A simple desand removal device for natural gas wellheads

Abstract

This invention discloses a simple sand removal device for natural gas wellheads, relating to the field of natural gas technology. It includes a main pipeline, with an inlet pipe connected to the inlet end of the main pipeline via a reducing joint. A first gate valve is installed on the inlet pipe, which is connected to an inlet pipe and a bypass pipe via a tee pipe. A vortex device, a venturi-like tube, and a slotted pipe are coaxially arranged sequentially inside the main pipeline. The venturi-like tube passes through the main pipeline via the first short pipe and communicates with a sand storage pipe. The main pipeline is connected to the sand storage pipe via a connecting short section. The outlet end of the main pipeline and one end of the slotted pipe are both connected to a second short pipe via flanges. The second short pipe is connected to a bend short section via a flange, and the bend short section is connected to a third gate valve. The third gate valve is connected to a connecting pipe, which is connected to an outlet pipe and a bypass pipe via a tee pipe. One end of the sand storage pipe is connected to a purge valve via a reducing joint, and the other end is connected to a drain valve via a reducing joint. This device can effectively remove sand from the natural gas wellhead and increase gas production.

Description

Technical Field

[0001] This invention relates to the field of natural gas technology, specifically to a simple sand removal device for natural gas wellheads. Background Technology

[0002] As some gas wells in oilfields age, their sand production also increases. Currently, solving the problem of wellhead sand removal and increasing natural gas production is a pressing issue in natural gas extraction. To effectively remove sand and reduce its impact on downstream pipelines and equipment, gas, sand, and water separation is necessary at the wellhead. Two common separation devices are used: one is a wellhead cyclone separator, mainly composed of a cyclone separator and a sand storage tank. Its disadvantages include a small storage tank, high maintenance frequency, and a large amount of manual sand removal work. The other is a sand removal skid, mainly composed of a high-pressure cyclone separator, a sand storage tank, pipelines, and gate valves. It is large, costly, and a pressure vessel, leading to complex post-construction monitoring. Additionally, on-site use of mechanical sand filters in the wellbore requires replacing the filter string after perforation, posing a high well control risk. Summary of the Invention

[0003] The purpose of this invention is to provide a simple desanding device for natural gas wellheads in order to solve the above-mentioned technical problems.

[0004] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0005] A simple desanding device for natural gas wellheads includes a main pipeline. The inlet end of the main pipeline is connected to an air inlet short pipe via a reducing joint. A first gate valve is installed on the air inlet short pipe. The air inlet short pipe is connected to an air inlet pipe and a bypass pipe via a tee pipe. A vortex device, a venturi-like tube, and a slotted pipe are coaxially arranged sequentially inside the main pipeline. The outlet end of the vortex device is connected to the air inlet end of the venturi-like tube. The venturi-like tube passes through the main pipeline via the first short pipe and is connected to a sand storage pipe. The main pipe is connected to the sand storage pipe via a connecting short section, and the connecting short section is located below the slotted pipe. The outlet end of the main pipe and one end of the slotted pipe are both connected to the second short pipe via flanges. The second short pipe is connected to a bend short section via a flange. The bend short section is connected to a third gate valve. The third gate valve is connected to a connecting pipe. The connecting pipe is connected to an air outlet pipe and a bypass pipe via a tee pipe. One end of the sand storage pipe is connected to a purge valve via a reducing joint, and the other end of the sand storage pipe is connected to a drain valve via a reducing joint.

[0006] Furthermore, the swirling device includes a spiral sleeve, a fixed core disposed inside the spiral sleeve and coaxial with the spiral sleeve, and a spiral body disposed around the fixed core on the inner wall of the spiral sleeve. A blocking plate is provided at one end of the fixed core near the air inlet end of the spiral sleeve, and the outer wall of the spiral sleeve is connected to the inner wall of the main pipe.

[0007] Furthermore, the fixed core is fixedly connected to the inner wall of the spiral sleeve via a support rod.

[0008] Furthermore, the venturi-like tube includes a contraction tube, a first rectifier tube, an expansion tube, a sand discharge tube, a sand baffle tube, and a second rectifier tube connected in sequence. The bottom of the sand discharge tube is provided with a sand discharge port, which is connected to the sand storage tube through the main line tube via a first short tube. The outer wall of the rectifier tube is connected to the outer wall of the main line tube.

[0009] Furthermore, the slotted pipe includes a pipe body, and the pipe body has a plurality of slots along its length.

[0010] Furthermore, a gap is reserved between the outer wall of the slotted pipe and the inner wall of the main line, and the slotted pipe is connected to the inner wall of the main line pipe by a support rod.

