Jet drainage system and method for natural gas field

Abstract

The invention discloses a jet drainage system for a natural gas field, which comprises a gas production tree connecting pipe, one end of the gas production tree connecting pipe is connected with a gas production tree, the other end of the gas production tree connecting pipe is connected to a throttle valve, then two branches are arranged on the throttle valve, one branch is connected to a jet drainage pump, and the other branch is used as a high-pressure gas shunt pipe to be connected to an external conveying system; the jet drainage pump is provided with a high-pressure gas inlet, a low-pressure gas inlet and a gas outlet, the high-pressure gas inlet is connected to the throttling valve, the low-pressure gas inlet is connected to the low-pressure gas inlet pipe, and the gas outlet is connected to the mixed gas outlet pipe; high-pressure gas sent from a gas production tree is used for pressurizing and conveying low-pressure gas sent from a low-pressure gas inlet pipe through a jet drainage pump, and a matched method is set. By designing a brand-new structure, the high-pressure well and the low-pressure well in the whole gas production block can be linked, and the low-pressure gas is drained and conveyed through the high-pressure gas, so that the production cost is greatly reduced; the device is simple in structure and convenient to disassemble and assemble, and personal safety is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas development, in particular to a production system, and specifically to a jet drainage system and method for a natural gas field. Background Art

[0002] Jet-drainage booster is a fluid machine that uses the turbulent diffusion of jets to transfer energy and mass. It can use the pressure energy of high-pressure gas to compress and boost low-pressure gas. It consists of nozzles, throats, diffusers, suction chambers and other components. It has no moving parts, long service life and extremely low maintenance costs. Its working principle is that high-pressure fluid is ejected from the nozzle, flows at high speed at the outlet and forms a low-pressure area. The high-speed fluid and the sucked low-speed fluid exchange momentum under the shear force generated by the speed difference and are fully mixed in the throat. Then it enters the diffuser. Due to the increase in flow cross-sectional area and the decrease in flow velocity, the kinetic energy of the mixed fluid is converted into pressure energy, and the pressure increases to achieve the effect of boosting. In natural gas production, there are high-pressure wells and low-pressure wells in some blocks. The natural gas in the high-pressure wells needs to be transported by reducing pressure, which requires additional equipment and may cause certain erosion damage. However, the natural gas in the low-pressure wells cannot achieve self-flow by its own pressure and requires additional pressure to be transported, which increases the cost. Therefore. Summary of the invention

[0003] In response to the aforementioned problems, the present invention provides a jet drainage system and method for a natural gas field. By designing a completely new structure, the high-pressure wells and low-pressure wells in the entire gas production block can be linked, and the low-pressure gas is drained and transported by the high-pressure gas, thereby greatly reducing the production cost; and the device has a simple structure, is easy to disassemble and assemble, and ensures personal safety.

[0004] The technical solution of the present invention is:

[0005] A jet drainage system for a natural gas field comprises a gas tree connecting pipe, one end of the gas tree connecting pipe is connected to the gas tree, and the other end is connected to a throttle valve, and then two branches are arranged on the throttle valve, one is connected to a jet drainage pump, and the other is connected to an external transmission system as a high-pressure gas diversion pipe; the jet drainage pump is provided with a high-pressure gas inlet, a low-pressure gas inlet, and an outlet, the high-pressure gas inlet is connected to the throttle valve, the low-pressure gas inlet is connected to a low-pressure gas inlet pipe, and the outlet is connected to a mixed gas outlet pipe; through the jet drainage pump, the high-pressure gas delivered from the gas tree is used to pressurize and transport the low-pressure gas delivered from the low-pressure gas inlet pipe.

[0006] Furthermore, a main channel is provided in a straight line inside the jet drainage pump and runs through the walls on both sides. One end of the main channel is an air outlet and the other end is a mounting hole. An internal thread is provided on the mounting hole, and a matching pressure cap is installed to seal the main channel. A sealing ring is provided at the inner end of the pressure cap. A plurality of steps are provided inside the main channel from the pressure cap to the air outlet, forming an effect of gradually reducing the inner diameter. A trumpet-shaped structure with an inner diameter increasing from the inside to the outside is provided at the position of the air outlet. A high-pressure gas inlet with a lateral opening and running through the side wall of the jet drainage pump is provided near the pressure cap, and a low-pressure gas inlet with a lateral opening and running through the side wall of the jet drainage pump is provided between the high-pressure gas inlet and the air outlet.

