High-efficiency centrifugal desanding device and method for natural gas

Abstract

This invention discloses a high-efficiency centrifugal desanding device and method for natural gas, relating to the field of natural gas extraction technology, with the aim of improving the desanding efficiency of natural gas. The technical solution adopted in this invention is as follows: the high-efficiency centrifugal desanding device for natural gas includes a horizontally arranged cylinder and a drum. The two ends of the cylinder are the inlet and outlet ends, respectively. A drum is installed inside the cylinder. At least two bearings are installed between the inner side of the cylinder and the outer side of the drum. The centerline of the drum coincides with the centerline of the cylinder. Blades are installed at any one or both ends of the drum. Through holes are provided in the cylinder wall. A sand discharge pipe is installed in the cylinder. The annular cavity formed by the cylinder and the drum is connected to the sand discharge pipe. A sand discharge valve is installed on the sand discharge pipe, and the outlet of the sand discharge pipe is connected to a settling tank. The high-efficiency centrifugal desanding method for natural gas involves desanding sand-containing natural gas using the above-mentioned high-efficiency centrifugal desanding device. This invention is used for desanding of initially extracted natural gas.

Description

Technical Field

[0001] This invention relates to the field of natural gas extraction technology, specifically to an apparatus and method for removing sand from natural gas. Background Technology

[0002] The high sand content in primary natural gas production has always been a significant problem hindering oil and gas extraction and centralized transportation. The high pressure and sand content of primary natural gas cause severe erosion of pipelines, valves, and other pipeline components, reducing equipment handling capacity and easily leading to blockages, posing significant safety hazards to pipelines and systems. The primary natural gas extraction process is sand fracturing, which increases the sand content of primary natural gas, resulting in a large amount of particulate matter carried within the gas. Furthermore, the high pressure and rapid gas flow pose serious challenges to subsequent equipment.

[0003] Currently, pretreatment of newly produced natural gas is generally carried out near the wellhead. The purpose of pretreatment is sand removal, and the main sand removal equipment is the hydrocyclone desander and the filter desander. The hydrocyclone desander utilizes the difference in density between sand particles and oil / gas, using centrifugal force to separate the sand particles; it requires a power unit to drive it. The filter desander uses screening technology, but the processing capacity and sand holding capacity of a single unit are relatively small, and the on-site operation and maintenance workload is relatively large. Both of these commonly used sand removal equipment suffer from low sand removal efficiency and require production to be stopped during sand discharge, making it impossible to achieve sand discharge without interrupting production.

[0004] Natural gas is typically transported via pipelines. Existing pipeline-type sand separators suffer from several problems, including rapid erosion of structural components, incomplete sand removal, easy damage to the filter screen, insufficient design flow rate to meet on-site conditions, sand leakage under peak operating conditions, safety hazards, and complex sand discharge operations. Over time, these issues can easily lead to pipeline blockages, affecting subsequent processing procedures, disrupting normal equipment operation and gas supply quality, and potentially even causing equipment damage. Summary of the Invention

[0005] The present invention first provides a high-efficiency centrifugal desanding device for natural gas, the purpose of which is to improve the desanding efficiency of natural gas.

[0006] The technical solution adopted in this invention is: a high-efficiency centrifugal desanding device for natural gas, comprising a horizontally arranged cylinder and a drum, with the two ends of the cylinder being the inlet end and the outlet end, respectively. The drum is installed inside the cylinder, and at least two bearings are installed between the inner side of the cylinder and the outer side of the drum. The center line of the drum coincides with the center line of the cylinder. Blades are installed at any one or both ends of the drum. Through holes are provided in the cylinder wall. A sand discharge pipe is installed in the cylinder. The annular cavity formed by the cylinder and the drum is connected to the sand discharge pipe. A sand discharge valve is installed on the sand discharge pipe, and the outlet of the sand discharge pipe is connected to the sedimentation tank.

[0007] To achieve uninterrupted sand removal, at least two sand removal valves are installed on the sand removal pipe, with each sand removal valve arranged in series along the sand removal pipe.

