Dual layer plasma slit composite screen pipe

Abstract

The utility model discloses double -deck plasma slit composite screen pipe, including outer layer protection screen pipe and inner layer precision screen pipe, the outer layer protection screen pipe is made of the cylindrical pipe body of corrosion -resistant alloy pipe material and is equipped with the outer layer slit that is arrayed arrangement through the plasma cutting on the pipe wall, the inner layer precision screen pipe is made of the cylindrical pipe body of high tenacity alloy pipe material, and inner layer precision screen pipe coaxially nests in the inside of outer layer protection screen pipe and is equipped with the inner layer slit that is arrayed arrangement through the plasma cutting on the pipe wall, the utility model relates to petroleum and natural gas exploitation technical field, and the outer layer protection screen pipe of wall relatively thick is as main force component, and the ability of compression crushing resistance, bending resistance and torsional loading of whole screen pipe is greatly improved, and the inner layer precision screen pipe of wall relatively thin can also maintain good flow performance when being protected, and screen mesh sand layer and support drainage layer, further guarantee the purity of fluid filtration.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas extraction technology, specifically to a double-layer plasma slotted composite screen pipe. Background Technology

[0002] In the process of oil and gas well development, formation sand production is one of the main causes of reduced well production, damage to surface equipment, and casing deformation. To prevent formation sand from entering the wellbore, screen pipes are usually installed inside the wellbore for sand control. The core function of the screen pipe is to effectively block formation sand particles while allowing fluids (oil, gas, and water) to pass through. Existing single-layer slotted screen pipes still have some shortcomings: 1. Single filtration accuracy: Usually, only a single size of slot is cut on a base pipe of a certain specification, which is difficult to adapt to complex and varied geological conditions, such as situations where there are both fine and coarse sands near the wellbore; 2. The contradiction between structural strength and filtration performance: Increasing the pipe wall thickness to improve strength will reduce the flow area and reduce production; conversely, thinning the pipe wall to increase the flow area will sacrifice mechanical strength. In view of this, this case was developed after in-depth research on the above problems. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention provides a double-layer plasma slotted composite screen tube, which solves the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model is implemented through the following technical solution: a double-layer plasma slit-cut composite screen tube, comprising an outer protective screen tube and an inner precision screen tube; The outer protective screen tube is a cylindrical tube made of corrosion-resistant alloy tubing, and the tube wall is provided with an array of outer cuts formed by plasma cutting. The inner precision screen tube is a cylindrical tube made of high-toughness alloy tubing. The inner precision screen tube is coaxially nested inside the outer protective screen tube, and the tube wall is provided with an array of inner layer cuts formed by plasma cutting. The wall thickness of the outer protective screen tube is more than 1.5 times greater than the wall thickness of the inner precision screen tube. The cross-sectional dimensions of the outer kerf are larger than those of the inner kerf; The ends of the outer protective screen tube and the inner precision screen tube are welded and fixed. The gap between the outer protective screen tube and the inner precision screen tube is provided with a screen sand-blocking layer and a supporting drainage layer.

[0005] The connection between the outer protective screen tube and the inner precision screen tube is fixed by welding with a positioning ring. The end of the inner precision screen tube is welded with a connecting seat, and the connecting seat is threaded for assembly connection with a coupling or oil pipe.

[0006] The aforementioned sand-blocking layer is a plain-weave filter screen covering the outer side of the inner precision screen tube, and the number of layers is no less than two.

[0007] The aforementioned support drainage layer is a gravel filling layer that is placed in the gap between the screen sand-blocking layer and the outer protective screen tube.

[0008] The outer layer cuts and the inner layer cuts are arranged alternately in the circumferential direction, or arranged with a certain phase difference in the axial direction.

[0009] The cross-sectional shape of the outer layer cut is rectangular, trapezoidal, or conical; the cross-sectional shape of the inner layer cut is a high-precision rectangle or micro-conical. Beneficial effects

[0010] This invention provides a double-layer plasma slotted composite screen tube. It offers the following advantages: This double-layer plasma slotted composite screen tube enables multi-stage synergistic filtration with high sand control precision. It innovatively employs a double-layer structure of "outer coarse filtration and inner fine filtration." The outer protective screen tube intercepts large particles and withstands the main impact and load, protecting the inner precision screen tube from direct impact and wear from large particles; the inner precision screen tube focuses on high-precision filtration of small particles. This division of labor and cooperation mode achieves effective control of sand particles with a wide range of particle size distributions, resulting in sand control precision far exceeding that of single-layer screen tubes.