[0007] Furthermore, in the jet drainage pump, a nozzle and a diffuser are arranged in sequence from the pressure cap to the air outlet, the nozzle is arranged between the high-pressure air inlet and the low-pressure air inlet, the diffuser is arranged between the low-pressure air inlet and the air outlet, and the nozzle and the diffuser are kept fixed to ensure that the gap between the two is fixed and the central flow channel is coaxial; at the position where the main channel is connected to the low-pressure air inlet, a circle of annular space with an enlarged pipe diameter is provided.

[0008] Furthermore, the outer part of the nozzle is sleeved with a nozzle base, and both the nozzle and the nozzle base are hollow rotating body structures. A step is provided between the nozzle and the nozzle base, so that the nozzle is fixed to the inner wall of the nozzle base through the step. After the nozzle is sleeved, the inner wall of the nozzle base has a section of the inner wall that does not contact the outer periphery of the nozzle. This section of the inner wall is provided with an internal thread and is connected to a matching nozzle clamping nut with an external thread. The nozzle clamping nut is fixedly screwed to the inner wall of the nozzle base and the rear end face abuts against the nozzle. The nozzle is fixed to the inside of the nozzle base through the nozzle clamping nut and the step of the nozzle base, and the small diameter end of the nozzle is extended from the nozzle The base extends out; a step is provided on the outer periphery of the nozzle base for fixing on the step of the main channel, so that the position of the nozzle is fixed; two sealing ring installation positions are provided on the outer periphery and inner periphery of the nozzle base, a one-way sealing ring is installed on the inner wall and outer periphery of the side close to the nozzle clamping nut, and an O-ring is installed on the inner wall and outer periphery slightly away from the nozzle clamping nut; a total clamping nut is provided at one end of the nozzle base close to the pressure cap, and a radial pin hole is provided on the total clamping nut, and a corresponding hole is also provided on the nozzle base, and a pin is inserted through the pin hole to fix the total clamping nut and the nozzle base;

[0009] The outer periphery of the total clamping nut is provided with threads, and the inner wall of the corresponding main flow channel is provided with matching internal threads to achieve the fixation of the total clamping nut and the main flow channel. One end of the interior of the total clamping nut is a hexagonal hole structure;

[0010] A plurality of nozzle clamping nut mounting countersunk holes are arranged at the end of the nozzle clamping nut, and the distance from the axis of the nozzle clamping nut mounting countersunk hole to the axis of the main flow channel is smaller than the distance from the hexagonal hole edge of the total clamping nut to the axis of the main flow channel.

[0011] Furthermore, the nozzle base is provided with a reduced diameter section on the outer periphery of one side of the diffuser, and an external thread is provided on the reduced diameter section, a support tube is fixed here, a plurality of annular air inlet holes corresponding to the annular space are provided on the side of the support tube, the inner wall of the other end of the support tube is screwed to the outer wall of the diffuser and pressed against the diffuser, the inner wall flow channel of the diffuser is a dumbbell-shaped structure, both ends are trumpet-shaped with a small inside and a large outside, the trumpet on the side close to the nozzle serves as an inlet, and the trumpet on the other side serves as an outlet, a straight pipe section is provided in the middle, and a diffuser is provided on this straight pipe section The expanded diameter section has one end connected to the inlet of the diffuser, where a carbide tube is fixedly installed, and the inner wall of the carbide tube has the same inner diameter as the straight section of the diffuser; a step is provided on the outer periphery of the diffuser toward the gas outlet, thereby pressing against the step of the main channel, and when the other end is pressed against by the support tube, the nozzle and the diffuser are axially fixed and pressed against by the total clamping nut, ensuring that the distance from the nozzle to the inlet of the diffuser is fixed; two adjacent sealing ring fixing grooves are provided on the outer periphery between the step of the diffuser and the inlet of the diffuser, and O-rings are respectively installed.

