Sucker-rod pump pumping well casing protection device

Abstract

The utility model discloses a sucker-rod pump pumping well casing protection device which comprises a pipe body, a ball seat is sleeved on the pipe body, a ball is arranged on the ball seat, the lower end of the pipe body is connected with a screwed plug body, and a pressure relief hole is arranged on the side wall of the screwed plug body. An upper carbon fiber centralizing ring is arranged above the ball seat, and a lower carbon fiber centralizing ring is arranged below the ball seat. According to the utility model, the plug under the tail pipe is replaced, the contact between the tail pipe under the pump and the sleeve in an oil pumping pipe column is isolated by utilizing the ball and the carbon fiber centralizing body, the friction coefficient between the tail pipe under the pump and the sleeve is reduced, the problem that the sleeve is eccentrically worn by the tail pipe under the pump is effectively solved, the sleeve is prevented from being broken and leaked due to eccentric wear, and the service life of the oil pumping well sleeve is prolonged. Pressure can be relieved through the pressure relief hole, and the high-pressure risk existing in the tail pipe is eliminated.

Description

Technical Field

[0001] The utility model relates to the technical field of oilfield cementing accessory devices, in particular to a casing protection device for a rod pump oil well. Background Art

[0002] According to the investigation of casing damage in oil wells in previous years, the locations of casing leakage in all oil wells have been confirmed through casing inspection and well temperature leak detection. Nearly 65% ​​of the casing damage wells are within 300 meters above the tail pipe of the oil pump, which is judged to be caused by eccentric wear of the casing by the tail pipe under the oil pump.

[0003] At present, in order to prevent the string from wearing the casing eccentrically, a tubing centralizer is used and set on the tubing. In order to center the string tubing in the center of the casing, the outer diameter of the tubing centralizer is designed to be 3 cm smaller than the inner diameter of the casing. This will affect the verticality of the tubing in the well section with a large inclination inflection point of the well trajectory. The large outer diameter centralizer forcibly straightens the tubing, causing the string and its pump pipe rod to wear more eccentrically, shortening the life of the pumping well. If the centralizer is set on the tail pipe, the outer diameter of the centralizer can be reduced, and the lower the centralizer is located, the better the straightening effect on the tail pipe. If you want to set the centralizer at the bottom of the tail pipe, you need to replace the original wire plug.

[0004] However, the mud and sand carried by the well fluid through the screen on the tail pipe are continuously deposited in the tail pipe below, and the organic matter and bacteria in it multiply and rot to produce gas, which is stored between the tail pipe and the plug at a higher pressure. When the plug is removed, the gas and mud inside are ejected at high pressure, endangering personal safety. If a centralizer is used instead of the plug, the mud ejected when the tubing is removed may also damage the centralizer, affecting its reuse.

[0005] Announcement No.: CN206503574U discloses a ball centralizer, which is used to protect the rubber sleeve of the packer lowered into the well from the wear of the casing and the wellbore, and improve the success rate of the operation. It includes a body, a ball mounting hole is provided in the middle of the body, and a ball is placed in the hole, and a pressure cap is threadedly connected to the body to seal the ball in the ball mounting hole.

[0006] This prior art makes full use of the balls to reduce resistance, but setting the lower end of the tail pipe instead of the wire plug will cause high-pressure spraying of mud paste, which will splash onto the balls and affect the reuse of the stabilizer.

[0007] Announcement No.: CN217813365U discloses a liner hanger that is easy to operate. Before going down the well, the bidirectional lead screw is rotated according to the size of the wellhead, and the connecting rod drives the outer support plate to move closer to or away from the casing, so that the liner hanger body can be supported. The arc-shaped outer support plate can conform to the shape of the wellhead, and the ball can reduce the friction of the outer support plate on the well wall. The telescopic rod and the spring can be used to buffer the ruggedness encountered during the downward movement of the outer support plate.

[0008] Announcement No.: CN209670934U discloses a tail pipe hanger that is easy to operate, which can facilitate the straightening of the tail pipe hanger; can flatten and clean protrusions or sand blocks on the well wall; before the tail pipe hanger is lowered into the well, the staff can adjust the length of the left sliding rod and the right sliding rod to the outside of the left sliding groove and the right sliding groove respectively according to the inner diameter of the well, so that there is a small gap between the left scraper and the right scraper and the well wall, so that the left scraper and the right scraper can remove the protrusions and sand blocks on the well wall when the tail pipe hanger is lowered into the well, thereby preventing the tail pipe hanger from being obstructed when entering the well and improving the reliability of use.

[0009] The above two existing technologies make full use of ball resistance reduction and are arranged on the tail pipe. However, when the lower end of the tail pipe is arranged instead of the wire plug, there will be a problem of high-pressure spraying of mud paste, which will splash onto precision parts such as balls or springs, affecting the reuse of the stabilizer.