[0011] Furthermore, the number of the connecting segments is at least one.

[0012] Furthermore, a sampling port is provided at the outlet of the sand storage pipe, and a sampling valve is installed at the sampling port.

[0013] Furthermore, it also includes a base, the sand storage pipe is connected to the base via a support, and the bypass pipe and connecting pipe are connected to the base via pipe supports.

[0014] Furthermore, it also includes a differential pressure gauge used to obtain the pressure of the main pipe and the second short pipe.

[0015] The beneficial effects of this invention are as follows:

[0016] This invention discloses a simple desanding device for natural gas wellheads. Incoming gas is redirected by a vortex device, changing the flow direction of the sand-carrying fluid from a straight line to a spiral, creating a rotating flow field. The fluid enters a Venturi-like tube, where, under the combined action of centrifugal force and gravity, relatively dense sand particles are separated and enter the sand storage pipe. A narrowing of the tube increases the natural gas flow velocity, removing larger sand particles. These larger sand particles settle by gravity into the lower sand storage pipe, where they undergo secondary filtration through a slotted pipe to remove finer sand particles before entering the sand storage pipe. The sand-removed natural gas passes through a second short pipe and a connecting pipe before exiting through the outlet pipe to the rear end. This device effectively removes sand from the natural gas wellhead, preventing erosion and wear on pipelines and equipment caused by sand and gravel, and increasing gas production. Furthermore, it features a simple structure, easy on-site installation, low manufacturing costs, convenient use and maintenance, reduced manual labor intensity, and effective control of well control risks. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the present invention;

[0018] Figure 2 This is a top view of the present invention;

[0019] Figure 3 This is a schematic diagram of the spiral device and venturi-like tube of the present invention.

[0020] Figure label:

[0021] 1-First gate valve, 2-Second gate valve, 3-Reducing connector, 4-Swirl device, 41-Spiral sleeve, 42-Fixed core tube, 43-Spiral body, 44-Blocking plate, 5-Venturi tube, 51-Contraction tube, 52-First rectifier tube, 53-Expanding tube, 54-Sand discharge tube, 55-Sand blocking tube, 56-Second rectifier tube, 6-Slotted tube, 7-Differential pressure gauge, 8-Bend short section, 9-Third gate valve, 10-Purge valve, 11-First short pipe, 12-Sand storage pipe, 13-Connecting short section, 14-Sampling port, 15-Drain valve, 16-Base, 17-Pipe support, 18-Bypass pipe, 19-Second short pipe, 20-Support seat, 21-Main line pipe, 22-Connecting pipe. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] Example 1

[0025] like Figure 1 , Figure 2 and Figure 3As shown, this embodiment provides a simple desanding device for natural gas wellheads, including a main line pipe 21. The inlet end of the main line pipe 21 is connected to an air inlet short pipe via a reducing connector 3. A first gate valve 1 is installed on the air inlet short pipe. The air inlet short pipe is connected to an air inlet pipe and a bypass pipe 18 via a tee pipe. A vortex device 4, a venturi-like tube 5, and a slotted pipe 6 are coaxially arranged in sequence inside the main line pipe 21. The outlet end of the vortex device 4 is connected to the inlet end of the venturi-like tube 5. The venturi-like tube 5 is connected to the sand storage tube 12 via a first short tube 11, which passes through the main line tube 21. The main line tube 21 is connected to the sand storage tube 12 via a connecting short section 13, which is located below the slotted tube 6. The outlet end of the main line tube 21 and one end of the slotted tube 6 are both connected to a second short tube 19 via flanges. The second short tube 19 is connected to a bent short section 8 via a flange. The bent short section 8 is connected to a third gate valve 9, which is connected to a connecting tube 22. The connecting pipe 22 is connected to the outlet pipe and the bypass pipe 18 respectively via a tee pipe. One end of the sand storage pipe 12 is connected to the purge valve 10 via a reducer 3, and the other end of the sand storage pipe 12 is connected to the drain valve 15 via a reducer 3. The cyclone device 4 includes a spiral sleeve 41, a fixed core disposed inside the spiral sleeve 41 and coaxial with the spiral sleeve 41, and a spiral body 43 disposed around the fixed core on the inner wall of the spiral sleeve 41. The fixed core is close to the inlet of the spiral sleeve 41. A blocking plate 44 is provided at one end of the gas end, and the outer wall of the spiral sleeve 41 is connected to the inner wall of the main line pipe 21; the venturi-like pipe 5 includes a contraction pipe 51, a first rectifier pipe 52, an expansion pipe 53, a sand discharge pipe 54, a sand baffle pipe 55, and a second rectifier pipe 56 connected in sequence. The bottom of the sand discharge pipe 54 is provided with a sand discharge port, which is connected to the sand storage pipe 12 through the main line pipe 21 via a first short pipe 11. The outer wall of the rectifier pipe is connected to the outer wall of the main line pipe 21.

