Sand discharging buffer device and method for sand remover

Abstract

The invention belongs to the technical field of natural gas and shale gas, and particularly discloses a desander sand discharge buffer device which comprises a sand storage tank and a gas storage tank, the upper portion of the sand storage tank is communicated with a gas inlet pipe, the bottom of the sand storage tank is communicated with a blow-off pipe, a first stop valve is installed on the gas inlet pipe, and a blow-off valve is installed on the blow-off pipe. An air pipe is connected between the air storage tank and the top end of the sand storage tank, a second stop valve is installed on the air pipe, a partition plate is connected into the air storage tank, and a spring is arranged in an upper cavity of the partition plate. A sand discharging buffering method for a sand remover comprises the following steps that S1, the sand remover and a sewage discharging tank are connected; s2, sand feeding: feeding sand into a sand storage tank by a sand remover; s3, gas is cached, and flash steam in the sand storage tank enters a gas storage tank through a gas pipe and pushes a partition plate to enable a spring to be compressed and deformed; and S4, sand discharging is conducted, specifically, a blow-down valve is opened, a spring rebounds, and solid and liquid in the sand storage tank are slowly discharged out of a blow-down pipe. The desander can solve the problem that in the sand discharging process of the desander, washout of a sand discharging pipeline valve is large.

Description

Technical Field

[0001] The present invention relates to the technical fields of natural gas and shale gas, and particularly relates to a sand discharge buffering device and method for a desander. Background Art

[0002] Currently, the main production process for natural gas and shale gas wellheads is sand removal + gas-liquid separation, and then metering and external transportation. Among them, the sand removal process mainly uses a filter-type desander or a hydrocyclone desander, whose purpose is to remove the sand grains contained in the gas-liquid two-phase flow. After sand removal, the gas-liquid two-phase flow enters a subsequent ordinary gravity separator for gas-liquid separation. Since the high-speed movement of sand grains in pipelines and equipment can cause serious erosion and corrosion to production facilities, in severe cases, it may lead to perforation of pipelines or gas valves. In the on-site process, the desander used usually directly discharges sand by connecting to a sand storage tank, and there is no buffer sand discharge process flow. Due to the relatively high operating pressure of the equipment, when discharging sand, the sand grains scour the inner wall surfaces of the sewage pipeline and elbows at high speed, which is extremely likely to cause the wall thickness to be reduced and even perforated. Therefore, the sand discharge process of the desander will play a key role in the safety of production facilities.

[0003] Currently, most of the literature reports and patents on natural gas or shale gas sand removal focus on the process of removing sand grains from the gas phase and liquid phase by sand removal equipment. Most of the patents related to the sand discharge process of desanders use water to wash the solid-liquid mixture in the desander.

[0004] By comparison, the existing technologies in related fields are as follows:

[0005] A sand washing skid for a desander (authorized announcement number CN219558907U) discloses a sand washing skid for a desander, which includes a skid-mounted frame body, several sand washing mechanisms and a water tank arranged in the skid-mounted frame body. A pipeline pump connected between the water tank and the outlet end of the sand storage bucket is detachably installed at the bottom of the skid-mounted frame body. The sand washing mechanism includes a sand washing pipe installed inside the skid-mounted frame body and connected between the inlet end of the sand storage bucket and the water tank, several filter sand boxes evenly arranged at the bottom of the sand washing pipe, and several filter sand meshes arranged in the sand washing pipe and connected to the side walls of the filter sand boxes. A support mechanism for supporting and installing the filter sand boxes and the sand washing pipe is arranged on the inner wall of the skid-mounted frame body, which solves the problems that when the traditional desander discharges sand, multiple workers need to use high-pressure water to carry out sand washing operations simultaneously, resulting in high labor intensity and large water resource consumption, thus increasing the cost.

