Wellhead sealing device

Abstract

The utility model relates to the technical field of well mouth sealing, in particular to a well mouth sealing device which comprises a lubricating mechanism, a first pressing end cover, a first sealing sleeve, a second sealing sleeve and a third sealing sleeve, and the first pressing end cover, the first sealing sleeve, the second sealing sleeve and the third sealing sleeve are detachably and fixedly installed together in sequence from top to bottom. An upper packing is sleeved on the inner side of the upper portion of the first sealing sleeve corresponding to the upper end of the first inner ring table, and a pressing sleeve is arranged at the upper end of the upper packing. The polish rod lubricating device is reasonable and compact in structure, lubricating liquid is added into the lubricating mechanism regularly, the lubricating liquid is injected into the liquid inlet through the lubricating mechanism, then the lubricating liquid is attached to the outer side of a polish rod after passing through the through hole of the oil passing cover, the polish rod is lubricated, the lubricating liquid is not prone to loss due to the arrangement of the upper packing and the lower packing, and the service life of the polish rod is prolonged. Therefore, sufficient lubrication of the polish rod can be guaranteed, dry grinding of the polish rod can be prevented, dry grinding of the polish rod and the packing, hot burning of the polish rod and no oil leakage after sealing failure when an intermittent oil outlet well only discharges air can be guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of wellhead sealing, and relates to a wellhead sealing device. Background Art

[0002] The wellhead sealing device is an important component to prevent the leakage of wellhead fluid during the production process of the pumping well. The working environment of the wellhead sealing device is relatively harsh. It needs to withstand the test of long-term repeated shuttling, friction, eccentric wear, shaking, etc. of the polished rod, keep the packing in close contact with the surface of the polished rod at all times, and prevent the fluid (oil, gas, water), mechanical impurities, etc. in the well from leaking out of the well.

[0003] In order to improve the sealing performance of the pumping wellhead, many packing boxes have been tested. For example, the Chinese patent document with the announcement number CN218439298U discloses a cone oiling packing box, which includes a bare rod, a large gland, a gland sleeve, an upper box body, a lower box body, an upper brass sleeve, an upper packing, a lower packing and a lower brass sleeve. The outer side of the bare rod is sequentially covered with a large gland, an upper box body and a lower box body from top to bottom. The upper box body is screwed to the inner side of the upper part of the lower box body, and the large gland is screwed to the upper side of the outer part of the upper box body. A T-shaped gland sleeve is covered on the inner side of the large gland, and the lower side of the gland sleeve extends to the upper side of the inner part of the upper box body. A sleeve is fixedly installed inside the upper box body. An upper brass sleeve is mounted on the outside of the bare rod, and an upper packing is mounted between the upper box body and the bare rod between the upper brass sleeve and the pressure sleeve; a refueling port that passes through inside and outside is arranged on the outside of the middle part of the lower box body, and an oil pressure sleeve is arranged between the lower box body and the bare rod at the position corresponding to the refueling port, and an oil inlet corresponding to the refueling port is arranged on the oil pressure sleeve, and the upper part of the oil pressure sleeve is against the bottom of the upper brass sleeve, and a lower packing is mounted between the lower box body and the bare rod at the position below the oil pressure sleeve, and a lower brass sleeve mounted on the outside of the bare rod is installed inside the lower box body at the position below the lower packing, and a fastening device capable of fixing the lower brass sleeve is arranged on the outside of the lower box body. The lower box body in the cone refueling packing box is arranged in an integrated manner, and the processing of the conical surface where the lower box body and the lower packing contact is relatively troublesome, and when replacing the lower packing, the entire cone refueling packing box needs to be disassembled before the lower packing can be taken out and replaced, which has high maintenance costs.

[0004] A Chinese patent document with announcement number CN205135510U discloses a novel medium-pressure polished rod sealer, which includes a polished rod sealer body, a through hole and a fixed cavity connected to the through hole are arranged in the polished rod sealer body, a polished rod is arranged in the through hole, a sealing packing and a packing upper pressure cover are arranged in sequence in the gap between the fixed cavity and the polished rod, a pressing cap for pressing the packing upper pressure cover is arranged at the upper end of the polished rod sealer, the fixed cavity is a truncated cone shape with a narrow lower end and a wide upper end, the width of the lower end of the fixed cavity is greater than the width of the through hole, the shape of the sealing packing is adapted to the shape of the fixed cavity, a lubricating device for lubricating the polished rod is arranged on the pressure cap, the compression amount of the spring in the novel medium-pressure polished rod sealer cannot be adjusted, and the lubrication effect between the sponge ring and the polished rod cannot be guaranteed.

