An automatic formal oil field sucker rod sealer

Abstract

The application discloses a kind of automatic straightening formal oilfield optical rod sealers belonging to optical rod sealer technical field.It includes packing box body, the packing box body is provided with packing cavity and positioning part, the packing cavity is slidably connected with gland, the packing cavity is provided with annular packing of equal interval distribution, further including pressure plate, the packing box body is provided with the sealing cavity in the lower side of the positioning part, the pressure plate is sealed and slidably connected in the sealing cavity, the second spring is fixed between the pressure plate and the packing box body, the pressure plate is slidably connected with the circumferential equal interval distribution and is commonly used for the slide bar of the optical rod, the sealing cavity is provided with the guide portion for extruding the slide bar.The application is moved upward by the pressure plate with the circumferential equal interval distribution slide bar, the circumferential equal interval distribution slide bar is guided by guide portion and mutually close to optical rod and is dynamically corrected, ensure that optical rod is located in the middle of packing box body during upstroke.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polished rod sealers, and particularly relates to an automatic straightening polished rod sealer for oil fields. BACKGROUND

[0002] In oil extraction operations, the reciprocating movement of the polished rod (referred to as "polished rod" for short) of the pumping unit is the key to realizing the lifting of crude oil. In order to prevent the leakage of crude oil, natural gas and high-pressure liquid along the surface of the polished rod, ensure production safety, environmental protection and energy saving, a reliable dynamic sealing device must be provided between the polished rod and the wellhead device, which is commonly referred to as a polished rod sealer or a packing box. The core structure of the commonly used polished rod sealer in the prior art includes a packing box body, a gland and a plurality of annular sealing fillers (also known as packing) filled in the box body.

[0003] In order to ensure the sealing effect and reduce the eccentric wear of the polished rod on the filler, most of the existing polished rod sealers are provided with a positioning part (or a deviation correcting part) at the inlet end or the lower part. The positioning part is usually a guide sleeve or a righting bearing with an inner diameter slightly larger than the diameter of the polished rod. The original design intention is to constrain the polished rod near the central axis of the packing box body. In order to reduce the severe wear between the polished rod and the positioning part due to long-term direct contact, a certain radial gap must be reserved between the polished rod and the inner wall of the positioning part in the design, which means that the positioning part is essentially a "non-sealing" loose guide structure. Due to the existence of the gap, the centering effect is greatly reduced, and the polished rod with an initial deviation cannot be effectively corrected, and only a limited constraint effect can be achieved. During the upstroke process, the lower end of the polished rod bears the huge tension of the entire sucker rod string and the liquid column. This tension will make the polished rod stretch and tend to straighten, causing the polished rod to be more likely to deviate in a certain direction and thus press and wear the annular filler on one side, resulting in damage to the annular filler and affecting the sealing performance of the polished rod. SUMMARY

[0004] In order to solve the technical problem that the existing polished rod sealer cannot effectively correct the polished rod with an initial deviation and can only play a limited constraint effect, the present application provides an automatic straightening polished rod sealer for oil fields which reduces wear.

[0005] The technical scheme is: an automatic formal oil field light rod sealing device, comprising a packing box body, the packing box body is provided with a packing cavity and a positioning part, the packing box body is slidably connected with a top plate on the upper side of the packing cavity, the packing box body is threadedly connected with a bolt for extruding the top plate, the packing cavity is slidably connected with a gland, the first spring is fixedly connected between the top plate and the gland, the packing cavity is provided with annular packing at equal intervals and below the gland, the annular packing is used for sealing the packing box body and the light rod, further comprising a pressure plate, the packing box body is provided with a sealing cavity below the positioning part, the pressure plate is sealingly and slidably connected in the sealing cavity, the second spring is fixedly connected between the pressure plate and the packing box body, the pressure plate is slidably connected with slide rods which are distributed at equal intervals in the circumferential direction and are used for correcting the light rod, the sealing cavity is provided with a guide part for extruding the slide rods.

[0006] Further, the diameter of the guide part gradually decreases from bottom to top.

[0007] Further, the end of the slide rod away from the light rod is lower than the end close to the light rod.

