Butt joint sealing device of hydraulic drive differential type drainage pump

Abstract

The utility model provides a butt joint sealing device of a hydraulic drive differential type drainage pump, which comprises a leather cup supporting mandrel, a hollow pipe joint is sleeved on the leather cup supporting mandrel, a plurality of supporting leather cups and metal sealing rings are arranged between the hollow pipe joint and the leather cup supporting mandrel, and the supporting leather cups and the metal sealing rings are overlapped in a staggered mode. The end of the leather cup supporting mandrel is provided with a pressing cap in threaded connection, and the pressing cap is screwed so that the supporting leather cup and the metal sealing ring can abut against the inner wall of the hollow pipe connector in an expanding mode. Under the triple sealing effects of the end face sealing effect of the matching face of the hollow pipe joint and the shoulder of the packing cup supporting mandrel, the hard sealing effect of the metal sealing ring and the interference fit sealing effect of the supporting packing cup, it can be effectively guaranteed that the pump can normally operate under the working pressure of 25 MPa, sealing connection is more reliable, and the service life of the pump is prolonged. And repeated butt joint use can be realized.

Description

Technical Field

[0001] The utility model relates to the technical field of drainage and production equipment, in particular to a butt joint sealing device for a hydraulic drive differential drainage and production pump. Background Technique

[0002] Coalbed methane is one of the important energy resources in the world. At present, in the utilization of coalbed methane drainage and production equipment, mechanical drainage and production of coalbed methane in China mainly uses equipment such as rod pumps. Although the normal production of coalbed methane is ensured, there are certain limitations. In the process of deep coalbed methane drainage and production, for large inclination and horizontal well coalbed methane well types, there are serious problems of rod and pipe eccentric wear in traditional rod pump drainage and production equipment.

[0003] At present, in this structure, most are designed as conical structures, and an O-ring is used for sealing in the middle. In actual application, this structure has the following defects:

[0004] (1) With an O-ring used for sealing in the middle, during the process of the hollow sucker rod being lowered and butt-jointed, the O-ring is extremely easy to be sheared and cannot achieve repeated butt-joints, which greatly increases the on-site operation cost and the difficulty of on-site construction;

[0005] (2) The working condition environment of this device needs to be 25 MPa. Relying solely on the O-ring seal cannot meet the working condition use requirements, increasing the risk of faults;

[0006] (3) In a coalbed methane well, in an environment of high temperature, high pressure and high corrosion, the O-ring is extremely easy to age, resulting in the failure of the entire pump.

[0007] (4) The processing difficulty of the conical structure sealing structure increases. To achieve the corresponding roughness, since it is conical, the grinding equipment needs to be customized, increasing the processing production cost. Content of the Utility Model

[0008] The main purpose of the utility model is to provide a butt joint sealing device for a hydraulic drive differential drainage and production pump to solve the problems in the above background technique.

[0009] To solve the above technical problems, the technical solution adopted by the utility model is: it includes a leather cup support mandrel, a hollow pipe joint is sleeved on the leather cup support mandrel, and a plurality of staggered and superimposed support leather cups and metal sealing rings are arranged between the hollow pipe joint and the leather cup support mandrel. A compression cap connected by threads is arranged at the end of the leather cup support mandrel, and the compression cap is tightened so that the support leather cups and the metal sealing rings are expanded and abutted against the inner wall of the hollow pipe joint.

[0010] Preferably, a support seat ring is arranged between the bottom of the support leather cup and the top of the metal sealing ring, and a support leather cup seat ring is arranged between the bottom of the metal sealing ring and the top of the support leather cup.

[0011] Preferably, a first inclined groove is provided on the compression cap, and the top of the support leather cup abuts against the first inclined groove.

[0012] Preferably, a first groove is provided at one end of the support seat ring, and the first groove abuts against the bottom of the support leather cup.

[0013] Preferably, inner inclined surfaces are provided at both ends of the metal sealing ring, and an inclined opening is provided on one side of the metal sealing ring;

[0014] A first inclined surface is provided on the outer side of the support seat ring, and a second inclined surface is provided on the top of the support leather cup seat ring. The first inclined surface and the second inclined surface respectively abut against the inner inclined surfaces at both ends of the metal sealing ring.

[0015] Preferably, a second inclined groove is provided on the outer side of the support leather cup seat ring, and the top of the support leather cup abuts against the second inclined groove.

[0016] Preferably, a shoulder is provided on the leather cup support mandrel, a second groove is provided on the inner side of the shoulder, the end of the hollow pipe joint abuts against the shoulder, and the bottom of the support leather cup abuts against the second groove.

