Medium-pressure sand removal, separation and metering integrated system for deep shale gas platform

Abstract

The utility model relates to the technical field of shale gas exploitation, and provides a medium-pressure desanding, separating and metering integrated system for a deep shale gas platform, which comprises a wellhead module comprising a wellhead pipeline and a two-stage throttling device; the two-phase flow meter sledge comprises a plurality of metering pipelines, and flow detection assemblies are arranged on the metering pipelines and communicated to the medium-pressure sand remover sledge; the medium-pressure sand remover sledge comprises a sand removing barrel and is further provided with a sand removing exhaust pipe. The gas-liquid separation metering sledge comprises a separator provided with a separation exhaust pipe, and the separation exhaust pipe is communicated with a pigging outbound valve bank sledge. The desanding cylinder and the separator are provided with liquid discharge pipes; the pigging outbound valve group sledge comprises an outbound pipeline. When the integrated system disclosed by the utility model is used for exploiting deep shale gas, the composition of the whole system can be simplified, a large number of component parts are simplified, the construction cost of ground engineering equipment is reduced, automatic management is realized, the exploiting efficiency is improved, the automatic operation of an exploiting treatment process is guaranteed, and the safety controllability is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of shale gas exploitation, in particular to ground engineering equipment for deep shale gas platform wells, and specifically to a medium-pressure sand removal, separation and metering integrated system for deep shale gas platforms. Background Art

[0002] With the deepening of deep shale gas exploration and development, facing more stringent wellhead production conditions and greater construction cost pressure, the standardized design of high-pressure processes currently used in shale gas is facing a series of challenges and has room for continuous optimization and improvement. This is mainly reflected in:

[0003] 1) Wellhead pressure control. The production of shale gas has changed from the "pressure-release production" mode to the "pressure-controlled production" mode. In order to control the early production pressure difference, reduce the backflow of proppant, protect the reservoir, and extend the stable production period of gas wells, it is necessary to improve the pressure control capacity of the wellhead pressure control device to meet the actual needs of pressure-controlled production.

[0004] 2) Low-cost construction. Deep shale gas adopts the method of large cluster wells. With the need for efficient development of shale gas fields, shale gas exploitation implements a low-cost strategy. How to achieve the goal of reducing investment and increasing efficiency while ensuring high-quality construction of gas fields is a new challenge for deep shale gas development.

[0005] 3) High corrosion resistance. In the early stage of deep shale gas well exploitation, there are characteristics such as high temperature, high pressure, large amount of return fluid, and large amount of sand production. The well depth in the block is more than 4,500 meters. The wellhead pressure is as high as 60MPa and the wellhead temperature is as high as 70°C in the early stage of well opening, which puts forward higher requirements on the erosion and corrosion resistance of ground processes and equipment.

[0006] Therefore, the deep shale gas extraction scheme needs to be optimized to meet the above extraction needs. Therefore, it is necessary to propose a more reasonable technical solution to solve the technical problems existing in the existing technology. Utility Model Content

[0007] In order to overcome at least one of the defects mentioned above, the utility model proposes a medium-pressure sand removal, separation and metering integrated system for deep shale gas platforms, which realizes the functions of wellhead secondary throttling, two-phase flow metering, sand removal, gas-liquid separation, overpressure alarm in the station and overpressure safety venting, maintenance venting, gas collection branch line cleaning, etc., and is suitable for shale gas platform well stations with different wellhead numbers and different scales through the combination of skid devices. Thereby simplifying the process of deep shale gas extraction, improving the efficiency of extraction, realizing the refined control of gas well pressure, and improving the safety and reliability of the extraction process.