[0008] Further, the side of the slide rod close to the light rod is provided with an arc surface coaxial with the light rod, the arc surface of the slide rod is rotatably connected with uniformly distributed balls, the balls of the slide rod are in contact with the light rod and are used for reducing the friction therebetween.

[0009] Further, the packing box body is provided with flow channels which are symmetrically distributed and communicate with the sealing cavity, the packing box body is provided with pressure cavities which are symmetrically distributed and located above the packing cavity, the pressure cavities communicate the adjacent flow channels with the packing cavity, the sealing member for extruding the gland is sealingly and slidably connected in the pressure cavity, the part of the sealing cavity on the pressure plate, the flow channels and the pressure cavities are filled with hydraulic oil.

[0010] Further, the sealing sleeve is made of a deformable material, the sealing sleeve does not contact the light rod, and the inner annular surface of the pressure plate does not contact the light rod.

[0011] Further, the inner diameter of the sealing sleeve is greater than the diameter of the light rod, and the diameter of the sealing sleeve gradually decreases from the middle part to both sides.

[0012] Further, the packing box body is fixedly connected with a support in the sealing sleeve, and the support is used for supporting the sealing sleeve.

[0013] Further, a pressure distribution ring is arranged between two adjacent ring-shaped packing, and a projection of the pressure distribution ring on the adjacent ring-shaped packing is located in the middle between the inner ring surface and the outer ring surface of the adjacent ring-shaped packing.

[0014] Further, the packing cartridge body is fixed with guide sleeves which are symmetrically distributed and located in the sealing cavity, the symmetrically distributed guide sleeves are sealingly and slidingly connected with the pressure disc, a pressure plug is sealingly and slidingly connected in the guide sleeve, the packing cartridge body is provided with channels which are symmetrically distributed and respectively communicate with adjacent guide sleeves, the channels are sealingly and slidingly connected with sealing columns, the third spring is arranged between the sealing column and the packing cartridge body and located on the upper side of the adjacent channel, the upper side of the pressure plug in the guide sleeve and the lower side of the sealing column in the channel are filled with hydraulic oil, the filler on the upper side of the sealing column in the channel is gas, the sealing column is provided with two through holes which are upwardly and downwardly distributed and respectively used for communicating with adjacent flow guide channels, and a one-way valve is arranged in the lower through hole.

[0015] The beneficial effects of the present application are as follows: the pressure disc drives the circumferentially and equidistantly distributed sliding rods to move upward, the circumferentially and equidistantly distributed sliding rods are guided by the guide portions to move close to each other to dynamically correct the light rod, so that the light rod is located in the middle of the packing cartridge body during the upward stroke, during the process that the gland extrudes the ring-shaped packing, the adjacent ring-shaped packings are guided by the pressure distribution ring therebetween, so that the extrusion force between the inner ring surface of the ring-shaped packing and the light rod and the extrusion force between the outer ring surface of the ring-shaped packing and the packing cartridge body are increased, and the sealing effect of the ring-shaped packing is improved, during the upward stroke, the downhole pressure is transmitted through the sealing element to extrude the gland and improve the sealing property of the ring-shaped packing to the light rod, during the downward stroke, the sealing element no longer extrudes the gland, so that the abrasion between the ring-shaped packing and the light rod is reduced, and the normal operation of the light rod is ensured, during the upward stroke, the flow direction of the hydraulic oil in the flow guide channel is limited, so that the sealing element generates a constant downward extrusion force on the gland, and the sealing property between the ring-shaped packing and the light rod is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a perspective structural schematic view of the present application;

[0017] Figure 2 It is a perspective structural sectional view of the present application from the side;

[0018] Figure 3 It is a perspective structural schematic view of the sliding rod and the light rod of the present application;

[0019] Figure 4 It is a perspective structural sectional view of the present application from the front;

[0020] Figure 5 It is a perspective structural sectional view of the pressure disc and the sealing sleeve of the present application;

[0021] Figure 6 For the invention Figure 5 Enlarged view of the stereoscopic structure at A in the invention;

[0022] Figure 7 For the invention ring packing and pressure ring stereoscopic structure explosion map.