[0005] A Chinese patent document with the announcement number CN204327027U discloses a packing box for heavy oil thermal recovery wells, comprising an upper packing box for loading upper packing before pumping and a lower packing box for loading lower packing before steam injection, wherein the lower packing box is detachably connected to the lower portion of the upper packing box, wherein the lower packing box is provided with a sealing section at the upper portion for loading the lower packing and a cavity section below the sealing section, wherein a venting port for releasing well fluid is provided on the cavity wall of the cavity section, wherein a venting valve for controlling the switch of the venting port is installed on the venting port, and a venting valve for controlling the switch of the venting port is provided at the lower portion of the lower packing box. A sealing sleeve is fixed below the vent port, and a sealing plug is installed in the sealing sleeve along the upward and downward guide direction, which is used to be fixedly connected to the lower end of the polished rod and seal the inner cavity of the sealing sleeve when the polished rod is lifted, and is released from the inner cavity of the sealing sleeve when the polished rod is lowered. The outer peripheral surface of the sealing plug and the peripheral surface of the inner wall of the sealing sleeve are sealed and matched. The packing box for heavy oil thermal recovery wells cannot lubricate the lower packing during use, so the lower packing and the polished rod of the intermittent oil well are prone to lose lubrication, resulting in heating and dry grinding of the polished rod, thereby shortening the service life.

[0006] Although the application of the above-mentioned packing box alleviates the problem of oil leakage due to failure of the seal at the pumping wellhead, the problem of oil leakage caused by the loss of lubrication and heating of the polished rods in intermittent oil wells and the rapid wear of the sealing materials has not been effectively solved. Utility Model Content

[0007] The utility model provides a wellhead sealing device, which overcomes the above-mentioned shortcomings of the prior art and can effectively solve the problems of intermittent dry grinding between the polished rod and the sealing material and short service life of the sealing material in the existing wellhead packing box.

[0008] The technical scheme of the utility model is realized by the following measures: a wellhead sealing device, comprising a lubricating mechanism and a first compression end cover, a first sealing sleeve, a second sealing sleeve and a third sealing sleeve which are detachably fixed and installed together from top to bottom in sequence, a first inner ring platform is fixed on the inner side of the upper part of the first sealing sleeve, an upper packing is sleeved on the inner side of the upper part of the first sealing sleeve corresponding to the upper end position of the first inner ring platform, a compression sleeve is arranged on the upper end of the upper packing, an elastic reset member is arranged between the upper end of the compression sleeve and the inner side of the upper part of the first compression end cover, a second inner ring platform is fixed on the inner side of the lower part of the third sealing sleeve, a lower packing is sleeved on the inner side of the upper part of the third sealing sleeve corresponding to the upper end position of the second inner ring platform, an oil hood located in the second sealing sleeve is arranged on the upper end of the lower packing, the upper part of the oil hood is detachably fixed and installed together with the lower part of the first sealing sleeve, at least one through hole connected inside and outside is distributed at intervals on the outer side of the oil hood, a liquid inlet connected inside and outside is arranged on the outer side of the second sealing sleeve, the lubricating mechanism is fixedly connected with the liquid inlet, and the lubricating mechanism is used to add lubricating liquid into the second sealing sleeve.

[0009] The following are further optimizations and / or improvements to the above utility model technical solution:

[0010] As a preferred embodiment, the lubrication mechanism may include a first liquid storage tank, a piston, a screw and a first plug. The first liquid storage tank is in the shape of a cylinder with an open upper end and a closed lower end. The outer side of the lower end of the first liquid storage tank is provided with a liquid outlet connected to the inside and outside. A first lubrication pipe is fixedly connected between the liquid outlet and the liquid inlet. A piston is sealed on the inner side of the first liquid storage tank. A screw is detachably fixedly installed on the upper end of the piston. A first plug is detachably fixedly installed on the upper end of the first liquid storage tank. A threaded hole is provided in the center of the first plug, which passes through the upper and lower ends. The outer side of the screw is screwed into the threaded hole.

