Anti-corrosion system for blow-off pipe of sulfur-containing gas well station

Abstract

The utility model discloses a sulfur-containing gas well station blow-off pipe anti-corrosion system which comprises a separator, a dirty liquid pool and a blow-off pipe connecting the separator and the dirty liquid pool, and further comprises an inert gas source and an alkali liquid pool, the two ends of the blow-off pipe are provided with a blow-off valve A and a blow-off valve B respectively, and the blow-off pipe is connected with a gas source access pipe. The communicating position of the gas source connecting-in pipe and the blow-off pipe is located at the downstream of the blow-off valve A, the connecting-in direction of the gas source connecting-in pipe is consistent with the trend of the blow-off pipe at the position, and the end, away from the blow-off pipe, of the gas source connecting-in pipe is connected with an inert gas source; the position, close to the blow-off valve B, of the blow-off pipe is connected with a purging discharge pipe, the communicating position of the purging discharge pipe and the blow-off pipe is located on the upstream of the blow-off valve B. The end, away from the blow-off pipe, of the purging discharge pipe extends into the alkali liquor pool. After pollution discharge is completed, liquid or acid gas and the like attached to the inner wall of the pipeline can be purged and replaced, the corrosion environment is damaged, the service life of the pollution discharge pipeline is prolonged, purged gas and liquid are neutralized, secondary environmental pollution is avoided, the structure is simple, and implementation is convenient.

Description

Technical Field

[0001] The utility model belongs to the technical field of pipeline anti-corrosion, and in particular relates to an anti-corrosion system for a sewage pipe of a sulfur-containing gas well station. Background Art

[0002] With the continuous advancement of the development history of oil and gas in my country, many well station equipment and pipelines have begun to enter the aging stage, especially in some natural gas well stations in Sichuan and Chongqing. The station sewage and venting pipelines have been in use for nearly ten years. In addition, the gas hydrogen sulfide content in these areas is high, resulting in varying degrees of corrosion in the station valves and pipelines. Among them, the sewage pipeline connected to the separator has a high water content, which provides a water environment for high-sulfur corrosion perforation, resulting in serious safety hazards in the sewage pipeline. At present, most well stations have entered the late stage of production, and completely replacing the pipeline is not in line with economic benefits. Therefore, how to extend the service life of the pipeline and ensure the safe and stable operation of the station while controlling the economic cost has become a problem that needs to be solved urgently. Utility Model Content

[0003] In view of this, the utility model provides a sewage pipe anti-corrosion system for a sulfur-containing gas well station to alleviate the problem that the pipelines of the old well station are severely corroded and the service life is affected.

[0004] The technical solution is as follows:

[0005] A sewage pipe anti-corrosion system for a sulfur-containing gas well station comprises a separator and a sewage tank, and a sewage pipe connected between the separator and the sewage tank, wherein a sewage valve A is provided at one end of the sewage pipe close to the separator, and a sewage valve B is provided at one end close to the sewage tank. The key point is that: an inert gas source and an alkali liquid tank are also provided, and a gas source access pipe is connected to the sewage pipe. The position where the gas source access pipe is connected to the sewage pipe is downstream of the sewage valve A and close to the sewage valve A. The gas source access pipe is connected in the same direction as the sewage pipe at this position, and the end of the gas source access pipe away from the sewage pipe is connected to the inert gas source;

[0006] A purge discharge pipe is connected to the sewage pipe near the sewage valve B, and the connection position between the purge discharge pipe and the sewage pipe is upstream of the sewage valve B. One end of the purge discharge pipe away from the sewage pipe extends into the alkali solution pool.

[0007] With the above structure, when the separator is not working, after closing the drain valve A and the drain valve B, nitrogen can be introduced into the drain pipe through the gas source access pipe, and the water attached to the wall of the drain pipe and the sulfur-containing gas in the pipeline are purged and replaced by nitrogen to avoid corrosion of the pipeline by acidic corrosive gas or liquid. The acidic gas and liquid blown out from the end enter the alkali liquid pool through the purge discharge pipe and are integrated in time, reducing pollution to the environment around the well station.

[0008] Preferably, an air pump is provided between the inert gas source and the gas source access pipe, and the air pump is used to pressurize the nitrogen in the inert gas source and send it into the gas source access pipe. With the above structure, the flow rate of the nitrogen sent into the sewage pipe can be controlled by the air pump to better purge, and the nitrogen consumption can also be optimized.

