Skid-mounted compressed natural gas (CNG) recovery device for shale gas scattered well

Abstract

The utility model provides a skid-mounted compressed natural gas (CNG) recovery device for a shale gas scattered well, which is characterized by comprising a main skid-mounted seat, a horizontal two-phase separator, an efficient oil removal filter, a molecular sieve dehydrating tower, a CNG compressor and a filling device which are sequentially connected are arranged on the main skid-mounted seat, a gas inlet end of the horizontal two-phase separator is connected with a well head gas inlet pipeline, and a gas outlet end of the horizontal two-phase separator is connected with a gas outlet pipeline. The horizontal two-phase separator, the efficient oil removal filter, the molecular sieve dehydrating tower and the CNG compressor are respectively provided with ports connected with a process pipeline and a blow-off pipeline, and are also provided with an emptying pipeline connected with the process pipeline, and the CNG compressor is connected with a CNG tank car through a filling device. The utility model can be integrally transported and hoisted, reduces the field work, and quickly builds a station and is put into production; the filling gun and the filling hose are adopted, so that efficient and convenient filling of the CNG tank car is realized, and the working efficiency is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of shale gas scattered well CNG processing, in particular to a skid-mounted shale gas scattered well CNG recovery device. Background Art

[0002] CNG (Compressed Natural Gas) is a clean and efficient energy source with the advantages of economical and flexible transportation and high storage efficiency. CNG has the same components as pipeline natural gas, with methane (CH4) as the main component.

[0003] In the context of new breakthroughs in domestic natural gas exploration and development, natural gas reserves and production have increased rapidly. At the same time, the utilization of scattered shale gas wells far from the work area, which are relatively scattered, inconvenient to manage, and inefficient, has gradually become prominent. The number of scattered wells increased significantly from 2019 to 2022, reaching about 385, mainly distributed in North China, Southwest China and East China. The production of scattered wells is also on the rise, roughly between 240 million and 460 million cubic meters from 2019 to 2022.

[0004] At present, the domestic CNG processing of scattered shale gas wells is in its infancy. Common wellhead gas export methods include wellhead LNG production export and gathering and transportation pipeline export. Wellhead LNG production export process equipment is large, the area is large, the process flow is complex, there are many on-site operations, and the labor intensity of workers is high, which makes it difficult to quickly build a station and put it into production. The approval process for the export of gathering and transportation pipelines is cumbersome and the construction investment is large, which also makes it difficult to quickly build a station and put it into production. The CNG processing and export method has simple equipment, less hoisting operations, and fewer operating personnel. It can quickly respond to the development of scattered shale gas wells and put them into production (transfer) operation. Utility Model Content

[0005] The utility model aims to provide a skid-mounted shale gas scattered well CNG recovery device which can be transported and hoisted as a whole and reduces on-site work.

[0006] The utility model is achieved in this way:

[0007] The utility model provides a skid-mounted shale gas scattered well CNG recovery device, which is characterized in that it comprises a main skid seat, on which a horizontal two-phase separator, a high-efficiency oil removal filter, a molecular sieve dehydration tower, a CNG compressor and a filler which are connected in sequence are arranged, the air inlet end of the horizontal two-phase separator is connected to the wellhead gas inlet pipeline, the horizontal two-phase separator, the high-efficiency oil removal filter, the molecular sieve dehydration tower and the CNG compressor are respectively provided with ports connected to the process pipeline and the sewage pipeline, and are also provided with a venting pipeline connected to the process pipeline, and the CNG compressor is connected to the CNG tank truck through the filler.

[0008] According to the above technical solution, the gas phase outlet of the horizontal two-phase separator is connected to the high-efficiency oil removal filter, and the liquid phase outlet is connected to the sewage pipeline.

[0009] According to the above technical solution, a sewage valve and a liquid storage tank are arranged on the sewage pipeline, a safety valve is arranged on the vent pipeline, and valves are arranged correspondingly on each pipeline in the skid.

[0010] According to the above technical solution, the main skid is also provided with a bypass pipeline which can be connected to the filler, one end of the bypass pipeline is connected to the molecular sieve dehydration tower outlet pipeline, and the other end of the bypass pipeline is connected to the filler.