[0008] In order to achieve the above purpose, the integrated system disclosed in the utility model can adopt the following technical solutions:

[0009] A medium-pressure sand removal, separation and metering integrated system for deep shale gas platform, including:

[0010] The wellhead module includes a wellhead pipeline, on which a primary throttling device and a secondary throttling device are provided for throttling and reducing the pressure of the gas coming from the wellhead twice;

[0011] A two-phase flow meter skid, comprising a plurality of metering pipes, on which two-phase flow detection components are arranged, including a gas phase flow detection component and a liquid phase flow detection component, and the ends of the metering pipes are connected to the two-phase converging pipe and extend to the medium-pressure desander skid;

[0012] The medium-pressure desander skid comprises a desander cylinder body, a desander exhaust pipe is arranged on the desander cylinder body and is connected to the gas-liquid separation metering skid, a liquid discharge pipe is also arranged, and a first liquid level gauge and a second liquid level gauge are arranged on the desander cylinder body;

[0013] The gas-liquid separation metering skid comprises a separator, on which a plurality of separation exhaust pipes are arranged, and at least one set of separation exhaust pipes is connected to the pigging outlet valve group skid; the separator is synchronously provided with a liquid discharge pipe for transmitting the liquid phase, and is also provided with a first liquid level meter and a second liquid level meter;

[0014] The pigging outlet valve group skid includes an outlet pipeline and is used to control the delivery of the outlet gas.

[0015] The above disclosed integrated system can realize automated processing for the exploitation and treatment of deep shale gas. Specifically, the gas from the wellhead is throttled to about 20MPa by the first-level throttling device, and then throttled to 5~8.5MPa by the second-level throttling device. After that, it enters the two-phase flow meter skid one by one for single well metering. After metering, the gas from each well is collected and enters the medium-pressure desander skid for desanding, and then separated and metered by the gas-liquid separation metering skid. The gas phase is transported to the downstream through the pig outlet valve group skid, and the liquid phase enters the produced liquid system. Thus, the exploitation and treatment of shale gas is realized.

[0016] Furthermore, the wellhead module can achieve two-stage throttling and pressure reduction through a variety of solutions, and its structure is not limited to a single one. Here, an optimization is made and one feasible option is proposed: the wellhead pipeline includes a section of pipeline, and the section of pipeline is connected to the second section of pipeline through a primary throttling device and is used to achieve the first-stage throttling and pressure reduction of the gas from the wellhead; the second section of pipeline is connected to the two-phase flow meter skid through a secondary throttling device and is used to achieve the second-stage throttling and pressure reduction of the gas from the wellhead. When the above solution is adopted, the primary throttling device includes a fixed oil nozzle, and the secondary throttling device includes a pneumatic cage-type throttle valve.

[0017] Furthermore, there are gas and liquid substances in the integrated system. In the process of two-phase flow metering, medium-pressure sand removal and gas-liquid separation, some pure gas substances need to be discharged to the outside for venting. Specifically, venting can be achieved through a variety of structures, and the structure is not limited to a single one. Here, optimization is performed and one of the feasible options is proposed: the metering pipeline, and / or the sand removal cylinder, and / or the separator are also connected to the vent main pipe through a vent branch pipe, and a control valve group is provided on the vent branch pipe. The vent main pipe extends to the vent module. When the above scheme is adopted, the centralized control and processing of the vented gas can be achieved by centrally transporting the gas to be vented to the vent module, and purification before venting can also be performed when necessary.

[0018] Furthermore, when the two-phase flow rate of the incoming gas from the wellhead is metered, it is metered according to the number of wellheads to improve the accuracy of the metering. Here, an optimization is made and one of the feasible options is proposed: the metering pipeline is set one by one with the gas well, and a flat gate valve is also set on the metering pipeline, and the connection between the metering pipeline and the two-phase converging pipeline is controlled by the flat gate valve. When the above scheme is adopted, the metering pipeline can flexibly and effectively adjust the amount of gas entering the two-phase converging pipeline by controlling the on-off of the flat gate valve.

[0019] Furthermore, the desanding cylinder is used to desand the received gas. Specifically, a variety of structures can be used to achieve this purpose. The structure is not limited to the only one. Here, an optimization is made and one of the feasible options is proposed: a cyclone is provided in the desanding cylinder, and the cyclone is used to guide the raw gas to form a cyclone and achieve gas-sand separation under the action of centrifugal force. When the above scheme is adopted, solid particles are prompted to move toward the inner wall of the cyclone tube, move along the inner wall of the cyclone tube to the bottom and be discharged, and the liquid flows in the opposite direction to the center of the axis and enters the lower cavity from the outlet, thereby removing solid particulate matter and part of the liquid matter in the gas.