[0023] Figure number: 1 - packing box body, 11 - packing cavity, 12 - positioning part, 13 - sealing cavity, 131 - guide part, 101 - polished rod, 102 - top plate, 103 - gland, 104 - first spring, 105 - ring packing, 201 - pressure plate, 202 - second spring, 203 - slide rod, 301 - flow guide, 302 - pressure cavity, 303 - sealing element, 4 - sealing sleeve, 5 - support, 6 - pressure ring, 7 - guide sleeve, 701 - pressure plug, 702 - channel, 703 - sealing column, 704 - third spring, 705 - through hole. DETAILED DESCRIPTION

[0024] The invention will be described in detail below with reference to the accompanying drawings. Example 1

[0025] The existing polished rod sealers generally set a positioning part (also called a correction part) to center the polished rod in the middle of the packing box body. In order to reduce the long-term wear of the polished rod by the positioning part, the polished rod and the positioning part are not completely sealed, which leads to poor centering effect of the positioning part. In the upstroke process, the tension on the lower end of the polished rod increases, which more easily leads to the polished rod to be deflected and to wear the ring packing. Long-term wear leads to poor sealing effect of the ring packing.

[0026] An automatic straightening oilfield polished rod sealer, such as Figures 1-5As shown, including the packing box body 1, packing box body 1 is provided with filler cavity 11 and positioning part 12, filler cavity 11 is located in the upper side of positioning part 12, positioning part 12 is used to ensure the centralization of the polished rod 101 in the packing box body 1, the packing box body 1 is slidably connected with the top plate 102 located in the upper side of the filler cavity 11, the packing box body 1 is threadedly connected with two bolts symmetrically distributed in front and back and commonly used for extruding the top plate 102, the filler cavity 11 is slidably connected with the gland 103, the first spring 104 is fixedly connected between the top plate 102 and the gland 103, the annular packing 105 equally spaced and located below the gland 103 is arranged in the filler cavity 11, the two bolts rotate and extrude the top plate 102 to move downward, the top plate 102 extrudes the gland 103 downward through the first spring 104, the gland 103 extrudes the four annular packings 105 below it, the annular packing 105 deforms to seal the packing box body 1 and the polished rod 101, further comprising a pressing plate 201, the packing box body 1 is provided with a sealing cavity 13 located below the positioning part 12, the pressing plate 201 is sealingly and slidably connected in the sealing cavity 13, the second spring 202 is fixedly connected between the pressing plate 201 and the packing box body 1, the lower side of the pressing plate 201 is slidably connected with three slide rods 203 distributed circumferentially at equal intervals, the end of the slide rod 203 away from the polished rod 101 is lower than the end close to the polished rod 101, under the action of external force, the slide rod 203 is away from the polished rod 101 under the action of its own gravity, the circumferentially equally spaced slide rods 203 are commonly used for correcting the polished rod 101, the lower inside diameter of the sealing cavity 13 is larger than the upper inside diameter, the sealing cavity 13 is provided with a guide part 131 for extruding the slide rod 203, the diameter of the guide part 131 gradually decreases from bottom to top, the three slide rods 203 are driven by the pressing plate 201 to move upward, the three slide rods 203 are guided by the guide part 131 to approach the polished rod 101 and perform centering treatment, the side of the slide rod 203 close to the polished rod 101 is provided with an arc surface coaxial with the polished rod 101, the arc surface of the slide rod 203 is rotatably connected with uniformly distributed balls, the balls of the slide rod 203 contact the polished rod 101 and are used to reduce the friction between them.

[0027] As Figures 4-6As shown, the packing box body 1 is provided with two flow channels 301 which are symmetrically distributed and are in communication with the sealing cavity 13, the packing box body 1 is provided with two pressure cavities 302 which are symmetrically distributed and are located on the upper side of the packing cavity 11, the pressure cavity 302 is in communication with the adjacent flow channel 301 and the packing cavity 11, the sealing element 303 for extruding the gland 103 is sealingly and slidingly connected in the pressure cavity 302, the sealing element 303 is composed of an upper sealing disc and a lower extrusion column, the part of the sealing cavity 13 on the pressure disc 201, the flow channel 301 and the pressure cavity 302 are filled with hydraulic oil, the upward movement of the pressure disc 201 pushes the hydraulic oil in the sealing cavity 13 to enter the two pressure cavities 302 through the two flow channels 301, so that the two sealing elements 303 move downward, the two sealing elements 303 extrude the gland 103, and the extrusion force of the gland 103 is increased.

