Rotatable screw pump centralizer

Abstract

The utility model discloses a rotatable screw pump centralizer, which relates to the field of oil extraction in oil fields, and comprises an oil pipe, a heavy centralizer is arranged in the oil pipe, a light centralizer is also arranged in the oil pipe, the heavy centralizer comprises a heavy shaft body, a heavy rotating bushing is rotatably mounted on the outer wall of the heavy shaft body, and the heavy rotating bushing is rotatably mounted on the outer wall of the heavy shaft body. The inner wall of the heavy rotating lining is in clearance contact with the outer wall of the heavy shaft body, a plurality of lining bosses are further arranged outside the heavy rotating lining, the included angle between the lining bosses is 120 degrees, the lining bosses can be in contact with the inner wall of an oil pipe, the light centralizer comprises a light shaft body, three attaching cambered surfaces are arranged on the outer wall of a light external thread, and the light shaft body is provided with a plurality of light outer threads. According to the oil pipe centralizer, the heavy centralizer is arranged on a well section with serious eccentric wear, and the light centralizer is arranged on a well section with slight eccentric wear, so that rotation of the rotary lining and the shaft body is reduced, the service life of the centralizer is prolonged, and the risk of jamming is reduced.

Description

Technical Field

[0001] The utility model relates to the field of oil field production, in particular to a rotatable screw pump centralizer. Background Art

[0002] In recent years, with the increase in demand for oil production, screw pumps have been widely used in oil field exploitation due to their advantages of small size, low energy consumption, convenient maintenance and high efficiency. As a result, various production contradictions have frequently emerged, among which the problem of eccentric wear of rods and pipes is particularly prominent, which has seriously affected the development of screw pumps. At present, the eccentric wear of rods and pipes in screw pump wells is affected by many factors such as wellbore trajectory, rod deformation and rod column vibration. Eccentric wear not only leads to the inability to operate normally, but also increases maintenance costs. Therefore, in order to develop oil resources more economically and reasonably, research on anti-eccentric wear technology for screw pump wells can not only reduce operating costs and improve corporate economic benefits, but also has important significance for alleviating energy shortages.

[0003] A Chinese invention patent with announcement number CN104153719B discloses a centralizer. The centralizer of this invention does not use elastic parts as centralizer blocks, so that it has a stable centralizing effect. At the same time, the centralizer of this invention has a slot on the center tube and a locking ring on the support shoe that matches the slot, so that after the pressure in the center tube is released, the centralizer can still be in a centralizing state and can maintain it for a long time.

[0004] However, in actual applications, due to the influence of oil well type, well conditions, its own structure, material and other factors, the eccentric wear phenomenon in some wells is still serious, and pipe breakage, pipe cracking, pipe detachment and sucker rod breakage still exist. The nested centralizer of screw pump wells has difficulty in rotating the centralizer sleeve under the bending of the rod column, resulting in a decrease in the anti-eccentric wear characteristics of the centralizer and failure to achieve the expected effect. At the same time, the problem of pump jamming and rework caused by heat, falling off, accumulation and displacement of the centralizer on the injection molded rod also restricts the effective implementation of pump inspection rate control. Utility Model Content

[0005] In view of the above technical problems, the utility model proposes the following technical solutions:

[0006] A rotatable screw pump centralizer, comprising an oil pipe, the oil pipe is arranged in an oil well, one end of the oil pipe is arranged outside the oil well, and the other end of the oil pipe is provided with a screw pump for driving the crude oil to move, characterized in that: a heavy centralizer is arranged in the oil pipe, a light centralizer is also arranged in the oil pipe, a sucker rod is also arranged in the oil pipe, and both ends of the sucker rod are respectively provided with an internal thread and an external thread;

[0007] The heavy centralizer comprises a heavy shaft body, a heavy rotating bushing is rotatably mounted on the outer wall of the heavy shaft body, the inner wall of the heavy rotating bushing is in gap contact with the outer wall of the heavy shaft body, a plurality of bushing bosses are arranged outside the heavy rotating bushing, the angles between the plurality of bushing bosses are all 120 degrees, and the bushing bosses are in contact with the inner wall of the oil pipe;

[0008] The light centralizer comprises a light shaft body, one end of which is provided with a light rotating bushing, the outer wall of which is provided with three fitting arc surfaces, the curvature of the fitting arc surfaces is the same as the curvature of the inner wall of the oil pipe, and the outer wall of the light rotating bushing contacts the inner wall of the oil pipe.