[0006] V-type cyclone sand cleaner (authorized announcement number CN219709183U) discloses a V-type cyclone sand cleaner, including: an upper cylinder, a water inlet pipe is arranged on the side surface of the upper cylinder, and the water inlet direction of the water inlet end of the water inlet pipe is tangent to the inner surface of the upper cylinder; a water outlet pipe is installed on the upper surface of the upper cylinder, and the water outlet pipe extends into the interior of the upper cylinder; a lower cylinder, the lower cylinder is a V-shaped cylinder, and the lower cylinder is installed on the lower surface of the upper cylinder; this V-type cyclone sand cleaner, through the combined design of the dredging rod, vibration spring and push plate in the sand storage box, can use the vibration of the dredging rod to push the sand and other particles in the sand discharge pipe to prevent the sand and other particles from blocking, which is beneficial to cleaning the sand and other particles inside the sand collection box. The design of the diversion port and filter screen in the water outlet pipe can convey water flow into the sand collection box through the water outlet pipe, and use the water flow to convey the sand and other particles to the sand storage box through the sand guide pipe. It is convenient to clean the sand and other particles.

[0007] A cyclone sand removal device (authorized announcement number CN219518107U) discloses a cyclone sand removal device, including a cyclone sand remover, a sedimentation cylinder is fixedly connected to the lower end of the cyclone sand remover, a sand discharge mechanism is fixedly connected to the middle part of the lower end of the sedimentation cylinder in an inserted manner, a support frame is fixedly connected between the upper parts of the outer surface of the sedimentation cylinder, and the support frame is fixedly connected to the right part of the outer surface of the sand discharge mechanism. A water inlet pipe is fixedly connected to the left part of the upper end of the cyclone sand remover in an inserted manner, a water outlet pipe is fixedly connected to the middle part of the upper end of the cyclone sand remover in an inserted manner, and a filtering mechanism is fixedly connected to the end of the water outlet pipe away from the cyclone sand remover in an inserted manner. A controller is fixedly connected to the lower part of the front end of the cyclone sand remover. The cyclone sand removal device of the present invention can quickly discharge sand particles by setting a sand discharge mechanism and a diversion mechanism, avoid the accumulation of sand particles, and can strengthen the sand removal effect of the device and make the sand removal more thorough by setting a filtering mechanism.

[0008] In summary, in the publicly disclosed patents, most of the sand discharge processes of sand cleaners use water as a medium for flushing for cleaning, and no introduction of the effect of reducing erosion is seen, which is significantly different from the present invention in terms of structural principle and achieved effects. Summary of the Invention

[0009] The present invention provides a sand discharge buffering device for a sand cleaner, aiming to solve the problem of large erosion of the sand discharge pipeline valve during the sand discharge process of the sand cleaner and reduce the operation risks of pipelines and equipment.

[0010] The present invention is achieved through the following technical solutions: A sand removal buffer device for a desander, comprising a sand storage tank. An air inlet pipe is connected to the upper part of the sand storage tank, and a sewage discharge pipe is connected to the bottom of the sand storage tank. A first stop valve is installed on the air inlet pipe, and a sewage discharge valve is installed on the sewage discharge pipe. It further includes an air storage tank. A gas pipe is connected between the air storage tank and the top end of the sand storage tank, and a second stop valve is installed on the gas pipe. A partition is connected inside the air storage tank, and the partition divides the air storage tank into an upper chamber and a lower chamber. A spring is provided in the upper chamber, and both ends of the spring are respectively connected to the partition and the top wall of the upper chamber.

[0011] Compared with the prior art, the present invention has the following advantages and beneficial effects: The invention utilizes the pressure change generated by the original liquid in the desander after entering the sand storage tank to flash vaporize and form gas. The generated gas enters the air storage tank through the gas pipe, pushing the partition in the air storage tank to move upward and compressing the spring to deform, enabling the spring to store energy. Then, by using the change in the elastic potential energy of the spring, the solid-liquid in the sand storage tank is slowly discharged from the sand storage tank. Since the pressure difference in the air storage tank decreases and the speed reduces, the erosion generated by sand grains in the pipeline and equipment is slowed down, solving the problem of large erosion of the sand discharge pipeline valve during the sand discharge process of the desander and reducing the operation risk of the pipeline and equipment.

[0012] Further, a plurality of springs are provided, and the plurality of springs are distributed at intervals.

[0013] Beneficial effect: In this way, the operation of the partition is more stable, and the plurality of springs can form a more stable sand discharge push.