[0011] Preferably, a first valve is installed on the first lubrication pipe, the lower end of the screw rod is provided with a threaded groove opening downward, a connecting bolt is screwed in the threaded groove, the upper end of the piston is provided with a mounting groove opening upward, the lower end of the connecting bolt is sleeved in the mounting groove, a sealing ring is fixed to the outer side of the lower end of the piston, a small pressure cover installed on the outer side of the lower part of the connecting bolt is screwed to the outer side of the upper end of the piston, a fixing ring in contact with the upper end surface of the head of the connecting bolt is fixed to the inner side of the upper end of the small pressure cover, and a first sealing ring is installed between the lower end of the small pressure cover and the upper end of the sealing ring.

[0012] As another preferred embodiment, the lubrication mechanism includes a second liquid storage tank, an upper connecting pipe, a lower connecting pipe, a second plug and a second lubrication pipe. The upper outer side of the second liquid storage tank is fixedly connected to the upper connecting pipe, the lower end of the second liquid storage tank is fixedly connected to the lower connecting pipe, the lower end of the lower connecting pipe is detachably fixedly installed with a second plug, and the second lubrication pipe is fixedly connected between the lower connecting pipe and the liquid inlet.

[0013] Preferably, a second valve is installed on the second lubrication pipe, the inner side of the lower end of the lower connecting pipe is threadedly connected with the outer side of the upper end of the second plug, a connecting short section is threadedly connected to the inner side of the upper end of the lower connecting pipe, the upper end of the connecting short section is fixedly connected to the lower end of the second liquid storage tank, and a third plug is fixedly installed on the upper end of the upper connecting pipe.

[0014] Preferably, the first clamping end cover, the first sealing sleeve, the second sealing sleeve and the third sealing sleeve are screwed together in sequence from top to bottom, and the inner side of the upper part of the first sealing sleeve corresponding to the position above the first inner ring platform has a conical upper sealing surface that is larger at the top and smaller at the bottom, and the inner side of the upper part of the third sealing sleeve at the upper end position of the second inner ring platform has a conical lower sealing surface that is larger at the top and smaller at the bottom.

[0015] Preferably, an inner ring groove is provided on the inner side of the upper end of the second sealing sleeve, a locking end cover is threadedly connected in the inner ring groove, and a second sealing ring is installed between the lower end of the locking end cover and the inner side of the lower part of the inner ring groove.

[0016] Preferably, a straightening sleeve sleeved in the first sealing sleeve is provided between the lower end of the first inner ring platform and the upper end of the oil-passing cover.

[0017] Preferably, an outer ring stage is fixed to the outer side of the upper end of the clamping sleeve, a third inner ring stage is fixed to the inner side of the upper end of the first clamping end cover, and the elastic reset member is installed between the outer ring stage and the third inner ring stage.

[0018] The utility model has a reasonable and compact structure. Lubricating liquid is regularly added to the lubricating mechanism. The lubricating liquid can be engine oil, transmission oil, butter, crude oil, etc. The lubricating liquid is injected into the liquid inlet by the lubricating mechanism, and then the lubricating liquid passes through the through hole of the oil cover and adheres to the outer side of the polished rod, so that the polished rod is lubricated. The arrangement of the packing under the first sealing sleeve can prevent the lubricating liquid from being easily lost, so that the polished rod can be fully lubricated and dry grinding of the polished rod can be prevented.

[0019] The first compression end cover is tightened regularly. The first compression end cover acts on the upper packing through the elastic reset piece and the compression sleeve. The elastic reset piece can be an existing well-known pressure spring. In this way, the compression force of the upper packing can be maintained after the first compression end cover is tightened. When the upper packing is worn, it is subjected to downward pressure and moves downward, and the clamping force on the polished rod is still maintained, thereby maintaining a lasting seal on the polished rod.

[0020] After the second sealing sleeve and the third sealing sleeve are disassembled, the first sealing sleeve, the second sealing sleeve, the oil cover and the lubricating mechanism are lifted upward as a whole, and then the lower packing can be added to the third sealing sleeve without separately disassembling the second sealing sleeve and the lubricating mechanism, which effectively solves the problem that the lower packing in the third sealing sleeve is difficult to update. The lubricating mechanism adds lubricating liquid into the liquid inlet, thereby ensuring that the pressure bearing capacity of the sealing sleeve is not lower than the pressure bearing capacity of the ordinary packing box. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the front cross-sectional structure of embodiments 1 to 3 of the utility model when in use.

[0022] Figure 2 It is a schematic diagram of the front cross-sectional structure of the fourth to ninth embodiments of the utility model when in use.