[0026] The working principle of this invention: Natural gas from the wellhead enters the intake pipe from A, passes through the second gate valve 2 and enters the vortex device 4, generating a strong rotational motion. It then passes through a Venturi-like tube 5, first contracting and then gradually expanding to accelerate the gas flow rate. Due to the different densities of sand and other media in the natural gas, under the combined action of centrifugal force, gravity, and fluid drag, the denser sand and water enter the sand storage pipe 12 radially through the first short pipe 11, while the less dense natural gas and fine sand enter the rear end axially. The gas then enters the slotted pipe 6 for secondary filtration and separation. The separated sand particles enter the sand storage pipe 12 through the connecting short section 13. When the sand storage volume in the sand storage pipe 12 reaches a certain amount, sand is discharged through the drain valve 15. The sand-removed natural gas is then discharged from B through the connecting pipe 22 and the outlet pipe. During maintenance and repair, the main steps are as follows: First, open the first gate valve 1, close the second gate valve 2 and the third gate valve 9, open the drain valve 15, remove the bent pipe section 8 at the front end of the third gate valve 9, inject inert gas or high-pressure water into the slotted pipe 6, and after cleaning, connect the bent pipe section 8 and close the drain valve 15 to restore the original process. When the sand storage pipe 12 of the sand removal device needs to be repaired and cleaned, first open the first gate valve 1, close the second gate valve 2 and the third gate valve 9, then open the drain valve 15, purge from the purge valve 10, inject inert gas or high-pressure water (pressure not exceeding 1MPa), clean the inside of the sand storage pipe 12, and after cleaning, close the drain valve 15 and the purge valve 10 to restore the original process. During the maintenance, repair, and cleaning of the sand storage pipe 12, natural gas is discharged from the outlet pipe B through the inlet pipe and bypass pipe. Among them, the swirl device 4 and the Venturi tube 5 are made of rolled steel plates and then assembled and welded into the main pipeline. The welding of the fixed core tube 42 and the spiral body 43 of the swirl device 4 can be done by end welding, while the other parts need to be fully welded. It is recommended to use welding methods with low heat input, such as high-frequency pulse mixed gas shielded welding.

[0027] In summary, the incoming gas changes the flow direction of the sand-carrying fluid through the vortex device 4, transforming it from a straight line to a spiral shape, creating a rotating flow field. It then enters the Venturi-like tube 5. Under the combined action of centrifugal force and gravity, the relatively dense sand particles are separated and enter the sand storage tube 12. The large sand particles are removed by increasing the natural gas flow velocity through a narrowing process. These sand particles settle into the lower sand storage tube 12 by gravity, and then undergo secondary filtration separation through the slotted tube 6 to remove fine sand particles before entering the sand storage tube 12. The sand-removed natural gas passes through the second short tube 19 and the connecting tube 22, and then enters the rear end through the gas outlet pipe. This effectively removes sand content at the natural gas wellhead, solves the erosion and wear of pipelines and equipment caused by gravel, and increases gas production. Furthermore, the structure is simple, easy to install on-site, has low manufacturing costs, is convenient to use and maintain, reduces manual labor intensity, and effectively controls well control risks.

[0028] Example 2

[0029] Based on Embodiment 1, the slotted tube 6 includes a tube body, and the tube body is provided with a plurality of slots along its length.

[0030] In this embodiment, the pipe body is provided with several slits along its length to facilitate secondary filtration and separation of the natural gas entering the pipe body. The separated sand particles fall into the main pipeline 21 through several slits and then enter the sand storage pipe 12 through the connecting short section 13.

[0031] Example 3

[0032] Based on Example 1, such as Figure 1 As shown, a gap is reserved between the outer wall of the slotted pipe 6 and the inner wall of the main line, and the slotted pipe 6 is connected to the inner wall of the main line pipe 21 by a support rod.

[0033] In this embodiment, a gap is reserved between the outer wall of the slotted pipe 6 and the inner wall of the main line to facilitate the entry of sand particles from the slotted pipe 6 into the main line pipe 21. The slotted pipe 6 is connected to the inner wall of the main line pipe 21 by a support rod, which facilitates the installation of the slotted pipe 6 inside the main line pipe 21 and its coaxial arrangement with the main line pipe 21.

[0034] Example 4

[0035] Based on Embodiment 1, the number of the connecting segments 13 is at least one.