[0012] Furthermore, pressure measuring ports are provided in the high-pressure gas inlet and outlet for connecting to a pressure gauge arranged outside the jet drainage pump.

[0013] Furthermore, sealing grooves are provided around the outer ends of the high-pressure gas inlet, the low-pressure gas inlet and the gas outlet of the jet drainage pump, and threaded holes for connecting flanges are provided outside the sealing grooves.

[0014] Furthermore, the throttle valve includes a first-level throttle valve and a second-level throttle valve. The first-level throttle valve is connected to the gas tree through a gas tree connecting pipe. A pipeline or multiple connecting short pipes are arranged between the first-level throttle valve and the second-level throttle valve. A high-pressure gas valve is arranged between the second-level throttle valve and the jet drainage pump. A low-pressure gas valve is arranged on the low-pressure gas inlet pipe. A mixed gas valve is arranged on the mixed gas outlet pipe.

[0015] Furthermore, the jet drainage pump, high-pressure gas valve, low-pressure gas valve, and mixed gas valve are all installed on the drainage skid, and the drainage skid is installed on a cement base.

[0016] A jet drainage method for a natural gas field, using the jet drainage system as described above, comprises the following steps:

[0017] Install and connect the jet drainage system, and connect it to the high-pressure gas and low-pressure gas pipelines, open the corresponding valves, at this time, part of the high-pressure gas is directly sent to the external transmission system through the high-pressure gas diversion pipe, and the other part is sent to the jet drainage pump from the high-pressure gas inlet, and the speed is increased through the nozzle, driving the low-pressure gas sent from the low-pressure gas inlet into the diffusion pipe to achieve pressurization and output from the mixed gas outlet pipe.

[0018] Compared with the prior art, the present invention is beneficial in that:

[0019] The present invention completely designs a specific gas collection system, so that it can well realize the drainage of low-pressure gas by high-pressure gas, thereby realizing effective utilization of energy, reducing production costs and improving production efficiency.

[0020] The entire jet drainage pump is an integrated structure, and all the required internal structures can be placed inside it from one end, which is convenient for installation and disassembly. It is also more conducive to the overall sealing effect inside the jet drainage pump, ensuring production safety in an environment where high and low pressures coexist. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0022] Figure 2 for Figure 1 main view.

[0023] Figure 3 It is a schematic diagram of the three-dimensional structure of the jet drainage pump.

[0024] Figure 4 for Figure 3 A schematic diagram of the three-dimensional structure from another angle.

[0025] Figure 5 for Figure 3 View from the perspective of the cap.

[0026] Figure 6 for Figure 5 Middle AA section view.

[0027] Figure 7 for Figure 5 Middle BB section view.

[0028] Figure 8 for Figure 7 Magnified image of .

[0029] In the figure:

[0030] 1-Xmas tree connecting pipe, 2-first-stage throttle valve, 3-connecting short pipe, 4-right-angle tee, 5-second-stage throttle valve, 6-high-pressure gas valve, 7-jet drainage pump, 8-drainage skid, 9-low-pressure gas valve, 10-low-pressure gas inlet pipe, 11-cement base, 12-mixed gas valve, 13-mixed gas outlet pipe, 14-high-pressure gas diversion pipe,

[0031] 700-installation hole, 701-pressure cap, 7011-pressure cap mounting countersunk hole, 702-high-pressure gas inlet, 703-low-pressure gas inlet, 704-gas outlet, 705-total clamping nut, 7051 hexagonal mouth, 7052-pin hole, 706-nozzle base, 707-nozzle clamping nut, 7071-nozzle clamping nut mounting countersunk hole, 708-nozzle, 709-support tube, 7091-annulus air inlet hole, 710-carbide tube, 711-diffuser, 712-pressure measuring port, 713-main flow channel, 714-safety O-type sealing ring 1, 715-safety O-type sealing ring 2. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings and embodiments. The words such as up, down, left, right, vertical, horizontal, front and back mentioned in the text do not constitute a specific limitation on the scope of protection, but only represent the explanation of the drawings.

