High-pressure buffering sand separation device for wellhead of compact gas well
Technical Field
The invention relates to the technical field of natural gas desanding, in particular to a high-pressure buffering sand separating device for a wellhead of a tight gas well.
Background
The compact gas reservoir (shale gas) is usually put into production after large sand fracturing, and fractured sand is discharged in a discharge and production period and a normal production process due to incomplete fracturing flow-back and rapid production, so that the normal production of a gas well, the yield of the gas well and the safety of ground equipment and pipelines are seriously influenced.
At present, a desander or a four-phase separator is commonly adopted for desanding at a wellhead, and the process and equipment for emulsifying and modifying condensate oil and separating sand cannot meet the field working conditions, so that the overflow parts (a water jacket furnace coil, a needle valve, a blow-off valve and the like) of downstream processing equipment are eroded and abraded too early to be damaged, the normal production of a gas well is seriously influenced, the production yield of the gas well is reduced, and the production cost is increased.
The pressure of a dense gas well mouth is up to 20MPa, the dense gas well mouth needs to be decompressed and then is separated and conveyed, the needle valve is adopted for decompressing in the prior general technical means, in order to prevent the valve from being blocked by low-temperature icing after the needle valve is decompressed, a water jacket furnace can be used for heating the upstream gas, the coil pipe in the water jacket furnace is bent more, the sand-containing dense gas seriously erodes the coil pipe of the water jacket furnace, the service life of the coil pipe is extremely short, and the production cost is greatly increased.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a high-pressure buffering sand separating device for a wellhead of a compact gas well, which solves the problems that in the sand separating process of sand remover equipment in the prior art, the overflow part of downstream processing equipment is eroded and worn to cause premature damage, the normal production of the gas well is seriously influenced, the production efficiency of the gas well is reduced, and the production cost is increased.
In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:
the high-pressure buffering and sand separating device for the wellhead of the compact gas well comprises a buffering separation tank and a gas collecting pipe; the buffer separation tank is provided with an inflow port and a sand outlet; the gas collecting pipe is arranged above the buffer separation tank, the middle part of the gas collecting pipe is provided with a plurality of exhaust pipes communicated with the inside of the gas collecting pipe, and the exhaust pipes are communicated with the buffer separation tank; the gas collecting pipe is provided with a gas discharge port, and one side of the gas discharge port is provided with a cyclone separator;
the cyclone separator comprises a feeding port, an overflow pipe and a sand setting port, and the air release port is communicated with the feeding port through a first pipeline;
a vortex tube assembly is arranged on the overflow tube and comprises a tube body, a tangential inlet communicated with the interior of the tube body is arranged on the outer wall of the tube body, and the tangential inlet is communicated with the overflow tube; the two ends of the pipe body are respectively connected with a hot air joint and a cold air joint in a sealing way;
the connecting end of the pipe body and the hot gas joint is of a cone mouth structure, the small diameter end of the cone mouth structure faces the middle part of the pipe body, a conical valve core matched with the cone mouth structure is arranged in the hot gas joint, and the conical valve core axially moves along the axis direction of the conical valve core;
a heater communicated with the hot gas joint is arranged on the outer wall of the connecting end of the pipe body and the cold gas joint; a mixing tank for collecting gas is arranged below the pipe body, and the cold air joint and the heater are communicated with the mixing tank.
The basic principle of the high-pressure buffering sand separating device for the wellhead of the tight gas well is as follows: the gas-water-sand mixture enters a buffer separation tank from an inflow port, and is subjected to layered separation in the buffer separation tank, a large amount of gas and a small amount of water and sand enter a gas collecting pipe, and the large amount of water and sand are discharged and recovered from a sand outlet; a large amount of gas and a small amount of water and sand in the gas collecting pipe enter the cyclone separator, the water and the sand are discharged from a sand setting port, the high-pressure gas is discharged from the overflow pipe and enters a tangential inlet of the vortex pipe assembly, the high-pressure gas rotates at a high speed in the vortex pipe along the tangential direction, the hot gas flow is finally separated and discharged from the hot gas joint, the cold gas flow is separated and discharged from the cold gas joint, the hot gas flow and the cold gas flow move in the reverse direction in the pipe body to generate severe friction to consume a large amount of energy, the gas pressure is rapidly reduced, the opening degree of a conical port at the right end of the pipe body is effectively adjusted by the movable conical valve core, and the ratio and the pressure loss of the hot gas flow and the cold gas flow are controlled; the hot air flow enters the heater to heat the cold air joint, so that the cold air joint is prevented from being frozen and blocking a channel due to too low temperature, and meanwhile, the volume of the cold air joint is contracted after the hot air flow is precooled, and the pressure is reduced; the hot air flow and the cold air flow are fully mixed in the mixing tank to form low-pressure pure gas which can be utilized by the gas gathering station.