[0010] In short, the technical solutions of the above-disclosed technologies, the technical problems to be solved and the beneficial effects produced are all different from the present utility model. Regarding more technical features, technical problems to be solved and the beneficial effects of the present utility model, there is no technical inspiration in the above-disclosed technical documents. Utility Model Content

[0011] In view of the above-mentioned defects in the prior art, the purpose of the utility model is to provide a casing protection device for a rod pump oil well, which is arranged at the lower end of the tail pipe by replacing the wire plug and providing pressure relief measures to avoid high-pressure spraying of sludge and gas.

[0012] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0013] A casing protection device for a rod pump oil well comprises a pipe body, a ball seat is sleeved on the pipe body, the ball seat is provided with balls, a thread plug is connected to the lower end of the pipe body, and a pressure relief hole is provided on the side wall of the thread plug.

[0014] An upper coupling hoop is installed at the upper end of the pipe body, and a lower coupling hoop is installed at the lower end of the pipe body.

[0015] The thread plugging body is connected to the pipe body through a lower coupling, and the upper end of the thread plugging body is threadedly connected to the lower end of the lower coupling;

[0016] A conical top screw is arranged at the lower end of the thread plugging body, and the conical top screw presses on the thread plugging body to play a plugging role.

[0017] One third of the ball radius is exposed on the surface of the ball seat.

[0018] An upper carbon fiber straightening ring is arranged above the ball seat, and a lower carbon fiber straightening ring is arranged below the ball seat.

[0019] A first middle locking nut is arranged between the ball seat and the upper carbon fiber straightening ring, and a second middle locking nut is arranged between the ball seat and the lower carbon fiber straightening ring. The first middle locking nut and the second middle locking nut lock the ball seat together.

[0020] An upper locking nut is installed on the upper end of the upper carbon fiber straightening ring, and a lower locking nut is installed on the lower carbon fiber straightening ring.

[0021] Compared with the prior art, the utility model has the following beneficial effects:

[0022] 1. The utility model replaces the wire plug under the tail pipe, utilizes the ball and the carbon fiber straightening body, isolates the contact between the tail pipe under the pump and the casing in the pumping pipe string, reduces the friction coefficient therebetween, effectively solves the problem of eccentric wear of the casing by the tail pipe under the pump, prevents the casing from breaking and leaking due to eccentric wear, and prolongs the service life of the casing of the pumping well.

[0023] 2. After the pumping pipe string is pulled out, the utility model can release pressure and air through the conical top screw and the pressure relief hole, thereby eliminating the high pressure risk in the tail pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of a casing protection device for a rod pump oil well according to the utility model;

[0025] Figure 2 The utility model is applied to the rod pump oil well schematic diagram.

[0026] In the figure: 1, upper coupling; 2, pipe body; 3, upper locking nut; 4, upper carbon fiber straightening ring; 5, first middle locking nut; 6, ball seat; 7, ball; 8, lower carbon fiber straightening ring; 9, lower locking nut; 10, lower coupling; 11, screw plug; 12, pressure relief hole; 13, conical top screw;

[0027] 14. Pumping pipe; 15. Rod pump; 16. Screen pipe; 17. Pump tail pipe; 18. A casing protection device for a rod pumping well; 19. Suspended drop packer; 20. Upper stabilizing body; 21. Sand filter tube; 22. Lower stabilizing body; 23. Completion tail pipe; 24. Thread plug. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] Embodiment 1:

[0030] See also Figure 1 The utility model provides a casing protection device for a rod pump well, comprising a pipe body 2, on which a ball seat 6 is sleeved, and the ball seat 6 is provided with a ball 7, and one third of the radius of the ball 7 is exposed on the surface of the ball seat 6.

[0031] The lower end of the lower coupling 10 is threadedly connected to a thread plug 11, and the side wall of the thread plug 11 is provided with a pressure relief hole 12. The upper end of the thread plug 11 is an inner conical closing, and the lower end of the thread plug 11 is provided with a conical top screw 13. The conical top screw 13 presses against the inner conical closing of the thread plug 11 to play a plugging role. If the conical top screw 13 is not provided, high pressure will not be generated in the lower tail pipe 17 of the pump, but some deposited gravel will leak out of the pressure relief hole, the recovery amount of the deposited gravel will be reduced, and the recovery amount of the completion tail pipe 23 of the completion string will increase.

[0032] An upper coupling 1 is installed at the upper end of the pipe body 2, and a lower coupling 10 is installed at the lower end.

[0033] Embodiment 2:

[0034] The balls in Example 1 are easily stuck and damaged by materials such as gravel in the well, so the following improvements are made: an upper carbon fiber straightening ring 4 is arranged above the ball seat 6, and a lower carbon fiber straightening ring 8 is arranged below the ball seat 6. The carbon fiber material has the characteristic of low friction, and will not increase resistance after being set, which can prevent some gravel from entering the ball seat 6.

