CN213392017U - Anti-tripping screen pipe coupling for oil well, gas well and water injection well - Google Patents

Abstract

The utility model relates to an anti-tripping screen pipe coupling used in oil wells, gas wells and water injection wells, which comprises a screen pipe coupling body, wherein the upper part of the screen pipe coupling body is in threaded connection with an upper screen pipe base pipe and the lower part is in threaded connection with a lower screen pipe base pipe; an anti-back-off end cap is arranged between the upper sieve tube base tube and the sieve tube coupling body, a movable anti-back-off pin capable of being connected with the upper sieve tube base tube is arranged in the anti-back-off end cap, and a fixed anti-back-off pin is arranged between the sieve tube coupling body and the lower sieve tube base tube. By adopting the device, the tensile strength of the whole screen pipe string in the well completion pipe string is guaranteed not to be influenced after the thread fastening between the screen pipe base pipe and the screen pipe coupling body is good, and the anti-tripping effect between the screen pipe base pipe and the screen pipe coupling body is guaranteed due to the existence of the movable anti-tripping pin. After the screw thread fastening between lower screen pipe base pipe and the screen pipe coupling body is good, fix with fixed anti-back-off pin, ensured the effect of anticreep knot between the two. The field operation is simple, and special training is not needed during use.

Description

Anti-tripping screen pipe coupling for oil well, gas well and water injection well

Technical Field

The utility model relates to a downhole tool of oil industry oil well, gas well and water injection well, especially an anticreep that oil well, gas well and water injection well used detain screen pipe coupling.

Background

At present, well completion pipe strings in oil wells, gas wells and water injection wells, particularly screen pipes in horizontal well completion pipe strings are in a free state in a shaft, no well cement is arranged outside the screen pipes, and the screen pipes are easily buried by sand setting in unconsolidated strata. When a new well is put into operation, because the well body tracks of the horizontal well have curvature changes of different degrees, if a large-diameter tool is adopted in operation construction, the rigidity of an oil pipe in an operation pipe column relative to a drill rod is reduced, and the contact area of the oil pipe and a sleeve is large, so that the running resistance of the operation pipe column is increased. At the moment, the operation pipe column is rotated, so that the screen pipe in a free state in the shaft can be subjected to tripping torque, and the screen pipe is further loosened if impact and rotation occur simultaneously.

In later-stage oil well maintenance, particularly when the maintenance is carried out by adopting an internal filling sand control mode, construction procedures such as milling, reversing, drilling, grinding and the like are necessary, the risk of screen pipe section tripping is aggravated, and the longer the operation processing time is, the greater the risk of screen pipe tripping is. After the sieve tube is released, the normal production of part of the sieve tube or the whole sieve tube section can be caused, and huge economic loss is caused for oil and gas exploitation.

Therefore, the anti-tripping screen pipe coupling is developed to solve the practical problems existing in the current production field, and has great significance.

Through patent retrieval, various tools and devices used for preventing tripping at present are more, and mainly have following several kinds, but can not solve the tripping problem of screen pipe:

the utility model provides a screw pump sucker rod reversal anti-back-off device, patent number "201921619932.9": the utility model relates to a technical field of petroleum machinery, a screw pump sucker rod reversal anti-back-off device specifically says so. Including connector, connecting axle and the anti-back-off device of setting between connector and connecting axle, anti-back-off device is including strengthening the axle and the suit is right the cover in strengthening the axle middle section, rights threaded connection between cover and the connecting axle, threaded connection between strengthening the axle and the connector, be provided with between strengthening the axle and the connecting axle and pop out the formula slider that pops out, the slider stretches out when sucker rod corotation and dies strengthening axle and connecting axle card, and the slider retracts into in the connecting axle when the reversal. The device is suitable for screw pumps of threaded connection type sucker rods, and can prevent the threads of the sucker rods from loosening and disjointing.