[0020] Furthermore, the structure of the separator can be constructed in various forms, and its structure is not limited to a single one. Here, an optimization is made and one feasible option is proposed: the separator includes a primary separation section, a secondary gravity separation section and a mist capture section, which are used to separate the liquid droplets and solid particles carried by the raw gas; a demister is provided on the separation exhaust pipe. When the above scheme is adopted, the liquid droplets and solid particles carried by the gas can be separated.

[0021] Furthermore, the separated liquid substances are collected and processed by the corresponding structure. A variety of schemes can be adopted, and the structure is not limited to a single one. Here, optimization is performed and one feasible option is proposed: the drainage pipes on the medium-pressure desander skid and the gas-liquid separation metering skid are connected to the produced liquid system, and a shut-off valve for controlling the overall on-off is provided on the drainage pipe. A regulating branch is formed on the drainage pipe and the on-off is controlled by the regulating valve. When the above scheme is adopted, the drainage pipe can be prevented from being blown by the wind by controlling the shut-off valve, and the drainage speed of the drainage pipe can be controlled by controlling the regulating valve, thereby controlling the amount of sand and water in the desander cylinder and the separator.

[0022] Furthermore, when realizing the control of the cut-off valve and the regulating valve, it is necessary to combine the liquid level in the desanding cylinder or the separator, which can be realized through a variety of schemes. Here, one feasible option is proposed: the first liquid level gauge is used to interlock the control of the cut-off valve of the discharge pipe, and the second liquid level gauge is used to interlock the control of the regulating valve of the regulating branch. When adopting the above scheme, the first liquid level gauge can be a magnetic float liquid level gauge, and the second liquid level gauge can be a double flange liquid level gauge.

[0023] Furthermore, when controlling the cut-off valve and the regulating valve, the following scheme may be adopted: when the lowest detection position of the first liquid level gauge is lower than the lowest detection position of the second liquid level gauge, when the liquid level in the medium-pressure desander skid or the gas-liquid separation metering skid is higher than the lowest detection position of the second liquid level gauge, the regulating valve opens the regulating branch; when the liquid level in the medium-pressure desander skid or the gas-liquid separation metering skid is lower than the lowest detection position of the second liquid level gauge, the regulating valve closes the regulating branch; when the liquid level in the medium-pressure desander skid or the gas-liquid separation metering skid drops to the lowest detection position of the first liquid level gauge, the cut-off valve is closed to prevent gas cross-talk.

[0024] Furthermore, when the integrated system is in operation, pressurized wind flow is required to promote airflow. An optimization is performed here and one of the feasible options is proposed: an instrument wind sled is also included, which supplies air to the wellhead module, the medium-pressure desander skid and the gas-liquid separation metering skid respectively.

[0025] Compared with the prior art, some beneficial effects of the technical solution disclosed in the utility model include:

[0026] Through the integrated system disclosed by the utility model, when deep shale gas is exploited, the composition of the overall system can be simplified and a large number of components can be streamlined, thereby reducing the construction cost of ground engineering equipment. In specific applications, automated management can be achieved, the efficiency of exploitation can be improved, and the automatic operation of the exploitation and processing process can be guaranteed, making the entire process more controllable, safer and more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is a process principle block diagram of the shale gas medium-pressure process (stable production period) of the utility model.

[0029] Figure 2 This is the process flow diagram for the medium pressure process (6-well type).

[0030] Figure 3 It is a schematic diagram of the wellhead module composition and process flow chart.

[0031] Figure 4 It is a schematic diagram of the two-phase flow meter skid composition and a two-well process pipeline instrumentation flow chart.

[0032] Figure 5 It is a schematic diagram of the components of the shale gas medium-pressure desander skid and the process pipeline and instrument flow chart.

[0033] Figure 6 It is a schematic diagram of the composition of the shale gas-liquid separation metering skid (platform well) and the process pipeline instrument flow chart.

[0034] Figure 7 It is a schematic diagram of the process pipeline composition of the pigging outlet valve group skid and the instrument flow chart.

[0035] Figure 8 It is a schematic diagram of the overall structure of the medium-pressure desander skid.

[0036] Fig. 9 This is a schematic diagram of the overall structure of the gas-liquid separation and metering skid.