[0028] As shown in Figure 4 , Figure 5 and Figure 7 , the sealing sleeve 4 located in the sealing cavity 13 is fixed between the pressure disc 201 and the packing box body 1, the sealing sleeve 4 is made of deformable material, the sealing sleeve 4 does not contact the polished rod 101, the sealing sleeve 4 is used to ensure the sealing between the pressure disc 201 and the packing box body 1, the inner diameter of the sealing sleeve 4 is larger than the diameter of the polished rod 101, the inner annular surface of the pressure disc 201 does not contact the polished rod 101, the diameter of the sealing sleeve 4 gradually decreases from the middle to both sides, the upward movement of the pressure disc 201 makes the sealing sleeve 4 more easily deformed, the packing box body 1 is fixed with the support 5 located in the sealing sleeve 4, the support 5 is used to support the sealing sleeve 4, when the pressure disc 201 moves upward to make the sealing sleeve 4 deform, the sealing sleeve 4 does not contact the polished rod 101, thereby reducing the wear of the sealing sleeve 4, the pressure distribution ring 6 is arranged between the two adjacent annular packings 105, the projection of the pressure distribution ring 6 on the adjacent annular packing 105 is located in the middle between the inner annular surface and the outer annular surface of the adjacent annular packing 105.

[0029] The polished rod sealer needs to be installed on the wellhead before use, and at the same time the operator rotates two bolts on the packing box body 1, the two bolts extrude the top plate 102 to move downward, the top plate 102 extrudes the gland 103 downward through the first spring 104, the first spring 104 stores force, the gland 103 extrudes the four annular packings 105 below, the annular packings 105 are deformed to seal between the packing box body 1 and the polished rod 101, since the sealing property of the annular packing 105 mainly reflects the inner and outer ring surfaces, therefore in the process of being extruded and deformed, the pressure distribution ring 6 guides the middle part between the inner and outer ring surfaces of the adjacent two annular packings 105, so that the middle part between the inner and outer ring surfaces of the annular packing 105 is extruded to both sides, thereby increasing the extrusion force between the inner ring surface of the annular packing 105 and the polished rod 101 and the extrusion force between the outer ring surface of the annular packing 105 and the packing box body 1, increasing the sealing effect of the annular packing 105, the state after the polished rod sealer is installed is shown in Figure 2 .

[0030] The dynamic correction of the polished rod 101 is performed by the slide bars 203 in the upstroke process. In the downstroke process, the polished rod 101 is subjected to a reduced pulling force, and thus the pressure between the polished rod 101 and the positioning part 12 is reduced, and the polished rod 101 does not excessively wear the positioning part 12, and the correction is completed only by the positioning part 12. The polished rod 101 is corrected in the upstroke and downstroke processes by the cooperation of the slide bars 203 and the positioning part 12, and the specific operation is as follows: In the initial state, the balls on the slide bars 203 are not in contact with the polished rod 101, and the end of the slide bar 203 away from the polished rod 101 is in contact with the lower side of the guide part 131. In the upstroke process, the polished rod 101 pulls the sucker rod to extract oil from the oil well, and thus the downhole pressure increases, the pressure under the pressure plate 201 increases, the second spring 202 is compressed, and the pressure plate 201 drives the three slide bars 203 to move upward. Taking the left slide bar 203 as an example, the left end of the slide bar 203 is extruded by the guide part 131 and starts to move to the right. The slide bar 203 drives the balls thereon to approach the polished rod 101. When the left end of the slide bar 203 is above the guide part 131, the balls on the slide bar 203 are in contact with the polished rod 101. The three slide bars 203 approach each other to center the polished rod 101. At the beginning of the upstroke process, the pulling force on the lower end of the polished rod 101 is small, which makes it easier for the slide bars 203 to center the polished rod 101. In the downstroke process, when the downhole pressure decreases, the elastic force of the second spring 202 is released, and thus the pressure plate 201 is driven to move downward, and the three slide bars 203 are driven to move downward. Since the end of the slide bar 203 away from the polished rod 101 is lower than the end close to the polished rod 101, the slide bar 203 moves away from the polished rod 101 under the action of its own gravity. When the second spring 202 returns to the initial state, the pressure plate 201 no longer moves downward. In the subsequent downstroke process of the polished rod 101, the polished rod 101 does not contact the balls on the slide bars 203.

