Centralizer

Abstract

The utility model discloses a centralizer, which belongs to the technical field of downhole tools and comprises a mandrel, a centralizing sliding sleeve and a rotary moving mechanism, the centralizing sliding sleeve is slidably sleeved on the outer wall of the mandrel, and an oil guide groove or an oil guide hole is arranged on the centralizing sliding sleeve and serves as a flow passage for fluid to penetrate through the centralizer; the rotary moving mechanism takes axial reciprocating motion between the centralizing sliding sleeve and the mandrel as driving force to drive the centralizing sliding sleeve to rotate in the same direction relative to the center line of the mandrel, so that the centralizing sliding sleeve rotates automatically, abrasion between the centralizing sliding sleeve and an oil pipe is more uniform, and local abrasion is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of downhole tools, in particular to a centralizer used for centralizing downhole equipment, such as a pumping rod. Background Art

[0002] A casing centralizer is a commonly used downhole tool. Its main function is to ensure that downhole equipment, such as sucker rods, are accurately located on the central axis of the casing to optimize oil production efficiency and protect the equipment from unnecessary wear. The sucker rod interacts with the fluid in the tubing through the plunger at its bottom to extract oil from the oil well. Specifically, the sucker rod drives the plunger to move up and down in the tubing. When the plunger moves up, the internal valve closes, pushing the upper fluid to flow upward; when the plunger moves down, the internal valve opens, allowing the lower liquid to pass through the plunger and transfer to the upper part, thereby achieving continuous extraction of bottom hole oil. However, the rigid centralizers in the existing rod pumping system show obvious structural limitations. These centralizers are usually fixed on the outer wall of the sucker rod, and maintain linear contact with the inner wall when moving along the axial direction of the tubing, resulting in serious local wear problems at the contact part, which in turn affects the overall life of the equipment. In addition, this eccentric wear phenomenon may also cause sucker rod breakage, tubing wear and leakage, seriously interfering with the normal production of the oil well. Therefore, the current inadequacy of centralizer technology has become an important factor restricting the efficient and stable exploitation of oil fields, and it is urgent to solve this problem through technological innovation. Utility Model Content

[0003] In order to solve the above problems, the utility model provides a centralizer, which, during operation, uses the power of the reciprocating movement of the sucker rod to drive the centralizer sleeve to rotate relative to the core shaft, so that the contact point between the centralizer sleeve and the inner wall of the oil pipe changes continuously, making the wear more uniform.

[0004] The specific scheme of the utility model is as follows:

[0005] A centralizer, comprising:

[0006] A mandrel, with connecting parts at both ends of the mandrel for connecting with other pipe strings;

[0007] A centralizing sleeve, wherein the centralizing sleeve is slidably mounted on the outer wall of the mandrel, and an oil guide groove or an oil guide hole is provided on the centralizing sleeve as a flow channel for the fluid to pass through the centralizer;

[0008] A rotary movement mechanism uses the axial reciprocating motion between the centralizing sleeve and the core shaft as a driving force to drive the centralizing sleeve to rotate in the same direction relative to the center line of the core shaft, thereby causing the centralizing sleeve to spin. In this way, the wear between the centralizing sleeve and the oil pipe is more uniform, reducing local wear.

[0009] As a specific embodiment of the utility model, the rotational movement mechanism includes a track groove and a guide pin, wherein one of the track groove and the guide pin is fixed on the straightening sleeve, and the other is fixed on the core shaft; the track groove is an annular structure connected end to end, and is composed of upper and lower serrated grooves with the same number of teeth, and the openings of the upper and lower serrated grooves are opposite and staggered in the circumferential direction; the guide pin is arranged along the radial direction of the core shaft, one end of which is inserted into the track groove and slides along the track groove, when the straightening sleeve and the core shaft move axially in a first direction, the guide pin enters the Nth upper serrated groove from the Nth lower serrated groove, and when the sleeve and the core shaft move axially in a second direction away from the first direction, the guide pin enters the N+1th lower serrated groove adjacent to the Nth lower serrated groove from the Nth upper serrated groove, thereby causing the sleeve to rotate relative to the core shaft.

[0010] As a specific embodiment of the utility model, the lower serrated groove includes a lower inclined side wall, and the upper serrated groove includes an upper inclined side wall. When the straightening sleeve and the core shaft move axially in the first direction, the guide pin moves from the Nth lower serrated groove along the first direction until it abuts the upper inclined side wall, and then under the guidance of the upper inclined side wall, the guide pin moves along the first direction while rotating around the center line of the core shaft to enter the Nth upper serrated groove. When the straightening sleeve and the core shaft move axially in the second direction, the guide pin moves from the Nth upper serrated groove along the second direction until it abuts the lower inclined side wall, and then under the guidance of the lower inclined side wall, the guide pin moves along the second direction while rotating around the center line of the core shaft to enter the N+1th lower serrated groove, and so on.