[0023] The codes in the attached drawings are: 1 is the first compression end cover, 2 is the first sealing sleeve, 3 is the second sealing sleeve, 4 is the third sealing sleeve, 5 is the first inner ring platform, 6 is the upper packing, 7 is the compression sleeve, 8 is the elastic reset member, 9 is the second inner ring platform, 10 is the lower packing, 11 is the oil cover, 12 is the through hole, 13 is the first liquid storage tank, 14 is the piston, 15 is the screw rod, 16 is the first plug, 17 is the first lubrication pipe, 18 is the first valve, 19 is the connecting bolt, 20 is Sealing ring platform, 21 is a small pressure cover, 22 is the first sealing ring, 23 is the second liquid storage tank, 24 is the upper connecting pipe, 25 is the lower connecting pipe, 26 is the second plug, 27 is the second lubrication pipe, 28 is the second valve, 29 is the connecting short section, 30 is the upper sealing surface, 31 is the lower sealing surface, 32 is the locking end cover, 33 is the second sealing ring, 34 is the straightening sleeve, 35 is the outer ring platform, 36 is the third inner ring platform, 37 is the fixed ring platform, 38 is the bare rod, and 39 is the third plug. DETAILED DESCRIPTION

[0024] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical solution of the present invention and actual conditions.

[0025] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached manual. Figure 1 The layout is described in detail, such as the positional relationship of front, back, top, bottom, left, right, etc., which is based on the attached manual. Figure 1 It is determined by the layout direction.

[0026] The present invention is further described below in conjunction with the embodiments and drawings:

[0027] Embodiment 1: As shown in the attached Figure 1 As shown, the wellhead sealing device includes a lubrication mechanism and a first compression end cover 1, a first sealing sleeve 2, a second sealing sleeve 3, and a third sealing sleeve 4 which are detachably fixed and installed together from top to bottom. A first inner ring platform 5 is fixed to the inner side of the upper part of the first sealing sleeve 2. An upper packing 6 is sleeved on the inner side of the upper part of the first sealing sleeve 2 corresponding to the upper end position of the first inner ring platform 5. A compression sleeve 7 is provided at the upper end of the upper packing 6. An elastic reset member 8 is provided between the upper end of the compression sleeve 7 and the inner side of the upper part of the first compression end cover 1. A second inner ring platform 5 is fixed to the inner side of the lower part of the third sealing sleeve 4. The inner ring platform 9 has a lower packing 10 mounted on the inner side of the upper part of the third sealing sleeve 4 corresponding to the upper end of the second inner ring platform 9. The upper end of the lower packing 10 is provided with an oil cover 11 located in the second sealing sleeve 3. The upper part of the oil cover 11 is detachably fixedly installed with the lower part of the first sealing sleeve 2. At least one through hole 12 connected inside and outside is spaced apart on the outside of the oil cover 11. The outer side of the second sealing sleeve 3 is provided with a liquid inlet connected inside and outside. The lubricating mechanism is fixedly connected with the liquid inlet, and the lubricating mechanism is used to add lubricating liquid into the second sealing sleeve 3.

[0028] Lubricating liquid is regularly added to the lubrication mechanism. The lubricating liquid can be engine oil, transmission oil, butter, crude oil, etc. The lubricating liquid is injected into the liquid inlet by the lubricating mechanism, and then the lubricating liquid passes through the through hole 12 of the oil cover 11 and evenly adheres to the outside of the polished rod 38, so that the polished rod 38 is lubricated. The arrangement of the upper packing 6 and the lower packing 10 can prevent the lubricating liquid from being easily lost, thus ensuring that the polished rod 38 is fully lubricated and preventing the polished rod 38 from being dry-ground. The oil cover 11 is a tubular structure. When tightening the second sealing sleeve 3, the lower packing can be pressed through the oil cover 11, so that the lower packing 10 is in sealing contact with the outside of the polished rod 38. The through hole on the outside of the oil cover 11 can not only allow the lubricating liquid to flow in evenly and adhere to the outside of the polished rod 38, but also filter out impurities in the lubricating liquid to prevent the polished rod 38 from being scratched by impurities.

[0029] The first compression end cover 1 is tightened regularly. The first compression end cover 1 acts on the upper packing 6 through the elastic reset piece 8 and the compression sleeve 7. The elastic reset piece 8 can be an existing well-known compression spring. In this way, the compression force of the upper packing 6 can be maintained after tightening the first compression end cover 1. When the upper packing 6 is worn, it is downwardly pressed by the elastic reset piece 8 and can still wrap the outer side of the light rod 38 to maintain a lasting seal on the light rod 38.