Further, as the concrete structure of cyclone, cyclone is including dividing a sand section of thick bamboo, divides sand section of thick bamboo upper portion to be cylindrical tube structure, divides sand section of thick bamboo lower part to be obconic tube structure, divides circumference tangential position on the outer wall of sand section of thick bamboo upper portion to be provided with the pan feeding mouth, divides sand section of thick bamboo upper portion top to be provided with the overflow pipe, divides sand section of thick bamboo lower part to be provided with the sand setting mouth.
Furthermore, as a specific structure of the buffer separation tank, the buffer separation tank is obliquely arranged, the inflow port is arranged at the high end of the buffer separation tank, and the sand outlet is arranged at the low end of the buffer separation tank;
the gas collecting pipe is arranged horizontally, a plurality of exhaust pipes are evenly arranged in the middle of the gas collecting pipe at intervals, the exhaust pipes are vertically arranged, and the bottoms of the exhaust pipes are communicated with the buffer separation tank.
Further, the bottom end of the overflow pipe penetrates through the sand separating cylinder and is located in the middle of the sand separating cylinder.
Furthermore, the top end of the conical valve core is a cone matched with the pipe body taper structure, the middle part of the conical valve core is a cylinder, and the tail end of the conical valve core is of a spline structure; the middle part of the conical valve core is in threaded connection with the inner wall of the hot gas joint; a fixed cylinder is arranged on the outer wall side of the bottom of the hot gas joint, a spline sleeve matched with the tail end of the conical valve core is arranged in the fixed cylinder, and the tail end of the conical valve core penetrates through the hot gas joint and is connected with the spline sleeve; the outer wall side in fixed cylinder bottom is provided with the motor, and the output and the spline housing fixed connection of motor, the rotation of motor drive the spline housing around self axis rotation.
Furthermore, the heater comprises a hollow cylindrical cavity, the cavity is sealed and sleeved on the outer wall of the pipe body, a spiral guide vane is arranged in the cavity, an air inlet and an air outlet which are communicated with the interior of the cavity are formed in the cavity, and the air inlet is communicated with the hot air joint through a second pipeline; the air inlet is communicated with the mixing tank.
Furthermore, a sieve tube is arranged in the mixing tank, the top end of the sieve tube is provided with a hot air inlet communicated with the air outlet, and the bottom end of the sieve tube is provided with a plurality of sieve pores; the outer wall both sides of blending tank are provided with the air conditioning entry and the mist export rather than inside intercommunication respectively, and the air conditioning entry passes through the third pipeline and connects the intercommunication with the air conditioning.
The invention has the beneficial effects that:
1. the invention utilizes the buffer separation tank and the cyclone separator to separate water and sand from the dense gas, thereby improving the purity of the dense gas.
2. The vortex tube assembly is adopted to carry out cold-hot separation on the dense gas, a large amount of air pressure is consumed, and the pressure reduction effect is achieved.
3. The invention utilizes hot air flow to heat the cold air end of the vortex tube component, thereby not only preventing the cold air end from freezing, but also reducing the temperature of the hot air flow, leading the volume of the hot air flow to shrink and reducing the pressure.
4. The vortex tube assembly used by the invention has a simple structure, enables airflow to rotate in the positive and negative directions in the inner part, consumes energy due to friction and collision, and overcomes the defects of long length, more bending and large erosion of fluid on the inner wall of the sand remover equipment coil in the prior art.
5. The invention utilizes the conical valve core to adjust the airflow channel, and can adjust the flow dividing ratio and the consumption pressure of the vortex tube, thereby adapting to various working conditions and meeting the production requirements.
Drawings
FIG. 1 is a schematic structural diagram of a sand removing part in a high-pressure buffering sand separating device at a wellhead of a tight gas well.
FIG. 2 is a schematic structural diagram of a pressure reduction part in a high-pressure buffering sand separation device at a wellhead of a tight gas well.
Wherein, 1, a buffer separation tank; 101. an inlet port; 102. A sand outlet; 2. a gas collecting pipe; 201. an exhaust pipe; 202. an air release port; 3. a first conduit; 4. a cyclone separator; 401. a feeding port; 402. an overflow pipe; 403. a sand setting port; 5. a vortex tube assembly; 501. a tangential inlet; 502. a hot gas joint; 503. a conical valve core; 504. a spline housing; 505. a fixed cylinder; 506. a motor; 507. a cold air joint; 508. a pipe body; 6. a heater; 601. a helical guide vane; 602. an air inlet; 603. an air outlet; 7. a second conduit; 8. a third pipeline; 9. a mixing tank; 901. A cold air inlet; 902. a mixed gas outlet; 903. a hot gas inlet; 904. a screen pipe.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.
