Pumping unit polish rod sealer with self-plugging function and capable of replacing packing without stopping pumping and method

Abstract

The invention provides a pumping unit polish rod sealer capable of replacing packing without stopping pumping and provided with a self-plugging function and a method, the pumping unit polish rod sealer comprises a stuffing box, a first sealer and a second sealer which are arranged from top to bottom, polish rod through holes are formed in the stuffing box, the first sealer and the second sealer, and a hydraulic discharging device is arranged in the stuffing box and used for ejecting stuffing out of the stuffing box. A hydraulic capsule is arranged in the first sealer and used for pressurizing, expanding and sealing the polish rod and the inner space of the sealer, and a movable sealing device is arranged in the second sealer and used for sealing a polish rod through hole in the second sealer when the polish rod breaks off. The device solves the problem that an operator is difficult to replace the filler and wastes time and labor, meanwhile, a channel can be automatically closed after the polish rod is broken and disengaged, the accident of oil gas leakage is prevented, and the device is suitable for all pumping unit well mouths.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas gathering and transportation, and in particular relates to a pumping unit polished rod sealer and a method thereof, which can replace packings without stopping pumping and has self-sealing function. Background Art

[0002] After the oil fields entered the secondary development stage, electric pumps and pumping units were widely used as the main oil production equipment. In some blocks with low production and shallow oil wells, pumping units were widely used as important oil production equipment, especially in the eastern oil fields, where the equipment was relatively simple to manage and maintain.

[0003] During operation, a pumping unit transmits power to a downhole pump through a polished rod and a sucker rod. The pump reciprocates within the pump barrel, pumping crude oil to the surface. As a moving component, the polished rod must be sealed against external pressure and wellbore pressure. A widely used wellhead sealing device in oil fields is a polished rod seal, commonly known as a rubber valve. The rubber packing inside the rubber valve is compressed by a gland and elastically deforms to seal the gap between the packing and the polished rod. When the packing fails, the pump must be stopped and the rubber valve closed to replace the packing. Due to the small clearance in the stuffing box, replacing the packing is time-consuming and laborious. This can result in significant production losses in oil fields where pumping units are the primary production equipment. Rapid or continuous packing replacement is highly economical for oilfields. Existing rubber valves employ a left-right open / close mechanism. When closing the rubber valve, workers struggle to position the left and right gates, resulting in uneven positioning of the gates, causing deformation and misalignment of the polished rod, which can also cause damage.

[0004] During the operation of the oil pump, the polished rod often breaks due to metal fatigue or other reasons. After the polished rod breaks, the polished rod sealer loses its seal, and crude oil sprays out from the sealer to pollute the environment. In serious cases, it may even cause a fire accident. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a pumping unit polished rod sealer and method with self-sealing packing that can replace the packing without stopping pumping, which solves the problem that it is difficult, time-consuming and labor-intensive for operators to replace the packing. At the same time, it can automatically seal the channel after the polished rod breaks off to prevent oil and gas leakage accidents. It is suitable for all pumping unit wellheads.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a pumping unit polished rod sealer with self-sealing packing that can be replaced without stopping pumping, comprising a stuffing box, a first sealer, and a second sealer arranged from top to bottom, the stuffing box, the first sealer, and the second sealer all having polished rod through holes, a hydraulic discharge device provided in the stuffing box for ejecting the stuffing from the stuffing box, a hydraulic capsule provided in the first sealer for pressurizing and expanding to seal the polished rod and the internal space of the sealer, and a movable sealing device provided in the second sealer for sealing the polished rod through hole on the second sealer when the polished rod is broken.

[0007] Furthermore, the stuffing box includes a stuffing box body, the hydraulic discharging device is arranged in the internal cavity of the stuffing box body, the hydraulic discharging device includes a cylinder base fixed on the top of the first sealer, the cylinder is fixed on the cylinder base, the cylinder is connected to the external hydraulic equipment through a hydraulic joint, the fixed end of the hydraulic push rod is placed inside the cylinder, and the movable end is connected to the lower part of the gland for pushing the stuffing out of the stuffing box body.

[0008] Furthermore, a pressure relief valve joint is connected to the stuffing box, and the pressure relief valve joint is communicated with the external atmosphere.