[0011] Optimized mechanical properties enhance reliability and lifespan: The thicker outer protective screen tube, serving as the primary load-bearing component, significantly improves the overall screen tube's resistance to crushing, bending, and torsional loads. The relatively thinner inner precision screen tube, while protected, maintains good flow performance. This structural design cleverly resolves the conflict between strength and flow area in traditional screen tubes, extending their service life.

[0012] A screen mesh sand-blocking layer and a support and drainage layer are set in the gap between the outer protective screen tube and the inner precision screen tube, which further ensures the purity of fluid filtration. In addition, the slits on the inner and outer screen tubes are arranged in an alternating pattern, which further breaks the continuity of the flow field and particle flow, effectively preventing the occurrence of "bridging" blockage and maintaining a long-term stable high liquid production. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the main cross-sectional structure of the double-layer plasma slit composite screen tube of this utility model.

[0014] Figure 2 This utility model Figure 1 A magnified schematic diagram of the structure at position a.

[0015] In the diagram: 1. Outer protective screen tube; 2. Inner precision screen tube; 3. Outer slit; 4. Inner slit; 5. Screen sand-blocking layer; 6. Supporting drainage layer; 7. Positioning ring; 8. Connecting seat; 9. Coupling. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] Example: Refer to the appendix of the instruction manual Figure 1-2 As can be seen, this application specifically designs a double-layer plasma-cut composite screen tube, including an outer protective screen tube 1 and an inner precision screen tube 2. The outer protective screen tube 1 is a cylindrical tube made of corrosion-resistant alloy material, and its wall has an array of outer layer cuts 3 formed by plasma cutting. The inner precision screen tube 2 is a cylindrical tube made of high-toughness alloy material, and is coaxially nested inside the outer protective screen tube 1, with an array of inner layer cuts 4 formed by plasma cutting on its wall. It can achieve multi-stage synergistic filtration with high sand control accuracy: it innovatively adopts a double-layer structure of "outer layer coarse filtration and inner layer fine filtration". The outer protective screen tube 1 intercepts large particles and bears the main impact and load, protecting the inner precision screen tube 2 from direct impact and wear of large particles; the inner precision screen tube 2 focuses on high-precision filtration of small particles. This collaborative model effectively controls sand particles with a wide range of size distributions, achieving a sand control precision far exceeding that of single-layer screen tubes. The outer protective screen tube 1 has a wall thickness more than 1.5 times greater than the inner precision screen tube 2. Optimized mechanical properties improve reliability and lifespan: the thicker outer protective screen tube 1, as the main load-bearing component, significantly enhances the entire screen tube's resistance to crushing, bending, and torsional loads. The relatively thinner inner precision screen tube 2, while protected, also maintains good flow performance. This structural design cleverly solves the contradiction between strength and flow area in traditional screen tubes, extending the service life of the screen tubes; the cross-sectional size of the outer slit 3 is larger than that of the inner slit 4; the ends of the outer protective screen tube 1 and the inner precision screen tube 2 are welded and fixed; a screen sand-blocking layer 5 and a supporting drainage layer 6 are provided in the gap between the outer protective screen tube 1 and the inner precision screen tube 2, and a screen sand-blocking layer 5 and a supporting drainage layer 6 are provided in the interlayer between the outer protective screen tube 1 and the inner precision screen tube 2, further ensuring the purity of fluid filtration.

[0018] In the specific implementation process, the connection position of the outer protective screen tube 1 and the inner precision screen tube 2 is fixed by welding with positioning ring 7. The end of the inner precision screen tube 2 is welded with a connecting seat 8, and the connecting seat 8 is threaded for assembly connection with coupling 9 or oil pipe.

[0019] In the specific implementation process, the above-mentioned screen sand-blocking layer 5 is a plain-weave filter screen covering the outside of the inner precision screen tube 2, and the number is not less than two layers.

[0020] In the specific implementation process, the above-mentioned supporting drainage layer 6 is a gravel filling layer filled in the gap between the screen sand-blocking layer 5 and the outer protective screen tube 1.

[0021] In the specific implementation process, the outer layer slit 3 and the inner layer slit 4 are arranged alternately in the circumferential direction or in the axial direction with a certain phase difference. The slits on the inner and outer screen tubes are arranged alternately, which further breaks the continuity of the flow field and particle flow, effectively prevents the occurrence of "bridging" blockage, and maintains a long-term stable high liquid production.