[0033] like Figure 1-8 As shown, a jet drainage system for a natural gas field includes a gas tree connecting pipe 1, one end of the gas tree connecting pipe 1 is connected to the gas tree, and the other end is connected to a throttle valve, the throttle valve includes a primary throttle valve 2 and a secondary throttle valve 5, and then two branches are arranged on the secondary throttle valve 5, one is connected to a jet drainage pump 7, and the other is connected to an external transmission system as a high-pressure gas diversion pipe 14, so as to transport the natural gas to the next stage for processing; the jet drainage pump 7 is provided with a high-pressure gas inlet 702, a low-pressure gas inlet 703, and an outlet 704, the high-pressure gas inlet 702 is connected to the throttle valve, the low-pressure gas inlet 703 is connected to a low-pressure gas inlet pipe 10, and the outlet 704 is connected to a mixed gas outlet pipe 13; through the jet drainage pump 7, the high-pressure gas sent from the gas tree is used to pressurize and transport the low-pressure gas sent from the low-pressure gas inlet pipe 10.

[0034] In particular, a high-pressure gas valve 6 is provided between the secondary throttle valve 5 and the jet drainage pump 7, a low-pressure gas valve 9 is provided on the low-pressure gas inlet pipe 10, and a mixed gas valve 12 is provided on the mixed gas outlet pipe 13. The jet drainage pump 7, the high-pressure gas valve 6, the low-pressure gas valve 9, and the mixed gas valve 12 are all installed on the drainage skid 8. The drainage skid 8 is a steel frame structure, so that the vibration can be absorbed by the steel frame, and the connection convenience of the steel frame makes it easier to align the positions of different pipelines. The drainage skid 8 is installed on the cement base 11. A pipeline or multiple connecting short pipes 3 are provided between the primary throttle valve 2 and the secondary throttle valve 5. This is because the cement base 11 may expand and contract in different seasons with different ambient temperatures, and it is possible that a customized pipeline cannot meet the requirements of sealing connection. Therefore, multiple connecting short pipes 3 can be used, which have better telescopic adaptability. Since there are many spare parts of connecting short pipes 3 in oil and gas fields, there is no need to increase the cost of customized pipelines.

[0035] A main flow channel 713 is provided inside the jet drainage pump 7, which runs through the two side walls in a straight line. One end of the main flow channel 713 is an air outlet 704, and the other end is a mounting hole 700. The mounting hole 700 is provided with an internal thread, and a matching pressure cap 701 is installed to block the main flow channel 713, and a sealing ring is provided at the inner end of the pressure cap 701; the inside of the main flow channel 713 is provided with a plurality of steps from the pressure cap 701 to the air outlet 704, forming an effect of gradually reducing the inner diameter, and a trumpet structure with an inner diameter increasing from the inside to the outside is provided at the position of the air outlet 704; a high-pressure gas inlet 702 with a lateral opening and running through the side wall of the jet drainage pump 7 is provided at a position close to the pressure cap 701, and a low-pressure gas inlet 703 with a lateral opening and running through the side wall of the jet drainage pump 7 is provided between the high-pressure gas inlet 702 and the air outlet 704.

[0036] In the jet drainage pump 7, a nozzle 708 and a diffuser 711 are arranged in sequence from the pressure cap 701 to the air outlet 704. The nozzle 708 is arranged between the high-pressure gas inlet 702 and the low-pressure gas inlet 703, and the diffuser 711 is arranged between the low-pressure gas inlet 703 and the air outlet 704. The nozzle 708 and the diffuser 711 are kept fixed to ensure that the gap between the two is fixed and the central flow channel is coaxial; at the position where the main channel 713 is connected to the low-pressure gas inlet 703, a circle of annular space 7131 with an enlarged pipe diameter is provided, so that the delivered low-pressure gas can enter between the nozzle 708 and the diffuser 711 from an entire circumferential annulus, which is more convenient for transportation.