[0009] Furthermore, a heavy external thread is provided at one end of the heavy shaft body, and the heavy external thread is engaged with the internal thread on the sucker rod. A heavy internal thread is provided at one end of the heavy shaft body away from the heavy external thread, and the heavy internal thread is engaged with the external thread on the sucker rod. A heavy lower thread is provided on the outer wall of the heavy shaft body close to the heavy external thread.

[0010] Furthermore, a lower stop cap is installed on the upper thread of the heavy lower thread, one end of the heavy rotating bushing is in contact with the lower stop cap, and a plurality of main bearings are also arranged on the outer wall of the heavy shaft body, the main bearings are arranged at both ends of the heavy rotating bushing, the outer ring of the main bearing is fixedly connected to the heavy rotating bushing, and the inner ring of the main bearing is fixedly connected to the heavy shaft body.

[0011] Furthermore, the main bearing is also arranged between the heavy rotating sleeve and the lower stop cap, and the lower stop cap contacts the main bearing to limit the movement of the main bearing and the heavy rotating sleeve. The main bearing is used to support the force perpendicular to the axis of the heavy shaft body on the heavy rotating sleeve. One end of the heavy shaft body on which the heavy internal thread is provided is also provided with a heavy external end thread, and a heavy upper thread is installed on the heavy external end thread. The heavy upper thread contacts one end of the heavy rotating sleeve to limit the position of the heavy rotating sleeve.

[0012] Furthermore, the light external thread is engaged with the internal thread on the sucker rod, a light internal thread is provided on the end of the light shaft body away from the light external thread, the light internal thread is engaged with the external thread on the sucker rod, and a light lower thread is provided on the outer wall of the light shaft body close to the light external thread.

[0013] Furthermore, a supporting stop cap is installed on the upper thread of the light lower thread, and a blocking convex ring is provided on the outer wall of the light shaft body near one end of the light inner thread to achieve a limiting effect, and a light rotating bushing is rotatably installed on the outer wall of the light shaft body, and the light rotating bushing is arranged between the blocking convex ring and the supporting stop cap.

[0014] Compared with the prior art, the present invention has the following advantages: (1) by setting a heavy stabilizer in a well section with severe eccentric wear, the heavy stabilizer can replace the hard friction between the remote heavy shaft body and the heavy rotating bushing through the rotation of the main bearing, the heavy rotating bushing and the heavy shaft body, thereby extending the service life of the stabilizer and reducing the risk of jamming; (2) the heavy shaft body and the heavy rotating bushing of the device can also rotate or rotate together. When the inner wall of the oil pipe is waxed or the oil is thick, the heavy rotating bushing and the inner wall of the oil pipe are stuck, and the heavy shaft body can rotate by itself, avoiding the hard friction between the heavy stabilizer and the inner wall of the oil pipe, thereby extending the maintenance-free period of the oil well; (3) by setting a light stabilizer in a well section with slight eccentric wear, the device can reduce the friction resistance between the stabilizer and the inner wall of the oil pipe by contacting the inner wall of the oil pipe with the three arc-shaped surfaces on the outer wall of the light external thread, thereby further reducing wear. (4) When the light rotating bushing on the light centralizer gets stuck with the inner wall of the oil pipe, the light shaft body and the light rotating bushing on the light centralizer can rotate independently without getting stuck, thereby reducing the risk of getting stuck and breaking. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0016] Figure 2 This is a schematic diagram of the structure of the heavy centralizer of the utility model.

[0017] Figure 3 It is a schematic diagram of the cross-section structure of the lower baffle cap, main bearing, heavy rotating bushing and heavy upper thread of the utility model.

[0018] Figure 4 It is a schematic diagram of the bushing boss structure of the utility model.

[0019] Figure 5 It is a structural schematic diagram of the light centralizer of the utility model.

[0020] Figure 6 It is a schematic diagram of the cross-sectional structure of the light shaft body, support cap and light rotating bushing of the utility model.