As shown in fig. 1-2, the invention provides a high-pressure buffering sand separation device for a wellhead of a tight gas well, which comprises a buffering separation tank 1 and a gas collection pipe 2; the buffer separation tank 1 is provided with an inflow port 101 and a sand outlet 102; the gas collecting pipe 2 is arranged above the buffer separation tank 1, the middle part of the gas collecting pipe 2 is provided with a plurality of exhaust pipes 201 communicated with the interior of the gas collecting pipe 2, and the plurality of exhaust pipes 201 are communicated with the buffer separation tank 1; an air release port 202 is arranged on the air collecting pipe 2, and a cyclone separator 4 is arranged on one side of the air release port 202; the cyclone 4 comprises a feed port 401, an overflow pipe 402 and a sand settling port 403, and the air release port 202 communicates with the feed port 401 through the first pipe 3.
The overflow pipe 402 is provided with a vortex tube assembly 5, the vortex tube assembly 5 comprises a tube body 508, the outer wall of the tube body 508 is provided with a tangential inlet 501 communicated with the interior of the tube body, and the tangential inlet 501 is communicated with the overflow pipe 402; the two ends of the tube body 508 are respectively connected with a hot air joint 502 and a cold air joint 507 in a sealing way; the connecting end of the pipe body 508 and the hot gas joint 502 is a taper structure, the small diameter end of the taper structure faces the middle part of the pipe body 508, a conical valve core 503 matched with the taper structure is arranged in the hot gas joint 502, and the conical valve core 503 axially moves along the axis direction of the conical valve core 503. The tangential inlet 501 faces the tapered end of the tube 508, so that after the high-pressure mixed gas enters the tangential inlet 501, the gas flow generates a vortex to separate the hot and cold gas flows. The vortex tube assembly 5 performs cold-hot separation on the dense gas, consumes a large amount of gas pressure and achieves the effect of pressure reduction.
The vortex tube component 5 has a simple structure, so that the airflow rotates in the positive and negative directions in the inner part, the energy is consumed by friction and collision, and the defects that the coil of the desander equipment in the prior art is long in length, is bent more and has large erosion on the inner wall by fluid are overcome.
A heater 6 communicated with the hot gas joint 502 is arranged on the outer wall of the connecting end of the pipe body 508 and the cold gas joint 507; a mixing tank 9 for collecting gas is arranged below the pipe body 508, and the cold air joint 507 and the heater 6 are both communicated with the mixing tank 9.
As a specific structure of the buffer separation tank 1, the buffer separation tank 1 is obliquely arranged, an inflow port 101 is arranged at the high end of the buffer separation tank 1, and a sand outlet 102 is arranged at the low end of the buffer separation tank 1; gas collecting pipe 2 is the level and arranges, and many blast pipes 201 interval evenly set up at gas collecting pipe 2 middle part, and many blast pipes 201 are vertical setting, and many blast pipes 201 bottom all communicates with buffer separation jar 1. The buffer separation tank 1 is arranged in an inclined mode, a large amount of water and sand in the gas-water-sand mixture are discharged from a sand setting port under the action of gravity, a large amount of gas and a small amount of water and sand enter the gas collecting pipe 2, and the buffer separation tank 1 completes primary screening of the gas-water-sand mixture. The buffer separation tank 1 and the cyclone separator 4 are used for separating water and sand from the dense gas, so that the purity of the dense gas is improved.
As a specific structure of the cyclone separator 4, the cyclone separator 4 comprises a sand separating cylinder, the upper part of the sand separating cylinder is of a cylindrical cylinder structure, the lower part of the sand separating cylinder is of an inverted cone cylinder structure, a feeding port 401 is arranged at a circumferential tangent position on the outer wall of the upper part of the sand separating cylinder, an overflow pipe 402 is arranged at the top of the upper part of the sand separating cylinder, and a sand setting port 403 is arranged at the lower part of the sand separating cylinder; the bottom end of the overflow pipe 402 passes through the sand separating cylinder and is positioned in the middle of the sand separating cylinder. The lower part of the sand separating cylinder is of an inverted cone-shaped cylinder structure, so that water and sand are easier to concentrate and drain from the sand setting port 403.