[0030] After the second sealing sleeve 3 and the third sealing sleeve 4 are disassembled, the first sealing sleeve 2, the second sealing sleeve 3, the oil cover 11 and the lubricating mechanism are lifted upward as a whole, and then the lower packing 10 can be added to the third sealing sleeve without separately disassembling the second sealing sleeve 3 and the lubricating mechanism, which effectively solves the problem that the lower packing 10 in the third sealing sleeve 4 is difficult to update.

[0031] The sealing sleeve is arranged into three sections (a first sealing sleeve 2, a second sealing sleeve 3, and a third sealing sleeve 4), so that it is convenient to add the lower packing 10, and it is also convenient to add the upper packing 6 and process and manufacture the lower packing 10.

[0032] The wellhead sealing device can achieve continuous lubrication of the pumping wellhead seal and more convenient packing maintenance, avoiding the phenomenon of lubricating fluid leaking downward or upward. When the intermittent oil well is only discharging gas, it can avoid the dry grinding between the polished rod 38 and the packing, which causes the polished rod 38 to become hot, and the phenomenon of oil leakage after the seal fails.

[0033] The wellhead sealing device can be further optimized and / or improved according to actual needs:

[0034] Embodiment 2: As an optimization of the above embodiment, as shown in the attached Figure 1As shown, the lubrication mechanism includes a first liquid storage tank 13, a piston 14, a screw 15 and a first plug 16. The first liquid storage tank 13 is in the shape of a cylinder with an open upper end and a closed lower end. The outer side of the lower end of the first liquid storage tank 13 is provided with a liquid outlet connected inside and outside, and a first lubrication pipe 17 is fixedly connected between the liquid outlet and the liquid inlet. The piston 14 is sealed on the inner side of the first liquid storage tank 13, and the screw 15 is detachably fixedly installed on the upper end of the piston 14. The first plug 16 is detachably fixedly installed on the upper end of the first liquid storage tank 13, and a threaded hole is provided in the center of the first plug 16, which passes through from top to bottom, and the outer side of the screw 15 is screwed into the threaded hole.

[0035] In order to facilitate the disassembly and assembly of the first plug 16 and the screw rod 15, a rotating handle is fixed on the outer side of the upper end of the screw rod 15 and the outer side of the upper end of the first plug 16, and the lubricating liquid is filled in the first liquid storage tank 13. After the screw rod 15 is rotated, the screw rod 15 drives the piston 14 to move downward, so that the lubricating liquid is injected into the second sealing sleeve 3 through the first lubrication pipe 17, which can lubricate the polished rod 38 and the lower packing 10, avoid dry grinding between the polished rod 38 and the lower packing 10, thereby extending the service life of the lower packing 10.

[0036] Embodiment 3: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a first valve 18 is installed on the first lubrication pipe 17, a threaded groove opening downward is provided at the lower end of the screw rod 15, a connecting bolt 19 is screwed into the threaded groove, a mounting groove opening upward is provided at the upper end of the piston 14, the lower end of the connecting bolt 19 is sleeved in the mounting groove, a sealing ring 20 is fixed to the outer side of the lower end of the piston 14, a small pressure cover 21 installed on the outer side of the lower part of the connecting bolt 19 is screwed to the outer side of the upper end of the piston 14, a fixing ring 37 in contact with the upper end surface of the head of the connecting bolt 19 is fixed to the inner side of the upper end of the small pressure cover 21, and a first sealing ring 22 is installed between the lower end of the small pressure cover 21 and the upper end of the sealing ring 20.

[0037] The first sealing ring 22 is a well-known sealing gasket or sealing ring, and the first valve 18 is a well-known regulating valve. In order to prevent the small gland 21 from rotating when tightening, which may cause the first sealing ring 22 to be squeezed and deformed too much and cause sealing failure, a fixed ring platform 37 is provided on the inner side of the upper end of the small gland 21, so that the upper end of the piston 14 can limit the small gland 21 after contacting the lower end surface of the fixed ring platform 37. The fixed ring platform 37 is hung on the head of the connecting bolt 19. At the same time, the setting of the fixed ring platform 37 can flexibly rotate the screw rod 15 so that the head of the connecting bolt 19 can generate pulling force on the small gland 21 and the piston 14 and then move upward. The setting of the small gland 21 facilitates the disassembly and assembly of the first sealing ring 22.