[0009] Furthermore, the first sealer includes a first sealer body, the hydraulic capsule is arranged in the internal cavity of the first sealer body, the first sealer body is a structure consisting of a sealer upper cover, a sealer lower cover and a side wall siege, the sealer upper cover is located at the lower part of the stuffing box for supporting the hydraulic discharge device, and a light rod through hole is provided in the center of the sealer upper cover and the sealer lower cover.

[0010] Furthermore, the hydraulic capsule is an annular hydraulic capsule, which consists of a hydraulic annular cavity in the middle and oil-resistant and wear-resistant rubber on the outside. The outer diameter of the annular hydraulic capsule is smaller than the inner diameter of the first sealer body, and the inner diameter is larger than the diameter of the polished rod through hole.

[0011] Furthermore, the hydraulic capsule is communicated with an external hydraulic device via a capsule hydraulic connector, and the capsule hydraulic connector passes through the first sealer body and is sealed and fixed to the first sealer body.

[0012] Furthermore, the second sealer includes a second sealer body, and a movable sealing device is fixed in the internal cavity of the second sealer body; the movable sealing device includes a hemispherical valve disc and a roller, the hemispherical valve disc can be rotatably fixed to the top of the second sealer body, the roller is rotatably set at the top of the spherical surface of the hemispherical valve disc, and an annular groove is provided on the outer edge of the roller for achieving rolling contact with the sucker rod, and a moving device is fixed on the bottom surface of the hemispherical valve disc, and the moving device is connected to the top of the inner wall of the second sealer body. The moving device is used to move the hemispherical valve disc and seal the light rod through hole on the second sealer when the hemispherical valve disc is not squeezed by the light rod.

[0013] Furthermore, the diameter of the bottom circular surface of the hemispherical valve disc is larger than the diameter of the polished rod through hole.

[0014] The present invention also provides a method for using a pumping unit polished rod sealer with self-sealing function, which can replace packing without stopping pumping. When replacing the sealing packing, the hydraulic capsule in the first sealer is pressurized and expanded to seal the polished rod and the internal space of the sealer, thereby relieving the pressure of the stuffing box, and the stuffing box is pushed out of the stuffing box by the hydraulic discharge device.

[0015] Furthermore, when the polished rod is broken off, the movable sealing device is no longer squeezed by the polished rod, and the movable sealing device moves the polished rod through hole on the second sealer to seal.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects:

[0017] The present invention provides a rod sealer for a pumping unit with self-sealing packing that can replace packing without stopping pumping. By arranging a hydraulic discharge device in the stuffing box 100, it is not necessary to use tools to take the packing out of the stuffing box when replacing the sealing packing. The packing only needs to be pushed out of the stuffing box by the hydraulic discharge device, thereby reducing the labor intensity of employees and saving downtime. The present invention arranges a hydraulic capsule in the first sealer, and replaces the two-wing rubber valve of the traditional sealer with the hydraulic capsule. The rod through-hole is sealed by the pressure expansion of the capsule, thereby avoiding deformation of the rod caused by the inconsistent progress of the traditional rubber valve. At the same time, the sealing packing can be replaced without stopping the unit in the sealed state of the hydraulic capsule. The present invention arranges a movable sealing device in the second sealer, which can seal the channel vacated by the rod when the rod is broken, thereby avoiding crude oil spraying out and polluting the environment.

[0018] Furthermore, the movable sealing device of the present invention adopts a hemispherical valve disc, and the displacement of the hemispherical valve disc is achieved by a hinge and a spring. At the same time, there is a roller at the top of the spherical surface of the hemispherical valve disc, and the roller can roll in contact with the polished rod to prevent the hemispherical valve disc from rubbing against the polished rod and causing damage to the polished rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0020] Figure 1 The present invention provides a schematic cross-sectional view of a polished rod sealer for a pumping unit with self-sealing and packing replacement capabilities without stopping pumping.