[0014] Further, the outer side of the partition is in sealed contact with the inner wall of the air storage pipe and can slide vertically along the inner wall of the air storage tank.

[0015] Beneficial effect: In this solution, the sealing between the partition and the air storage tank is better, so that the thrust generated by the spring reset later is greater and the sand discharge effect is better.

[0016] Further, an annular guide groove is formed on the inner wall of the air storage tank, and the outer side of the partition is located in the guide groove and is in vertical sliding fit with the guide groove.

[0017] Beneficial effect: In this solution, the guide groove can play a guiding role in the vertical movement of the partition, making the up and down movement of the partition more stable.

[0018] Further, a stirring unit for stirring the sand grains at the lower part of the sand storage tank is provided at the lower part of the sand storage tank.

[0019] Beneficial effect: In this solution, the setting of the stirring unit can stir the sand grains at the bottom of the sand storage tank, avoiding sand grain accumulation and blockage, and thus making the sand discharge smoother.

[0020] Further, the stirring unit includes a turbine, a worm, a connecting shaft, and a stirring plate. The connecting shaft is coaxially connected to the worm, and one end of the connecting shaft is rotatably connected to the sand storage tank. The other end of the connecting shaft extends out of the sand storage tank. The turbine is coaxially connected to a rotating shaft, and both ends of the rotating shaft are rotatably connected to the inner wall of the sand storage tank. The worm meshes with the turbine. A connecting plate is connected to the rotating shaft, and the stirring plate is connected to the connecting plate.

[0021] Beneficial effects: In this solution, the connecting shaft is rotated to make the worm rotate forward and backward, and the forward and backward rotation of the stirring plate is driven by the mutual meshing of the turbine and the worm, so as to stir the bottom of the sand storage tank and prevent sand particles from accumulating and affecting normal sand discharge.

[0022] Further, connecting plates are provided on both sides of the turbine, and the connecting plates are both connected to the rotating shaft.

[0023] Beneficial effects: Such a setting can increase the stirring range, thereby improving the effect of the stirred sand particles.

[0024] Further, the outer side of the connecting shaft extending out of the sand storage tank is provided with anti-slip lines.

[0025] Beneficial effects: Such a setting of the anti-slip lines can achieve an anti-slip effect.

[0026] Further, an inspection opening is provided on one side of the sand storage tank.

[0027] Beneficial effects: The setting of the inspection opening facilitates later manual inspection and maintenance of the inside of the sand storage tank.

[0028] A method for buffering sand discharge of a desander, using the above-mentioned desander sand discharge buffering device, includes the following steps:

[0029] S1, Connect the intake pipe of the sand storage tank to the desander, and connect the sewage discharge pipe of the sand storage tank to the sewage tank.

[0030] S2, Close the second stop valve and the sewage discharge valve, and then open the first stop valve. The multiphase fluid enters the sand storage tank from the desander, and flash evaporation occurs due to volume change in the sand storage tank, generating flash vapor.

[0031] S3, Close the first stop valve, and keep the sewage discharge valve closed. Then open the second stop valve to connect the sand storage tank and the gas storage tank. The flash vapor in the sand storage tank enters the lower cavity of the gas storage tank, and the liquid in the sand storage tank continues to flash evaporate. The flash vapor pushes the partition plate upward in the lower cavity of the gas storage tank and causes the spring to be compressed and deformed.

[0032] S4, Open the sewage discharge valve, keep the first stop valve closed, the pressure in the sand storage tank gradually decreases, and the spring in the gas storage tank rebounds to push the partition plate downward to exhaust gas, and the multiphase fluid in the sand storage tank is slowly discharged.

[0033] The present invention has the following beneficial effects:

[0034] 1. The sand discharge flow rate can be reduced by reducing the pressure, greatly reducing the erosion rate and risk;

[0035] 2. Other media such as water do not need to be added, reducing additional energy consumption;

[0036] 3. The sand discharge operation can be carried out without stopping production or reversing the process, reducing the safety risk;

[0037] 3. Only three valves need to be controlled in sequence, without the need for multiple people to operate simultaneously, reducing labor costs and being economical and applicable;

[0038] 4. The operation principle is simple and the effect is reliable.