[0021] Figure 7 This is a schematic diagram of the light external thread structure of the utility model.

[0022] Figure markings: 11-sucker rod; 44-oil pipe; 55-screw pump; 22-heavy centralizer; 201-heavy external thread; 202-heavy lower thread; 203-lower stop cap; 204-main bearing; 205-heavy rotating bushing; 206-heavy internal thread; 207-heavy upper thread; 208-bushing boss; 209-heavy shaft body; 210-heavy external end thread; 33-light centralizer; 301-light external thread; 302-light lower thread; 303-support stop cap; 304-light rotating bushing; 305-blocking convex ring; 306-light internal thread; 308-light shaft body. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0024] like Figure 1 As shown, a rotatable screw pump centralizer includes an oil pipe 44, wherein the oil pipe 44 is arranged in an oil well, one end of the oil pipe 44 is arranged outside the oil well, and the other end of the oil pipe 44 is provided with a screw pump 55 for driving the crude oil to move, a heavy centralizer 22 is arranged in the oil pipe 44, a light centralizer 33 is also arranged in the oil pipe 44, and a sucker rod 11 is also arranged in the oil pipe 44, and both ends of the sucker rod 11 are respectively provided with an internal thread and an external thread.

[0025] like Figure 2 Shown to Figure 4 As shown, the heavy centralizer 22 includes a heavy shaft body 209, one end of which is provided with a heavy external thread 201, and the heavy external thread 201 can be engaged with the internal thread on the sucker rod 11. The end of the heavy shaft body 209 away from the heavy external thread 201 is provided with a heavy internal thread 206, and the heavy internal thread 206 can be engaged with the external thread on the sucker rod 11. When the heavy internal thread 206 on the heavy shaft body 209 is engaged with the heavy external thread 201 at the same time, the heavy centralizer 22 can enter the working state.

[0026] like Figures 2 to 4As shown, a heavy lower thread 202 is provided on the outer wall of the heavy shaft body 209 near the heavy outer thread 201, and a lower stop cap 203 is threadedly installed on the heavy lower thread 202. The lower stop cap 203 needs to be coated with anaerobic glue before being installed on the heavy lower thread 202 to achieve a tightening effect. A heavy rotating bushing 205 is rotatably installed on the outer wall of the heavy shaft body 209, and the inner wall of the heavy rotating bushing 205 is in gap contact with the outer wall of the heavy shaft body 209, and one end of the heavy rotating bushing 205 is in contact with the lower stop cap 203. A plurality of main bearings 204 are also provided on the outer wall of the heavy shaft body 209, and the main bearings 204 are arranged at both ends of the heavy rotating bushing 205, and the outer ring of the main bearing 204 is fixedly connected to the heavy rotating bushing 205, and the inner ring of the main bearing 204 is fixedly connected to the heavy shaft body 209. It is also arranged between the heavy rotating bushing 205 and the lower stop cap 203. The lower stop cap 203 contacts the main bearing 204 to limit the movement of the main bearing 204 and the heavy rotating bushing 205. The main bearing 204 is used to support the force perpendicular to the axis of the heavy shaft body 209 on the heavy rotating bushing 205. The end of the heavy shaft body 209 on which the heavy internal thread 206 is arranged is also provided with a heavy external end thread 210. The heavy external end thread 210 is threadedly installed with a heavy upper thread 207. The heavy upper thread 207 contacts the end of the heavy rotating bushing 205 away from the lower stop cap 203 to limit the position of the heavy rotating bushing 205. A plurality of bushing bosses 208 are also arranged outside the heavy rotating bushing 205. The angles between the plurality of bushing bosses 208 are all one hundred and twenty degrees. The bushing bosses 208 can contact the inner wall of the oil pipe 44.