[0022] In the specific implementation process, the cross-sectional shape of the outer layer slit 3 is rectangular, trapezoidal or conical; the cross-sectional shape of the inner layer slit 4 is a high-precision rectangle or micro-conical.

[0023] In the specific implementation process, as a preferred configuration, the aforementioned outer protective screen pipe 1 is made of 316L stainless steel with a wall thickness of 8mm and an outer diameter of 150mm. Rectangular outer slits 3, 0.8mm wide, 30mm long, and 5mm deep, are machined on its pipe wall using CNC plasma cutting technology, with a slit spacing of 2mm, arranged in a spiral array. These outer slits 3 are mainly used to intercept formation sand with a particle size greater than 0.6mm and provide the main annular compressive strength.

[0024] The inner precision screen tube 2 is made of 2205 duplex stainless steel with a wall thickness of 3mm and an outer diameter of 100mm, allowing it to be tightly nested inside the outer protective screen tube 1. High-precision rectangular inner slits 4, 0.15mm wide, 20mm long, and 2mm deep, are machined on its wall using CNC plasma cutting technology, with a slit spacing of 1mm, also arranged in a spiral array. These inner slits 4 are used for fine filtration of the fluid, blocking fine particles larger than 0.12mm.

[0025] The outer slit 3 and the inner slit 4 are staggered with a 60° phase difference in the circumferential direction. This design ensures that when the fluid flowing in from the outer slit passes through the inner screen tube, the residual particles it carries will not directly align with the inner slit, thus greatly reducing the risk of the inner screen tube being quickly blocked.

[0026] The screen and sand-blocking layer 5 further ensures the purity of the fluid filtration.

[0027] The support drainage layer 6 promotes uniform fluid distribution, avoids local sand blockage, and improves the overall stability of the screen tube. The gravel filling layer has a thickness of 0.5-1.5mm, which effectively optimizes the fluid flow path.

[0028] The sand control period is extended to 36 months, the daily production of a single well is increased by 25%, and the sand blockage rate in the fracture is reduced by 60%, significantly improving mining efficiency. This design can flexibly customize screen pipe products suitable for different well conditions (such as different temperatures, pressures, and corrosive environments) and different geological conditions (such as different sand particle size distributions) by adjusting the material, wall thickness, and the size, shape, and arrangement of the inner and outer base pipes. It has extremely strong versatility and adaptability.

[0029] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dual layer plasma slotted composite screen pipe characterized by, The outer protective screen pipe and the inner precision screen pipe are arranged in the wellbore. The outer protective screen pipe is a cylindrical pipe body made of corrosion-resistant alloy pipe material, and the pipe wall is provided with outer layer slits arranged in an array by plasma cutting. The inner precision screen pipe is a cylindrical pipe body made of high-toughness alloy pipe material, and the inner precision screen pipe is coaxially nested in the inner part of the outer protective screen pipe and is provided with inner layer slits arranged in an array by plasma cutting. The pipe wall thickness of the outer protective screen pipe is greater than the pipe wall thickness of the inner precision screen pipe by more than 1.5 times. The cross-sectional size of the outer layer slit is greater than the cross-sectional size of the inner layer slit. The end parts of the outer protective screen pipe and the inner precision screen pipe are welded and fixed. A screen mesh sand blocking layer and a support flow layer are arranged in the gap between the outer protective screen pipe and the inner precision screen pipe.

2. The double-layer plasma slotted composite screen tube according to claim 1, characterized in that, The end connection position of the outer protective screen pipe and the inner precision screen pipe is welded and fixed by a positioning ring, the end part of the inner precision screen pipe is welded with a connecting seat, and the connecting seat is provided with threads for assembling and connecting with a coupling or a tubing.

3. The double-layer plasma slotted composite screen tube according to claim 1, characterized in that, The screen mesh sand blocking layer is a flat-woven filter screen wrapped outside the inner precision screen pipe, and the number of layers is not less than two.

4. The dual laterally offset straddle screen composite pipe of claim 1, wherein, The support flow layer is a gravel packing layer filled in the gap between the screen mesh sand blocking layer and the outer protective screen pipe.

5. The dual laterally offset straddle screen composite pipe of claim 1, wherein, The outer layer slits and the inner layer slits are staggered in the circumferential direction or arranged with a certain phase difference in the axial direction.

6. The dual laterally offset straddle screen composite pipe of claim 1, wherein, The cross-sectional shape of the outer layer slit is rectangular, trapezoidal or conical; and the cross-sectional shape of the inner layer slit is high-precision rectangular or micro-conical.

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