[0037] In the above drawings, the meanings of the symbols are as follows:

[0038] 1. One section of pipeline; 2. Two sections of pipeline; 3. Metering pipeline; 4. Primary throttling device; 5. Secondary throttling device; 6. Gas-liquid two-phase flowmeter; 7. Vent branch pipe; 8. Flat gate valve; 9. Two-phase converging pipeline; 10. Desanding cylinder; 11. Desanding exhaust pipe; 12. First liquid level gauge; 13. Second liquid level gauge; 14. Drain pipe; 15. Shut-off valve; 16. Regulating valve; 17. Separator; 18. Separation exhaust pipe; 19. Vent main pipe; 20. Outlet pipeline; 21. Emergency pneumatic shut-off valve; 22. Pressure transmitter. DETAILED DESCRIPTION

[0039] The present embodiment is further explained below in conjunction with the accompanying drawings and specific embodiments.

[0040] In view of the shortcomings of existing deep shale gas extraction solutions, the following embodiments are optimized and overcome the defects in the prior art.

[0041] Example

[0042] like Figure 2 As shown, this embodiment provides a medium-pressure sand removal, separation and metering integrated system for a deep shale gas platform, aiming to improve the convenience of deep shale gas extraction and processing and ensure the efficiency, safety and reliability of the process.

[0043] like Figure 3 As shown, as an integrated system provided in this embodiment, one of its structures includes:

[0044] The wellhead module comprises a wellhead pipeline, on which a primary throttling device 4 and a secondary throttling device 5 are arranged for throttling and reducing the pressure of the gas coming from the wellhead twice.

[0045] The wellhead module can achieve two-stage throttling and pressure reduction through a variety of solutions, and its structure is not limited to a single one. This embodiment is optimized and adopts one of the feasible options: the wellhead pipeline includes a section of pipeline 1, and the section of pipeline 1 is connected to the second section of pipeline 2 through the first-level throttling device 4 and is used to achieve the first-level throttling and pressure reduction of the gas from the wellhead; the second section of pipeline 2 is connected to the two-phase flow meter skid through the second-level throttling device 5 and is used to achieve the second-level throttling and pressure reduction of the gas from the wellhead. When the above solution is adopted, the first-level throttling device 4 includes a fixed oil nozzle, and the second-level throttling device 5 includes a pneumatic cage-type throttle valve.

[0046] like Figure 4 As shown, as the integrated system disclosed in this embodiment, its structure 2 includes:

[0047] The two-phase flow meter skid comprises a plurality of metering pipes 3, on which two-phase flow detection components are arranged, including a gas phase flow detection component and a liquid phase flow detection component. The ends of the metering pipes 3 are connected to the two-phase converging pipe 9 and extend to the medium-pressure desander skid.

[0048] Preferably, the gas phase flow detection component and the liquid phase flow detection component include a gas-liquid two-phase flowmeter 6, which is a component of the two-phase flowmeter skid. The gas-liquid two-phase flowmeter 6 is combined with other components such as pipes to form a two-phase flowmeter skid; the gas-liquid two-phase flowmeter 6 utilizes the relationship between multiple differential pressure signals and changes in gas-liquid two-phase flow rates to achieve one-to-one single-well metering and perform gas-liquid two-phase metering on the wellhead produced gas.

[0049] When two-phase metering is performed on the incoming gas from the wellhead, metering is performed separately according to the number of wellheads to improve the accuracy of metering. This embodiment is optimized and adopts one of the feasible options: the metering pipeline 3 is set one by one with the gas production well, and a flat gate valve 8 is also provided on the metering pipeline 3, and the connection between the metering pipeline 3 and the two-phase converging pipeline 9 is controlled by the flat gate valve 8. When the above solution is adopted, the metering pipeline 3 can flexibly and effectively adjust the amount of gas entering the two-phase converging pipeline 9 by controlling the on-off of the flat gate valve 8.

[0050] like Figure 5 , Figure 8 As shown, as the integrated system disclosed in this embodiment, the third structure includes:

[0051] The medium-pressure desander skid comprises a desander cylinder 10 , on which a desander exhaust pipe 11 is arranged to communicate with a gas-liquid separation metering skid, and a liquid discharge pipe 14 is also arranged. Meanwhile, a first liquid level gauge 12 and a second liquid level gauge 13 are arranged on the desander cylinder 10 .