[0038] Embodiment 4: As another optimization of the above embodiment, the difference between this embodiment and embodiment 2 is only that the lubrication mechanism is different. Figure 2 As shown, the lubrication mechanism includes a second liquid storage tank 23, an upper connecting pipe 24, a lower connecting pipe 25, a second plug 26 and a second lubrication pipe 27. The upper outer side of the second liquid storage tank 23 is fixedly connected to the upper connecting pipe 24, the lower end of the second liquid storage tank 23 is fixedly connected to the lower connecting pipe 25, the lower end of the lower connecting pipe 25 is detachably fixedly installed with a second plug 26, and the lower connecting pipe 25 is fixedly connected to the second lubrication pipe 27 between the lower connecting pipe 25 and the liquid inlet.

[0039] The upper connecting pipe 24 and the lower connecting pipe 25 are both well-known oil pipe couplings. The upper connecting pipe 24 is used to add lubricating liquid into the second liquid storage tank 23, and the pressurized oil produced at the wellhead is used to lubricate the lower packing 10 to avoid dry grinding between the polished rod 38 and the lower packing 10, thereby extending the service life of the lower packing 10.

[0040] Embodiment 5: As an optimization of the above embodiment, as shown in the attached Figure 2 As shown, a second valve 28 is installed on the second lubrication pipe 27, the inner side of the lower end of the lower connecting pipe 25 is threadedly connected with the outer side of the upper end of the second plug 26, a connecting short section 29 is threadedly connected to the inner side of the upper end of the lower connecting pipe 25, the upper end of the connecting short section 29 is fixedly connected to the lower end of the second liquid storage tank 23, and a third plug 39 is fixedly installed on the upper end of the upper connecting pipe 24.

[0041] The second valve 28 is a conventionally known regulating valve. The second valve 28 can close the second lubrication pipe 27 when replacing the lower packing 10, thereby preventing the lubricating fluid from flowing into the second sealing sleeve 3, facilitating the disassembly and assembly of the sealing sleeve and the replacement of the packing. The provision of the connecting nipple 29 facilitates the standardized production of the second liquid storage tank 23. The inner side of the lower end of the lower connecting pipe 25 is threadedly connected to the outer side of the upper end of the second plug 26. The inner side of the upper end of the lower connecting pipe 25 is threadedly connected with a connecting nipple 29, which is convenient for installation at the well site, thereby improving the disassembly and assembly efficiency of the second liquid storage tank 23 and the second sealing sleeve 3. The inner side of the upper end of the connecting pipe 24 is threadedly connected with the outer side of the lower end of the third plug 39. A disassembly handle is fixed to the outer side of the upper end of the third plug 39. By setting the third plug 39, leakage of the lubricating liquid in the second liquid storage tank 23 can be avoided. The second lubrication pipe 27 includes two connecting short pipes. The outer side of the left end of the left connecting short pipe is threadedly connected to the liquid inlet, the outer side of the right end of the left connecting short pipe is threadedly connected to the inner side of the left end of the second valve 28, the inner side of the right end of the second valve 28 is threadedly connected to the outer side of the left end of the right connecting short pipe, and the right end of the right connecting short pipe is welded to the lower connecting pipe 25.

[0042] Embodiment 6: As an optimization of the above embodiment, as shown in the attached Figure 1 , 2As shown, the first clamping end cover 1, the first sealing sleeve 2, the second sealing sleeve 3 and the third sealing sleeve 4 are screwed together in sequence from top to bottom, and the upper inner side of the first sealing sleeve 2 corresponding to the position above the first inner ring platform 5 has a conical upper sealing surface 30 that is larger at the top and smaller at the bottom, and the upper inner side of the third sealing sleeve 4 at the upper end position of the second inner ring platform 9 has a conical lower sealing surface 31 that is larger at the top and smaller at the bottom.

[0043] The first compression end cover 1, the first sealing sleeve 2, the second sealing sleeve 3 and the third sealing sleeve 4 are screwed together in sequence from top to bottom, which facilitates the disassembly and assembly of the first compression end cover 1, the first sealing sleeve 2, the second sealing sleeve 3 and the third sealing sleeve 4, and facilitates the replacement of the upper packing 6 and the lower packing 10. When the first sealing sleeve 2 is rotated and tightened, the oil cover 11 not only plays the role of lubricating the polished rod 38 with oil, but also can play the role of transmitting the pressure of the first sealing sleeve 2, thereby compressing the lower packing 10 and ensuring the sealing effect between the lower packing 10 and the polished rod 38.