[0011] As a specific implementation of the utility model, the track groove is embedded in the inner wall of the straightening sleeve, and the guide pin is fixed on the peripheral side wall of the core shaft.

[0012] In some embodiments, a first limiting portion and a second limiting portion are provided at intervals on the outer wall of the core shaft; the straightening sleeve is slidably sleeved on the outer wall of the core shaft and is located between the first limiting portion and the second limiting portion.

[0013] Compared with the existing technology, it has the following advantages:

[0014] The centralizer of the utility model utilizes the power of the reciprocating movement of the sucker rod to drive the centralizer sliding sleeve in the centralizer to rotate relative to the core shaft, so that the contact position between the centralizer sliding sleeve and the inner wall of the oil pipe changes continuously, making the wear more uniform and reducing local wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1It is a three-dimensional schematic diagram of a specific embodiment of the centralizer of the utility model;

[0016] Figure 2 It is a three-dimensional schematic diagram of another specific embodiment of the centralizer of the utility model;

[0017] Figure 3 for Figure 2 Schematic diagram of the structure of the central shaft;

[0018] Figure 4 for Figure 2 A schematic diagram of the structure of the middle track groove;

[0019] Figure 5 for Figure 2 A trajectory diagram of the middle guide pin moving along the trajectory groove;

[0020] In the figure, the mandrel 1000, the straightening sleeve 2000,

[0021] The connecting portion 1100, the oil guide groove 1200, the track groove 3100, the guide pin 3200, the upper sawtooth groove 3110, the lower sawtooth groove 3120,

[0022] The upper inclined side wall 3111 and the lower inclined side wall 3121 . DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with the embodiments and drawings, but the implementation manner of the present invention is not limited thereto.

[0024] Example

[0025] Please refer to Figure 1 to Figure 5 , which shows the structure of two specific embodiments of the centralizer of the utility model. A centralizer of the utility model includes a core shaft 1000, a centralizing sleeve 2000 and a rotation and movement mechanism. Both ends of the core shaft 1000 are provided with connecting parts 1100 for connecting with other pipe columns. For example, in this embodiment, it is connected with a sucker rod (not shown in the figure); the centralizing sleeve 2000 is slidably sleeved on the outer wall of the core shaft 1000, and the centralizing sleeve 2000 is provided with an oil guide groove 1200 or an oil guide hole as a flow The body passes through the flow channel of the stabilizer; the rotary movement mechanism uses the axial reciprocating motion between the centralizing sleeve 2000 and the core shaft 1000 as the driving force, driving the centralizing sleeve 2000 to rotate in the same direction relative to the center line of the core shaft 1000, so that when the sucker rod reciprocates, the centralizing sleeve 2000 spins around the sucker rod, so that the contact point between the centralizing sleeve 2000 and the oil pipe on the circumference is constantly changing, which can make the wear of the two on the circumference more uniform and reduce local wear.