The technical field of the application of the tool and petroleum machinery, in particular to a reverse-rotation anti-back-off device for a screw pump sucker rod, the anti-back-off device is suitable for a screw pump of a threaded connection type sucker rod, a slider stretches out to clamp a reinforcing shaft and a connecting shaft when the sucker rod rotates positively, the slider retracts into the connecting shaft when the sucker rod rotates reversely, the reinforcing shaft and the connecting shaft can rotate relatively, and the phenomenon that the sucker rod is loosened and disconnected due to reverse torque can be prevented. Is suitable for the anti-tripping of rods and is not suitable for the anti-tripping of the screen pipe coupling.

An inner tube back-buckling prevention stabilizing mechanism for coring, which is disclosed in the patent number 201721189347.0: the utility model relates to an oil and natural gas drilling coring technical field, in particular to anti-back-off stabilizing mean of inner tube for coring. The connecting sleeve is connected to the lower end of the inner barrel of the device, the clamp seat is connected to the lower end of the connecting sleeve, the inner barrel, the connecting sleeve and the clamp seat are arranged inside a core bit cavity, an inner barrel centering device is arranged on the end face of the inner wall of the lower end of the core bit cavity, the inner barrel centering device is sleeved on the outer side of the lower end of the clamp seat, and a plurality of bearing balls are arranged on the upper end face of the inner barrel centering device at equal angles in the circumferential. The utility model discloses a prevent that inner tube screw thread back-off from throwing away, guarantee the safety reservation clearance between inner tube and the drill bit, maintain the pump pressure stable, keep the inner tube between two parties, improve inner tube stability, rock core quality and coring harvest rate all obtain improving, simple structure, simple to operate, the dependable performance.

Above-mentioned utility model relates to an oil and natural gas well drilling coring technical field, in particular to anti-back-off stabilizing mean is prevented with inner tube to coring. The structure is characterized in that a plurality of bearing balls are circumferentially arranged on the upper end surface of the inner cylinder centering device at equal angles. Keep the inner tube between two parties and rotate, prevent that the inner tube for coring from preventing back-off stabilizing mean. This is not suitable for preventing the screen joint from tripping because the screen is not allowed to rotate in the well.

An oil drill pipe tripping prevention device, patent number "201420820898.2": the utility model provides an oil drill pipe anticreep spiral-lock device, its characterized in that detains brill, left-handed thread including left-handed thread knot sleeve pipe, crossover sub, casing string, cement head, the crossover sub upside is left-handed thread structure, and the downside is left-handed thread structure, left-handed thread knot is bored and left-handed thread knot bushing coupling, left-handed thread knot sleeve pipe downside and casing string connection, casing string and cement head pass through the crossover sub and connect, casing string and crossover sub upside are connected, the utility model discloses a left-handed thread knot anticreep sleeve pipe structure, fundamentally has solved because frictional force and the back-off and the pine that lead to detain the phenomenon, has less the emergence of dangerous accident in the work progress, has also guaranteed staff's life safety when guaranteeing the construction normal clear, has huge economic benefits and extensive application prospect.

Above-mentioned utility model relates to an oil exploration field especially relates to an oil drill pipe anticreep spiral-lock device. The pipe cluster adopts positive and negative screw thread design, can solve partial back-off problem, nevertheless not complete, if the sleeve pipe tubular column lower part all is the free section, upper portion sleeve pipe will throw off in the construction somewhere, if the sleeve pipe cluster all has cement to seal, this design is possible, and the moment of torsion restricts each other between positive and negative knot, consequently is not applicable to the anticreep of free section screen pipe and detains.

Anti-back-off tool, patent No. 201420607672.4: the utility model provides a prevent back-off tool belongs to coal bed gas well drilling field, include: the first fixing ring is sleeved on the outer side of the production sleeve and provided with at least two first semi-rings which are separated from each other; the second fixing ring is sleeved on the outer side of the surface casing pipe and provided with at least two second semi-rings which are separated from each other; two ends of each first semi-ring and two ends of each second semi-ring are respectively provided with a locking block, and the two corresponding locking blocks are locked or detached through locking pieces; and two ends of the connecting piece are respectively connected with a first half ring and a second half ring. The production casing and the surface casing cannot rotate relatively depending on friction force, and the threaded connection part between two adjacent sections of production casings cannot loosen or slip, so that the production casing is prevented from being reversed, chain tongs do not need to be held manually, and the labor intensity of constructors is reduced.