[0027] The specific assembly process of the heavy centralizer 22 is as follows: first wipe each component clean with diesel, place the heavy shaft body 209 on the mounting table, then sleeve the heavy rotating bushing 205 on the outer wall of the heavy shaft body 209, and then slowly knock the main bearings 204 on both sides of the heavy rotating bushing 205 to the installation position on the heavy shaft body 209 with a wooden hammer or a rubber hammer. Here, the inner ring of the main bearing 204 and the outer wall of the heavy shaft body 209 are interference connected, and then the inner wall of the heavy rotating bushing 205 and the outer ring of the lower stop cap 203 are interference connected. After the main bearing 204 is assembled, the lower stop cap 203 and the heavy upper thread 207 are respectively screwed into the heavy lower thread 202 and the heavy outer end thread 210 on the heavy shaft body 209. Note that before screwing in, anaerobic glue needs to be applied to the threads of the lower stop cap 203 and the heavy upper thread 207 to tighten them to prevent the lower stop cap 203 and the heavy upper thread 207 from falling off when the heavy centralizer 22 is working.

[0028] like Figures 5 to 7As shown, the light centralizer 33 includes a light shaft body 308, one end of the light shaft body 308 is provided with a light external thread 301, the light external thread 301 can be engaged with the internal thread on the sucker rod 11, and the end of the light shaft body 308 away from the light external thread 301 is provided with a light internal thread 306, the light internal thread 306 can be engaged with the external thread on the sucker rod 11. When the light external thread 301 on the light shaft body 308 is engaged with the light internal thread 306 at the same time, the light centralizer 33 can enter the working state, and the outer wall of the light shaft body 308 close to the light external thread 301 is provided with a light lower thread 302, and the light lower thread 302 is threadedly installed with a support cap 303. Before being installed on the light lower thread 302, the support cap 303 needs to be coated with anaerobic glue for tightening effect. A blocking convex ring 305 is provided on the outer wall of the light shaft body 308 near one end of the light inner thread 306 for limiting effect. A light rotating bushing 304 is rotatably installed on the outer wall of the light shaft body 308. The light rotating bushing 304 is arranged between the blocking convex ring 305 and the support cap 303. The outer wall of the light rotating bushing 304 is provided with three fitting arc surfaces. The curvature of the fitting arc surfaces is the same as the curvature of the inner wall of the oil pipe 44. The outer wall pattern of the light rotating bushing 304 can refer to the Lelo triangle, and the outer wall of the light rotating bushing 304 can contact the inner wall of the oil pipe 44.

[0029] The assembly method of the light straightener 33 is as follows: first wipe each component clean with diesel, place the light shaft body 308 on the mounting table, put the light rotating bushing 304 on the outer wall of the light shaft body 308, let one end of the light rotating bushing 304 contact with the blocking convex ring 305, then apply anaerobic glue to the thread of the support cap 303, and then screw the support cap 303 on the light lower thread 302. Here, the support cap 303 will limit the position of the light rotating bushing 304, so the support cap 303 will contact with the light rotating bushing 304.

[0030] Working principle: When using the heavy centralizer 22 and the light centralizer 33 in the oil well, firstly optimize the design of the lifting string of the constructed oil well with the help of the lifting design software, and then optimize the anti-eccentric wear according to the well depth structure data of the oil well. During the construction, the stator in the screw pump 55 is lowered to the specified position along with the oil pipe 44 according to the construction design, and then the rotor in the screw pump 55 is connected to the sucker rod 11. According to the anti-eccentric wear optimization in the previous design, in the well section with severe eccentric wear, a heavy centralizer 22 needs to be connected between the couplings of each sucker rod 11. In the well section with slight eccentric wear, a light centralizer 33 is connected to every other sucker rod 11, and no connection is required in the place without eccentric wear, until the rotor in the screw pump 55 is lowered to the specified position, and finally the sucker rod 11 is connected to the ground drive device.

[0031] When the ground drive device is started, the sucker rod 11 will drive the heavy shaft body 209 and the light shaft body 308 to continuously transmit force, so that the rotor in the screw pump 55 rotates, and the crude oil is driven to move by the rotation of the rotor. In the well section with severe eccentric wear, the multiple bushing bosses 208 on the heavy rotating bushing 205 will be in close contact with the inner wall of the heavy rotating bushing 205, and the heavy shaft body 209 will rotate within the inner wall of the bushing boss 208. In the well section with slight eccentric wear, the light rotating bushing 304 can also support the light centralizer 33 through the special outer wall shape, so that the light shaft body 308 on the light centralizer 33 can rotate freely for power transmission, thereby reducing friction resistance and extending the life of the centralizer.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention.