[0037] The nozzle 708 is sleeved with a nozzle base 706 on the outside. Both the nozzle 708 and the nozzle base 706 are hollow rotating body structures. A step is provided between the nozzle 708 and the nozzle base 706, so that the nozzle 708 is fixed to the inner wall of the nozzle base 706 through the step. After the nozzle 708 is sleeved, the inner wall of the nozzle base 706 has a section of the inner wall that does not contact the outer periphery of the nozzle 708. This section of the inner wall is provided with an internal thread and is connected to a matching nozzle clamping nut 707 with an external thread. The rear end face of the nozzle clamping nut 707 abuts against the nozzle 708 after being fixed and tightened to the inner wall of the nozzle base 706. The nozzle 708 is fixed to the inside of the nozzle base 706 by the nozzle clamping nut 707 and the step of the nozzle base 706. The small diameter end of the nozzle 708 is extended from The nozzle base 706 extends out; a step is provided on the outer periphery of the nozzle base 706 for fixing on the step of the main channel 713, so that the position of the nozzle 708 is fixed; two sealing ring installation positions are provided on the outer periphery and inner periphery of the nozzle base 706, and a one-way sealing ring is installed on the inner wall and outer periphery of the side close to the nozzle clamping nut 707, and an O-ring is installed on the inner wall and outer periphery slightly away from the nozzle clamping nut 707; a total clamping nut 705 is provided at one end of the nozzle base 706 close to the pressure cap 701, and a radial pin hole 7052 is provided on the total clamping nut 705, and a corresponding hole is also provided on the nozzle base 706, and a pin is inserted from the pin hole 7052 to achieve the fixation of the total clamping nut 7052 and the nozzle base 706;

[0038] The outer periphery of the total clamping nut 705 is provided with threads, and the inner wall of the corresponding main flow channel 713 is provided with matching internal threads to achieve the fixation of the total clamping nut 705 and the main flow channel 713. One end of the interior of the total clamping nut 705 is a hexagonal hole structure;

[0039] A plurality of nozzle clamping nut mounting countersunk holes 7071 are provided at the end of the nozzle clamping nut 707, and the distance between the axis of the nozzle clamping nut mounting countersunk hole 7071 and the axis of the main channel 713 is smaller than the distance between the hexagonal hole edge of the main clamping nut 705 and the axis of the main channel 713. This design ensures that the nozzle clamping nut 707 will not be interfered by the main clamping nut 705 when being installed.

[0040] In particular, the nozzle clamping nut 707 and the pressure cap 701 are both installed by setting countersunk holes at the ends, so a special installation tool is required. The installation tool is a multi-claw structure that can be inserted into the corresponding countersunk holes of the nozzle clamping nut 707 and the pressure cap 701 to achieve rotation, tightening and fixing.

[0041] The nozzle base is provided with a reduced diameter section on the outer circumference of one side close to the diffuser 711, and the reduced diameter section is provided with an external thread, a support tube 709 is fixed here, and a plurality of annular space air inlet holes 7091 corresponding to the annular space 7131 are provided on the side of the support tube 709, and the inner wall of the other end of the support tube 709 is screwed with the outer wall of the diffuser 711 and pressed against the diffuser 711, and the inner wall flow channel of the diffuser is a dumbbell-shaped structure, and both ends are trumpet-shaped with a small inside and a large outside, the trumpet on the side close to the nozzle 708 is used as an inlet, and the trumpet on the other side is used as an outlet, a straight pipe section is provided in the middle, and an expanded diameter section is provided on this straight pipe section, one end of the expanded diameter section is connected to the inlet of the diffuser 711, and a hard alloy tube 710 is fixedly installed here, and the hard alloy The inner wall of the gold tube 710 has the same inner diameter as the straight section of the diffuser 711, and together they form the throat of the diffuser. The carbide tube 710 is used because the impact force of the high-pressure gas after being accelerated and ejected from the nozzle 708 is large, and the carbide tube 710 can reduce the impact of erosion; a step is provided on the outer periphery of the diffuser 711 toward the gas outlet 704, so as to press against the step of the main channel 713, and when the other end is pressed against by the support tube 709, the nozzle 708 and the diffuser 711 are axially fixed and pressed against by the total clamping nut 705, ensuring that the distance from the nozzle 708 to the entrance of the diffuser 711 is fixed; two adjacent sealing ring fixing grooves are provided on the outer periphery between the step of the diffuser 711 and the entrance of the diffuser 711, and O-rings are installed respectively. Specifically, the two sealing ring fixing grooves, from far to near, near the outlet of the diffuser 711 are safety O-ring 1 714 and safety O-ring 2 715.