[0021] In the attached figure: 100 stuffing box: 101 gland, 102 gland, 103 gland, 104 hydraulic push rod, 105 hydraulic cylinder, 106 pressure relief valve connector, 107 hydraulic connector, 108 stuffing box body, 109 hydraulic cylinder base;

[0022] First sealer 200: 201 hydraulic capsule, 202 sealer upper cover, 203 sealer lower cover, 204 capsule hydraulic joint;

[0023] The second sealer 300 includes: 301 hemispherical valve disc, 302 roller, 303 spring, and 304 hinge. DETAILED DESCRIPTION

[0024] In order to further illustrate the technical means and effects adopted by the present invention to achieve the purpose of the predetermined invention embodiment, the following is a detailed description of the specific implementation method, structure, characteristics and effects of the present invention in conjunction with the accompanying drawings and preferred embodiments.

[0025] like Figure 1 As shown, the present invention provides a pumping unit polished rod sealer with self-sealing function and packing replacement without stopping pumping. The sealer mainly includes three parts: upper, middle and lower parts, namely a stuffing box 100, a first sealer 200, a second sealer 300 and matching external hydraulic joints and pressure relief joints. Polished rod through holes are opened on the stuffing box 100, the first sealer 200 and the second sealer 300.

[0026] The stuffing box 100 includes a gland 101, a cap 102, a gland 103, a hydraulic discharge device and a stuffing box body 108. A polished rod through hole is provided in the center of the gland 101. The gland 101 is connected to the upper part of the stuffing box body 108 by a threaded connection. The cap 102 is provided on the inner side of the lower end of the gland 101 and is located between the gland 101 and the upper edge of the stuffing box body 108. The cap 102 is a combination of two concentric cylinders of different diameters. The upper diameter is consistent with the outer diameter of the stuffing box body 108, and the lower cylinder diameter is slightly smaller than the outer diameter of the stuffing box body 108. The inner diameter of the stuffing box body 108 and the center of the pressure cap 102 have a polished rod through hole with the same diameter as the pressure cap 101. The downward rotation of the pressure cap 101 causes the pressure cap 102 to compress the packing downward, so that the gap between the packing and the polished rod is sealed; the hydraulic discharge device is arranged inside the stuffing box body 108, and the gland 103 is placed on the hydraulic discharge device to realize the function of lifting the packing. The outer diameter of the gland 103 is slightly smaller than the inner diameter of the stuffing box body 108, and the inner diameter is consistent with the diameter of the polished rod through hole of the pressure cap 101, forming a circular ring with a certain strength.

[0027] Preferably, the outer surface of the pressure cover 101 is hexagonal to facilitate rotation operation.

[0028] The hydraulic discharge device includes a hydraulic ejector 104, a cylinder 105, a pressure relief valve connector 106, a hydraulic connector 107, and a cylinder base 109. The cylinder base 109 is fixed to the top of the first sealer 200. The cylinder 105 is fixed to the cylinder base 109. The cylinder 105 is connected to external hydraulic equipment via the hydraulic connector 107. The hydraulic connector 107 passes through the stuffing box body 108 and is provided with a sealing structure on the stuffing box body 108 to prevent pressure or medium leakage within the stuffing box body 108. The hydraulic ejector 104 is located below the gland 103 and placed inside the cylinder 105. When the hydraulic ejector 104 is fully extended from the cylinder 105, the gland 103 can access the uppermost portion of the stuffing box body 108. Its function is to eject the stuffing from the stuffing box body 108 by raising the hydraulic ejector under the action of hydraulic pressure. The pressure relief valve connector 106 is located below the stuffing box body 108 and connects the internal cavity of the stuffing box body 108 to the external atmosphere.

[0029] Preferably, the hydraulic push rod 104 can be several hydraulic push rods or a circular hydraulic push rod, and can be a single-stage or multi-section hydraulic push rod.

[0030] Preferably, the cylinder 105 may be an annular cylinder or a combination of multiple cylinders, which are connected via a cylinder base 109 , and the hydraulic oil connects the multiple cylinders 105 via pipelines in the cylinder base 109 .

[0031] Preferably, the pressure relief valve joint 106 is connected to the lower part of the stuffing box body 108 by welding or threading. Specifically, the pressure relief valve joint 106 is set within the height range of the hydraulic push rod 104 set on the stuffing box body 108. The pressure relief valve joint 106 connects the external atmosphere with the internal cavity of the stuffing box body 108. Its function is to relieve pressure in the cavity of the stuffing box body 108 before replacing the packing.