Above-mentioned utility model relates to a coal bed gas well drilling field particularly, relates to anti-back-off tool. The tool adopts the fixing ring to realize the anti-back-off function, and the outside of the pipe body needs to have enough space when in use, so the tool is not suitable for the anti-back-off of a screen pipe coupling.

Screw pump oil production pipe anticreep device, patent number "201420576638.5": the utility model discloses a screw pump oil production pipe anti-disengaging device, including the cone, with the cone through threaded connection's inner tube, the outside of inner tube is equipped with dropout and tile holder, the outside of dropout is equipped with the protection casing, the protection casing is equipped with the dish spring with the intermediate position of dropout, the dish spring passes through "O" shape sealing washer and cone lock, the lower extreme of protection casing is installed the anti-disengaging steel sheet, the anti-disengaging steel sheet passes through the supporting rail and is connected with the dropout, the supporting rail is the slope shape, and the side of supporting rail is equipped with spacing screw; the bottom of the tile support is provided with a buffer spring, the bottom of the buffer spring is fixed through a positioning steel plate, and a pressure reducing flat pad is arranged between the buffer spring and the positioning steel plate. Adopt the utility model discloses screw pump oil production pipe anticreep device, simple structure facilitates the use, can not cause oil pipe crooked, has reduced the damage of oil pipe and sucker rod.

Above-mentioned utility model relates to an underground equipment for oil development especially relates to a screw pump oil production pipe anticreep device. The technical problem of main solution is to provide screw pump oil production pipe anticreep device, reasonable in design has reduced the damage of oil pipe, sucker rod. The device adopts a cone, a protective cover, an O-shaped sealing ring with a ball and the like, and the more the outer diameter is, the more the resistance of casing running is, the larger the risk is, so the design is not suitable for preventing the screen pipe coupling from being tripped.

A tubular column anti-tripping fixing device for downhole operation is disclosed in patent number 201420007546.5: the utility model discloses a tubular column anti-tripping fixing device for downhole operation, which comprises an upper joint, an inner tube, an arc-shaped cavity, a lower joint, a friction ring, a spring ring, an outer tube, a bearing washer and a righting shaft; the upper end of the inner pipe is in threaded connection with the lower end of the upper joint, the upper end of the outer pipe is in threaded connection with the lower end of the upper joint, the lower end of the inner pipe is in threaded connection with the upper end of the lower joint, the lower end of the outer pipe is in threaded connection with the upper end of the lower joint, and the outer pipe is sleeved outside the inner pipe; the arc-shaped cavity is arranged in the middle of the inner pipe and is positioned in the outer pipe; the friction ring is arranged on the inner wall of the arc-shaped cavity, and the spring ring is arranged in the friction ring; the bearing cushion ring is sleeved on the inner pipe, the centering shaft is arranged in the arc-shaped cavity, and the friction ring is fixedly arranged in the arc-shaped cavity through the centering shaft. The utility model can increase the friction between the pipe column and the sleeve, reduce the phenomenon of pipe falling, further reduce the fishing cost and improve the mining efficiency; the deformation and the fracture of the sleeve can be reduced, and the purpose of protecting the pipe column is achieved.

The utility model provides an operation is with tubular column anti-disengaging fixing device in pit can prevent that the tubular column from droing when borehole operation. The diameter of the arc-shaped cavity designed by the design is relatively large, and if the design idea is adopted, great potential safety hazards exist in the screen pipe descending process, so that the design is not suitable for preventing the screen pipe coupling from being tripped.

Disclosure of Invention

The utility model aims at providing an anticreep that oil well, gas well and water injection well used is detained screen pipe coupling, strengthens the joint strength of screen pipe base pipe and screen pipe coupling body down, prevents that the screen pipe that is in free state from tripping in borehole operation construction, giving the huge loss that production caused. The production cost is reduced, and the production benefit of oil gas exploitation is improved.