[0052] The desanding cylinder 10 is used to desand the received gas. Specifically, a variety of structures can be used to achieve this purpose. The structure is not limited to the only one. This embodiment is optimized and adopts one of the feasible options: a cyclone is provided in the desanding cylinder 10. The cyclone is used to guide the raw gas to form a cyclone and achieve gas-sand separation under the action of centrifugal force. When the above scheme is adopted, solid particles are urged to move toward the inner wall of the cyclone tube, move along the inner wall of the cyclone tube to the bottom and be discharged, and the liquid flows in the opposite direction to the center of the axis and enters the lower cavity from the outlet, thereby removing solid particulate matter and part of liquid matter in the gas.

[0053] like Figure 6 , Fig. 9 As shown, as the integrated system disclosed in this embodiment, the fourth structure thereof includes:

[0054] The gas-liquid separation metering skid comprises a separator 17, on which a plurality of separation exhaust pipes 18 are arranged, and at least one group of separation exhaust pipes 18 is connected to the pigging outlet valve group skid; the separator 17 is synchronously provided with a discharge pipe 14 for transporting the liquid phase outward, and is also provided with a first liquid level meter 12 and a second liquid level meter 13.

[0055] The structure of the separator 17 can be constructed in various forms, and its structure is not limited to a single one. This embodiment optimizes and adopts one of the feasible options: the separator 17 includes a primary separation section, a secondary gravity separation section and a mist capture section, which are used to separate the liquid droplets and solid particles carried by the raw gas; a demister is provided on the separation exhaust pipe 18. When the above solution is adopted, the liquid droplets and solid particles carried by the gas can be separated.

[0056] Preferably, a manhole is provided at the end of the separator 17, and a discharge port is provided at the bottom, and the liquid level is interlocked with the drain valve to achieve full-automatic drainage, thereby achieving unattended operation.

[0057] There are gas and liquid substances in the integrated system. In the process of metering the gas-liquid two-phase flow, medium-pressure sand removal and separation, some pure gas substances need to be discharged and vented. The venting can be achieved through a variety of structures, and the structure is not limited to the only one. This embodiment is optimized and adopts one of the feasible options: the metering pipeline 3, and / or the sand removal cylinder 10, and / or the separator 17 are also connected to the vent main pipe 19 through the vent branch pipe 7. The vent branch pipe 7 is provided with a control valve group, and the vent main pipe 19 extends to the vent module. When the above scheme is adopted, the centralized control and processing of the vented gas can be achieved by centrally transporting the gas to be vented to the vent module, and purification before venting can also be performed when necessary.

[0058] The separated liquid substances are collected and processed by the corresponding structures, and various schemes can be adopted, and the structures are not limited to the only one. This embodiment is optimized and adopts one of the feasible options: the drainage pipes 14 on the medium-pressure desander skid and the gas-liquid separation metering skid are both connected to the produced liquid system, and the drainage pipe 14 is provided with a cut-off valve 15 for controlling the overall on-off. A regulating branch is formed on the drainage pipe 14 and the on-off is controlled by the regulating valve 16. When the above scheme is adopted, the drainage pipe 14 can be prevented from being blown by wind by controlling the cut-off valve 15, and the drainage speed of the drainage pipe 14 can be controlled by controlling the regulating valve 16, thereby controlling the amount of sand and water inside the desander cylinder 10 and the separator 17.

[0059] When realizing the control of the cut-off valve 15 and the regulating valve 16, it is necessary to combine the liquid level in the sand removal cylinder 10 or the separator 17, which can be realized through a variety of schemes. This embodiment adopts one of the feasible options: the first liquid level gauge 12 is used to interlock the control of the cut-off valve 15 of the discharge pipe 14, and the second liquid level gauge 13 is used to interlock the control of the regulating valve 16 of the regulating branch. When adopting the above scheme, the first liquid level gauge 12 can be a magnetic float liquid level gauge, and the second liquid level gauge 13 can be a double flange liquid level gauge.