[0031] Because the downhole pressure increases during the upstroke process, the sealing between the polished rod 101 and the packing box body 1 needs to be improved, and the specific operation is as follows: during the upward movement of the pressure disc 201, the pressure disc 201 pushes the hydraulic oil in the sealing cavity 13 to enter the two pressure cavities 302 through the two flow channels 301, so that the two sealing elements 303 move downward, and when the polished rod 101 is corrected by the slide rod 203, the two sealing elements 303 contact the upper side of the pressure cover 103 and generate a downward extrusion force on the pressure cover 103, at this time, the pressure cover 103 not only receives the downward extrusion force of the first spring 104, but also receives the downward extrusion force of the sealing element 303, the extrusion force between the four annular packings 105 increases, thereby improving the sealing between the packing box body 1 and the polished rod 101. Because the downhole pressure decreases during the downstroke process, the annular packing 105 does not need to excessively seal the polished rod 101 and the polished rod 101, and the specific operation is as follows: during the downstroke process, the pressure on the pressure disc 201 decreases, the elastic force of the second spring 202 is released, thereby pushing the pressure disc 201 to move downward, and the two sealing elements 303 move upward and no longer generate a downward extrusion force on the pressure cover 103, at this time, the pressure cover 103 only receives the downward extrusion force of the first spring 104, thereby reducing the extrusion force of the annular packing 105 on the polished rod 101, thereby reducing the wear between the annular packing 105 and the polished rod 101 (excessive extrusion force will increase the wear between the annular packing 105 and the polished rod 101, and a gap will be generated between the annular packing 105 and the polished rod 101, resulting in poor sealing effect), the sealing between the annular packing 105 and the polished rod 101 is improved by the two sealing elements 303 extruding the pressure cover 103 during the upstroke process, and the wear between the annular packing 105 and the polished rod 101 is reduced during the downstroke process, thereby ensuring the normal operation of the polished rod 101.

[0032] The sealing sleeve 4 ensures the sealing between the pressure disc 201 and the packing box body 1, and during the upward movement of the pressure disc 201, the pressure disc 201 causes the sealing sleeve 4 to deform, but the support 5 supports the sealing sleeve 4, thereby avoiding the deformation of the sealing sleeve 4 caused by the increase in the pressure in the sealing cavity 13 and the contact between the sealing sleeve 4 and the polished rod 101, thereby affecting the operation of the polished rod 101, and during the downward movement of the pressure disc 201, the sealing sleeve 4 deforms and recovers.

[0033] After the annular packing 105 is worn, the spring force of the first spring 104, which is in a stored state, is released. The first spring 104 pushes the gland 103 downward, so that the inner ring surface of the annular packing 105 is pressed against the smooth rod 101. Although the first spring 104 provides a compressive force to the annular packing 105, the length of the first spring 104 increases as the gland 103 moves downward. Compared with the initial state, the spring force of the first spring 104 decreases, and the compressive force of the gland 103 on the annular packing 105 decreases, reducing the sealing performance between the annular packing 105 and the smooth rod 101. When the above situation occurs, the smooth rod sealer will provide additional compressive force through the sealing element 303 to ensure the compressive force of the gland 103 on the annular packing 105, thereby ensuring the sealing performance between the annular packing 105 and the smooth rod 101. Example 2