[0009] As a preferred embodiment, the end of the gas source access pipe close to the sewage pipe is provided with a switch valve A. The above structure can prevent the sewage in the sewage pipe from flowing back into the gas source access pipe when the purge operation is not performed.

[0010] As a preferred embodiment: a switch valve B is provided at one end of the purge discharge pipe close to the sewage pipe, and the direction of the connection between the purge discharge pipe and the sewage pipe is perpendicular to the direction of the sewage pipe. The above structure can prevent the sewage from entering the alkali liquid pool through the purge discharge pipe during sewage discharge, and at the same time will not greatly affect the speed of the sewage entering the sewage pool, ensuring smooth sewage discharge.

[0011] As a preferred embodiment, the position where the purging discharge pipe is connected to the alkali liquid pool is close to the top of the alkali liquid pool. The above solution can avoid the backflow of alkali liquid and increase the reaction time of the purged acidic gas and liquid with the alkali liquid.

[0012] As a preferred embodiment, an acid-base indicator is installed on the purge discharge pipe, and the acid-base indicator is located between the switch valve B and the alkali liquid pool, and is outside the alkali liquid pool. With the above scheme, during the purge process, the acid-base indicator can be used to observe the acid-base value of the gas and liquid purged at any time to determine whether to continue the purge, which is conducive to optimizing the purge process and scientific management.

[0013] Preferably, the sewage pipe has a branch pipe section at one end close to the purge discharge pipe, and a three-way joint A is provided at the end of the branch pipe section, one connecting end of the three-way joint A is connected to the branch pipe section, one connecting end is blocked by a plug adapted thereto, and a pressure gauge is installed on one connecting end.

[0014] By adopting the above scheme, the pressure in the pipeline during purging can be monitored by the pressure gauge. At the same time, after the plug is removed, the gas sample in the pipeline can be collected more conveniently to detect the oxygen content of the gas sample to see whether it meets the requirements, and then proceed to the next process based on the results.

[0015] As a preference, the inert gas source is a nitrogen source. With the above solution, desulfurization plants usually produce more nitrogen, and nitrogen is preferably used for purging, which is relatively easier to obtain and has lower economic cost.

[0016] As a preferred embodiment, the section of the purge discharge pipe extending into the alkali liquid pool is in a circuitous structure and is provided with a plurality of overflow holes. The above scheme can increase the contact time between the purge gas and the alkali liquid, so that they can be fully neutralized, and facilitate the rapid treatment of the alkali liquid pool after the purge operation is completed, thereby shortening the waiting time.

[0017] Compared with the prior art, the beneficial effects of the utility model are:

[0018] By adopting the sewage pipe anti-corrosion system of the sulfur-containing gas well station provided by the utility model, after the sewage is discharged, inert gas such as nitrogen can be filled into the sewage pipeline to purge and displace the liquid or acidic gas attached to the inner wall of the pipeline, thereby destroying the corrosive environment and extending the service life of the sewage pipeline. At the same time, the acidic gas and liquid purged are neutralized in time to avoid secondary environmental pollution. The structure is simple and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the utility model;

[0020] Figure 2 This is a schematic diagram of the partial structure of the purge discharge pipe extending into the alkali solution pool. DETAILED DESCRIPTION

[0021] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0022] refer to Figure 1 The sewage pipe anti-corrosion system of the sulfur-containing gas well station shown in the present application mainly includes a separator 1, a sewage tank 2, an inert gas source 5 and an alkali liquid tank 6. As shown in the figure, the sewage generated by the separator 1 can be discharged into the sewage tank 2 through the sewage pipe 3, that is, the two ends of the sewage pipe 3 are respectively connected to the separator 1 and the sewage tank 2, and sewage valves A30 and sewage valves B31 are also distributed near the ends of the two ends of the sewage pipe 3, wherein the sewage valve A30 is close to the separator 1, and the sewage valve B31 is close to the sewage tank 2.

[0023] The drain pipe 3 is connected to an air source access pipe 4 at a position near the drain valve A30 through a three-way joint B 37. The access position is downstream of the drain valve A30 (the upstream and downstream in this article are both based on the flow direction of the sewage liquid), and the direction of the air source access pipe 4 at the connection position is consistent with the direction of the downstream drain pipe 3. In this embodiment, the diameter of the air source access pipe 4 can be slightly larger than the diameter of the drain pipe 3, so that the nitrogen entering the drain pipe 3 from the air source access pipe 4 can directly purge it without pressure damage due to the bend at the entry position. At the same time, because the pipe diameter becomes smaller, the purging effect of the nitrogen can be relatively improved. In order to prevent the sewage liquid from backflowing into the air source access pipe 4, a switch valve A41 is provided on the air source access pipe 4 near the drain pipe 3.

