tank for recovering low-pressure natural gas, comprising a tank body 1, a partition is installed inside the tank body 1, a gas channel is formed between the partition and the tank body 1, and an air inlet pipe and an air outlet pipe 7 are arranged on the tank body 1.

[0022] The partition includes a perforated partition 2 and a non-porous partition 3. The perforated partition 2 is located at the front end of the non-porous partition 3 (in this embodiment, the left side of the tank body is the front and the right side is the rear, that is, the perforated partition 2 is located on the left side of the non-porous partition 3). The perforated partition 2 and the non-porous partition 3 are arranged at intervals. The non-porous partition 3 is used to separate the tank body 1 into a liquid chamber 4 and a gas chamber 5. Drain pipes 6 are provided at the bottom of the liquid chamber 4 and the gas chamber 5. When the water seal liquid level exceeds the non-porous partition 3 and overflows to the gas chamber 5, the overflowed water seal liquid will be discharged from the drain pipe 6; the perforated partition 2 is used to ensure the connectivity of the liquid chambers on both sides thereof, and at the same time ensure that the water seal liquid level is relatively stable.

[0023] A plurality of through holes 12 are arranged on the perforated partition plate 2. The plurality of through holes 12 are evenly distributed along concentric arcs, and the diameter of the through holes 12 is 10 mm.

[0024] The air inlet pipe is inserted below the water seal liquid level, and includes a first air inlet pipe 8 and a second air inlet pipe 9. The bottom end of the first air inlet pipe 8 extends to the front end (left side) of the perforated partition 2, and the bottom end of the second air inlet pipe 9 extends to the rear end (right side) of the perforated partition 2. The insertion depth of the bottom end pipe opening of the first air inlet pipe 8 is greater than the insertion depth of the bottom end pipe opening of the second air inlet pipe 9, that is, the bottom end pipe opening of the first air inlet pipe 8 is close to the bottom of the tank body 1, and the bottom end pipe opening of the second air inlet pipe 9 is close to the water seal liquid level.

[0025] The diameter of the first air inlet pipe 8 is greater than that of the second air inlet pipe 9. The bottom end of the first air inlet pipe 8 is at an angle of 30°, and the bottom end of the first air inlet pipe 8 faces the front end; the bottom end of the second air inlet pipe 9 is at an angle of 30°, and the bottom end of the second air inlet pipe 9 faces the rear end.

[0026] The first air inlet pipe 8 is used to transport relatively stable low-pressure natural gas; the second air inlet pipe 9 is used to transport unstable low-pressure natural gas.

[0027] The gas outlet pipe 7 is installed on the tank body 1 above the gas chamber 5 .

[0028] Sealing heads 10 are installed at both ends of the tank body 1 , a support 11 is installed at the bottom, a liquid replenishing pipe is also arranged on the tank body 1 , and a liquid level sensor and a temperature sensor are also arranged inside the tank body 1 .

[0029] The working principle of the utility model is:

[0030] Liquid is injected into the tank body 1 of the utility model to form a water seal, and the height of the water seal liquid level is required not to exceed the height of the non-porous partition 3. Relatively stable low-pressure natural gas enters the tank body 1 from the first air inlet pipe 8. Since the bottom end of the first air inlet pipe 8 is close to the bottom of the tank body 1 and has a sufficient depth, it has sufficient recovery back pressure, and the back pressure is relatively stable, so that the relatively stable low-pressure natural gas returns to the original path, thereby realizing the recovery of relatively stable low-pressure natural gas; unstable low-pressure natural gas enters the tank body 1 from the second air inlet pipe 9. Since the bottom end of the second air inlet pipe 9 is close to the water seal liquid level, the water pressure is very small, and the unstable low-pressure natural gas is output from the bottom end of the inclined second air inlet pipe 9, rises to the water seal liquid level and is released, and then output from the air outlet pipe 7, thereby realizing the recovery of unstable low-pressure natural gas.

[0031] The above embodiments of the utility model are described in detail, but the above contents are only preferred embodiments of the utility model and cannot be considered to limit the scope of implementation of the utility model. All equivalent changes and improvements made within the scope of the utility model should still fall within the scope of this patent.

Claims

1. A water seal tank for recovering low-pressure natural gas, characterized in that: It includes a tank body, a partition is installed inside the tank body, a gas channel is formed above the partition and between the tank body, an air inlet pipe and an air outlet pipe are arranged on the tank body, the partition includes a perforated partition and a non-porous partition, the perforated partition and the non-porous partition are arranged at intervals, the non-porous partition divides the tank body into a liquid cavity and a gas cavity, the perforated partition is located in the liquid cavity; the air inlet pipe extends into the tank body, the air inlet pipe includes a first air inlet pipe and a second air inlet pipe, the second air inlet pipe is located between the perforated partition and the non-porous partition, and the first air inlet pipe is located on the side of the perforated partition away from the second air inlet pipe.

2. The water seal tank for recovering low-pressure natural gas according to claim 1, characterized in that: The insertion depth of the bottom end pipe opening of the first air inlet pipe is greater than the insertion depth of the bottom end pipe opening of the second air inlet pipe.

3. The water seal tank for recovering low-pressure natural gas according to claim 1, characterized in that: The diameter of the first air inlet pipe is greater than that of the second air inlet pipe, and the bottom end opening of the first air inlet pipe and the bottom end opening of the second air inlet pipe are both inclined.

4. The water seal tank for recovering low-pressure natural gas according to claim 1, characterized in that: The bottoms of the liquid cavity and the gas cavity are both provided with drainage pipes.

5. The water seal tank for recovering low-pressure natural gas according to claim 1, characterized in that: The perforated partition plate is provided with a plurality of through holes.

6. The water seal tank for recovering low-pressure natural gas according to claim 1, characterized in that: The gas outlet pipe is installed on the tank body above the gas cavity.

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