[0044] The upper sealing surface 30 is a conical surface with a larger upper portion and a smaller lower portion. The first sealing sleeve 2 and the first inner ring platform 5 can be provided as an integral unit, or the conical sleeve of a conical tube shape can be fixedly installed with the inner side of the first sealing sleeve 2 of a tubular structure by a plurality of connecting screws distributed at intervals along the circumference to form the first inner ring platform 5. The conical sleeve can be integral or can be two symmetrical semi-conical sleeves. In this way, the sealing surface can always exert force on the upper packing 6 and the lower packing 10. When the upper packing 6 and the lower packing 10 are worn, the upper packing 6 moves downward under the action of the elastic reset member 8 and then contacts the polished rod 38 in a sealed manner, thereby To ensure the sealing effect between the upper packing 6 and the polished rod 38, because the inclination angle of the polished rod 38 is small, the lateral component of the suspension point load is small, and usually the lateral force of the eccentric wear of the polished rod 38 on the packing is not large, so the upper packing 6 and the lower packing 10 can play a straightening effect on the polished rod 38, and the taper of the lower sealing surface 31 can be set to be the same as the taper of the upper sealing surface 30, and the second sealing sleeve 3 and the third sealing sleeve 4 are screwed together, so that the position of the lower sealing surface 31 is relatively shallow, and the cutting force position of the tool is shallow when processing the lower sealing surface 31, which is convenient for processing the lower sealing surface 31.

[0045] The arrangement of the upper sealing surface 30 and the lower sealing surface 31 can also realize that only new packings need to be added to the first sealing sleeve 2 and the third sealing sleeve 4 without replacing the old packings, thereby further reducing the difficulty of maintenance.

[0046] Embodiment 7: As an optimization of the above embodiment, as shown in the attached Figure 1 , 2 As shown, an inner ring groove is provided on the inner side of the upper end of the second sealing sleeve 3, a locking end cover 32 is threadedly connected in the inner ring groove, and a second sealing ring 33 is installed between the lower end of the locking end cover 32 and the inner side of the lower part of the inner ring groove.

[0047] In order to facilitate the disassembly and assembly of the locking end cover 32, a disassembly and assembly handle is fixedly installed on the outer side of the upper end of the locking end cover 32. When the locking end cover 32 is rotated, the lower end of the locking end cover 32 and the inner wall of the lower part of the inner ring groove approach each other and squeeze the second sealing ring 33. The second sealing ring 33 is a well-known sealing gasket or sealing ring. In this way, the second sealing ring 33 can improve the sealing between the first sealing sleeve 2 and the second sealing sleeve 3 to avoid oil and gas leakage.

[0048] Embodiment 8: As an optimization of the above embodiment, as shown in the attached Figure 1 , 2 As shown, a straightening sleeve 34 sleeved in the first sealing sleeve 2 is provided between the lower end of the first inner ring platform 5 and the upper end of the oil cover 11 .

[0049] In order to prevent the polished rod 38 and the first sealing sleeve 2 from eccentric wear, the straightening sleeve 34 is a copper straightening sleeve, thereby reducing the wear of the polished rod 38 and preventing the polished rod 38 from contacting the inner side of the sealing sleeve and causing burrs or wear.

[0050] Embodiment 9: As an optimization of the above embodiment, as shown in the attached Figure 1 , 2 As shown, an outer ring stage 35 is fixed to the outer side of the upper end of the clamping sleeve 7 , a third inner ring stage 36 is fixed to the inner side of the upper end of the first clamping end cover 1 , and the elastic reset member 8 is installed between the outer ring stage 35 and the third inner ring stage 36 .

[0051] The provision of the outer ring platform 35 and the third inner ring platform 36 can increase the force-bearing area at both ends of the elastic reset member 8, thereby preventing the elastic reset member 8 from failing due to concentrated force. The upper end of the outer side of the outer ring platform 35 can also bulge upward to form a sleeve that is sleeved on the outer side of the lower part of the elastic reset member 8, thereby preventing the elastic reset member 8 from wearing against the light rod 38 after being offset.

[0052] The above technical features respectively constitute various embodiments of the present utility model, which have strong adaptability and implementation effect, and non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A wellhead sealing device, characterized in that The seal is secured to the seal member and is adapted to engage with the sealant in the sealant so that the sealant is secured to the sealant at the outer edge of the sealant.

