Blowout preventer for tripping sucker rod in operating well

Abstract

The invention relates to a blowout preventer for tripping a sucker rod in an operating well, and belongs to the technical field of wellhead blowout preventers. The blowout prevention device comprises a sleeve, a flexible oil scraping disc is arranged on the sleeve, a shell is arranged outside the sleeve, an upper opening allowing a sucker rod to penetrate out is formed in the shell, a lower connector used for being connected with a wellhead is arranged at the bottom of the shell, and a movable space is formed between the sleeve and the inner wall of the shell. According to the blowout prevention device, when the sucker rod inclines and deviates from the central axis of a tripping rod channel in the tripping process, the sleeve can drive the oil scraping disc to move in the horizontal direction along with the sucker rod, the friction force of the sucker rod to the oil scraping disc is reduced, and the service life of the oil scraping disc is prolonged; and the sleeve can be driven by the sucker rod to rotate along with the sucker rod in the upward or upward moving process, so that the oil scraping disc is prevented from being damaged due to long-time abrasion of the specific position of the oil scraping disc when the sucker rod inclines and deviates from the central axis of a shaft, and the service life of the oil scraping disc is further prolonged.

Description

Technical Field

[0001] The present invention relates to a blowout preventer device for pulling and lowering sucker rods in a work well, belonging to the technical field of wellhead blowout preventers. Background Art

[0002] The sucker rod is an important component of a pumping well. It is connected to the polished rod at the upper end and the plunger of the submersible pump at the lower end, playing a role in transmitting power. Sucker rods generally have and three types, about 8 meters long. When in use, multiple sucker rods are connected together in the tubing through couplings. At the same time, according to different well inclinations, centralizers are installed at both ends of the sucker rod to reduce the wear between the sucker rod and the tubing. During workover operations, it is necessary to continuously pull and lower the sucker rods. The sucker rods are adhered with crude oil and water, which are likely to fall around the wellhead, polluting the environment and increasing the difficulty of disassembly for operators. For some work wells with associated gas, gas often spurts out from the wellbore during the process of pulling and lowering the sucker rods, and oil-water splashing will also occur. This not only causes waste of resources and environmental pollution, but also seriously affects the operation progress and is not conducive to safe and environmental production.

[0003] In the prior art, there are many devices for preventing liquid splashing during continuous pulling and lowering of sucker rods. For example, the Chinese utility model patent with the authorization publication number CN210829189U and the authorization publication date of June 23, 2020 discloses a sucker rod blowout prevention and oil scraping device. The device includes a main body and an oil scraping component (scraping disc); the main body is connected to the wellhead, and it has a rod lifting channel inside; the oil scraping component is connected in the rod lifting channel; the oil scraping component is an elastic component with a central hole, and there is a split structure around the central hole; the diameter of the central hole corresponds to the outer diameter of the rod body of the sucker rod; the split structure is used to expand the diameter of the central hole to the outer diameter of the centralizer when the centralizer passes through the central hole.

[0004] The oil scraping component of the above-mentioned sucker rod blowout prevention and oil scraping device is designed with a split structure. The central hole on it has a variable diameter function during the process of pulling and lowering the sucker rod. It can ensure that the centralizer and the larger-sized joints and couplings on the continuous sucker rod can smoothly pass through the central hole while ensuring that the rod lifting channel is always in a sealed state, avoiding the occurrence of oil-water splashing. However, the sucker rod is prone to tilt and deviate from the central axis of the wellbore during the process of pulling and lowering, and thus it is prone to cause excessive wear (eccentric wear) at a certain position with a large force on the oil scraping component fixedly connected to the main body during continuous pulling and lowering, greatly shortening the service life of the oil scraping component. Summary of the Invention

[0005] The purpose of the present invention is to provide a blowout preventer device for pulling and lowering sucker rods in a work well to solve the problem that the sucker rod is prone to cause eccentric wear to the oil scraping component during the rod lifting process.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A blowout preventer device for tripping sucker rods in a working well, comprising a sleeve, a scraping disk is arranged on the sleeve, a through hole for the sucker rod to pass through is arranged on the scraping disk, an outer shell is arranged outside the sleeve, an upper opening for the sucker rod to pass through is arranged on the outer shell, a lower joint for connecting to the wellhead is arranged at the bottom of the outer shell, and a movable space is arranged between the inner walls of the sleeve and the outer shell.