The technical scheme of the utility model is realized like this:

an anti-tripping screen pipe coupling used for an oil well, a gas well and a water injection well comprises a screen pipe coupling body, wherein the upper part of the screen pipe coupling body is in threaded connection with an upper screen pipe base pipe, and the lower part of the screen pipe coupling body is in threaded connection with a lower screen pipe base pipe; an anti-back-off end cap is arranged between the upper sieve tube base tube and the sieve tube coupling body, a movable anti-back-off pin capable of being connected with the upper sieve tube base tube is arranged in the anti-back-off end cap, and a fixed anti-back-off pin is arranged between the sieve tube coupling body and the lower sieve tube base tube.

The lower inner cavity of the anti-back-off end cap is larger than the upper inner cavity, and threads are arranged in the lower inner cavity of the anti-back-off end cap and are in threaded connection with the upper part of the sieve tube coupling body; at least two movable anti-back-off pin installation windows are arranged in the upper body of the anti-back-off end cap.

The connecting thread between the anti-back-off end cap and the screen pipe coupling body and the connecting thread between the screen pipe coupling body and the upper screen pipe base pipe are reverse threads.

The screen tube base tube is provided with movable anti-back-off pin mounting holes, and the number of the movable anti-back-off pin mounting windows is equal to that of the movable anti-back-off pin mounting holes in the screen tube base tube.

The length and the width of the movable anti-back-off pin installation window are both larger than the aperture of a movable anti-back-off pin installation hole in the base pipe of the upper sieve pipe; the length of the movable anti-back-off pin installation window is 5 mm-15 mm longer than the aperture of the movable anti-back-off pin installation hole in the upper sieve tube base pipe; the width of the movable anti-back-off pin installation window is 1 mm-5 mm wider than the aperture of the movable anti-back-off pin installation hole in the upper sieve tube base pipe.

The diameter of the lower part of the movable anti-back-off pin body is smaller than that of the upper part body, and external threads are arranged in the lower part body and are in threaded connection with a movable anti-back-off pin mounting hole in the upper sieve tube base tube; the diameter of the upper body of the movable anti-reversing pin conforms to the width of the movable anti-reversing pin installation window in the anti-reversing end cap, and a spring washer is arranged between the upper body of the movable anti-reversing pin and the upper sieve tube base tube.

The maximum outer diameter formed by the movable anti-back-off pin 4 connected with the upper screen pipe base pipe is smaller than or equal to the outer diameters of the anti-back-off end cap and the screen pipe coupling body.

The fixed anti-back-off pin is connected in a threaded connection section between the screen pipe coupling body and the lower screen pipe base pipe, and the maximum outer diameter formed by the connected fixed anti-back-off pin is smaller than or equal to the outer diameter of the screen pipe coupling body.

And lock catch glue is smeared outside the movable anti-reversing pin and the thread section of the fixed anti-reversing pin.

The outer diameter of the sieve tube coupling body is smaller than the outer diameter of an upper sieve tube filter screen welded together with the upper sieve tube base pipe and the outer diameter of a lower sieve tube filter screen welded together with the lower sieve tube base pipe.

Compare with the sieve tube coupling of current connection in the well completion tubular column, the utility model discloses a show the result of use as follows:

