Gas well spiral degassing and sand prevention device
By combining the spiral central pipe section and the laser-cut sand-proof screen pipe, the problem of easy clogging of the gas anchor was solved, achieving gas-liquid separation and sand prevention effects, and improving the gas well drainage efficiency.
Patent Information
- Application Number
- CN202610582496.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-29
- Publication Date
- 2026-07-21
AI Technical Summary
During gas well development, traditional gas anchors are easily blocked by fracturing sand, leading to gas locks and sand blockages, reducing drainage efficiency, and failing to effectively remove formation water.
The system combines a spiral central pipe section with a laser-cut sand-prevention screen pipe. Through the spiral steel wire and laser-cut filtration, gas-liquid separation is achieved, preventing sand particles from entering the pump cylinder and ensuring effective drainage of formation water.
It effectively blocks sand particles of different sizes, prevents sand from getting stuck in the pump barrel and valves from malfunctioning, improves drainage speed and efficiency, and ensures timely discharge of formation water.
Smart Images
Figure CN122428882A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of oilfield development technology, specifically to a gas well drainage spiral degassing composite sand control device. Background Technology
[0002] During gas well development, it is usually necessary to use a pump to drain water and produce gas. Ideally, formation water is extracted through the tubing and gas is produced through the annulus. However, in actual production conditions, especially in gas wells after fracturing, there are two major technical problems: first, gas entering the pump barrel leads to gas lock and reduced pump efficiency; second, fracturing sand and formation sand entering the pump barrel cause sand blockage and valve failure, which significantly shortens the pump inspection cycle.
[0003] Currently, the commonly used tool for solving downhole gas-liquid separation is the gas anchor. Traditional gas anchors mostly use centrifugal impellers or gravity separation to achieve downhole separation. Due to the small gap between the spiral flow channels or guide vanes of traditional gas anchors, they are easily blocked by fracturing sand, leading to the overall failure of the gas anchor and a sharp drop in separation efficiency. Since the core of gas well drainage is to extract formation water, reduce formation pressure, and promote gas desorption, water is extracted from the tubing and gas is produced from the casing. The role of the gas anchor is to separate gas, which will cause the produced water to be entrained by the gas and unable to be effectively discharged from the formation, thus reducing the drainage efficiency. Moreover, if the gas separated by the gas anchor cannot be discharged in time, it will form a gas lock downhole, hindering the flow of formation water and further reducing the drainage speed.
[0004] In view of this, we propose a gas well drainage spiral degassing composite sand control device to solve the existing problems. Summary of the Invention
[0005] The purpose of this invention is to provide a gas well drainage spiral degassing composite sand control device to solve the problems mentioned in the background art.
[0006] To achieve the above objectives, the present invention provides the following technical solution: a gas well drainage spiral degassing composite sand prevention device, including a sand prevention oil pump, wherein a lower oil pipe section is connected below the sand prevention oil pump;
[0007] The lower part of the oil pipe section is connected to a special-shaped buckle;
[0008] The irregular buckle has an outer connecting part and an inner connecting part at both the upper and lower ends. The outer connecting part at the lower end is connected to a sand sinking tail pipe assembly. The sand sinking tail pipe assembly includes at least one sand sinking pipe and a bottom plug connected to the bottommost end.
[0009] The sand settling pipe is coaxially provided with a central pipe assembly. The central pipe assembly includes a clear varnish central pipe section and a spiral central pipe section connected sequentially from bottom to top. The outer wall of the spiral central pipe section is fixedly connected with a spirally extending steel wire spiral strip. The uppermost end of the spiral central pipe section is installed in the inner connection part of the lower end of the irregular buckle.
[0010] The outer wall of the uppermost sedimentation pipe is connected to a wire-wound screen tube;
[0011] The upper inner connecting part of the irregular buckle is connected to a laser-cut sand-proof screen tube, and the top end of the laser-cut sand-proof screen tube is provided with a top sealing plug.
[0012] Preferably, the steel wire spiral is made of alloy steel wire.