Claims

1. A rotatable screw pump centralizer, comprising an oil pipe (44), wherein the oil pipe (44) is arranged in an oil well, one end of the oil pipe (44) is arranged outside the oil well, and a screw pump (55) is arranged at the other end of the oil pipe (44) to drive the movement of crude oil, characterized in that: A heavy centralizer (22) is arranged in the oil pipe (44), a light centralizer (33) is also arranged in the oil pipe (44), a sucker rod (11) is also arranged in the oil pipe (44), and both ends of the sucker rod (11) are respectively provided with an internal thread and an external thread; The heavy centralizer (22) includes a heavy shaft body (209), a heavy rotating bushing (205) is rotatably mounted on the outer wall of the heavy shaft body (209), the inner wall of the heavy rotating bushing (205) is in gap contact with the outer wall of the heavy shaft body (209), a plurality of bushing bosses (208) are further arranged outside the heavy rotating bushing (205), the angles between the plurality of bushing bosses (208) are all 120 degrees, and the bushing bosses (208) are in contact with the inner wall of the oil pipe (44); The light centralizer (33) comprises a light shaft body (308), on the outer wall of which a light rotating bushing (304) is rotatably mounted, the outer wall of which is provided with three fitting arc surfaces, the curvature of which is the same as the curvature of the inner wall of the oil pipe (44), and the outer wall of the light rotating bushing (304) is in contact with the inner wall of the oil pipe (44).

2. A rotatable screw pump centralizer according to claim 1, characterized in that: One end of the heavy shaft body (209) is provided with a heavy external thread (201), and the heavy external thread (201) is meshed with the internal thread on the sucker rod (11); one end of the heavy shaft body (209) away from the heavy external thread (201) is provided with a heavy internal thread (206), and the heavy internal thread (206) is meshed with the external thread on the sucker rod (11); and a heavy lower thread (202) is provided on the outer wall of the heavy shaft body (209) close to the heavy external thread (201).

3. A rotatable screw pump centralizer according to claim 2, characterized in that: A lower stop cap (203) is threadedly installed on the heavy lower thread (202), one end of the heavy rotating bushing (205) is in contact with the lower stop cap (203), and a plurality of main bearings (204) are also arranged on the outer wall of the heavy shaft body (209), the main bearings (204) are arranged at both ends of the heavy rotating bushing (205), the outer ring of the main bearing (204) is fixedly connected to the heavy rotating bushing (205), and the inner ring of the main bearing (204) is fixedly connected to the heavy shaft body (209).

4. A rotatable screw pump centralizer according to claim 3, characterized in that: The main bearing (204) is also arranged between the heavy rotating sleeve (205) and the lower stop cap (203). The lower stop cap (203) contacts the main bearing (204) to limit the movement of the main bearing (204) and the heavy rotating sleeve (205). The main bearing (204) is used to support the force perpendicular to the axis of the heavy shaft body (209) on the heavy rotating sleeve (205). One end of the heavy shaft body (209) on which the heavy internal thread (206) is arranged is also provided with a heavy external thread (210). A heavy upper thread (207) is threadedly installed on the heavy external thread (210). The heavy upper thread (207) contacts one end of the heavy rotating sleeve (205) to limit the position of the heavy rotating sleeve (205).

5. The rotatable screw pump centralizer according to claim 1, characterized in that: One end of the light shaft body (308) is provided with a light external thread (301), and the light external thread (301) is engaged with the internal thread on the sucker rod (11); the end of the light shaft body (308) away from the light external thread (301) is provided with a light internal thread (306), and the light internal thread (306) is engaged with the external thread on the sucker rod (11); and a light lower thread (302) is provided on the outer wall of the light shaft body (308) close to the light external thread (301).

6. A rotatable screw pump centralizer according to claim 5, characterized in that: A support cap (303) is threadedly mounted on the upper light lower thread (302), and a blocking convex ring (305) is arranged on the outer wall of the light shaft body (308) near one end of the light inner thread (306) to achieve a limiting effect, and the light rotating bushing (304) is arranged between the blocking convex ring (305) and the support cap (303).

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