[0008] To ensure the balance of the drum during rotation, a further step is to install a bearing at least at each end of the drum.

[0009] To facilitate the connection of pipes to both ends of the cylinder, flanges are further installed at the inlet and outlet ends of the cylinder.

[0010] To address the issue of insufficient natural gas pressure to drive the drum rotation, the high-efficiency centrifugal desanding device for natural gas further includes a booster pump. A branch pipe is installed at the outlet end of the cylinder. A control valve is installed on the inlet pipe of the booster pump and connected to the branch pipe at the outlet end of the cylinder. A shut-off valve is installed on the outlet pipe of the booster pump, and a nozzle is installed at the outlet end, with the nozzle pointing towards the blades.

[0011] To further reduce or prevent impurities from entering the booster pump, a filter is also installed on the booster pump's air intake pipe.

[0012] To further reduce frictional resistance, the bearing is an air bearing, and the air supply line of the air bearing is equipped with a shut-off valve and connected to the air outlet line of the booster pump.

[0013] To achieve automated control, the high-efficiency centrifugal desanding device for natural gas also includes a PLC controller. The sand discharge valve, booster pump, control valve, and shut-off valve are all electrically connected to the PLC controller. Pressure gauges are installed at the inlet and outlet ends of the cylinder and are electrically connected to the PLC controller.

[0014] The present invention also provides a method for high-efficiency centrifugal desanding of natural gas. The sand-containing natural gas is desanded by any of the above-mentioned high-efficiency centrifugal desanding devices. The sand-containing natural gas is introduced into the inlet end of the cylinder. The roller is driven to rotate relative to the cylinder by the impact blades. The sand enters the annular cavity formed by the cylinder and the roller from the cylinder and enters the sedimentation tank through the sand discharge pipe. The desanded natural gas is discharged from the outlet end of the cylinder.

[0015] The beneficial effects of this invention's high-efficiency centrifugal desanding device and method for natural gas are as follows: the drum is driven entirely or primarily by high-pressure natural gas. When the natural gas pressure at the drum inlet is insufficient, a booster pump assists in driving the drum's rotation via impellers, avoiding the drum's complete reliance on a separate power mechanism. The drum is supported by bearings, resulting in low rotational resistance, high rotational speed, high desanding efficiency, and good sealing. Two or more desanding valves are installed on the desanding pipe, allowing for gradual pressure relief and desanding without interrupting production. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the high-efficiency centrifugal desanding device for natural gas of the present invention.

[0017] Reference numerals in the attached drawings: 1. Cylinder body; 11. Inlet end; 12. Outlet end; 2. Drum; 21. Blade; 22. Through hole; 3. Bearing; 4. Sand discharge pipe; 41. Sand discharge valve; 5. Settling box; 6. Booster pump; 7. Filter; 8. PLC controller. Detailed Implementation

[0018] The invention will now be further described with reference to the accompanying drawings.

[0019] like Figure 1 As shown, the present invention provides a high-efficiency centrifugal desanding device for natural gas, comprising a horizontally arranged cylinder 1 and a drum 2. The two ends of the cylinder 1 are an inlet end 11 and an outlet end 12, respectively. The inlet end 11 is used for the entry of sand-containing natural gas, and the outlet end 12 is used for the discharge of natural gas after desanding. To facilitate the connection of pipelines to both ends of the cylinder 1, flanges can be respectively installed at the inlet end 11 and the outlet end 12 of the cylinder 1.