[0034] Based on Example 1, an automatic straightening oilfield polished rod seal, such as... Figures 4-6 As shown, the packing box 1 is fixedly connected to two guide sleeves 7, which are symmetrically distributed on the left and right and located within the sealing cavity 13. Both guide sleeves 7 are sealed and slidably connected to the pressure plate 201. A pressure plug 701 is sealed and slidably connected inside the guide sleeve 7. The packing box 1 is provided with two channels 702, which are symmetrically distributed and communicate with the adjacent guide sleeves 7 respectively. A sealing post 703 is sealed and slidably connected to the channel 702. A third spring 704 located on the upper side of the adjacent channel 702 is fixed between the sealing post 703 and the packing box 1. The upper side of the pressure plug 701 inside the guide sleeve 7 and the channel 702 are connected to the pressure plate 201. The lower side of the sealing column 703 inside channel 702 is filled with hydraulic oil, and the upper side of the sealing column 703 inside channel 702 is filled with gas. The sealing column 703 is provided with two through holes 705 distributed vertically and used to connect adjacent guide channels 301. A one-way valve is provided in the lower through hole 705. In the initial state, the upper through hole 705 connects the adjacent guide channel 301. After the lower through hole 705 connects the adjacent guide channel 301, the hydraulic oil in the guide channel 301 can enter the adjacent pressure chamber 302, and the hydraulic oil in the pressure chamber 302 cannot be discharged.

[0035] During the upstroke process, the downhole pressure fluctuates, which causes the pressure disc 201 to float up and down in a small range, and the sealing element 303 also floats up and down, which causes the sealing element 303 to fail to generate a constant downward extrusion force on the pressure cover 103, resulting in a change in the extrusion force of the pressure cover 103 on the annular packing 105, thereby affecting the sealing performance of the annular packing 105 on the polished rod 101. Therefore, it is necessary to ensure that the sealing element 303 generates a constant downward extrusion force on the pressure cover 103 during the upstroke process. The specific operation is as follows: during the process in which the downhole pressure pushes the pressure disc 201 to move upward, the downhole pressure also pushes the two pressure plugs 701 to move upward. Taking the right pressure plug 701 as an example, the pressure plug 701 pushes the sealing column 703 to move upward through the hydraulic oil, and the third spring 704 is compressed. The gas above the sealing column 703 in the channel 702 is compressed. During the upward movement of the sealing column 703, the hydraulic oil in the flow guide 301 enters the pressure chamber 302 through the upper through hole 705. When the lower through hole 705 is communicated with the flow guide 301, the one-way valve in the lower through hole 705 opens, and the hydraulic oil in the flow guide 301 enters the pressure chamber 302 through the lower through hole 705. Due to the one-way transmission of the one-way valve in the lower through hole 705, the upper hydraulic oil in the flow guide 301 cannot flow to the right, and the hydraulic oil in the pressure chamber 302 cannot be discharged. Therefore, the sealing element 303 cannot move upward, and the position of the sealing element 303 does not change, thereby generating a constant downward extrusion force on the pressure cover 103, ensuring the sealing performance between the annular packing 105 and the polished rod 101.

[0036] After the downhole pressure fluctuates, for example, the downhole pressure decreases. Due to the one-way transmission of the one-way valve in the lower through hole 705, the pressure disc 201 does not move downward. The fluctuation of the downhole pressure causes the pressure plug 701 to move longitudinally and reciprocally, and the sealing column 703 also moves longitudinally and reciprocally. However, the lower through hole 705 is always communicated with the flow guide 301, and the hydraulic oil in the pressure chamber 302 cannot be discharged. After the downhole pressure fluctuates, the downhole pressure decreases during the downstroke process. The elastic force of the two third springs 704 is released. Taking the right third spring 704 as an example, the third spring 704 pushes the sealing column 703 to move downward, and the sealing column 703 pushes the pressure plug 701 to move downward through the hydraulic oil. When the upper through hole 705 is communicated with the flow guide 301, the elastic force of the second spring 202 is released and pushes the pressure disc 201 to move downward. The sealing element 303 moves upward and no longer generates a downward extrusion force on the pressure cover 103.

[0037] Those skilled in the art should understand that the above embodiments do not limit the present application in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the protection scope of the present application.