[0042] The above-mentioned structural design can ensure that the interior of the entire jet drainage pump 7 is easy to disassemble and assemble. The diffuser 711, support tube 709, nozzle base 706, total clamping nut 705, and nozzle 706 that have been connected in sequence can be inserted from one side of the mounting hole 700 and fixed in the main channel 713, and the pressure cap 701 can be installed.

[0043] In particular, the distance between the safety O-ring 1 714 and the safety O-ring 2 715 needs to be kept relatively close, preferably not more than 2 cm. The reason for this design is that during use, if a single sealing ring is used, it is impossible to ensure the seal between the low-pressure area on the side of the air outlet 704 with a certain pressure after mixing and the annular space 7131. However, after using two sealing rings, there may be a relatively high-pressure area between the safety O-ring 1 714 and the safety O-ring 2 715. When disassembly and maintenance is required, if the diffuser 711 is directly pulled out and the distance between the safety O-ring 1 714 and the safety O-ring 2 715 is large, more high-pressure gas will remain. When the safety O-ring 1 714 is first disassembled and separated from the sealing fit with the main channel 713 and the safety O-ring 2 715 has not yet separated from the fit, this part of the high-pressure gas will be released instantly, causing greater noise and vibration, posing a safety hazard to workers who manually disassemble.

[0044] Pressure measuring ports 712 are provided in the high-pressure gas inlet 702 and the gas outlet 704 for connecting to a pressure gauge provided outside the jet drainage pump 7, so as to confirm that the pressure of each working area of ​​the jet drainage pump 7 during operation can be fed back in real time, and the throttle valve, etc. can be adjusted based on this.

[0045] Sealing grooves are provided around the outer ends of the high-pressure gas inlet 702, the low-pressure gas inlet 703 and the gas outlet 704 of the jet drainage pump 7, and threaded holes for connecting flanges are provided outside the sealing grooves.

[0046] A jet drainage method for a natural gas field, using the jet drainage system as described above, comprises the following steps:

[0047] Install and connect the jet drainage system, especially install the nozzle 708 and the diffuser 711 in the jet drainage pump 7 according to the drainage needs on site, and ensure that the spacing is appropriate. Connect the pipelines to the high-pressure gas and the low-pressure gas, open the corresponding valves, and at this time, part of the high-pressure gas is directly sent to the external transmission system through the high-pressure gas diversion pipe 14, and the other part is sent to the jet drainage pump 7 from the high-pressure gas inlet 702, and the speed is increased through the nozzle 708, driving the low-pressure gas sent from the low-pressure gas inlet 703 to enter the diffuser 711 to achieve pressurization and output from the mixed gas outlet pipe 13.

[0048] Specifically, how to use the system can be determined based on the environment of the gas field block, especially the incoming gas flow and pressure of the high-pressure gas and low-pressure gas in the gas field block. When the high-pressure gas flow is large and the flow required for diversion is small, the throttle valve can be adjusted to allow most of the gas to flow away from the high-pressure gas diversion pipe 14, thereby better meeting the optimal effect of on-site production and transportation.

[0049] Taking a gas field block in Karamay as an example, among the multiple gas wells in the block, the wellhead pressure of a high-pressure well is 47Mpa. According to the existing technology, the pressure is 29Mpa after the first-level throttling, and the final pipeline pressure after throttling is 11.2Mpa. The process will cause great energy loss and require the addition of multiple equipment. The wellhead pressures of multiple adjacent low-pressure wells are 5-10Mpa. After jet drainage through this system, even if only the first-level jet drainage is used, the low-pressure gas can be pressurized to 11.5Mpa or higher.