[0024] One end of the gas source access pipe 4 away from the sewage pipe 3 is connected to the inert gas source 5 through an air pump 40. The inert gas source 5 in the present application can be a mobile gas source or a fixed gas source. In the present embodiment, nitrogen is preferably used as the inert gas source. It can be stored at the well station in the form of a gas tank, or it can be a nitrogen pipeline directly connected to the desulfurization plant. The nitrogen generated in the desulfurization process of the desulfurization plant is transported to the well station through the nitrogen pipeline, and then pressurized by the air pump 40 and sent into the gas source access pipe 4.

[0025] A purge discharge pipe 7 is connected to the three-way joint C36 at one end of the sewage pipe 3 close to the sewage pool 2. The connection position between the purge discharge pipe 7 and the sewage pipe 3 is upstream of the sewage valve B31, and the direction of the purge discharge pipe 7 is perpendicular to the direction of the sewage pipe 3 at this position. The end of the purge discharge pipe 7 away from the sewage pipe 3 is bent downward and extends into the alkali liquid pool 7 from the upper end thereof, and the lower end thereof is close to the bottom of the alkali liquid pool 7, and the alkali liquid pool 7 is filled with alkaline liquid.

[0026] A switch valve B70 is installed on the purge discharge pipe 7 near the three-way joint C36. A pH indicator 71 is also provided on the purge discharge pipe 7. The pH indicator 71 is located between the switch valve B70 and the alkali solution pool 6. The pH value of the gas and liquid in the purge discharge pipe 7 can be observed in real time during the purge process through the pH indicator 71, that is, the probe of the pH indicator 71 extends into the purge discharge pipe 7, and its display screen is outside the purge discharge pipe 7. The pH value of the detected fluid can be read through the display screen.

[0027] In the present application, in order to strengthen the monitoring of the pressure and air quality in the sewage pipe 3, a branch pipe section 32 extending in the opposite direction is provided near the purge discharge pipe 7. The branch pipe section 32 is located upstream of the three-way joint C36. As shown in the figure, a three-way joint A33 is connected to the end of the branch pipe section 32. The three-way joint A33 is a T-shaped joint. Among the two facing interfaces, one interface is connected to the end of the straight pipe section 32, and the other is provided with a plug 35 adapted thereto. The plug 35 is threadedly connected thereto, and a pressure gauge 34 is detachably mounted on the third interface.

[0028] In this embodiment, the drain valve A30, the drain valve B31, the switch valve A41 and the switch valve B70 can adopt a manual flat valve or ball valve structure, etc., which can close the pipeline and isolate the liquid. The structure of the three-way joint B37 and the three-way joint C36 is similar to the three-way joint A33, both of which are right-angled T-shaped structures.

[0029] In the specific implementation, the section of the purge discharge pipe 7 extending into the alkali liquid pool 6 is a circuitous structure, as shown in FIG. Figure 2As shown, it is a top view structure, in which the circuitous purge discharge pipe 7 is basically laid flat on the bottom of the alkali liquid pool 6, or is suspended at the bottom of the alkali liquid pool 6, and has multiple overflow holes 72 distributed along its length direction and circumference. This can greatly increase the contact area between the gas and liquid sprayed by the purge and the alkali liquid, thereby achieving the purpose of rapid neutralization.

[0030] like Figure 1 As shown, when the system is in operation, the drain valve A30 and the drain valve B31 are closed, the switch valve A41 and the switch valve B70 are opened, and high-pressure nitrogen is pumped into the gas source access pipe 4 through the air pump 40. After the nitrogen enters the drain pipe 3, the acidic gas and liquid attached to and corroded by the inner wall of the pipe are purged and replaced. The purged acidic gas and liquid directly enter the alkali liquid pool 6 to be neutralized and treated, and will not enter the sewage liquid pool 2, and will be discharged into the atmosphere through bubbles, ensuring that the purging process will not cause secondary environmental pollution.