[0032] The first sealer 200 is located at the lower part of the stuffing box 100. The first sealer 200 includes a first sealer body and a hydraulic capsule 201 arranged in the internal cavity of the first sealer body. The first sealer body is a structure of a sealer upper cover 202, a sealer lower cover 203 and a side wall siege. The sealer upper cover 202 is located at the lower part of the stuffing box body 108 and is used to support the hydraulic cylinder base 109. There is a light rod through hole in the center of the sealer upper cover 202 and the sealer lower cover 203. The diameters of the two light rod through holes are the same as the diameter of the light rod through hole of the pressure cover 101 for passing the light rod; the hydraulic capsule 201 is an annular hydraulic capsule, and the capsule hydraulic joint 204 is connected to the hydraulic capsule 201. The capsule hydraulic joint 204 passes through the first sealer body, and the capsule hydraulic joint 204 is sealed and fixed to the first sealer body by a sealing structure to isolate the internal oil, gas and pressure.

[0033] Preferably, the annular hydraulic capsule is composed of a hydraulic annular cavity in the middle and oil-resistant and wear-resistant rubber on the outside. The outer diameter of the annular hydraulic capsule is smaller than the inner diameter of the first sealer body, and the inner diameter is larger than the diameter of the polished rod through hole of the gland 101.

[0034] Preferably, the sealer upper cover 202 is connected to the top of the first sealer body by welding or threading.

[0035] The second sealer 300 includes a second sealer body and a movable sealing device fixed in the internal cavity of the second sealer body. The movable sealing device includes a hemispherical valve disc 301, a roller 302, a moving device and a hinge 304. The movable sealing device is fixed to the top of the second sealer body, that is, the lower end surface of the sealer lower cover 203 of the middle capsule sealer 200, through the hinge 304. The diameter of the hemispherical bottom circular surface of the hemispherical valve disc 301 is larger than the diameter of the polished rod through hole of the sealer lower cover 203. The roller 302 is located at the top of the spherical surface of the hemispherical valve disc 301 and is fixed to the hemispherical valve disc 301 through an axis. 01 top, the outer edge of the roller 302 has an annular groove equivalent to the diameter of the sucker rod; the moving device adopts a spring 303, one end of the spring 303 is fixed to the bottom surface of the hemispherical valve disc 301, and the other end is in a free state and abuts the inner wall of the second sealer body. When the hemispherical valve disc 301 is in a free state, that is, when the hemispherical valve disc 301 is not blocked by the polished rod, the spring 303 pushes the hemispherical valve disc 301 to the position where the polished rod through hole on the second sealer body passes through the center line to achieve the sealing of the polished rod through hole on the top of the second sealer body, that is, the sealing of the polished rod through hole on the sealer lower cover 203;

[0036] Preferably, the hinge 304 is welded to the lower end surface of the sealer lower cover 203 , and the hinge 304 is used to suspend the hemispherical valve flap 301 and allow the hemispherical valve flap 301 to move freely.

[0037] When replacing the packing in the polished rod seal, the hydraulic bladder 201 is first pressurized through the bladder hydraulic connector 204, causing it to expand and seal the polished rod and the internal space of the seal. The pressure in the stuffing box body 108 is then released through the pressure relief valve connector 106. After removing the gland 101 and cap 102, the gland 103 is lifted by the upwardly extending hydraulic push rod 104, ultimately ejecting the packing from the stuffing box. The hemispherical valve disc 301 is primarily used to seal the passage vacated by the polished rod in the event of a broken polished rod, achieving an oil-gas seal.

[0038] The above are merely preferred embodiments of the present invention and do not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A polished rod sealer for a pumping unit with self-sealing function and packing replacement without stopping pumping, characterized in that: The invention comprises a stuffing box (100), a first sealer (200), and a second sealer (300) arranged from top to bottom. The stuffing box (100), the first sealer (200), and the second sealer (300) are all provided with a polished rod through hole. A hydraulic discharge device is provided in the stuffing box (100) for ejecting the stuffing from the stuffing box (100). A hydraulic capsule (201) is provided in the first sealer (200) for pressurizing and expanding to seal the polished rod and the inner space of the sealer. A movable sealing device is provided in the second sealer (300) for sealing the polished rod through hole on the second sealer (300) when the polished rod is broken.