[0026] In some embodiments, Figure 3 and Figure 4 As shown, the rotation movement mechanism includes a track groove 3100 and a guide pin 3200, wherein one of the track groove 3100 and the guide pin 3200 is fixed on the straightening sleeve 2000, and the other is fixed on the core shaft 1000, as shown in FIG. Figure 1 , 2 In the embodiment shown, the track groove 3100 is embedded in the inner wall of the centralizing sleeve 2000, and the guide pin 3200 is fixed on the peripheral side wall of the mandrel 1000. Of course, in other embodiments, the track groove 3100 can also be embedded in the outer peripheral side wall of the mandrel 1000, and the guide pin 3200 can be fixed on the inner wall of the centralizing sleeve 2000. The track groove 3100 is an annular structure connected end to end, such as Figure 4 As shown, it is composed of upper and lower sawtooth grooves with the same number of teeth, the openings of the upper and lower sawtooth grooves are opposite and staggered in the circumferential direction; the guide pin 3200 is arranged along the radial direction of the core shaft 1000, one end of which is inserted into the track groove 3100 and slides along the track groove 3100, as shown in FIG. Figure 5 As shown, when the straightening sleeve 2000 and the core shaft 1000 move axially in the first direction, the guide pin 3200 enters the Nth upper serrated groove 3110 from the Nth lower serrated groove 3120; when the sleeve and the core shaft 1000 move axially in the second direction away from the first direction, the guide pin 3200 enters the N+1th lower serrated groove 3120 adjacent to the Nth lower serrated groove 3120 from the Nth upper serrated groove 3110, thereby causing the sleeve to rotate relative to the core shaft 1000. Specifically, the lower sawtooth groove 3120 includes a lower oblique side wall 3121, and the upper sawtooth groove 3110 includes an upper oblique side wall 3111. When the straightening sleeve 2000 and the core shaft 1000 move axially in the first direction, the guide pin 3200 moves from the Nth lower sawtooth groove 3120 along the first direction until it abuts against the upper oblique side wall 3111, and then the guide pin 3200 moves along the first direction under the guidance of the upper oblique side wall 3111 while rotating around the center line of the core shaft 1000 to enter the Nth lower sawtooth groove 3120. N upper serrated grooves 3110. When the straightening sleeve 2000 and the core shaft 1000 move axially in the second direction, the guide pin 3200 moves from the Nth upper serrated groove 3110 along the second direction until it abuts against the lower inclined side wall 3121. Then, under the guidance of the lower inclined side wall 3121, the guide pin 3200 moves in the second direction while rotating around the center line of the core shaft 1000 to enter the N+1th lower serrated groove 3120. By analogy, the straightening sleeve 2000 rotates relative to the core shaft.

[0027] In some embodiments, the outer wall of the core shaft 1000 is spaced apart with a first limit portion and a second limit portion; the straightening sleeve 2000 is slidably sleeved on the outer wall of the core shaft 1000 and is located between the first limit portion and the second limit portion, thereby limiting the straightening sleeve 2000 to slide between the first limit portion and the second limit portion of the core shaft.

[0028] The above is only a preferred specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the embodiments of the present invention should be covered within the protection scope of the present invention.

Claims

1. A centralizer, characterized in that: include: A mandrel, wherein both ends of the mandrel are provided with connecting parts; A centralizing sleeve, wherein the centralizing sleeve is slidably mounted on the outer wall of the mandrel, and an oil guide groove or an oil guide hole is provided on the centralizing sleeve as a flow channel for the fluid to pass through the centralizer; A rotational movement mechanism uses the axial reciprocating motion between the centralizing sleeve and the core shaft as a driving force to drive the centralizing sleeve to rotate in the same direction relative to the center line of the core shaft.

2. A centralizer according to claim 1, characterized in that: The rotational movement mechanism includes a track groove and a guide pin, wherein one of the track groove and the guide pin is fixed on the straightening sleeve, and the other is fixed on the core shaft; the track groove is an annular structure connected end to end, and is composed of upper and lower serrated grooves with the same number of teeth, and the openings of the upper and lower serrated grooves are opposite and staggered in the circumferential direction; the guide pin is arranged along the radial direction of the core shaft, one end of which is inserted into the track groove and slides along the track groove, when the straightening sleeve and the core shaft move axially in a first direction, the guide pin enters the Nth upper serrated groove from the Nth lower serrated groove, and when the sleeve and the core shaft move axially in a second direction away from the first direction, the guide pin enters the N+1th lower serrated groove adjacent to the Nth lower serrated groove from the Nth upper serrated groove.

3. A centralizer according to claim 2, characterized in that: The lower serrated groove includes a lower inclined side wall, and the upper serrated groove includes an upper inclined side wall; when the straightening sleeve and the core shaft move along the first direction, the guide pin moves from the Nth lower serrated groove along the first direction until it abuts the upper inclined side wall, and then, under the guidance of the upper inclined side wall, the guide pin moves along the first direction while rotating around the center line of the core shaft to enter the Nth upper serrated groove; when the straightening sleeve and the core shaft move along the second direction, the guide pin moves from the Nth upper serrated groove along the second direction until it abuts the lower inclined side wall, and then, under the guidance of the lower inclined side wall, the guide pin moves along the second direction while rotating around the center line of the core shaft to enter the N+1th lower serrated groove.

4. A centralizer according to claim 2, characterized in that: The track groove is embedded in the inner wall of the straightening sleeve, and the guide pin is fixed on the peripheral side wall of the core shaft.

5. A centralizer according to claim 1, characterized in that: The outer wall of the core shaft is provided with a first limiting portion and a second limiting portion at intervals; the straightening sleeve is slidably sleeved on the outer wall of the core shaft and is located between the first limiting portion and the second limiting portion.

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