[0011] According to the above technical solution, the wellhead gas inlet pipeline and the filling pipeline are respectively provided with pneumatic shut-off valves; the filling pipeline is also provided with a filling flow meter.

[0012] According to the above technical solution, the filler is also provided with a control skid, and combustible gas detection equipment, video monitoring equipment, and control cabinet installed on the control skid; the control skid is detachably connected to the main skid; the combustible gas detection equipment, monitoring equipment, and control cabinet are all connected to the distribution cabinet; the monitoring area of ​​the monitoring equipment covers the entire main skid; the monitoring equipment, safety alarm equipment, and each pneumatic emergency shut-off valve are respectively connected to the control cabinet, and the control cabinet obtains monitoring information and controls the on and off of each pipeline by controlling the opening of the pneumatic emergency shut-off valve.

[0013] According to the above technical solution, the recovery device is also provided with a shielding shed, and the four sides of the shielding shed are fixed on the main skid seat through support rods respectively.

[0014] According to the above technical solution, the main skid seat and the control skid seat have the same structure, and each includes a plurality of main cross beams, a plurality of main longitudinal beams, a plurality of secondary cross beams, a plurality of secondary longitudinal beams and steel plates. The plurality of main cross beams, secondary cross beams, main longitudinal beams and secondary longitudinal beams are arranged at intervals and connected to form a skeleton, and the steel plate is installed on the upper part of the skeleton.

[0015] The beneficial effects of the utility model are:

[0016] The utility model can be transported and hoisted as a whole, reduces on-site work, and quickly builds a station and puts it into production; the utility model adopts a filling gun and a filling hose to achieve efficient and convenient filling of the CNG tank truck, further improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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 certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The figure is a flow chart of a specific embodiment of the utility model.

[0019] Figure 2 It is a structural schematic diagram of a specific embodiment of the utility model.

[0020] Figure 3 and Figure 4 Schematic diagram of the structure of the main skid in this embodiment.

[0021] Among them: 1. Wellhead gas tree; 2. Horizontal two-phase separator; 3. High-efficiency oil removal filter; 4. Molecular sieve dehydration tower (regeneration tower); 5. CNG compressor; 6. Liquid storage tank; 7. Vent riser; 8. CNG tank truck; 9. Wellhead gas inlet pipeline; 10. Filter separator outlet pipeline; 11. Molecular sieve inlet pipeline; 12. Compressor inlet pipeline; 13. Bypass pipeline; 14. Filling pipeline; 15. Drain pipeline; 16. Vent pipeline; 17. Emergency shut-off valve; 18. Automatic switching valve 1; 19. Automatic switching valve 2; 20. Bypass valve; 21; Switch valve; 22. Mass flow meter; 23. Automatic drain valve; 24. Check valve; 25. Filler 25; 26. Main crossbeam; 27. Main longitudinal beam; 28. Secondary crossbeam; 29. ​​Secondary longitudinal beam; 30. Steel plate. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0025] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0026] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0027] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0029] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0030] like Figure 1As shown, this embodiment provides a skid-mounted shale gas scattered well CNG recovery device, including a main skid seat, a process pipeline, a horizontal two-phase separator 2, a high-efficiency oil removal filter 3, a molecular sieve dehydration tower (regeneration tower) 4, a CNG compressor 5, a venting pipeline 16, a sewage pipeline, and a charger 25. Among them, the horizontal two-phase separator 2, the high-efficiency oil removal filter 3, the molecular sieve dehydration tower (regeneration tower) 4, the CNG compressor 5, and the charger 25 are connected in sequence, and the wellhead gas of the wellhead gas tree is connected to the air inlet of the horizontal two-phase separator 2 through the wellhead gas inlet pipeline. The horizontal two-phase separator 2, the high-efficiency oil removal filter 3, the molecular sieve dehydration tower (regeneration tower) 4, and the CNG compressor 5 are respectively provided with ports connected to the process pipeline and the sewage pipeline, the venting pipeline is connected to the process pipeline, and the CNG compressor is connected to the CNG tank truck through the charger 25. After the wellhead gas is separated by the horizontal two-phase separator, the gas phase enters the high-efficiency oil removal filter to remove condensate and solid impurities, and then enters the molecular sieve dehydration tower for deep dehydration to obtain dry gas. The dry gas is pressurized by the CNG compressor to obtain CNG gas, and the CNG gas is connected to the CNG tank truck through the filler 25 to realize CNG filling and transportation. The horizontal two-phase separator, molecular sieve dehydration tower, and CNG compressor exhaust pipeline are all equipped with sewage pipelines and venting pipelines, wherein a liquid storage tank 6 is provided on the sewage pipeline, a sewage valve 23 is provided on the liquid storage tank 6, and a safety valve and a venting riser 7 are provided on the venting pipeline. Valves are correspondingly provided on each pipeline in the skid.