[0017] The utility model provides a docking sealing device for a hydraulic drive differential drainage pump. The support leather cup and the hollow pipe joint are in interference fit. Under the triple sealing effects of the end face sealing at the mating surface of the shoulder between the hollow pipe joint and the leather cup support mandrel, the hard sealing of the metal sealing ring, and the interference fit sealing of the support leather cup, it can effectively ensure that the pump can operate normally under a working pressure of 25 MPa. The support leather cup is made of glass fiber reinforced polytetrafluoroethylene, which has good heat resistance, cold resistance, acid and alkali resistance, and an extremely low friction coefficient, and this structure can be used for repeated docking multiple times. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following further describes the utility model with reference to the drawings and embodiments:

[0019] Figure 1 is the front sectional view of the overall structure of the utility model;

[0020] Figure 2 is the front sectional view of the installation structure on the leather cup support mandrel of the utility model;

[0021] Figure 3 is the front sectional view of the leather cup support mandrel of the utility model;

[0022] Figure 4 is the front sectional view of the compression cap of the utility model;

[0023] Figure 5 is the front sectional view of the support seat ring of the utility model;

[0024] Figure 6 is the front sectional view of the metal sealing ring of the utility model;

[0025] Figure 7 It is a front cross-sectional view of the support leather cup seat ring of the present utility model;

[0026] In the figure: hollow pipe joint 1; compression cap 2; first inclined groove 201; support leather cup 3; support seat ring 4; first groove 401; first inclined surface 402; metal sealing ring 5; inner inclined surface 501; opening 502; support leather cup seat ring 6; second inclined surface 601; second inclined groove 602; leather cup support mandrel 7; shoulder 701; second groove 702. Specific embodiments

[0027] As Figures 1 to 7 shown, a docking and sealing device for a hydraulic-driven differential drainage and production pump includes a leather cup support mandrel 7. A hollow pipe joint 1 is sleeved on the leather cup support mandrel 7. A plurality of support leather cups 3 and metal sealing rings 5 are arranged in an alternating and overlapping manner between the hollow pipe joint 1 and the leather cup support mandrel 7. A compression cap 2 is provided at the end of the leather cup support mandrel 7 by means of threaded connection. When the compression cap 2 is tightened, the support leather cups 3 and the metal sealing rings 5 are expanded and abutted against the inner wall of the hollow pipe joint 1. One end of the leather cup support mandrel 7 is fixed on the drainage and production pump, and a plurality of support leather cups 3 and metal sealing rings 5 are installed in an alternating and overlapping manner at the other end. When the compression cap 2 threaded to the end of the leather cup support mandrel 7 is tightened, the plurality of support leather cups 3 and metal sealing rings 5 are pressed tightly so that they are expanded and abutted against the inner wall of the hollow pipe joint 1, thereby realizing fixed connection and sealing.

[0028] After the assembly of each component, the whole is connected to the upper part of the drive-type drainage and production pump and goes down the well to the predetermined position together with the whole pump; after the hollow sucker rod goes down from the wellhead to the position of the whole pump, it is docked with the hollow pipe joint 1 under the action of the gravity of the hollow sucker rod. Under the action of the ground hydraulic drive system, the hollow pipe can achieve a working pressure of 25 MPa, driving the plunger assembly of the hydraulic-driven differential drainage and production pump to move upward to complete the liquid intake process.

[0029] The leather cup support mandrel 7 bears the weight of the sealing assembly and also provides a fixed connection point with the main body of the drainage and production pump. The hollow pipe joint 1 makes physical connection with the external hollow sucker rod and is also the inner wall against which the sealing assembly expands and abuts.

[0030] The support leather cup 3 is made of elastic material and is arranged alternately with the metal sealing ring, and forms a tight seal through expansion. The metal sealing ring 5 increases the reliability of the seal, prevents the penetration of fluid under high pressure, and also plays a role in supporting the positioning of the leather cup. The compression cap 2 is connected to one end of the leather cup support mandrel 7 by means of threaded connection. When tightened, it will apply pressure to the support leather cup 3 and the metal sealing ring 5, prompting them to expand and closely adhere to the inner wall of the hollow pipe joint 1 to achieve sealing.

[0031] Preferably, a support seat ring 4 is provided between the bottom of the support leather cup 3 and the top of the metal sealing ring 5, and a support leather cup seat ring 6 is provided between the bottom of the metal sealing ring 5 and the top of the support leather cup 3. The support seat ring 4 and the support leather cup seat ring 6 isolate the support leather cup 3 and the metal sealing ring 5, and can be compressed and tightened against the support leather cup 3 and the metal sealing ring 5 through the support seat ring 4 and the support leather cup seat ring 6.

[0032] Preferably, a first inclined groove 201 is provided on the compression cap 2, and the top of the support leather cup 3 abuts against the first inclined groove 201. The first inclined groove 201 can effectively limit the position of the support leather cup 3. By adjusting the tightness of the compression cap 2, the fitting clearance between the support leather cup 3 and the metal sealing ring 5 and the hollow pipe joint 1 is controlled, so as to achieve the sealing effect.

[0033] Preferably, a first groove 401 is provided at one end of the support seat ring 4, and the first groove 401 abuts against the bottom of the support leather cup 3. The first groove 401 can effectively limit the position of the support leather cup 3 and avoid damaging it during compression.