[0013] Preferably, the upper and lower outer connecting parts of the irregular buckle are both flat male buckles, and the upper and lower inner connecting parts of the irregular buckle are both flat female buckles.
[0014] Preferably, the lower oil pipe section is composed of multiple flat oil pipes connected end to end in sequence.
[0015] Preferably, the laser-cut sand screen tube has several laser cuts vertically distributed at a 90-degree phase angle on its tube wall, and the length of the laser cuts is 150 mm and the width is 0.15 mm.
[0016] Preferably, the slit width of the wire-wound screen tube is 0.2 mm.
[0017] Preferably, the sand settling pipe is a horizontal oil pipe.
[0018] Preferably, the central tube section of the clear varnish tube is formed by connecting two central tubes that are not wrapped with the steel wire spiral strip, and the spiral central tube section is formed by connecting three central tubes with the steel wire spiral strip welded on them.
[0019] Compared with the prior art, the beneficial effects of the present invention are:
[0020] 1. This invention filters the formation water for the first time by connecting a wire-wound screen tube with a 0.2 mm gap to the outer wall of the uppermost sand settling pipe, and filters the formation water for the second time by connecting a laser-cut sand-proof screen tube with a 0.15 mm gap to the irregular buckle. This effectively prevents sand particles of different sizes from entering the sand-proof oil pump and avoids sand jamming in the pump barrel and valve failure.
[0021] 2. This invention welds alloy steel wire spiral strips onto the central tube of the spiral central tube section, thereby changing the linear motion of the mixture into high-speed rotational motion. Due to the high density of the liquid, it is thrown towards the inner wall of the sand settling tube under centrifugal force, while the low density of the gas accumulates near the outer wall of the spiral central tube section. Under the action of gravity, the separated liquid settles downward along the inner wall of the sand settling tube and enters the internal channel of the central tube assembly through the bottom opening of the central tube section of the clear oil pipe. The separated gas continues to move upward along the spiral channel of the spiral central tube section, thereby preventing gas from entering the pump cylinder and causing airlock. Attached Figure Description
[0022] Figure 1 This is a three-dimensional structural diagram of the present invention;
[0023] Figure 2 This is a bottom view of the present invention;
[0024] Figure 3 This is a partial cross-sectional view of the present invention;
[0025] Figure 4 This is a schematic diagram of the lower oil pipe section structure of the present invention;
[0026] Figure 5 This is a schematic diagram of the spiral central tube section structure of the present invention;
[0027] Figure 6 This is a partial cross-sectional view of the irregular variable buckle of the present invention.
[0028] In the diagram: 1. Sand-proof oil pump; 2. Lower oil pipe section; 3. Special-shaped coupling; 5. Central section of clear oil pipe; 6. Spiral central section; 7. Steel wire spiral strip; 8. Wire-wound screen pipe; 9. Sand settling pipe; 10. Bottom plug; 11. Laser-cut sand-proof screen pipe; 12. Top sealing plug. Detailed Implementation
[0029] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0030] like Figures 1-6 As shown, the present invention proposes a gas well drainage spiral degassing composite sand prevention device, including a sand prevention oil pump 1, and a lower oil pipe section 2 connected below the sand prevention oil pump 1.
[0031] The lower part of the oil pipe section 2 is connected to a special-shaped buckle 3;
[0032] The irregular buckle 3 has an outer connecting part and an inner connecting part at both the upper and lower ends. The outer connecting part at the lower end is connected to a sand sinking tail pipe assembly. The sand sinking tail pipe assembly includes at least one sand sinking pipe 9 and a bottom plug 10 connected to the bottommost end.
[0033] The interior of the sand settling pipe 9 is coaxially provided with a central pipe assembly. The central pipe assembly includes a clear varnish central pipe section 5 and a spiral central pipe section 6 connected sequentially from bottom to top. The outer wall of the spiral central pipe section 6 is fixedly connected with a spirally extending steel wire spiral strip 7. The uppermost end of the spiral central pipe section 6 is installed in the inner connection part at the lower end of the irregular buckle 3.