[0035] A first middle locking nut 5 is arranged between the ball seat 6 and the upper carbon fiber straightening ring 4, and a second middle locking nut is arranged between the ball seat 6 and the lower carbon fiber straightening ring 8. The first middle locking nut 5 and the second middle locking nut lock the ball seat 6 together.

[0036] The upper end of the upper carbon fiber straightening ring 4 is installed with an upper locking nut 3 to lock the upper carbon fiber straightening ring 4 , and the lower carbon fiber straightening ring 8 is installed with a lower locking nut 9 to lock the lower carbon fiber straightening ring 8 .

[0037] It should be noted that the carbon fiber centralizer itself is a prior art, such as the carbon fiber centralizer disclosed in CN214616403U, which can play the role of centralizing and slowing down the passage of gravel, and those skilled in the art are clear about this.

[0038] Embodiment 3:

[0039] The specific use method of the utility model in combination with all embodiments is as follows:

[0040] like Figure 2 As shown, the rod pump oil well to which the utility model is applied comprises an oil pumping string and a completion string.

[0041] The completion string includes a hanging release packer 19, an upper stabilizing body 20, a sand filter tube 21, a lower stabilizing body 22, a completion tail pipe 23, and a wire plug 24 which are arranged on the casing from top to bottom in sequence. The completion string is lowered into the well through the oil pipe to be set and released, and the two stabilizing bodies prevent the casing from being damaged.

[0042] The pumping string includes a pumping pipe 14, a rod pump 15, a screen 16, a pump tail pipe 17, and a rod pump well casing protection device 18, which are connected in sequence from top to bottom. Specifically, the upper coupling 1 is connected to the bottom of the pump tail pipe 17 to replace the original wire plug.

[0043] A casing protection device 18 for a rod pump well changes the contact between the lower tail pipe 18 of the pump and the inner wall of its casing to the contact between the upper carbon fiber straightening ring 4, the ball 7, and the lower carbon fiber straightening ring 8 and the inner wall of the casing of the rod pump well, that is, the direct eccentric friction contact is changed to rolling contact, which reduces friction and protects the casing.

[0044] During oil production, the oil in the oil layer enters the completion string from the sand filter tube 21, enters the pumping string from the screen tube 16, and is produced to the ground.

[0045] During repair and maintenance work, after the pumping pipe is pulled out, the personnel avoid the pressure relief hole 12 of the screw plug 11, and slowly loosen the conical top screw 13 several times, so that the gas and mud in the tail pipe 17 and the pipe body 2 are ejected in a controlled manner to eliminate the risk of high pressure.

[0046] All components and connection methods of components not discussed in this application belong to the known technologies in this technical field and can be directly applied without further explanation.

[0047] In the present invention, the term "plurality" means two or more than two, unless otherwise clearly defined. The terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0048] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0049] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0050] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A casing protection device for a rod pump oil well, comprising a pipe body, a ball seat is sleeved on the pipe body, and the ball seat is provided with a ball, characterized in that: The lower end of the tube body is connected with a thread plugging body, and a pressure relief hole is arranged on the side wall of the thread plugging body.

2. The casing protection device for a sucker rod pump oil well according to claim 1, characterized in that: An upper coupling hoop is installed at the upper end of the pipe body, and a lower coupling hoop is installed at the lower end of the pipe body.

3. The casing protection device for a sucker rod pump oil well according to claim 2, characterized in that: The thread plugging body is connected to the pipe body through a lower coupling, and the upper end of the thread plugging body is threadedly connected to the lower end of the lower coupling; A conical top screw is arranged at the lower end of the thread plugging body, and the conical top screw presses on the thread plugging body to play a plugging role.

4. The casing protection device for a sucker rod pump oil well according to claim 1, characterized in that: One third of the ball radius is exposed on the surface of the ball seat.

5. The casing protection device for a sucker rod pump oil well according to claim 1, characterized in that: An upper carbon fiber straightening ring is arranged above the ball seat, and a lower carbon fiber straightening ring is arranged below the ball seat.

6. The casing protection device for a sucker rod pump oil well according to claim 5, characterized in that: A first middle locking nut is arranged between the ball seat and the upper carbon fiber straightening ring, and a second middle locking nut is arranged between the ball seat and the lower carbon fiber straightening ring. The first middle locking nut and the second middle locking nut lock the ball seat together.

7. The casing protection device for a sucker rod pump oil well according to claim 6, characterized in that: An upper locking nut is installed on the upper end of the upper carbon fiber straightening ring, and a lower locking nut is installed on the lower carbon fiber straightening ring.

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