[0031] In this embodiment, the CNG compressor is a hydraulic compressor.

[0032] Preferably, the wellhead gas inlet pipeline 9 is connected to the inlet of the horizontal two-phase separator 2, the outlet pipeline of the horizontal two-phase separator 2 is connected to the inlet of the high-efficiency oil removal filter 3, one end of the molecular sieve inlet pipeline 4 is connected to the outlet of the high-efficiency oil removal filter 3, and the other end is connected to the molecular sieve dehydration tower 4, one end of the CNG compressor 5 inlet pipeline is connected to the outlet of the molecular sieve dehydration tower 4, and the outlet of the CNG compressor 5 is connected to the filler 25.

[0033] Preferably, a bypass pipeline 13 which can be communicated with the filler 25 is further provided on the main skid, one end of the bypass pipeline 13 is communicated with the outlet pipeline of the molecular sieve dehydration tower 4 , and the other end of the bypass pipeline is communicated with the filler 25 .

[0034] Preferably, the wellhead gas inlet pipeline 9 and the filling pipeline 14 are respectively provided with an emergency shut-off valve 17 and an automatic switching valve 18; and a mass flow meter 22 is also provided on the filling pipeline.

[0035] Preferably, the filler 25 is also provided with a control skid, and combustible gas detection equipment, video monitoring equipment, and control cabinet installed on the control skid; the control skid is detachably connected to the main skid; the combustible gas detection equipment, monitoring equipment, and control cabinet are all connected to the distribution cabinet; the monitoring area of ​​the monitoring equipment covers the entire main skid; the monitoring equipment, safety alarm equipment, and each pneumatic emergency shut-off valve are respectively connected to the control cabinet, and the control cabinet obtains monitoring information and controls the on and off of each pipeline by controlling the opening of the pneumatic emergency shut-off valve.

[0036] Preferably, the processing device is further provided with a shielding shed, and the four sides of the shielding shed are fixed to the main skid seat through support rods respectively.

[0037] Preferably, if Figure 3 , 4 As shown, the main skid seat and the control skid seat have the same structure, and each comprises a plurality of main cross beams 26, a plurality of main longitudinal beams 27, a plurality of secondary cross beams 28, a plurality of secondary longitudinal beams 29 and a steel plate 30. The plurality of main cross beams, secondary cross beams, main longitudinal beams and secondary longitudinal beams are arranged at intervals and connected to form a skeleton. The steel plate 30 is installed on the upper part of the skeleton. The main cross beams and main longitudinal beams can be made of channel steel, and the secondary cross beams and secondary longitudinal beams can be made of H-shaped steel. Other structures of the recovery device are all installed on the steel plates.

[0038] The utility model is usually installed in scattered well sites. The specific working principle is:

[0039] 1. Wellhead gas treatment: Wellhead natural gas - horizontal two-phase separator 2 - high-efficiency oil removal filter 3 - molecular sieve dehydration tower 4. The natural gas produced from the wellhead enters the horizontal two-phase separator 2 through a pipeline to remove free water in the gas. The liquid phase enters the liquid storage tank 6 through the sewage pipeline, and the gas phase enters the high-efficiency oil removal filter 3 through the filter separator outlet pipeline 10. After removing the condensate oil and solid impurities in the gas phase, the gas phase enters the molecular sieve dehydration tower 4 through the molecular sieve inlet pipeline 11 for deep dehydration (water dew point ≤-50℃), and the dehydrated dry gas enters the natural gas compression link.

[0040] 2. Natural gas compression: molecular sieve dehydration tower - CNG compressor 5

[0041] The dry natural gas treated by the molecular sieve dehydration tower enters the CNG compressor 5 through the compressor intake pipe 12, and the piston reciprocates in the cylinder to process the natural gas into 22Mpa high-pressure compressed natural gas (CNG), and the qualified CNG gas enters the filling stage.