[0034] The outer wall of the uppermost sand settling pipe 9 is connected to a wire-wound screen pipe 8;
[0035] The upper inner connecting part of the irregular buckle 3 is connected to a laser-cut sand-proof screen tube 11, and the top end of the laser-cut sand-proof screen tube 11 is provided with a top sealing plug 12.
[0036] The lower oil pipe section 2 is composed of multiple horizontal oil pipes connected end to end in sequence.
[0037] The slit width of the wire-wound screen tube 8 is 0.2 mm.
[0038] The laser-cut sand screen tube 11 has several laser cuts vertically distributed at a phase angle of 90 degrees on its tube wall. The length of each laser cut is 150 mm and the width is 0.15 mm.
[0039] Start the sand-proof oil pump 1. The suction effect of the sand-proof oil pump 1 reduces the bottom pressure of the well, so that the formation fluid first contacts the outermost wire screen tube 8 under the action of pressure difference. The gap width of the wire screen tube 8 is 0.2 mm. Sand particles with a diameter greater than 0.2 mm are blocked outside. Fine sand with a diameter less than 0.2 mm, formation water and gas pass through the wire screen tube 8 and enter the space between the sand settling tube 9 and the central tube assembly. The outer diameter of the sand settling tube 9 is 73 mm.
[0040] Subsequently, the gas-water mixture passes through the spiral central tube section 6. Under the forced flow guidance of the steel wire spiral strip 7, the fluid changes from linear motion to high-speed rotational motion. Due to the high density of water, it is thrown towards the inner wall of the sand settling tube 9 under the action of centrifugal force. The low density of gas accumulates near the outer wall of the spiral central tube section 6. At the same time, under the action of gravity, the separated liquid settles down along the inner wall of the sand settling tube 9 and enters the internal channel of the central tube assembly through the bottom opening of the oil-coated central tube section 5. The separated gas continues to move upward along the spiral central tube section 6.
[0041] After being separated by a spiral, the liquid carrying fine sand particles smaller than 0.2 mm continues to flow upward under the suction force of the sand-proof oil pump 1. When it reaches the laser-cut sand-proof screen pipe 11, because the top of the laser-cut sand-proof screen pipe 11 is equipped with a top sealing plug 12, the liquid must pass through the slits on the inner wall of the laser-cut sand-proof screen pipe 11 from the inside out. The slit width is 0.15 mm (i.e., the slit gap is 0.15 mm) to enter the upper space. In this scheme, the outer diameter of the laser-cut sand-proof screen pipe 11 is 48.26 mm, and the length is 2.0 m to 2.5 m. Fine sand particles with a diameter between 0.15 mm and 0.2 mm are intercepted twice inside the laser-cut sand-proof screen pipe 11 and fall back to the bottom of the central section 5 of the clear oil pipe by gravity, and finally fall into the sand settling pipe 9. Only particles with a diameter smaller than 0.15 mm are trapped inside. Extremely fine sand and formation water can pass through the cuts, thus effectively blocking sand particles of different sizes from entering the sand-proof oil pump, avoiding sand jamming in the pump barrel and valve failure. The fracturing sand commonly used on site is 40-70 mesh, with a particle size of 0.212 mm-0.425 mm.
[0042] After secondary filtration, the formation water enters the space above the irregularly shaped transformer 3 and flows sequentially through the lower oil pipe section 2. It should be noted that the lower oil pipe section 2 is composed of multiple horizontal oil pipes with an outer diameter of 73 mm connected end to end. The specific number of horizontal oil pipes that make up the lower oil pipe section 2 can be determined according to the actual situation and is not limited here. In this scheme, the number of horizontal oil pipes in the lower oil pipe section 2 is 5. Then it enters the pump barrel of the sand-proof oil pump 1. Under the action of the sand-proof oil pump 1, the formation water is lifted to the surface oil pipe for production.
[0043] Furthermore, the steel wire spiral 7 is made of alloy steel wire.
[0044] Furthermore, the central tube segment 5 of the clear varnish tube is formed by connecting two central tubes that are not wrapped with the steel wire spiral 7, and the spiral central tube segment 6 is formed by connecting three central tubes with the steel wire spiral 7 welded on them.