[0060] Specifically, when the shut-off valve 15 and the regulating valve 16 are controlled, the following scheme may be adopted: when the lowest detection position of the first liquid level gauge 12 is lower than the lowest detection position of the second liquid level gauge 13, when the liquid level in the medium-pressure desander skid or the gas-liquid separation metering skid is higher than the lowest detection position of the second liquid level gauge 13, the regulating valve 16 opens the regulating branch; when the liquid level in the medium-pressure desander skid or the gas-liquid separation metering skid is lower than the lowest detection position of the second liquid level gauge 13, the regulating valve 16 closes the regulating branch; when the liquid level in the medium-pressure desander skid or the gas-liquid separation metering skid drops to the lowest detection position of the first liquid level gauge 12, the shut-off valve 15 is closed to prevent cross-flow of gas.

[0061] Preferably, Figure 7 As shown, in this embodiment, the pigging outlet valve assembly skid includes an outlet pipeline 20 for controlling the delivery of the outlet gas.

[0062] Preferably, a pigging valve is provided to realize the downstream pigging function. An emergency pneumatic shut-off valve 21 and a pressure transmitter 22 are provided before the station exit, and the station exit valve is automatically interlocked and shut off once the pressure of the pipeline outside the station exceeds the limit or the pipe breaks and loses pressure.

[0063] When the integrated system is running, pressure airflow is required to promote airflow, such as Figure 2 As shown, this embodiment is optimized and adopts one of the feasible options: it also includes an instrument wind sled, which supplies air to the wellhead module, the medium-pressure desander skid and the gas-liquid separation metering skid respectively.

[0064] The integrated system disclosed in this embodiment can realize automated processing for the exploitation and treatment of deep shale gas. Specifically, the gas from the wellhead is throttled to about 20MPa by the first-level throttling device, and then throttled to 5~8.5MPa by the second-level throttling device. After that, it enters the two-phase flow meter skid one by one for single well metering. After metering, the gas from each well is collected and enters the medium-pressure desander skid for desanding, and then separated and metered by the gas-liquid separation metering skid. The gas phase is transported to the downstream through the pig outlet valve group skid, and the liquid phase enters the produced liquid system. Thus, the exploitation and treatment of shale gas is realized.

[0065] According to the contents disclosed in the above embodiments, some data are listed here to verify the corresponding effects.

[0066] Table 1 Key performance of medium-pressure sand removal, separation and metering integrated device in shale gas cluster well field

[0067]

[0068] As can be seen from Table 1 above, compared with the prior art, this embodiment has the following improvements:

[0069] (1) The process flow has been optimized and simplified. Compared with the standardized design of shale gas of PetroChina (high-pressure standardization 2.0), taking the 6-well cluster well site as an example, the number of process skid-mounted devices has been optimized from 7 to 4, the number of pressure vessels has been optimized from 12 to 2, and the number of safety valves has been reduced from 12 to 2. The process pipelines between skids have been significantly optimized, and the overall process has been greatly simplified.

[0070] (2) It can realize a high degree of functional integration, such as "one-to-one" two-phase metering for a single well, online sand removal, desander backwashing, gas-liquid separation, gas-liquid phase metering, overpressure alarm and overpressure safety venting, and venting of equipment and pipelines in the station during maintenance.

[0071] (3) Strong adaptability. The use of high-efficiency cyclone desanders effectively solves the problem of high-pressure filter desanders being easily broken and ineffective, and automatic sand discharge is more convenient and efficient. The cyclone desanders and horizontal gas-liquid separators have a wide range of adjustable processing capacities and can adapt to shale gas cluster well sites with different numbers of single wells and different scales.

[0072] (4) Improved process safety and reliability. It has safety guarantees such as overpressure alarm and overpressure safety venting, venting of equipment and pipelines in the station during maintenance, etc. The sewage pipeline uses 20G thickened material, the sewage pipeline fittings use 825 alloy cladding, and the sewage regulating valve uses tungsten carbide valve stem, which significantly improves the anti-erosion and corrosion performance of the pipeline and pipeline, and improves the reliability and safety of the control system.

[0073] (5) Save space and optimize overall layout. Compared with the standardized design of China National Petroleum Corporation's shale gas (high-pressure standardization 2.0), the number of process skid-mounted devices is reduced, the device structure size is streamlined, the layout is compact and practical, and the floor space is reduced.

[0074] (6) Digital management, intelligent operation, and unmanned on-site operation. Automated operation, through the remote terminal control system real-time data collection, analysis, upload and other digital management functions, real-time monitoring and daily management of the device production situation, accepting superior instructions, realizing remote control, and having self-safety protection function.