the utility model provides a screen pipe coupling body and lower screen pipe base pipe between through threaded connection, before going into the well section of thick bamboo under, just fix the anti-back-off pin on the workshop. The direction of the connecting thread between the anti-back-off end cap and the sieve tube coupling body is opposite to that of the connecting thread between the upper sieve tube base tube and the sieve tube coupling body. Before well completion construction operation, the anti-back-off end cap is connected with the sieve tube coupling body through manual back-off. After the upper sieve tube base tube is fastened to reach the rated torque in construction, the threaded connection condition of the upper sieve tube base tube and the sieve tube coupling body is checked through the movable anti-reverse-fastening pin installation window. After the movable anti-back-off pin installation window and the movable anti-back-off pin installation hole are coincided through forward rotation fine adjustment, the movable anti-back-off pin is tightened, and the anti-back-off end cap and the upper sieve tube base pipe are connected together through the movable anti-back-off pin. And because the threads between the upper sieve tube base tube and the sieve tube coupling body and the threads between the anti-back-off end cap and the upper sieve tube base tube are reverse threads, when the threads of the upper sieve tube base tube tend to be back-off, the anti-back-off end cap and the upper sieve tube base tube tend to be fastened, and the loosening tendency between the upper sieve tube base tube and the sieve tube coupling body is effectively prevented. The utility model discloses a show result of use still lies in:

(1) by adopting the device, the tensile strength of the whole screen pipe string in the well completion pipe string is not affected;

(2) after the threads between the base pipe of the lower sieve tube and the sieve tube coupling body are fastened, the base pipe of the lower sieve tube and the sieve tube coupling body are fixed by a fixing anti-back-off pin, so that the anti-back-off effect between the base pipe of the lower sieve tube and the sieve tube coupling body is ensured;

(3) after the threads between the upper sieve tube base tube and the sieve tube coupling body are fastened, the anti-tripping effect between the upper sieve tube base tube and the sieve tube coupling body is ensured due to the existence of the movable anti-tripping pin;

(4) the upper end of the screen pipe coupling body is connected with the anti-back-off end cap and the upper screen pipe base pipe in opposite directions, and the function of mutual restriction of the positive and negative buttons is fully utilized; if four movable anti-back-off pin mounting windows are arranged in the anti-back-off end cap, the anti-back-off end cap rotates 1/4 circles at most during forward rotation adjustment, the adjustment range during mounting is small, and meanwhile, the trend of loosening threads between the upper sieve tube base tube and the sieve tube coupling body can be restricted in time;

(5) the maximum outer diameter of the device is less than or equal to the maximum outer diameter of the filter screen welded with the upper sieve tube base tube and the lower sieve tube base tube, and construction frictional resistance is not additionally increased, so that construction potential safety hazards do not exist;

(6) the movable anti-reversing pin and the fixed anti-reversing pin are made of high-quality steel and lock catch glue is coated outside the thread section of the movable anti-reversing pin and the fixed anti-reversing pin, so that the shearing capacity of the movable anti-reversing pin and the sealing performance between the sieve tube strings are ensured;

(7) the field operation is simple, and special training is not needed during use.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description, serve to explain the invention and not to limit the invention.

Fig. 1 is a schematic structural diagram of the present invention.

Figure 2 is a schematic structural view of the screen coupling body of figure 1.

Fig. 3 is a schematic structural view of the anti-back-off end cap of fig. 1.

Fig. 4 is a schematic view of the structure a-a in fig. 3.

FIG. 5 is a view of the movable back-off prevention pin window of FIG. 1 in registration with the movable back-off prevention pin hole of the upper screen base.

Detailed Description

The drawings are for reference and illustration purposes only and are not intended to limit the scope of the present disclosure. The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only some embodiments of the invention, and not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are merely for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. In addition, in the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

Referring to fig. 1 to 5, an anti-tripping screen pipe coupling for an oil well, a gas well and a water injection well comprises a screen pipe coupling body 5, wherein the upper part of the screen pipe coupling body 5 is in threaded connection with an upper screen pipe base pipe 1, the lower part of the screen pipe coupling body is in threaded connection with a lower screen pipe base pipe 7, an anti-tripping end cap 2 is arranged between the upper screen pipe base pipe 1 and the screen pipe coupling body 5, a movable anti-tripping pin 4 capable of being connected with the upper screen pipe base pipe 1 is arranged in the anti-tripping end cap 2, and a fixed anti-tripping pin 6 is arranged between the screen pipe coupling body 5 and the lower screen pipe base pipe 7.