2. The wellhead sealing device according to claim 1, characterized in that The lubrication mechanism includes a first liquid storage tank, a piston, a screw and a first plug. The first liquid storage tank is in the shape of a cylinder with an open upper end and a closed lower end. The outer side of the lower end of the first liquid storage tank is provided with a liquid outlet that is connected to the inside and outside. A first lubrication pipe is fixedly connected between the liquid outlet and the liquid inlet. A piston is sealed on the inner side of the first liquid storage tank. A screw is detachably fixedly installed on the upper end of the piston. A first plug is detachably fixedly installed on the upper end of the first liquid storage tank. A threaded hole that passes through from top to bottom is provided in the center of the first plug. The outer side of the screw is screwed into the threaded hole.

3. The wellhead sealing device according to claim 2, characterized in that A first valve is installed on the first lubrication pipe, a threaded groove opening downward is provided at the lower end of the screw rod, a connecting bolt is screwed in the threaded groove, a mounting groove opening upward is provided at the upper end of the piston, the lower end of the connecting bolt is sleeved in the mounting groove, a sealing ring is fixed to the outer side of the lower end of the piston, a small pressure cover installed on the outer side of the lower part of the connecting bolt is screwed to the outer side of the upper end of the piston, a fixing ring in contact with the upper end surface of the head of the connecting bolt is fixed to the inner side of the upper end of the small pressure cover, and a first sealing ring is installed between the lower end of the small pressure cover and the upper end of the sealing ring.

4. The wellhead sealing device according to claim 1, characterized in that The lubrication mechanism includes a second liquid storage tank, an upper connecting pipe, a lower connecting pipe, a second plug and a second lubrication pipe. The upper outer side of the upper portion of the second liquid storage tank is fixedly connected to the upper connecting pipe, the lower end of the second liquid storage tank is fixedly connected to the lower connecting pipe, a second plug is detachably fixedly installed on the lower end of the lower connecting pipe, and a second lubrication pipe is fixedly connected between the lower connecting pipe and the liquid inlet.

5. The wellhead sealing device according to claim 4, characterized in that A second valve is installed on the second lubrication pipe, the inner side of the lower end of the lower connecting pipe is threadedly connected with the outer side of the upper end of the second plug, a connecting short section is threadedly connected to the inner side of the upper end of the lower connecting pipe, the upper end of the connecting short section is fixedly connected to the lower end of the second liquid storage tank, and a third plug is fixedly installed on the upper end of the upper connecting pipe.

6. The wellhead sealing device according to claim 1, 2, 3, 4 or 5, characterized in that The first clamping end cover, the first sealing sleeve, the second sealing sleeve and the third sealing sleeve are screwed together in sequence from top to bottom. The inner side of the upper portion of the first sealing sleeve corresponding to the position above the first inner ring platform has a conical upper sealing surface that is larger at the top and smaller at the bottom. The inner side of the upper portion of the third sealing sleeve at the upper end position of the second inner ring platform has a conical lower sealing surface that is larger at the top and smaller at the bottom.

7. The wellhead sealing device according to claim 1, 2, 3, 4 or 5, characterized in that An inner ring groove is provided on the inner side of the upper end of the second sealing sleeve, a locking end cover is threadedly connected in the inner ring groove, and a second sealing ring is installed between the lower end of the locking end cover and the inner side of the lower part of the inner ring groove.

8. The wellhead sealing device according to claim 6, characterized in that An inner ring groove is provided on the inner side of the upper end of the second sealing sleeve, a locking end cover is threadedly connected in the inner ring groove, and a second sealing ring is installed between the lower end of the locking end cover and the inner side of the lower part of the inner ring groove.

9. The wellhead sealing device according to claim 1 or 2 or 3 or 4 or 5 or 8, characterized in that A straightening sleeve is provided between the lower end of the first inner ring platform and the upper end of the oil cover and is sleeved in the first sealing sleeve; and / or an outer ring platform is fixed to the outer side of the upper end of the clamping sleeve, and a third inner ring platform is fixed to the inner side of the upper end of the first clamping end cover, and the elastic reset member is installed between the outer ring platform and the third inner ring platform.

10. The wellhead sealing device according to claim 6, characterized in that A straightening sleeve is provided between the lower end of the first inner ring platform and the upper end of the oil cover and is sleeved in the first sealing sleeve; and / or an outer ring platform is fixed to the outer side of the upper end of the clamping sleeve, and a third inner ring platform is fixed to the inner side of the upper end of the first clamping end cover, and the elastic reset member is installed between the outer ring platform and the third inner ring platform.

Images