2. The oil pumping unit polished rod sealer with self-sealing packing that can be replaced without stopping the pumping according to claim 1 is characterized in that: The stuffing box (100) includes a stuffing box body (108), and the hydraulic discharge device is arranged in the internal cavity of the stuffing box body (108). The hydraulic discharge device includes a cylinder base (109) fixed on the top of the first sealer (200), the cylinder (105) is fixed on the cylinder base (109), the cylinder (105) is connected to the external hydraulic equipment through a hydraulic joint (107), the fixed end of the hydraulic push rod (104) is placed inside the cylinder (105), and the movable end is connected to the lower part of the gland (103) for pushing the stuffing out of the stuffing box body (108).

3. The oil pumping unit polished rod sealer with self-sealing packing that can be replaced without stopping the pumping according to claim 2 is characterized in that: A pressure relief valve connector (106) is connected to the stuffing box (100), and the pressure relief valve connector (106) is communicated with the external atmosphere.

4. The oil pumping unit polished rod sealer with self-sealing packing that can be replaced without stopping pumping according to claim 1 is characterized in that: The first sealer (200) includes a first sealer body, a hydraulic capsule (201) is arranged in the internal cavity of the first sealer body, and the first sealer body is a structure consisting of a sealer upper cover (202), a sealer lower cover (203) and a side wall circumference. The sealer upper cover (202) is located at the lower part of the stuffing box (100) and is used to support the hydraulic discharge device. A light rod through hole is provided in the center of each of the sealer upper cover (202) and the sealer lower cover (203).

5. The oil pumping unit polished rod sealer with self-sealing function and packing replacement capability without stopping pumping according to claim 4, characterized in that: The hydraulic capsule (201) is an annular hydraulic capsule, which consists of a hydraulic annular cavity in the middle and oil-resistant and wear-resistant rubber on the outside. The outer diameter of the annular hydraulic capsule is smaller than the inner diameter of the first sealer body, and the inner diameter is larger than the diameter of the polished rod through hole.

6. The oil pumping unit polished rod sealer with self-sealing packing capable of replacing packing without stopping pumping according to claim 4 is characterized in that: The hydraulic capsule (201) is communicated with an external hydraulic device via a capsule hydraulic connector (204), and the capsule hydraulic connector (204) passes through the first sealer body and is sealed and fixed to the first sealer body.

7. The oil pumping unit polished rod sealer with self-sealing packing capable of replacing packing without stopping pumping according to claim 1 is characterized in that: The second sealer (300) includes a second sealer body, and a movable sealing device is fixed in the internal cavity of the second sealer body; the movable sealing device includes a hemispherical valve disc (301) and a roller (302); the hemispherical valve disc (301) is rotatably fixed to the top of the second sealer body, the roller (302) is rotatably set at the top of the spherical surface of the hemispherical valve disc (301), and an annular groove is provided on the outer edge of the roller (302) for achieving rolling contact with the sucker rod; a moving device is fixed to the bottom surface of the hemispherical valve disc (301), and the moving device is connected to the top of the inner wall of the second sealer body. The moving device is used to move the hemispherical valve disc (301) and seal the polished rod through hole on the second sealer (300) when the hemispherical valve disc (301) is not squeezed by the polished rod.

8. The oil pumping unit polished rod sealer with self-sealing function and packing replacement capability without stopping pumping according to claim 7, characterized in that: The diameter of the bottom circular surface of the hemispherical valve flap (301) is larger than the diameter of the polished rod through hole.

9. The method for using the self-sealing packing sealer for a pumping unit capable of replacing packing without stopping pumping as claimed in claim 1, characterized in that: When replacing the sealing packing, the hydraulic capsule (201) in the first sealer (200) is pressurized and expanded to seal the polished rod and the inner space of the sealer, depressurize the stuffing box (100), and push the packing out of the stuffing box through the hydraulic discharge device.

10. The method for using the self-sealing packing sealer for a pumping unit capable of replacing packing without stopping pumping according to claim 9, characterized in that: When the polished rod is broken off, the movable sealing device is no longer squeezed by the polished rod, and the movable sealing device moves the polished rod through hole on the second sealer (300) to seal.

Images