[0045] In this design, to ensure the stability of the spiral structure while also providing resistance to fluid erosion and corrosion, the diameter of the steel wire spiral 7 must not be too large to avoid it being unable to fit into the 62 mm inner diameter sand settling pipe 9. Furthermore, the spiral channel area must not be excessively reduced, as this would affect the degassing effect. Also, the steel wire spiral 7 must not be too thick and block the fluid channel. Ultimately, an alloy steel wire diameter of 4 mm and a pitch of 150 mm to 300 mm were determined. Welded onto a 46.26 mm central pipe, the maximum outer diameter is 54.26 mm. This design satisfies the requirement of fitting into the 62 mm inner diameter sand settling pipe 9 while also providing sufficient resistance to erosion. The steel wire spiral 7 uses readily available, inexpensive, and easily replaceable ordinary alloy steel wire.
[0046] Furthermore, the upper and lower outer connecting parts of the irregular buckle 3 are both flat male buckles, and the upper and lower inner connecting parts of the irregular buckle 3 are both flat female buckles.
[0047] The lower outer connecting part of the irregular buckle 3 is used to connect to the uppermost sand-removing pipe 9, the upper outer connecting part is used to connect to the lower oil pipe section 2, the upper inner connecting part is used to connect to the laser-cut sand-proof screen pipe 11, and the lower inner connecting part is connected to the uppermost central pipe on the spiral central pipe section 6. The diameter of the upper and lower outer connecting parts of the irregular buckle 3 is 73 mm, and the diameter of the upper and lower inner connecting parts of the irregular buckle 3 is 46.26 mm.
[0048] Furthermore, the sand settling pipe 9 is a horizontal oil pipe.
[0049] The bottom plug 10 has a diameter of 73 mm, and the top sealing plug 12 has a diameter of 48.26 mm. The bottom plug 10 is installed on the bottommost sand-collecting pipe 9. In this scheme, there are 7 sand-collecting pipes 9, and multiple sand-collecting pipes (9) are connected end to end in sequence. The specific number of sand-collecting pipes 9 can be determined according to the actual situation and is not limited here. The bottom plug 10 allows the gas-water mixture to enter the inner cavity of the sand-collecting tail pipe assembly only through the wire-wound screen pipe 8. The top sealing plug 12 is installed on the laser-cut sand-proof screen pipe 11, so that the liquid must pass through the laser-cut sand-proof screen pipe 11 from the inside to the outside.
[0050] Working principle: Connect the bottom plug 10 with a diameter of 73 mm to the bottom sand-collecting pipe 9, and connect 7 flat oil pipes with an outer diameter of 73 mm to form a sand-collecting tail pipe assembly. Install the wire-wound screen pipe 8 on the outer wall of the top sand-collecting pipe 9. The gap width of the wire-wound screen pipe 8 is 0.2 mm. Coaxially install the central pipe assembly inside the sand-collecting pipe 9. The central pipe assembly is composed of the bare oil pipe central pipe section 5 and the spiral central pipe section 6 connected from bottom to top.
[0051] The spiral central pipe section 6 has an outer diameter of 46.26 mm. Its outer wall is welded with alloy steel wire spiral strips 7 with a diameter of 4 mm and a pitch of 150 mm to 300 mm. After welding, the maximum outer diameter is 54.26 mm. The inner diameter of the sand-collecting pipe 9 is 62 mm. The central pipe assembly can be easily inserted. The lower outer connecting part of the irregular buckle 3 is connected to the uppermost sand-collecting pipe 9, and its lower inner connecting part is connected to the uppermost central pipe of the spiral central pipe section 6. Its upper inner connecting part is connected to the laser-cut sand-proof screen pipe 11. The upper and lower outer connecting parts of the irregular buckle 3 are both 73 mm flat male threads, and the upper and lower inner connecting parts are both 46.26 mm flat female threads. The diameter of the 48.26 mm spiral pipe section 9 is... The top sealing plug 12 of mm is installed at the top of the laser-cut sand screen pipe 11, so that the gas-water mixture must pass through the cut of the laser-cut sand screen pipe 11 from the inside to the outside. The lower end of the lower oil pipe section 2 is connected to the upper external connection part of the special-shaped buckle 3. The lower oil pipe section 2 is composed of multiple flat oil pipes with an outer diameter of 73 mm connected end to end in sequence. The sand-proof oil pump 1 is connected above the lower oil pipe section 2 and continues to be connected upward to the production oil pipe to the wellhead hanger.