[0075] Table 2 Comparison with high-voltage standardization scheme

[0076]

[0077] As can be seen from Table 2 above, the two-phase flow medium-pressure automatic sand discharge solution requires less equipment investment, occupies a smaller area after achieving 5-well mining, and has higher accuracy in gas phase measurement compared to the traditional high-pressure standardized 2.0 solution.

[0078] According to the solution disclosed in this embodiment, it can also be determined that the following effects can be achieved:

[0079] Fine pressure control significantly increases the EUR (estimated ultimate recovery) of a single well. Fine pressure control achieves a gas well pressure rate of less than 0.1MPa / day, and is matched with the early pressure-down tubing process. Preliminary estimates show that the EUR of a single well has increased by 17%.

[0080] The efficiency index has been greatly improved. Sand removal efficiency: the removal rate of quartz sand and ceramsite with a particle size of ≥0.1mm is ≥99.8%, and the total removal rate of solid particles is ≥99%; the separation efficiency of droplets of 80μm and above is >99%; the gas phase measurement accuracy is ±5% (under the measurement range of 10%-100%), and the liquid phase measurement accuracy is ±10% (under the measurement range of 10%-100%).

[0081] The process flow is optimized and simplified. Compared with the shale gas high-pressure process, taking the six-well type as an example, the number of process skids is reduced from 13 to 5, the number of pressure vessels is reduced from 12 to 2, and the number of safety valves is reduced from 12 to 2, and the platform process is greatly simplified.

[0082] Improved safety and reliability. The skid-mounted equipment with improved technology has safety features such as overpressure alarm and overpressure safety venting, venting of equipment and pipelines in the station during maintenance, etc. The sewage pipeline adopts 20G thickened material, the sewage pipeline fittings adopt 825 alloy cladding, and the sewage regulating valve adopts tungsten carbide valve stem, which significantly improves the anti-erosion and corrosion performance of pipelines and pipelines, as well as the reliability and safety of the control system.

[0083] The efficiency of platform construction has been significantly improved. Compared with the original high-pressure process, the number of platform skids, equipment, pipe fittings, and welds has been reduced by about 80%, and both the in-plant skid assembly and on-site installation have been greatly reduced. The on-site skid assembly work has been reduced by about 90%, the processing and manufacturing cycle has been shortened by about 80% on average, and the on-site construction cycle has been shortened by about 10% on average, effectively supporting the production needs of the rapid construction of shale gas surface projects.

[0084] The platform construction investment is greatly reduced. Compared with the high-pressure process, it is estimated that the main equipment purchase cost of the 6-well platform construction is reduced by about 17%, and the overall investment is reduced by about 15%.

[0085] Digital management, intelligent operation, unattended on-site operation. Automated operation, through the remote terminal control system real-time data collection, analysis, upload and other digital management functions, real-time monitoring and daily management of the production situation of the device, accepting superior instructions, realizing remote control, and having self-safety protection function.

[0086] The above are the implementation methods listed in this embodiment, but this embodiment is not limited to the above optional implementation methods. Those skilled in the art can arbitrarily combine the above methods to obtain other various implementation methods. Anyone can derive other various implementation methods under the inspiration of this embodiment. The above specific implementation methods should not be understood as limiting the protection scope of this embodiment. The protection scope of this embodiment should be based on the definition in the claims.

Claims

1. A medium-pressure sand removal, separation and metering integrated system for deep shale gas platform, characterized in that: include: The wellhead module comprises a wellhead pipeline, on which a primary throttling device (4) and a secondary throttling device (5) are arranged for throttling and reducing the pressure of the gas coming from the wellhead twice; A two-phase flow meter skid comprises a plurality of metering pipes (3), on which a gas phase flow detection component and a liquid phase flow detection component are arranged, and the ends of the metering pipes (3) are connected to a two-phase converging pipe (9) and extend to a medium-pressure desander skid; A medium-pressure desander skid comprises a desander cylinder (10), a desander exhaust pipe (11) is arranged on the desander cylinder (10) and is used to communicate with a gas-liquid separation metering skid, a liquid discharge pipe (14) is also arranged, and a first liquid level gauge (12) and a second liquid level gauge (13) are arranged on the desander cylinder (10); The gas-liquid separation metering skid comprises a separator (17), a plurality of separation exhaust pipes (18) are arranged on the separator (17), and at least one set of separation exhaust pipes (18) is connected to the pigging outlet valve group skid; the separator (17) is synchronously provided with a liquid discharge pipe (14) for transmitting the liquid phase to the outside, and is also provided with a first liquid level meter (12) and a second liquid level meter (13); The pigging outlet valve assembly skid comprises an outlet pipeline (20) for controlling the delivery of outlet gas.