On the basis of the first embodiment, the utility model discloses still have following embodiment:

the lower inner cavity of the anti-back-off end cap 2 is larger than the upper inner cavity, and the lower inner cavity of the anti-back-off end cap 2 is internally provided with threads which are in threaded connection with the upper part of the sieve tube coupling body 5; at least two movable anti-back-off pin installation windows 8 are arranged in the upper body of the anti-back-off end cap 2.

The connecting thread between the anti-back-off end cap 2 and the screen pipe coupling body 5 and the connecting thread between the screen pipe coupling body 5 and the upper screen pipe base pipe 1 are reverse threads.

The upper sieve tube base tube 1 is internally provided with movable anti-back-off pin mounting holes 9, and the number of the movable anti-back-off pin mounting windows 8 is equal to that of the movable anti-back-off pin mounting holes 9 in the upper sieve tube base tube 1.

The length and the width of the movable anti-back-off pin installation window 8 are both larger than the aperture of the movable anti-back-off pin installation hole 9 in the upper sieve tube base tube 1; the length of the movable anti-back-off pin installation window 8 is 5 mm-15 mm longer than the aperture of the movable anti-back-off pin installation hole 9 in the upper sieve tube base pipe 1; the width of the movable anti-back-off pin installation window 8 is 1 mm-5 mm wider than the aperture of the movable anti-back-off pin installation hole 9 in the upper sieve tube base pipe 1.

The diameter of the lower part of the movable anti-back-off pin 4 body is smaller than that of the upper part body, and an external thread is arranged in the lower part body and is in threaded connection with a movable anti-back-off pin mounting hole 9 in the upper sieve tube base pipe 1; the diameter of the upper body of the movable anti-back-off pin 4 is consistent with the width of the movable anti-back-off pin installation window 8 in the anti-back-off end cap 2, and a spring washer 3 is arranged between the upper body of the movable anti-back-off pin 4 and the upper sieve tube base tube 1.

The maximum outer diameter formed by the movable anti-back-off pin 4 connected with the upper sieve tube base tube 1 is less than or equal to the outer diameters of the anti-back-off end cap 2 and the sieve tube coupling body 5.

The fixed anti-back-off pin 6 is connected in a threaded connection section between the screen pipe coupling body 5 and the lower screen pipe base pipe 7, and the maximum outer diameter formed by the connected fixed anti-back-off pin 6 is smaller than or equal to the outer diameter of the screen pipe coupling body 5.

And lock catch glue is smeared outside the thread sections of the movable anti-reversing pin 4 and the fixed anti-reversing pin 6, so that the connection strength is further enhanced.

The outer diameter of the sieve tube coupling body 5 is smaller than the outer diameter of an upper sieve tube filter screen welded together with the upper sieve tube base pipe 1 and the outer diameter of a lower sieve tube filter screen welded together with the lower sieve tube base pipe 7, the outer diameter of the sieve tube coupling is consistent with that of a sieve tube string, and construction friction is not additionally increased.

The utility model discloses at the income in-process of well completion tubular column, go up screen pipe base pipe 1 and screen pipe coupling body 5 and tightly detain and reach the rated torque after, prevent down through the activity and detain the tight circumstances of detaining of screw thread between pin installation window 8 looks upper screen pipe base pipe 1 and the screen pipe coupling body 5. After the movable anti-back-off pin installation window 8 in the anti-back-off end cap 2 is finely adjusted through positive rotation and the superposition condition of the movable anti-back-off pin installation hole 9, the movable anti-back-off pin 4 can be fastened. The anti-back-off end cap 2 is connected with the upper sieve tube base pipe 1 through the movable anti-back-off pin 4. When the threads of the upper screen pipe base pipe 1 tend to be buckled reversely, the anti-reversing end cap 2 tends to be buckled tightly, and the threads of the upper screen pipe base pipe 1 are prevented from loosening.

The embodiments described above are merely exemplary embodiments, but the present invention is not limited to these embodiments, and those skilled in the art can make modifications without departing from the spirit and teaching of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and modifications can be made, and equivalents can be substituted for elements thereof. Any modification, equivalent replacement, improvement and the like made within the spirit and the concept of the present invention should be included in the protection scope of the present invention. The scope of protection is therefore not limited to the description above.