[0052] Then, the sand-proof pump 1 is started. The suction action of the sand-proof pump 1 reduces the bottom hole pressure. Under the pressure difference, the sand first contacts the outermost wire-wound screen 8. Since the gap width of the wire-wound screen 8 is 0.2 mm, sand particles with a diameter greater than 0.2 mm are blocked on the outer wall of the wire-wound screen 8, while sand particles with a diameter less than 0.2 mm are blocked. Fine sand, formation water, and gas (approximately 0.2 mm in diameter) enter the space between the settling pipe 9 and the central pipe assembly through the gaps in the wire-wound screen tube 8. The gas-water mixture then passes through the spiral central pipe section 6, where, under the action of the steel wire spiral strip 7, the mixture changes from linear motion to high-speed rotational motion. Due to its higher density, the liquid is thrown towards the inner wall of the settling pipe 9 under centrifugal force, while the gas, with its lower density, accumulates near the outer wall of the spiral central pipe section 6. Under gravity, the separated liquid settles downwards along the inner wall of the settling pipe 9 and enters the internal channel of the central pipe assembly through the bottom opening of the varnished central pipe section 5. The separated gas continues to move upwards along the spiral channel of the spiral central pipe section 6. The formation water accumulating inside the central pipe assembly carries particles smaller than 0.2 mm in diameter. The residual fine sand (mm) continues to flow upward under the suction force of the sand-proof oil pump 1. When the formation water flows to the laser-cut sand-proof screen pipe 11, the formation water passes through the laser cut on the pipe wall of the laser-cut sand-proof screen pipe 11 from the inside to the outside and enters the upper space. Since the laser cut is vertically distributed at a 90-degree phase angle, with a cut length of 150 mm and a cut width of 0.15 mm, the fine sand with a particle size between 0.15 mm and 0.2 mm is intercepted twice inside the laser-cut sand-proof screen pipe 11 during this process. The fine sand falls back to the bottom of the central pipe section 5 of the light oil pipe by gravity and finally falls into the sand settling pipe 9 for storage. Only the extremely fine sand with a particle size less than 0.15 mm and pure formation water can pass through the cut. The purified formation water after secondary filtration enters the space above the shaped buckle 3, flows through the lower oil pipe section 2 in sequence, and enters the pump barrel of the sand-proof oil pump 1. Under the action of the sand-proof oil pump 1, the formation water is lifted to the surface oil pipe for production.
[0053] The present invention also provides a method for drainage and gas production operations using the above-mentioned gas well drainage spiral degassing composite sand control device, specifically including the following steps:
[0054] S1: 1. Connect the bottom plug 10 to the bottommost sand-collecting pipe 9, and connect multiple sand-collecting pipes 9 in sequence to form a sand-collecting tail pipe assembly.
[0055] S1: 2. Install a wire-wound screen tube 8 on the outer wall of the uppermost sand settling pipe 9, with a slot width of 0.2mm;
[0056] S1:3. The central tube assembly is coaxially installed into the sand-collecting pipe 9. The central tube assembly is composed of the lower varnished central tube section 5 and the upper spiral central tube section 6 connected in sequence. The outer wall of the spiral central tube section 6 is welded with a spiral steel wire spiral strip 7.
[0057] S1:4. Connect the lower outer connection part of the irregular buckle 3 to the uppermost sand sinking pipe 9, connect the lower inner connection part to the uppermost center pipe of the spiral center pipe section 6, connect the upper inner connection part to the laser-cut sand-proof screen pipe 11, and install the top sealing plug 12 at the top of the laser-cut sand-proof screen pipe 11.