[0034] Preferably, inner inclined surfaces 501 are provided at both ends of the metal sealing ring 5, and an inclined opening 502 is provided on one side of the metal sealing ring 5;

[0035] A first inclined surface 402 is provided on the outside of the support seat ring 4, and a second inclined surface 601 is provided on the top of the support leather cup seat ring 6. The first inclined surface 402 and the second inclined surface 601 respectively abut against the inner inclined surfaces 501 at both ends of the metal sealing ring 5.

[0036] During the process of tightening the compression cap 2, the first inclined surface 402 and the second inclined surface 601 on the support seat ring 4 and the support leather cup seat ring 6 abut against the inner inclined surfaces 501 at both ends of the metal sealing ring 5, so as to be able to extrude the metal sealing ring 5. The metal sealing ring 5 can increase its diameter through the opening 502, so as to abut against the inner wall of the hollow pipe joint 1 to achieve expansion and tightening.

[0037] Preferably, a second inclined groove 602 is provided on the outside of the support leather cup seat ring 6, and the top of the support leather cup 3 abuts against the second inclined groove 602. The second inclined groove 602 can effectively limit the position of the support leather cup 3.

[0038] Preferably, a shoulder 701 is provided on the leather cup support mandrel 7, and a second groove 702 is provided inside the shoulder 701. The end of the hollow pipe joint 1 abuts against the shoulder 701, and the bottom of the support leather cup 3 abuts against the second groove 702.

[0039] The end of the hollow pipe joint 1 abutting against the shoulder 701 can play a limiting role, and can limit the position of the hollow pipe joint 1 going down the well during the process of downhole docking. The end face of the hollow pipe joint 1 and the shoulder 701 can also form an end face hard seal, so as to ensure the overall sealing effect.

[0040] The supporting leather cup 3 is made of glass fiber reinforced polytetrafluoroethylene, which has good heat resistance, cold resistance, acid and alkali resistance, extremely low friction coefficient, and this structure can achieve repeated docking and use.

[0041] In this example, the device is designed with 1 end face hard seal, 2 metal hard seals with metal seal ring structures, and 3 soft seals with supporting leather cup structures, so as to ensure normal operation under the condition of a working pressure of 25 MPa.

[0042] The above embodiments are only the preferred technical solutions of the present invention and should not be regarded as limitations on the present invention. The protection scope of the present invention should be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, the equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A butt sealing device for a hydraulically driven differential drainage pump, characterized in that: The invention comprises a leather cup supporting spindle (7), a hollow pipe joint (1) is sleeved on the leather cup supporting spindle (7), a plurality of staggered supporting leather cups (3) and metal sealing rings (5) are arranged between the hollow pipe joint (1) and the leather cup supporting spindle (7), and a threaded pressure cap (2) is arranged at the end of the leather cup supporting spindle (7), and the pressure cap (2) is tightened so that the supporting leather cup (3) and the metal sealing ring (5) are expanded and pressed against the inner wall of the hollow pipe joint (1).

2. According to claim 1, a butt sealing device for a hydraulically driven differential drainage pump is characterized by: A support seat ring (4) is provided between the bottom of the support leather cup (3) and the top of the metal sealing ring (5), and a support leather cup seat ring (6) is provided between the bottom of the metal sealing ring (5) and the top of the support leather cup (3).

3. According to claim 1, a butt sealing device for a hydraulically driven differential drainage pump is characterized by: The pressing cap (2) is provided with a first inclined groove (201), and the top of the supporting leather cup (3) is pressed against the first inclined groove (201).

4. The docking sealing device of a hydraulically driven differential drainage pump according to claim 2, characterized in that: A first groove (401) is provided at one end of the support seat ring (4), and the first groove (401) abuts against the bottom of the support leather cup (3).

5. The docking sealing device of a hydraulically driven differential drainage pump according to claim 2, characterized in that: Both ends of the metal sealing ring (5) are provided with inner bevels (501), and one side of the metal sealing ring (5) is provided with an inclined opening (502); A first inclined surface (402) is provided on the outside of the support seat ring (4), and a second inclined surface (601) is provided on the top of the support leather cup seat ring (6). The first inclined surface (402) and the second inclined surface (601) respectively abut against the inner inclined surfaces (501) at both ends of the metal sealing ring (5).

6. The docking sealing device of a hydraulically driven differential drainage pump according to claim 2, characterized in that: A second inclined groove (602) is provided on the outer side of the supporting leather cup seat ring (6), and the top of the supporting leather cup (3) abuts against the second inclined groove (602).

7. The docking sealing device of a hydraulically driven differential drainage pump according to claim 1, characterized in that: A shoulder (701) is provided on the leather cup supporting spindle (7), a second groove (702) is provided inside the shoulder (701), the end of the hollow pipe joint (1) abuts against the shoulder (701), and the bottom of the supporting leather cup (3) abuts against the second groove (702).

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