[0039] The present invention has been improved in terms of scientificity and operability compared with the past. The function module can be supplemented and added to a large number of existing sand removal devices, providing a new technology and device for the comprehensive design and manufacturing of sand removal devices in the future, and having a broad application space for the current natural gas extraction needs in China. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not limit the embodiments of the present invention. In the drawings:

[0041] Figure 1 is a longitudinal sectional view of Embodiment 1 of a sand removal buffer device for a sand remover according to the present invention;

[0042] Figure 2 is a longitudinal sectional view of Embodiment 2 of a sand removal buffer device for a sand remover according to the present invention.

[0043] Marks in the drawings and corresponding component names:

[0044] Sand storage tank 1, gas storage tank 2, upper cavity 201, lower cavity 202, intake pipe 3, first stop valve 301, air pipe 4, second stop valve 401, sewage pipe 5, sewage valve 501, partition plate 6, guide groove 601, spring 7, sealing cylinder 8, worm 9, turbine 10, stirring plate 11, inspection opening 12, connecting plate 13, rotating shaft 14, connecting shaft 15. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the embodiments and the drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and do not limit the present invention.

[0046] As Figure 1As shown in the figure, Embodiment 1 of the present invention provides a sand removal buffer device for a sand remover, which includes a sand storage tank 1. An air inlet pipe 3 is connected to the upper part of the sand storage tank 1. The air inlet pipe 3 is used to connect to the sand remover. A sewage discharge pipe 5 is connected to the bottom of the sand storage tank 1. The sewage discharge pipe 5 is used to connect to a sewage tank. A first stop valve 301 is installed on the air inlet pipe 3, and a sewage discharge valve 501 is installed on the sewage discharge pipe 5.

[0047] The sand removal buffer device in this embodiment further includes an air storage tank 2. The air storage tank 2 is located at the top of the sand storage tank 1, and a trachea 4 is connected between the air storage tank 2 and the top of the sand storage tank 1. A second stop valve 401 is installed on the trachea 4. The air storage tank 2 and the sand storage tank 1 are connected through the trachea 4.

[0048] A partition 6 is connected inside the air storage tank 2. The partition 6 divides the air storage tank 2 into an upper chamber 201 and a lower chamber 202. The outside of the partition 6 is in sealed contact with the inner wall of the air storage pipe 4 and can slide vertically along the inner wall of the air storage tank 2. A spring 7 is provided in the upper chamber 201. The two ends of the spring 7 are respectively connected to the partition 6 and the top wall of the upper chamber 201. There are three springs, and the three springs are distributed at intervals.

[0049] This embodiment discloses a sand removal buffer method for a sand remover. Using the above-mentioned sand removal buffer device for a sand remover, it includes the following steps:

[0050] S1, Connect the air inlet pipe 3 of the sand storage tank to the sand remover, and connect the sewage discharge pipe 5 of the sand storage tank to the sewage tank;

[0051] S2, Close the second stop valve and the sewage discharge valve, and then open the first stop valve. The multiphase fluid (the gas entering the sand storage tank from the sand remover contains liquid and sand particles) enters the sand storage tank from the sand remover and undergoes flashing due to volume change in the sand storage tank, generating flash steam. The pressure inside the sand storage tank 1 is relatively high when it is not initially filled with gas, and the pressure decreases after gas enters. The liquid in the sand storage tank 1 gradually flashes to generate flash steam;

[0052] S3, Close the first stop valve 301 and keep the sewage discharge valve 501 closed, and then open the second stop valve 401 to connect the sand storage tank 1 and the air storage tank 2. The flash steam in the sand storage tank 1 enters the lower chamber 202 of the air storage tank 2. At this time, the volume continues to increase and the pressure decreases again. The liquid in the sand storage tank 1 continues to flash. The flash steam pushes the partition upward in the lower chamber 202 of the air storage tank 2 and causes the spring to be compressed and deformed;

[0053] S4. Open the sewage discharge valve 501, keep the first stop valve 301 closed, the pressure in the sand storage tank 1 gradually decreases, the spring 7 in the gas storage tank 2 rebounds to push the partition plate 6 downward to exhaust gas, and the multiphase fluid in the sand storage tank 1 is slowly discharged from the sewage discharge pipe 5. In this embodiment, the original liquid in the desander enters the sand storage tank 1, causing the volume change and resulting in pressure reduction, forming flash steam. The flash steam pushes the partition plate 6 in the gas storage tank 2 to move, deforming the spring. When the second stop valve 401 is opened, after the gas storage tank 2 is connected to the sand storage tank 1, the volume further changes, the pressure decreases, and the liquid flashes again, so that the spring is continuously compressed to store energy.