[0020] The cylinder 1 is a cylindrical body, and a roller 2 is installed inside the cylinder 1. At least two bearings 3 are installed between the inner side of the cylinder 1 and the outer side of the roller 2, and the roller 2 is supported by the bearings 3. To reduce wear and frictional resistance, the bearings 3 are preferably air bearings, and the air bearings are connected to the gas supply line. The number of bearings 3 is determined according to the length and mass of the cylinder 1, and generally 2 to 4 bearings 3 are installed. To ensure the balance of the roller 2's rotation, a bearing 3 is installed at each end of the roller 2, and another bearing 3 can also be installed in the middle of the roller 2. The centerline of the roller 2 coincides with the centerline of the cylinder 1, so that the roller 2 can rotate stably. Blades 21 are installed at any one or both ends of the roller 2. High-pressure natural gas flows through the roller 2, and the airflow acts on the blades, driving the roller 2 to rotate around the cylinder 1. The cylinder wall of the roller 2 is provided with through holes 22. The roller 2 is equivalent to a sieve cylinder. The through holes 22 are used to separate sand from sand-containing natural gas. The diameter of the through holes 22 is larger than the diameter of the sand. The cylinder 1 is equipped with a sand discharge pipe 4, which is connected to the annular cavity formed by the cylinder 1 and the drum 2. The sand discharge pipe 4 is used to discharge the separated sand from the cylinder 1. To facilitate sand discharge, the sand discharge pipe 4 is connected to the middle and lowest point of the cylinder 1. The sand discharge pipe 4 is arranged vertically and is equipped with a sand discharge valve 41. The outlet of the sand discharge pipe 4 is connected to the sedimentation tank 5.

[0021] One or more sand discharge valves 41 are installed on the sand discharge pipe 4. To achieve sand discharge without interrupting production, two or more sand discharge valves 41 are installed on the sand discharge pipe 4, and the sand discharge valves 41 are arranged in series along the sand discharge pipe 4. For ease of description, the sand discharge valves 41 are sequentially referred to as the first sand discharge valve to the Nth sand discharge valve along the sand discharge direction of the sand discharge pipe 4. When the sand in the annular cavity formed by the cylinder 1 and the drum 2 accumulates to a certain amount, the second sand discharge valve is first ensured to be closed and the first sand discharge valve 41 is opened. Under the pressure of high-pressure natural gas, the sand automatically enters the pipe section between the first sand discharge valve 41 and the second sand discharge valve 41. Then the first sand discharge valve 41 is closed and then opened again, and the pipe section between the first sand discharge valve 41 and the second sand discharge valve 41 is depressurized. This operation is repeated until the Nth sand discharge valve is opened, so that sand can be discharged gradually without interrupting production.

[0022] To address the issue of insufficient natural gas pressure to drive the drum 2 to rotate within its designed speed range, the present invention's high-efficiency centrifugal desanding device for natural gas also includes a booster pump 6, which assists in driving the drum 2. (See also...) Figure 1 A branch pipe is installed at the outlet end 12 of the cylinder 1. A control valve is installed on the inlet pipe of the booster pump 6 and connected to the branch pipe at the outlet end 12 of the cylinder 1. The booster pump 6 uses natural gas after sand removal as its gas source, avoiding the introduction of impurities into the natural gas and ensuring safety. A control valve is installed on the inlet pipe of the booster pump 6; when the booster pump 6 is not needed, the control valve and the booster pump 6 are closed. A shut-off valve is installed on the outlet pipe of the booster pump 6, and multiple nozzles are installed at the outlet end, pointing towards the blade 21. The airflow ejected from the nozzles acts on the blade 21, assisting in driving the drum 2. To reduce or prevent impurities from entering the booster pump 6 and causing damage, a filter 7 is also installed on the inlet pipe of the booster pump 6. When the bearing 3 between the cylinder 1 and the drum 2 is an air bearing, the air bearing can be supplied with air by the booster pump 6. The air bearing supply line is equipped with a shut-off valve and connected to the outlet pipe of the booster pump 6.

[0023] To achieve automated control, the high-efficiency centrifugal desanding device for natural gas also includes a PLC controller 8. The sand discharge valve 41, booster pump 6, control valve, and shut-off valve are all electrically connected to the PLC controller 8. For example, the sand discharge valve 41 is a pneumatic sand discharge valve, and the control valve and shut-off valve are both pneumatic control valves. Pressure gauges are installed at the inlet end 11 and outlet end 12 of the cylinder 1 and are electrically connected to the PLC controller 8. The pressure gauges are used to monitor the air pressure at the inlet end 11 of the cylinder 1.