[0050] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A jet drainage system for a natural gas field, comprising a gas tree, characterized in that: The gas tree is connected to the throttle valve via a gas tree connecting pipe (1), and then two branches are arranged on the throttle valve, one of which is connected to the jet drainage pump (7), and the other is connected to the external transmission system as a high-pressure gas diversion pipe (14); the jet drainage pump (7) is provided with a high-pressure gas inlet (702), a low-pressure gas inlet (703), and an outlet (704); the high-pressure gas inlet (702) is connected to the throttle valve, the low-pressure gas inlet (703) is connected to the low-pressure gas inlet pipe (10), and the outlet (704) is connected to the mixed gas outlet pipe (13); the high-pressure gas delivered from the gas tree is used to pressurize and transport the low-pressure gas delivered from the low-pressure gas inlet pipe (10) through the jet drainage pump (7).

2. The jet drainage system for a natural gas field according to claim 1, characterized in that: A main flow channel (713) is provided inside the jet drainage pump (7) and runs through the two side walls in a straight line. One end of the main flow channel (713) is an air outlet (704), and the other end is a mounting hole (700). An internal thread is provided on the mounting hole, and a matching pressure cap (701) is installed to block the main flow channel (713). A sealing ring is provided at the inner side end of the pressure cap (701). The inside of the main flow channel (713) is provided with a plurality of steps from the pressure cap (701) to the air outlet (704), forming an effect of gradually reducing the inner diameter. A bell-shaped structure with an inner diameter that increases from the inside to the outside is provided at the position of the air outlet (704). A high-pressure gas inlet (702) with a lateral opening and running through the side wall of the jet drainage pump (7) is provided at a position close to the pressure cap (701), and a low-pressure gas inlet (703) with a lateral opening and running through the side wall of the jet drainage pump (7) is provided between the high-pressure gas inlet (702) and the air outlet (704).

3. The jet drainage system for a natural gas field according to claim 2, characterized in that: In the jet drainage pump (7), a nozzle (708) and a diffuser (711) are arranged in sequence from the pressure cap (701) to the air outlet (704), the nozzle (708) is arranged between the high-pressure air inlet (702) and the low-pressure air inlet (703), the diffuser (711) is arranged between the low-pressure air inlet (703) and the air outlet (704), and the nozzle (708) and the diffuser (711) are kept fixed to ensure that the gap between the two is fixed and the central flow channel is coaxial; at the position where the main flow channel (713) is connected to the low-pressure air inlet (703), a circle of annular space (7131) with an enlarged pipe diameter is provided.

4. The jet drainage system for a natural gas field according to claim 3, characterized in that: The nozzle (708) is sleeved with a nozzle base (706) on the outside. Both the nozzle (708) and the nozzle base (706) are hollow rotating body structures. A step is provided between the nozzle (708) and the nozzle base (706) so that the nozzle (708) can be fixed to the inner wall of the nozzle base (706) through the step. After the nozzle (708) is sleeved, the inner wall of the nozzle base (706) has a section of the inner wall that does not contact the outer periphery of the nozzle (708). This section of the inner wall is provided with an internal thread and is connected to a matching nozzle clamping nut (707) with an external thread. The rear end face of the nozzle clamping nut (707) abuts against the nozzle (708) after being fixed and screwed onto the inner wall of the nozzle base (706). The nozzle (708) is fixed to the inside of the nozzle base (706) through the nozzle clamping nut (707) and the step of the nozzle base (706). The small diameter end extends from the nozzle base (706); a step is provided on the outer periphery of the nozzle base (706) for fixing on the step of the main channel (713), so that the position of the nozzle (708) is fixed; two sealing ring installation positions are provided on the outer periphery and inner periphery of the nozzle base (706), a one-way sealing ring is installed on the inner wall and outer periphery of the side close to the nozzle clamping nut (707), and an O-ring is installed on the inner wall and outer periphery slightly away from the nozzle clamping nut (707); a total clamping nut (705) is provided at one end of the nozzle base (706) close to the pressure cap (701), and a radial pin hole (7052) is provided on the total clamping nut (705), and a corresponding hole is also provided on the nozzle base (706), and a pin is inserted through the pin hole (7052) to achieve the fixation of the total clamping nut (7052) and the nozzle base (706); The outer periphery of the total clamping nut (705) is provided with threads, and the inner wall of the corresponding main flow channel (713) is provided with matching internal threads, so as to achieve the fixation of the total clamping nut (705) and the main flow channel (713), and one end of the interior of the total clamping nut (705) is a hexagonal hole structure; A plurality of nozzle clamping nut mounting countersunk holes (7071) are provided at the end of the nozzle clamping nut (707), and the distance between the axis of the nozzle clamping nut mounting countersunk hole (7071) and the axis of the main channel (713) is smaller than the distance between the hexagonal hole edge of the total clamping nut (705) and the axis of the main channel (713).