Claims (10)

1. The utility model provides an anticreep screen pipe coupling that oil well, gas well and water injection well used, includes screen pipe coupling body, the upper portion and the last screen pipe base pipe threaded connection of screen pipe coupling body and lower part and lower screen pipe base pipe threaded connection, characterized by: an anti-back-off end cap is arranged between the upper sieve tube base tube and the sieve tube coupling body, a movable anti-back-off pin capable of being connected with the upper sieve tube base tube is arranged in the anti-back-off end cap, and a fixed anti-back-off pin is arranged between the sieve tube coupling body and the lower sieve tube base tube.

2. The anti-tripping screen pipe coupling for oil wells, gas wells and water injection wells as claimed in claim 1, wherein the lower inner cavity of the anti-tripping end cap is larger than the upper inner cavity, and threads are arranged in the lower inner cavity of the anti-tripping end cap to be in threaded connection with the upper part of the screen pipe coupling body; at least two movable anti-back-off pin installation windows are arranged in the upper body of the anti-back-off end cap.

3. The anti-tripping screen collar for oil, gas and water injection wells of claim 2, wherein the connecting threads between the anti-tripping end cap and the screen collar body and the connecting threads between the screen collar body and the upper screen base pipe are opposite threads to each other.

4. The anti-tripping screen pipe joint for oil wells, gas wells and water injection wells as claimed in claim 2, wherein the upper screen pipe base pipe is provided with movable anti-tripping pin mounting holes, and the number of the movable anti-tripping pin mounting windows is equal to the number of the movable anti-tripping pin mounting holes in the upper screen pipe base pipe.

5. The anti-tripping screen pipe coupling for oil wells, gas wells and water injection wells as defined in claim 4, wherein the length and width of the movable anti-tripping pin mounting window are both greater than the diameter of the movable anti-tripping pin mounting hole in the base pipe of the upper screen pipe; the length of the movable anti-back-off pin installation window is 5 mm-15 mm longer than the aperture of the movable anti-back-off pin installation hole in the upper sieve tube base pipe; the width of the movable anti-back-off pin installation window is 1 mm-5 mm wider than the aperture of the movable anti-back-off pin installation hole in the upper sieve tube base pipe.

6. The anti-tripping screen pipe coupling for oil wells, gas wells and water injection wells as claimed in claim 4, wherein the diameter of the lower part of the movable anti-tripping pin body is smaller than that of the upper part body, and the lower part body is provided with external threads which are in threaded connection with the mounting hole of the movable anti-tripping pin in the base pipe of the upper screen pipe; the diameter of the upper body of the movable anti-reversing pin conforms to the width of the movable anti-reversing pin installation window in the anti-reversing end cap, and a spring washer is arranged between the upper body of the movable anti-reversing pin and the upper sieve tube base tube.

7. The anti-tripping screen collar for oil, gas and water injection wells as claimed in claim 6, wherein the maximum outer diameter of the movable anti-tripping pin 4 connected with the upper screen base is less than or equal to the outer diameters of the anti-tripping end cap and the screen collar body.

8. The anti-tripping screen collar for oil, gas and water injection wells as defined in claim 2, wherein the fixed anti-tripping pin is connected in the threaded connection between the screen collar body and the lower screen base pipe, and the maximum outer diameter of the connected fixed anti-tripping pin is smaller than or equal to the outer diameter of the screen collar body.

9. The anti-tripping screen pipe coupling for oil, gas and water injection wells as defined in claim 1, wherein the movable anti-tripping pin and the fixed anti-tripping pin are coated with a locking glue on the outside of the thread section.

10. The anti-trip screen collar for oil, gas and water injection wells of claim 1, wherein the screen collar body has an outer diameter less than the outer diameter of the upper screen welded to the upper screen base and the outer diameter of the lower screen welded to the lower screen base.

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