[0054] When the sewage discharge valve 501 is opened, the spring slowly discharges the solid, liquid, and gas in the sand storage tank 1 from the sand storage tank 1 during the rebounding process, realizing sand discharge. The device in this embodiment can buffer the sand grains discharged from the desander during sand discharge, so that the sand grains and liquid are slowly discharged, and the sand discharge speed is reduced, slowing down the erosion of the sand grains in the pipeline and equipment.

[0055] Embodiment 2. The difference between this embodiment and Embodiment 1 is that: in this embodiment, an annular guide groove 601 is provided on the inner wall of the gas storage tank 2, and the partition plate 6 is in sealed sliding fit with the guide groove 601. The outer side of the partition plate 6 is located in the guide groove 601 and is in vertical sliding fit with the guide groove 601.

[0056] In this embodiment, a rubber ring is sleeved on the outer side of the partition plate 6. In this way, the cooperation between the partition plate 6 and the gas storage tank 2 is similar to the cooperation between the piston of a syringe and the syringe barrel in the prior art, so that the sealing performance between the partition plate 6 and the inner wall of the gas storage tank 2 is better, which is convenient for the gas generated in the sand storage tank 1 to push the partition plate 6 upward, and is also convenient for the spring to recover later and push the partition plate 6 downward, making the sand discharge process proceed smoothly.

[0057] Embodiment 3, as Figure 2 shown, the difference between this embodiment and Embodiment 1 is that: a stirring unit for stirring the sand grains at the lower part of the sand storage tank 1 is provided at the lower part of the sand storage tank 1.

[0058] The stirring unit includes a turbine 10, a worm 9, a connecting shaft 15, and a stirring plate 11. The connecting shaft 15 is coaxially connected with the worm 9, and one end of the connecting shaft 15 is rotatably connected to the side wall of the sand storage tank 1 through a bearing. The other end of the connecting shaft 15 extends out of the sand storage tank 1, and the part of the connecting shaft 15 located on the left side of the sand storage tank 1 is coaxially connected with a sealing cylinder 8 inside the sand storage tank 1. The sealing cylinder 8 is hermetically connected to the sand storage tank 1, and the connecting shaft 15 is in sealed rotational fit with the sealing cylinder 8. The setting of the sealing cylinder 8 can improve the sealing performance between the connecting shaft 15 and the sand storage tank 1.

[0059] In this embodiment, the outer side of the connecting shaft 15 extending out of the sand storage tank 1 is provided with anti-slip lines, which is convenient for anti-slip when manually rotating the connecting shaft 15 later.

[0060] The turbine 10 is coaxially connected to a rotating shaft 14. Both ends of the rotating shaft 14 are rotatably connected to the inner wall of the sand storage tank 1. In this embodiment, both ends of the rotating shaft 14 are rotatably connected to the front and rear sides of the sand storage tank 1 through bearings, and the worm 9 meshes with the turbine 10.

[0061] A connecting plate 13 is connected to the rotating shaft 14, and the stirring plate 11 is connected to the connecting plate 13. In this embodiment, connecting plates 13 are provided on both sides of the turbine 10. The connecting plates 13 are both connected to the rotating shaft 14, and the number of connecting plates 13 on both sides of the turbine 10 is set according to the actual inner diameter of the sand storage tank 1. In this embodiment, it is taken as an example that one connecting plate 13 is provided on both sides of the turbine 10. In this embodiment, three stirring plates 11 are provided on the connecting plate 13, and there is an included angle of 30-50° between the three stirring plates 11.

[0062] In this embodiment, a maintenance opening 12 is provided on one side of the sand storage tank 1, which is convenient for later maintenance of the inside of the sand storage tank 1.