Claims

1. An automatic straightening oilfield polished rod sealer, comprising a packing box (1), wherein the packing box (1) is provided with a packing cavity (11) and a positioning part (12), a top plate (102) located on the upper side of the packing cavity (11) is slidably connected inside the packing box (1), a bolt for pressing the top plate (102) is threadedly connected to the packing box (1), a pressure cap (103) is slidably connected inside the packing cavity (11), a first spring (104) is fixed between the top plate (102) and the pressure cap (103), and annular packing (105) with equal spacing and located below the pressure cap (103) is provided inside the packing cavity (11), the annular packing (105) being used to seal the packing box (1) and the polished rod (101), characterized in that, It also includes a pressure plate (201), the packing box (1) is provided with a sealing cavity (13) located below the positioning part (12), the pressure plate (201) is sealed and slidably connected in the sealing cavity (13), a second spring (202) is fixedly connected between the pressure plate (201) and the packing box (1), the pressure plate (201) is slidably connected with slide rods (203) that are circumferentially evenly distributed and used together to correct the light rod (101), and the sealing cavity (13) is provided with a guide part (131) for squeezing the slide rod (203). The diameter of the guide portion (131) gradually decreases from bottom to top; The end of the slide rod (203) away from the light rod (101) is lower than the end close to the light rod (101); the packing box (1) is provided with symmetrically distributed guide channels (301) that are all connected to the sealing cavity (13); the packing box (1) is provided with symmetrically distributed pressure cavities (302) that are all located on the upper side of the packing cavity (11); the pressure cavities (302) connect the adjacent guide channels (301) to the packing cavity (11); the pressure cavities (302) are sealed and slidably connected with a sealing element (303) for squeezing the pressure cap (103); the portion of the sealing cavity (13) on the pressure plate (201), the guide channels (301), and the pressure cavities (302) are all filled with hydraulic oil; the packing box (1) is fixedly connected with symmetrically distributed guide sleeves (7) that are all located in the sealing cavity (13); the symmetrically distributed guide sleeves (7) are all connected to the pressure plate (201). The pressure plate (201) is sealed and slidably connected. The guide sleeve (7) is sealed and slidably connected with a pressure plug (701). The packing box (1) is provided with symmetrically distributed channels (702) that are respectively connected to the adjacent guide sleeves (7). The channel (702) is sealed and slidably connected with a sealing column (703). A third spring (704) located on the upper side of the adjacent channel (702) is fixed between the sealing column (703) and the packing box (1). The upper side of the pressure plug (701) in the guide sleeve (7) and the lower side of the sealing column (703) in the channel (702) are both filled with hydraulic oil. The filling material on the upper side of the sealing column (703) in the channel (702) is gas. The sealing column (703) is provided with two through holes (705) that are distributed vertically and are used to connect the adjacent guide channels (301). A one-way valve is provided in the lower through hole (705).

2. The automatic straightening oilfield polished rod seal according to claim 1, characterized in that, The slide bar (203) has an arc-shaped surface coaxial with the light rod (101) on the side near the light rod (101). The arc-shaped surface of the slide bar (203) is rotatably connected with uniformly distributed balls. The balls of the slide bar (203) contact the light rod (101) and are used to reduce the friction between them.

3. The automatic straightening oilfield polished rod seal according to claim 1, characterized in that, A sealing sleeve (4) located in the sealing cavity (13) is fixed between the pressure plate (201) and the packing box (1). The sealing sleeve (4) is made of deformable material. The sealing sleeve (4) does not contact the light rod (101), and the inner ring surface of the pressure plate (201) does not contact the light rod (101).

4. The automatic straightening oilfield polished rod seal according to claim 3, characterized in that, The inner diameter of the sealing sleeve (4) is larger than the diameter of the light rod (101), and the diameter of the sealing sleeve (4) gradually decreases from the middle to both sides.

5. The automatic straightening oilfield polished rod seal according to claim 4, characterized in that, The packing box (1) is fixedly connected to a support member (5) located inside the sealing sleeve (4), and the support member (5) is used to support the sealing sleeve (4).

6. The automatic straightening oilfield polished rod seal according to claim 1, characterized in that, A pressure dividing ring (6) is provided between two adjacent annular packings (105), and the projection of the pressure dividing ring (6) on the adjacent annular packings (105) is located at the middle between the inner and outer annular surfaces of the adjacent annular packings (105).

Images