[0031] During the purging process, the pressure in the sewage pipe 3 is monitored at any time through the pressure gauge 34, and the pH of the purged gas and liquid is observed through the acid-base indicator 71. When the displayed pH value tends to be stable and the substrate is neutral, the nitrogen pumping speed is slowed down accordingly until the pressure value of the pressure gauge 34 is observed to drop to near normal pressure, and then the plug 35 is opened to collect the gas sample in the sewage pipe 3 at the opened interface position, and detect whether its oxygen content is lower than 3%. If it is confirmed that the sample oxygen content is lower than 3%, it can be determined that the purging is qualified, and the purging can be stopped, and the switch valve A41 and the switch valve B70 are closed. The structure is simple and reasonable, and the excess nitrogen generated in the production process of the desulfurization plant can be fully utilized, which is beneficial to improving resource utilization efficiency, while slowing down the corrosion rate of the pipeline, extending its service life, and reducing economic losses.

[0032] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make a variety of similar expressions without violating the purpose and claims of the present invention, and such changes fall within the scope of protection of the present invention.

Claims

1. A sewage pipe anti-corrosion system for a sulfur-containing gas well station, comprising a separator (1) and a sewage tank (2), and a sewage pipe (3) connected between the separator (1) and the sewage tank (2), wherein the sewage pipe (3) is provided with a sewage valve A (30) at one end close to the separator (1) and a sewage valve B (31) at one end close to the sewage tank (2), and characterized in that: It also includes an inert gas source (5) and an alkali liquid pool (6), the sewage pipe (3) is connected to a gas source access pipe (4), the gas source access pipe (4) is connected to the sewage pipe (3) at a position downstream of the sewage valve A (30) and close to the sewage valve A (30), the gas source access pipe (4) is connected in a direction consistent with the direction of the sewage pipe (3) at this position, and the end of the gas source access pipe (4) away from the sewage pipe (3) is connected to the inert gas source (5); A purge discharge pipe (7) is connected to the sewage pipe (3) at a position close to the sewage valve B (31), and the position where the purge discharge pipe (7) communicates with the sewage pipe (3) is upstream of the sewage valve B (31), and one end of the purge discharge pipe (7) away from the sewage pipe (3) extends into the alkali solution pool (6).

2. The anti-corrosion system for sewage pipes of a sour gas well station according to claim 1, characterized in that: An air pump (40) is provided between the inert gas source (5) and the gas source access pipe (4), and the air pump (40) is used to pressurize the nitrogen in the inert gas source (5) and then send it into the gas source access pipe (4).

3. The anti-corrosion system for sewage pipes of a sour gas well station according to claim 1 or 2, characterized in that: An on-off valve A (41) is provided at one end of the gas source access pipe (4) close to the sewage discharge pipe (3).

4. The anti-corrosion system for sewage pipes of a sour gas well station according to claim 1, characterized in that: An on-off valve B (70) is provided at one end of the purge discharge pipe (7) close to the sewage discharge pipe (3), and the direction of the connection between the purge discharge pipe (7) and the sewage discharge pipe (3) is perpendicular to the direction of the sewage discharge pipe (3).

5. The anti-corrosion system for sewage pipes of a sour gas well station according to claim 4 is characterized in that: The position where the purge discharge pipe (7) is connected to the alkali liquid pool (6) is close to the top of the alkali liquid pool (6).

6. The anti-corrosion system for sewage pipes of a sour gas well station according to claim 5, characterized in that: The purge discharge pipe (7) is provided with an acid-base indicator (71), and the acid-base indicator (71) is located between the switch valve B (70) and the alkali liquid pool (6), and is located outside the alkali liquid pool (6).

7. The anti-corrosion system for sewage pipes of a sour gas well station according to any one of claims 1 or 4-6, characterized in that: The sewage discharge pipe (3) has a branch pipe section (32) at one end close to the purge discharge pipe (7), and a three-way joint A (33) is provided at the end of the branch pipe section (32). One connection end of the three-way joint A (33) is connected to the branch pipe section (32), one connection end is blocked by a plug (35) adapted thereto, and a pressure gauge (34) is installed on one connection end.

8. The anti-corrosion system for sewage pipes of a sour gas well station according to claim 1 or 2, characterized in that: The inert gas source (5) is a nitrogen source.

9. The anti-corrosion system for sewage pipes of a sour gas well station according to claim 1 or 2, characterized in that: The section of the purge discharge pipe (7) extending into the alkali solution pool (6) has a circuitous structure and is provided with a plurality of overflow holes (72).

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