[0058] S1:5. Connect the lower end of the lower tubing section 2 to the upper external connection part of the special-shaped buckle 3, connect the upper end of the lower tubing section 2 to the sand-proof oil pump 1, and continue to connect the production tubing upwards to the wellhead.
[0059] S2: Start the sand-proof oil pump 1, the bottom pressure of the well decreases, the formation fluid is filtered through the wire-wound screen tube 8, sand particles with a diameter greater than 0.2mm are blocked outside, and fine sand, water and gas smaller than 0.2mm enter between the sand settling tube 9 and the central tube assembly.
[0060] S3: The gas-water mixture passes through the spiral central tube section 6 and is swirled under the guidance of the steel wire spiral strip 7. The water is thrown to the outside and sinks into the internal channel of the central tube, while the gas gathers on the inside and rises.
[0061] S4: Water entering the interior of several central pipes carries residual fine sand upwards and is filtered from the inside out through the laser-cut sand screen 11. The laser-cut sand screen 11 has a slit width of 0.15 mm, and fine sand with a particle size of 0.15 mm to 0.2 mm is intercepted and falls back to the settling pipe 9, while fine sand smaller than 0.15 mm and clean water pass through.
[0062] S5: After filtration, the clean water passes through the upper space of the irregular buckle 3 and the lower oil pipe section 2 in sequence and enters the sand-proof oil pump 1, where it is lifted to the ground for production.
[0063] The above specific embodiments are merely several preferred embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.
Claims
1. A gas well drainage spiral degassing composite sand control device, comprising a sand control oil pump (1), characterized in that: The lower part of the oil pipe section (2) is connected to the sand-proof oil pump (1). The lower oil pipe section (2) is connected to a special-shaped buckle (3); The upper and lower ends of the irregular buckle (3) are both external connecting parts and internal connecting parts. The lower external connecting part is connected to a sand sinking tail pipe assembly. The sand sinking tail pipe assembly includes at least one sand sinking pipe (9) and a bottom plug (10) connected to the bottommost end. The interior of the sand settling pipe (9) is coaxially provided with a central pipe assembly. The central pipe assembly includes a light oil pipe central pipe section (5) and a spiral central pipe section (6) connected sequentially from bottom to top. The outer wall of the spiral central pipe section (6) is fixedly connected with a spiral steel wire spiral strip (7) extending in a spiral shape. The uppermost end of the spiral central pipe section (6) is installed in the inner connection part at the lower end of the special-shaped buckle (3). The outer wall of the uppermost sedimentation pipe (9) is connected to a wire-wound screen pipe (8); The upper inner connection part of the irregular buckle (3) is connected to a laser-cut sand-proof screen tube (11), and the top end of the laser-cut sand-proof screen tube (11) is provided with a top sealing plug (12).
2. The sand-control device according to claim 1, characterized in that: The steel wire spiral (7) is an alloy steel wire.
3. The sand-prevention device according to claim 1, characterized in that: The upper and lower outer connecting parts of the irregular buckle (3) are both flat male buckles, and the upper and lower inner connecting parts of the irregular buckle (3) are both flat female buckles.
4. The sand-prevention device according to claim 1, characterized in that: The lower oil pipe section (2) is composed of multiple flat oil pipes connected end to end in sequence.
5. The sand-control device according to claim 1, characterized in that: The laser-cut sand screen tube (11) has several laser cuts vertically distributed at a phase angle of 90 degrees on its tube wall. The length of the laser cuts is 150 mm and the width is 0.15 mm.
6. The sand-control device according to claim 1, characterized in that: The slit width of the wire-wound screen tube (8) is 0.2 mm.
7. The sand-control device according to claim 1, characterized in that: The sand settling pipe (9) is a flat oil pipe.
8. The sand-prevention device according to claim 1, characterized in that: The light oil pipe central section (5) is formed by connecting two central pipes that are not wrapped with the steel wire spiral strip (7), and the spiral central section (6) is formed by connecting three central pipes with the steel wire spiral strip (7) welded on them.