5. The jet drainage system for a natural gas field according to claim 4, characterized in that: The nozzle base is provided with a reduced diameter section on the outer periphery of one side close to the diffuser (711), and the reduced diameter section is provided with an external thread, a support tube (709) is fixed here, and a plurality of annular air inlet holes (7091) corresponding to the annular space (7131) are provided on the side of the support tube (709), the inner wall of the other end of the support tube (709) is screwed to the outer wall of the diffuser (711) and pressed against the diffuser (711), the inner wall flow channel of the diffuser is a dumbbell-shaped structure, both ends are trumpet-shaped with a small inside and a large outside, the trumpet on the side close to the nozzle (708) is used as an inlet, and the trumpet on the other side is used as an outlet, a straight pipe section is provided in the middle, and an expanded diameter section is provided on this straight pipe section, one end of the expanded diameter section is connected to the diffuser (711 ) is connected to the inlet of the diffuser (711), where a carbide tube (710) is fixedly installed, and the inner wall of the carbide tube (710) has the same inner diameter as the straight section of the diffuser (711); a step is provided on the outer periphery of the diffuser (711) toward the gas outlet (704), thereby pressing against the step of the main channel (713), and when the other end is pressed against by the support tube (709), the nozzle (708) and the diffuser (711) are axially fixed and pressed against each other by the total clamping nut (705), ensuring that the distance from the nozzle (708) to the inlet of the diffuser (711) is fixed; two adjacent sealing ring fixing grooves are provided on the outer periphery between the step of the diffuser (711) and the inlet of the diffuser (711), and O-rings are respectively installed thereon.

6. The jet drainage system for a natural gas field according to claim 5, characterized in that: A pressure measuring port (712) is provided in the high-pressure gas inlet (702) and the gas outlet (704) for connecting to a pressure gauge provided outside the jet drainage pump (7).

7. The jet drainage system for a natural gas field according to claim 6, characterized in that: Sealing grooves are provided around the outer ends of the high-pressure gas inlet (702), the low-pressure gas inlet (703) and the gas outlet (704) of the jet drainage pump (7), and threaded holes for connecting flanges are provided outside the sealing grooves.

8. The jet drainage system for a natural gas field according to claim 1, characterized in that: The throttle valve comprises a primary throttle valve (2) and a secondary throttle valve (5); the primary throttle valve (2) is connected to the gas tree via a gas tree connecting pipe (1); a pipeline or a plurality of connecting short pipes (3) are provided between the primary throttle valve (2) and the secondary throttle valve (5); a high-pressure gas valve (6) is provided between the secondary throttle valve (5) and the jet drainage pump (7); a low-pressure gas valve (9) is provided on the low-pressure gas inlet pipe (10); and a mixed gas valve (12) is provided on the mixed gas outlet pipe (13).

9. The jet drainage system for a natural gas field according to claim 1, characterized in that: The jet drainage pump (7), the high-pressure gas valve (6), the low-pressure gas valve (9), and the mixed gas valve (12) are all installed on the drainage skid (8), and the drainage skid (8) is installed on the cement base (11).

10. A jet drainage method for a natural gas field, characterized in that: The jet drainage system as claimed in claims 1 to 8 comprises the following steps: After the jet drainage system is installed and connected, and connected to the high-pressure gas and low-pressure gas pipelines, the corresponding valves are opened. At this time, a part of the high-pressure gas is directly sent to the external transmission system through the high-pressure gas diversion pipe (14), and the other part is sent to the jet drainage pump (7) from the high-pressure gas inlet (702), and the speed is increased through the nozzle (708), driving the low-pressure gas sent from the low-pressure gas inlet (703) to enter the diffusion pipe (711) to achieve pressurization and output from the mixed gas outlet pipe (13).

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