[0036] In this embodiment, at least one connecting section 13 is provided to facilitate the entry of sand particles into the sand storage pipe 12 through the connecting section 13.

[0037] Example 5

[0038] Based on Example 1, such as Figure 1 As shown, a sampling port 14 is provided at the outlet of the sand storage pipe 12, and a sampling valve is installed at the sampling port 14.

[0039] In this embodiment, the sand storage status of the sand storage pipe 12 can be obtained through the sampling valve. When the sampling port 14 contains a lot of sand, the sand storage pipe 12 of the sand removal device needs to be inspected and cleaned.

[0040] Example 6

[0041] Based on Example 1, such as Figure 1 As shown, it also includes a base 16, the sand storage pipe 12 is connected to the base 16 through a support 20, and the bypass pipe 18 and the connecting pipe 22 are connected to the base 16 through a pipe support 17.

[0042] In this embodiment, to ensure the stability and safety of the entire device, the entire device is installed on the base 16, which facilitates transportation and on-site installation.

[0043] Example 7

[0044] Based on Example 1, such as Figure 1 As shown, it also includes a differential pressure gauge 7, which is used to obtain the pressure of the main pipe 21 and the second short pipe 19.

[0045] In this embodiment, when the differential pressure gauge 7 displays a value greater than 200 kPa, cleaning the slotted pipe 6 can extend the service life of the device.

Claims

1. A simple desanding device for natural gas wellheads, characterized in that, The system includes a main pipeline. The inlet end of the main pipeline is connected to an air inlet short pipe via a reducing joint. A first gate valve is installed on the air inlet short pipe. The air inlet short pipe is connected to an air inlet pipe and a bypass pipe via a tee pipe. A cyclone device, a venturi-like tube, and a slotted pipe are coaxially arranged sequentially inside the main pipeline. The outlet end of the cyclone device is connected to the air inlet end of the venturi-like tube. The venturi-like tube passes through the main pipeline and connects to a sand storage pipe via the first short pipe. The main pipeline is connected to the sand storage pipe via a connecting short section located below the slotted pipe. The outlet end of the main pipeline and one end of the slotted pipe are both connected to a second short pipe via flanges. The second short pipe is connected to a bent short section via a flange. The bent short section is connected to a third gate valve. The third gate valve is connected to a connecting pipe. The connecting pipe is connected to an outlet pipe and a bypass pipe via a tee pipe. One end of the sand storage pipe is connected to a purge valve via a reducing joint, and the other end of the sand storage pipe is connected to a drain valve via a reducing joint.

2. The simple desanding device for natural gas wellheads according to claim 1, characterized in that, The swirling device includes a spiral sleeve, a fixed core disposed inside the spiral sleeve and coaxial with the spiral sleeve, and a spiral body disposed around the fixed core on the inner wall of the spiral sleeve. A blocking plate is provided at one end of the fixed core near the air inlet end of the spiral sleeve, and the outer wall of the spiral sleeve is connected to the inner wall of the main pipe.

3. A simple desanding device for natural gas wellheads according to claim 2, characterized in that, The fixed core is fixedly connected to the inner wall of the spiral sleeve by a support rod.

4. A simple desanding device for natural gas wellheads according to claim 1, characterized in that, The venturi-like tube includes a contraction tube, a first rectifier tube, an expansion tube, a sand discharge tube, a sand baffle tube, and a second rectifier tube connected in sequence. The bottom of the sand discharge tube is provided with a sand discharge port, which is connected to the sand storage tube through the main line tube via a first short tube. The outer walls of the first rectifier tube and the second rectifier tube are both connected to the inner wall of the main line tube.

5. A simple desanding device for natural gas wellheads according to claim 1, characterized in that, The slotted pipe includes a pipe body, and the pipe body has a number of slots along its length.

6. A simple desanding device for natural gas wellheads according to claim 1, characterized in that, A gap is reserved between the outer wall of the slotted pipe and the inner wall of the main pipe, and the slotted pipe is connected to the inner wall of the main pipe by a support rod.

7. A simple desanding device for natural gas wellheads according to claim 1, characterized in that, The number of the connecting segments is at least one.

8. A simple desanding device for natural gas wellheads according to claim 1, characterized in that, A sampling port is provided at the outlet of the sand storage pipe, and a sampling valve is installed at the sampling port.

9. A simple desanding device for natural gas wellheads according to claim 1, characterized in that, It also includes a base, the sand storage pipe is connected to the base through a support, and the bypass pipe and connecting pipe are connected to the base through pipe supports.

10. A simple desanding device for natural gas wellheads according to claim 1, characterized in that, It also includes a differential pressure gauge, which is used to obtain the pressure of the main pipe and the second short pipe.

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