[0008] The blowout preventer device for tripping sucker rods in a working well of the present invention is modified on the existing sucker rod blowout preventer device. The scraping disk is arranged on the sleeve and a movable space for the sleeve is arranged between the sleeve and the housing, so that when the sucker rod inclines and deviates from the central axis of the tripping rod channel during the tripping process, the sleeve can drive the scraping disk to generate a displacement in the horizontal direction following the sucker rod, reducing the friction force of the sucker rod on the scraping disk, prolonging the service life of the scraping disk, and enabling the sleeve to rotate following the sucker rod during the upward or downward movement driven by the sucker rod, thereby avoiding damage to the scraping disk caused by long-term wear of a specific position of the scraping disk when the sucker rod inclines and deviates from the central axis of the wellbore, and further prolonging the service life of the scraping disk; at the same time, the blowout preventer device of the present invention has a simple structure, is convenient to use, easy to install and promote, and can greatly improve the operation efficiency when tripping sucker rods in a working well.

[0009] Further, the scraping disk comprises elastic scraping blades, the through hole is formed by a central hole arranged on the elastic scraping blades, at least two slitting seams extending from the central hole to the edge are arranged on the elastic scraping blades, at least two layers of elastic scraping blades are stacked, and the slitting seams on at least two layers of elastic scraping blades are arranged circumferentially staggered. At least two slitting seams arranged on the elastic scraping blades of the scraping disk and communicating with the central hole can expand the diameter of the through hole to the diameter of the centralizer, the maximum radial dimension of the joint or the diameter of the coupling when the centralizer, the sucker rod joint or the coupling passes through the through hole, ensuring a good sealing state of the scraping component at the centralizer, the joint of the sucker rod and the coupling, and avoiding the spraying of oil, water and gas in the wellbore due to the diameter change of the sucker rod at the joint and the coupling. Arranging the slitting seams on at least two layers of elastic scraping blades of the scraping disk arranged on the sleeve circumferentially staggered can, when the scraping disk deforms, make the staggered elastic scraping blades block the widened slitting seams from each other, better preventing the spraying of oil and water.

[0010] Further, the scraping disk comprises elastic scraping blades, the through hole is formed by a central hole arranged on the elastic scraping blades, at least two slitting seams extending from the central hole to the edge are arranged on the elastic scraping blades, and anti-cracking holes are arranged at the ends of the slitting seams far away from the central hole of the scraping blades. Arranging anti-cracking holes at the ends of the slitting seams far away from the central hole can avoid the elastic scraping blades of the scraping disk being torn and damaged when undergoing large deformation, and further prolong the service life of the scraping disk.

[0011] Further, oil scraping discs are arranged at both the upper and lower ends of the sleeve; the distance between the oil scraping discs arranged at the upper and lower ends of the sleeve is greater than the total length of the coupling in the sucker rod and the joints extending from both sides of the coupling beyond the coupling; the oil scraping disc includes an elastic oil scraping blade, the through hole is formed by a central hole provided on the elastic oil scraping blade, and at least two dividing slits extending from the central hole to the edge are provided on the elastic oil scraping blade. The distance between the two oil scraping discs arranged at both ends of the sleeve being greater than the total length of the coupling in the sucker rod and the joints extending from both sides of the coupling beyond the coupling enables one oil scraping disc to scrape oil from the joints and the coupling of the sucker rod while the other oil scraping disc scrapes oil from the rod body of the sucker rod all the time, avoiding the situation where the oil and water spray out from the deformed dividing slits due to the two oil scraping discs at both ends scraping oil from relatively large parts such as the joints and / or the coupling at the same time, so that the blowout preventer can better play the role of preventing blowout.