[0042] 3. CNG filling: CNG compressor-filler 25

[0043] After the qualified CNG is pressurized by the CNG compressor, it is measured by the mass flow meter 22, and then the filler 25 and the high-pressure hose are used to fill the gas cylinder of the CNG tank truck 8. When the pressure of the tank truck gas cylinder reaches 20Mpa, the filler 25 is automatically disconnected and the filling is completed.

[0044] This embodiment is a scale of 2 to 5×10 4 Nm 3 / d's skid-mounted scattered well site CNG processing device has been put into use. At present, the device has good performance and is easy to operate. It has effectively solved the problem of natural gas processing and transmission in scattered well sites, and achieved good economic and social environmental protection benefits.

[0045] The embodiments described above are part of the embodiments of the utility model, but not all of the embodiments. The detailed description of the embodiments of the utility model is not intended to limit the scope of the utility model claimed for protection, but only represents selected embodiments of the utility model. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

Claims

1. A skid-mounted shale gas scattered well CNG recovery device, characterized in that: It comprises a main skid, on which are arranged a horizontal two-phase separator, a high-efficiency oil removal filter, a molecular sieve dehydration tower, a CNG compressor and a charger which are connected in sequence. The air inlet end of the horizontal two-phase separator is connected to the wellhead gas inlet pipeline. The horizontal two-phase separator, the high-efficiency oil removal filter, the molecular sieve dehydration tower and the CNG compressor are respectively provided with ports connected to the process pipeline and the sewage pipeline, and are also provided with a venting pipeline connected to the process pipeline. The CNG compressor is connected to the CNG tank truck through the charger. The charger is also provided with a control skid, and combustible gas detection equipment, video monitoring equipment and a control cabinet installed on the control skid; the control skid is detachably connected to the main skid; the combustible gas detection equipment, the video monitoring equipment and the control cabinet are all connected to the power distribution cabinet; the monitoring area of ​​the video monitoring equipment covers the entire main skid; the video monitoring equipment, the safety alarm equipment and each pneumatic emergency shut-off valve are respectively connected to the control cabinet, the control cabinet obtains monitoring information, and controls the on-off of each pipeline by controlling the opening of the pneumatic emergency shut-off valve.

2. The skid-mounted shale gas scattered well CNG recovery device according to claim 1 is characterized in that: The gas phase outlet of the horizontal two-phase separator is communicated with a high-efficiency oil removal filter, and the liquid phase outlet is communicated with a sewage discharge pipeline.

3. The skid-mounted shale gas scattered well CNG recovery device according to claim 1 or 2, characterized in that: A sewage valve and a liquid storage tank are arranged on the sewage pipeline, a safety valve is arranged on the vent pipeline, and valves are arranged correspondingly on each pipeline in the skid.

4. The skid-mounted shale gas scattered well CNG recovery device according to claim 1 or 2, characterized in that: The main skid is also provided with a bypass pipeline which can be connected to the filler, one end of the bypass pipeline is connected to the outlet pipeline of the molecular sieve dehydration tower, and the other end of the bypass pipeline is connected to the filler.

5. The skid-mounted shale gas scattered well CNG recovery device according to claim 4 is characterized in that: The wellhead gas inlet pipeline and the filling pipeline are respectively provided with pneumatic shut-off valves; the filling pipeline is also provided with a filling flow meter.

6. The skid-mounted shale gas scattered well CNG recovery device according to claim 1 or 2, characterized in that: The recovery device is also provided with a shielding shed, and the four sides of the shielding shed are respectively fixed on the main skid seat through support rods.

7. The skid-mounted shale gas scattered well CNG recovery device according to claim 1 is characterized in that: The main skid seat and the control skid seat have the same structure, and each comprises a plurality of main cross beams, a plurality of main longitudinal beams, a plurality of secondary cross beams, a plurality of secondary longitudinal beams and steel plates. The plurality of main cross beams, secondary cross beams, main longitudinal beams and secondary longitudinal beams are arranged at intervals and connected to form a skeleton, and the steel plates are installed on the upper part of the skeleton.

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