2. According to claim 1, the medium-pressure sand removal, separation and metering integrated system for deep shale gas platform is characterized by: The wellhead pipeline comprises a section of pipeline (1), wherein the section of pipeline (1) is connected to the second section of pipeline (2) via a first-level throttling device (4) and is used to achieve first-level throttling and pressure reduction of gas from the wellhead; and the second section of pipeline (2) is connected to a two-phase flow meter skid via a second-level throttling device (5) and is used to achieve second-level throttling and pressure reduction of gas from the wellhead.

3. According to claim 1, the medium-pressure sand removal, separation and metering integrated system for deep shale gas platform is characterized by: The metering pipeline (3), and / or the sand removal cylinder (10), and / or the separator (17) are also connected to the vent main pipe (19) via the vent branch pipe (7), and a control valve group is provided on the vent branch pipe (7). The vent main pipe (19) extends to be connected to the vent module.

4. The medium-pressure sand removal, separation and metering integrated system for deep shale gas platform according to claim 1 is characterized by: The metering pipeline (3) is arranged in one-to-one correspondence with the gas production wells, and a flat gate valve (8) is also arranged on the metering pipeline (3), and the connection between the metering pipeline (3) and the two-phase converging pipeline (9) is controlled by the flat gate valve (8).

5. According to claim 1, the medium-pressure sand removal, separation and metering integrated system for deep shale gas platform is characterized by: A cyclone tube is arranged in the desanding cylinder (10), and the cyclone tube is used to guide the raw gas to form a cyclone and realize gas-sand separation under the action of centrifugal force.

6. The medium-pressure sand removal, separation and metering integrated system for deep shale gas platform according to claim 1 is characterized by: The separator (17) comprises a primary separation section, a secondary gravity separation section and a mist collection section, and is used to separate liquid droplets and solid particles carried by the raw gas; a demister is provided on the separation exhaust pipe (18).

7. The medium-pressure sand removal, separation and metering integrated system for deep shale gas platform according to claim 1 is characterized by: The drainage pipes (14) on the medium-pressure desander skid and the gas-liquid separation metering skid are both connected to the produced liquid system. A shut-off valve (15) for controlling the overall on-off is provided on the drainage pipe (14). A regulating branch is formed on the drainage pipe (14) and the on-off is controlled by a regulating valve (16).

8. The medium-pressure sand removal, separation and metering integrated system for deep shale gas platform according to claim 7 is characterized by: The first liquid level meter (12) is used to interlock and control the on-off of the cut-off valve (15) of the discharge pipe (14), and the second liquid level meter (13) is used to interlock and control the on-off of the regulating valve (16) of the regulating branch.

9. The medium-pressure sand removal, separation and metering integrated system for deep shale gas platform according to claim 8 is characterized by: The lowest detection position of the first liquid level gauge (12) is lower than the lowest detection position of the second liquid level gauge (13). When the liquid level in the medium-pressure desander skid or the gas-liquid separation metering skid is higher than the lowest detection position of the second liquid level gauge (13), the regulating valve (16) opens the regulating branch; when the liquid level in the medium-pressure desander skid or the gas-liquid separation metering skid is lower than the lowest detection position of the second liquid level gauge (13), the regulating valve (16) closes the regulating branch; when the liquid level in the medium-pressure desander skid or the gas-liquid separation metering skid drops to the lowest detection position of the first liquid level gauge (12), the shut-off valve (15) is closed to prevent cross-flow of gas.

10. The medium-pressure sand removal, separation and metering integrated system for deep shale gas platform according to claim 1 is characterized by: It also includes an instrument wind skid, which supplies air to the wellhead module, the medium-pressure desander skid and the gas-liquid separation metering skid respectively.

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