[0063] In this embodiment, the rotating connection shaft 15 extends out of one side of the sand storage tank 1, so that the worm 9 rotates synchronously. During the rotation of the worm 9, the gear meshing with it will be driven to rotate. In this way, by alternately rotating the connection shaft 15 forward and backward, the gear can be rotated forward and backward, thereby driving the three stirring plates 11 to rotate forward and backward to stir the sand grains at the bottom of the sand storage tank 1 and avoid accumulation and blockage.

[0064] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A sand removal buffer device for a desander, comprising a sand storage tank. An air inlet pipe is connected to the upper part of the sand storage tank, and a sewage discharge pipe is connected to the bottom of the sand storage tank. Characterized in that, A first stop valve is installed on the air inlet pipe, and a sewage discharge valve is installed on the sewage discharge pipe. It further includes an air storage tank. A gas pipe is connected between the air storage tank and the top end of the sand storage tank. A second stop valve is installed on the gas pipe. A partition plate is connected inside the air storage tank. The partition plate divides the air storage tank into an upper chamber and a lower chamber. A spring is arranged in the upper chamber. Two ends of the spring are respectively connected to the partition plate and the top wall of the upper chamber.

2. The sand removal buffer device for a desander according to claim 1, Characterized in that, There are multiple springs, and the multiple springs are distributed at intervals.

3. The sand removal buffer device for a desander according to claim 1, Characterized in that, The outer side of the partition plate is in sealed contact with the inner wall of the air storage pipe and can slide vertically along the inner wall of the air storage tank.

4. The sand removal buffer device for a desander according to claim 3, Characterized in that, An annular guide groove is formed on the inner wall of the air storage tank. The outer side of the partition plate is located in the guide groove and is in vertical sliding fit with the guide groove.

5. The sand removal buffer device for a desander according to claim 1, Characterized in that, A stirring unit for stirring the sand particles at the lower part of the sand storage tank is arranged at the lower part of the sand storage tank.

6. The sand removal buffer device for a desander according to claim 5, Characterized in that, The stirring unit includes a turbine, a worm, a connecting shaft and a stirring plate. The connecting shaft is coaxially connected with the worm, and one end of the connecting shaft is rotationally connected to the sand storage tank. The other end of the connecting shaft extends out of the sand storage tank. The turbine is coaxially connected with a rotating shaft. Two ends of the rotating shaft are rotationally connected to the inner wall of the sand storage tank. The worm is meshed with the turbine. A connecting plate is connected to the rotating shaft. The stirring plate is connected to the connecting plate.

7. The sand removal buffer device for a desander according to claim 6, Characterized in that, Connecting plates are arranged on both sides of the turbine, and the connecting plates are both connected to the rotating shaft.

8. The sand removal buffer device for a desander according to claim 6, Characterized in that, The outer side of the connecting shaft extending out of the sand storage tank is provided with anti-slip lines.

9. The sand removal buffer device for a desander according to claim 1, Characterized in that, An inspection opening is arranged on one side of the sand storage tank.

10. A sand removal buffer method for a desander, using the sand removal buffer device for a desander according to any one of claims 1-9, Characterized in that, It includes the following steps: S1. Connect the air inlet pipe of the sand storage tank to the desander, and connect the sewage discharge pipe of the sand storage tank to the sewage discharge tank; S2. Close the second stop valve and the sewage discharge valve, and then open the first stop valve. The multiphase fluid enters the sand storage tank from the desander and undergoes flash evaporation due to volume change in the sand storage tank, generating flash vapor. S3. Close the first shut-off valve, and keep the blowdown valve closed. Then open the second shut-off valve to connect the sand storage tank and the gas storage tank. The flash steam in the sand storage tank enters the lower cavity of the gas storage tank. The liquid in the sand storage tank continues to flash vaporize, and the flash steam in the lower cavity of the gas storage tank pushes the partition plate upward and compresses the spring to deform. S4. Open the blowdown valve and keep the first shut-off valve closed. The pressure in the sand storage tank gradually decreases, and the spring in the gas storage tank rebounds to push the partition plate downward to exhaust gas, slowly discharging the multiphase fluid in the sand storage tank.

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