[0024] The second subject of this invention is: a method for efficient centrifugal desanding of natural gas. Sand-containing natural gas is desanded by the efficient centrifugal desanding device for natural gas described in the first subject above. The sand-containing natural gas is introduced into the inlet end 11 of the cylinder 1. The roller 2 is driven to rotate relative to the cylinder 1 by the impact blade 21. The sand enters the annular cavity formed by the cylinder 1 and the roller 2 from the cylinder 1 and enters the sedimentation tank 5 through the sand discharge pipe 4. The desanded natural gas is discharged from the outlet end 12 of the cylinder 1.

Claims

1. A high-efficiency centrifugal desanding device for natural gas, characterized in that: The system includes a horizontally arranged cylinder (1) and a drum (2). The two ends of the cylinder (1) are the inlet end (11) and the outlet end (12), respectively. The drum (2) is installed inside the cylinder (1). At least two bearings (3) are installed between the inner side of the cylinder (1) and the outer side of the drum (2). At least one bearing (3) is installed at each end of the drum (2). The centerline of the drum (2) coincides with the centerline of the cylinder (1). Blades (21) are installed at any one or both ends of the drum (2). High-pressure natural gas The airflow passes through the drum (2), and the airflow acts on the blades (21), driving the drum (2) to rotate around the cylinder (1). The drum (2) has a through hole (22) on its wall, and a sand discharge pipe (4) is provided at the bottom of the cylinder (1). The annular cavity formed by the cylinder (1) and the drum (2) is connected to the sand discharge pipe (4). At least two sand discharge valves (41) are provided on the sand discharge pipe (4). Each sand discharge valve (41) is arranged in series along the sand discharge pipe (4). The outlet of the sand discharge pipe (4) is connected to the sedimentation tank (5).

2. The high-efficiency centrifugal desanding device for natural gas as described in claim 1, characterized in that: Flanges are provided at the inlet end (11) and outlet end (12) of the cylinder (1).

3. The high-efficiency centrifugal desanding device for natural gas as described in claim 1 or 2, characterized in that: It also includes a booster pump (6), a branch pipe is provided at the outlet end (12) of the cylinder (1), a control valve is provided in the air inlet pipe of the booster pump (6) and connected to the branch pipe at the outlet end (12) of the cylinder (1), a shut-off valve is provided in the air outlet pipe of the booster pump (6) and a nozzle is provided at the air outlet end, with the nozzle pointing towards the blade (21).

4. The high-efficiency centrifugal desanding device for natural gas as described in claim 3, characterized in that: A filter (7) is installed on the air intake pipe of the booster pump (6).

5. The high-efficiency centrifugal desanding device for natural gas as described in claim 3, characterized in that: The bearing (3) is an air bearing, and the pipeline of the air bearing is equipped with a shut-off valve and connected to the air outlet pipe of the booster pump (6).

6. The high-efficiency centrifugal desanding device for natural gas as described in claim 5, characterized in that: It also includes a PLC controller (8), a sand discharge valve (41), a booster pump (6), a control valve and a shut-off valve, all of which are electrically connected to the PLC controller (8). Pressure gauges are installed at the inlet end (11) and outlet end (12) of the cylinder (1) and are electrically connected to the PLC controller (8).

7. A high-efficiency centrifugal sand removal method for natural gas, characterized in that: Sand-containing natural gas is desanded by the high-efficiency centrifugal desanding device for natural gas as described in any one of claims 1 to 6. The sand-containing natural gas is introduced into the inlet end (11) of the cylinder (1), and the drum (2) is driven to rotate relative to the cylinder (1) by the impact blade (21). The sand enters the annular cavity formed by the cylinder (1) and the drum (2) from the cylinder (1), and enters the sedimentation tank (5) through the sand discharge pipe (4). The desanded natural gas is discharged from the outlet end (12) of the cylinder (1).

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