The top end of the conical valve core 503 is a cone matched with the conical opening structure of the tube body 508, the middle part of the conical valve core 503 is a cylinder, and the tail end of the conical valve core 503 is of a spline structure; the middle part of the conical valve core 503 is in threaded connection with the inner wall of the hot gas joint 502; a fixed cylinder 505 is arranged on the outer wall side of the bottom of the hot gas joint 502, a spline housing 504 matched with the tail end of the conical valve core 503 is arranged in the fixed cylinder 505, and the tail end of the conical valve core 503 penetrates through the hot gas joint 502 to be connected with the spline housing 504; the outer wall side of the bottom of the fixed cylinder 505 is provided with a motor 506, the output end of the motor 506 is fixedly connected with the spline housing 504, and the rotation of the motor 506 drives the spline housing 504 to rotate around the axis of the spline housing. The output end of the motor 506 drives the whole conical valve core 503 to rotate through the spline sleeve 504, the middle part of the conical valve core 503 is in threaded connection with the inner wall of the hot gas joint 502, the tail end of the conical valve core 503 axially slides in the spline sleeve 504 to further drive the top end of the conical valve core 503 to move, the top end of the axially moving conical valve core 503 is matched with the conical opening end of the pipe body 508, the opening degree of the conical opening end of the pipe body 508 is effectively adjusted, and the purposes of controlling the ratio of hot gas flow to cold gas flow and pressure loss are achieved; the larger the opening degree of the cone end of the pipe body 508 is, the larger the flow in the direction of hot air flow is, and meanwhile, the smaller the flow in the direction of cold air flow is, so that the proper flow of cold air flow is controlled to control the whole pressure drop of the sand separating device, thereby adapting to various working conditions and meeting the production requirements.
The heater 6 comprises a hollow cylindrical cavity, the cavity is arranged on the outer wall of the tube body 508 in a sealing manner, the spiral guide vane 601 is arranged in the cavity, an air inlet 602 and an air outlet 603 which are communicated with the interior of the cavity are arranged on the cavity, and the air inlet 602 is communicated with the hot gas joint 502 through a second pipeline 7; the air inlet 602 communicates with the mixing tank 9. The hot air flow in the vortex tube component 5 enters the heater 6 to heat the cold air joint 507, so that the cold air joint 507 is prevented from being frozen to block a channel due to too low temperature, and meanwhile, the volume of the hot air flow is shrunk after the hot air flow meets the cold condition, and the pressure is reduced.
A sieve pipe 904 is arranged in the mixing tank 9, the top end of the sieve pipe 904 is provided with a hot gas inlet 903 communicated with the gas outlet 603, and the bottom end of the sieve pipe 904 is provided with a plurality of sieve holes; the two sides of the outer wall of the mixing tank 9 are respectively provided with a cold air inlet 901 and a mixed gas outlet 902 which are communicated with the interior of the mixing tank, and the cold air inlet 901 is communicated with a cold air joint 507 through a third pipeline 8. The screen 904 can filter impurities in the hot gas flow, and the hot gas flow and the cold gas flow are fully mixed in the mixing tank 9 to form low-pressure pure gas which can be utilized by the gas gathering station, and the low-pressure pure gas is discharged from the mixed gas outlet 902.
The basic principle of the high-pressure buffering sand separating device for the wellhead of the tight gas well is as follows: the gas-water-sand mixture enters the buffer separation tank 1 from the inflow port 101, the gas-water-sand mixture is subjected to layered separation in the buffer separation tank 1, a large amount of gas and a small amount of water and sand enter the gas collecting pipe 2, and the large amount of water and sand are discharged and recovered from the sand outlet 102; a large amount of gas and a small amount of water and sand in the gas collecting pipe 2 enter the cyclone separator 4, the water and the sand are discharged from a sand setting port, high-pressure gas is discharged from the overflow pipe 402 and enters the tangential inlet 501 of the vortex tube assembly 5, the high-pressure gas rotates at a high speed in the vortex tube along the tangential direction, hot gas flow is finally separated and discharged from the hot gas joint 502, cold gas flow is separated and discharged from the cold gas joint 507, the hot gas flow and the cold gas flow move in the tube body 508 in opposite directions to generate severe friction to consume a large amount of energy, the gas pressure is rapidly reduced, the opening degree of the conical opening at the right end of the tube body 508 is effectively adjusted by the movable conical valve core 503, and the ratio and the pressure loss of the hot gas flow and the cold gas flow are controlled; the hot air flow enters the heater 6 to heat the cold air joint 507, so that the cold air joint 507 is prevented from being frozen and blocking a channel due to too low temperature, and meanwhile, the volume of the precooled hot air flow is reduced, and the pressure is reduced; the hot air flow and the cold air flow are fully mixed in the mixing tank 9 to form low-pressure pure gas which can be utilized by the gas gathering station.