[0012] Further, the diameter of the through hole on the oil scraping disc is smaller than the rod body diameter of the sucker rod. By making the diameter of the through hole on the oil scraping disc smaller than the rod body diameter of the sucker rod, a better sealing effect can be achieved between the oil scraping disc and the sucker rod, enhancing the blowout prevention effect of the blowout preventer. It can be understood that the diameter of the through hole on the oil scraping disc refers to the diameter of the through hole when the oil scraping disc does not undergo elastic deformation.

[0013] Further, the oil scraping disc is fixedly arranged at the upper end of the sleeve through a flange, and the oil scraping disc arranged at the upper end of the sleeve extends beyond the flange to form a first extension part; a conical surface is arranged on the inner wall of the upper end of the housing, which is used to provide an abutting sealing surface for the first extension part when the sleeve moves upward. The contact between the oil scraping disc at the upper end of the sleeve and the conical surface on the inner wall of the upper end of the housing is used to form a seal, which can further prevent the pressurized gas in the wellbore from surging upward when the sucker rod is pulled out, and prevent the oil and water from splashing out through the through hole on the upper end cover of the housing. Further still, the housing includes an upper end cover, the upper end cover is detachably connected to the top of the housing body, the upper opening is arranged on the upper end cover, and the conical surface at the upper end of the housing is arranged on the upper end cover. Setting the upper end cover as detachably connected and arranging the conical surface on the upper end cover facilitates the replacement of the oil scraping disc on the sleeve inside the housing.

[0014] Further, the oil scraping disc is fixedly arranged at the lower end of the sleeve through a flange, and the oil scraping disc arranged at the lower end of the sleeve extends beyond the flange to form a second extension part; a conical surface is arranged on the inner wall of the lower end of the housing, which is used to provide an abutting sealing surface for the second extension part when the sleeve moves downward. The contact between the oil scraping disc at the lower end of the sleeve and the conical surface arranged on the inner wall of the lower end of the housing is used to form a seal, which can further prevent the pressurized gas from surging upward when the sucker rod is lowered into the wellbore, and prevent the oil and water from splashing out through the through hole on the housing.

[0015] Further, the outer casing includes an upper end cap which is detachably connected to the top of the housing, and the upper opening is provided on the upper end cap. This facilitates the repair and replacement of the oil scraping disc provided on the sleeve.

[0016] Further, the blowout preventer device for tripping the sucker rod in the work well further includes a three-way joint. The three-way joint includes a straight main pipe and a branch pipe. The lower joint is connected to the interface at one end of the straight main pipe of the three-way joint. The interface at the other end of the straight main pipe is used to connect to the wellhead, and the interface of the branch pipe is used to connect to the wellhead overflow liquid collection device. Connecting the lower joint of the outer casing to the straight main pipe of the three-way joint facilitates the discharge and recovery of the oil and water accumulated in the outer casing from the branch pipe of the three-way joint, which is environmentally friendly and clean.

[0017] Furthermore, the three-way joint is detachably connected to the lower joint. This facilitates the connection of the sucker rod blowout preventer to wellheads of different sizes and improves the flexibility of the use of the blowout preventer device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 FIG. is a usage state diagram of the blowout preventer device for tripping the sucker rod in the work well according to Embodiment 1 of the present invention;

[0019] Figure 2 FIG. is a structural schematic diagram of the elastic oil scraping sheet of the oil scraping disc of the blowout preventer device for tripping the sucker rod in the work well according to Embodiment 1 of the present invention and the first elastic oil scraping sheet of the oil scraping disc of the blowout preventer device for tripping the sucker rod in the work well according to Embodiment 2 of the present invention;

[0020] Figure 3 FIG. is a structural schematic diagram of the second elastic oil scraping sheet of the oil scraping disc of the blowout preventer device for tripping the sucker rod in the work well according to Embodiment 2 of the present invention;

[0021] Figure 4 FIG. is a structural schematic diagram of the third elastic oil scraping sheet of the oil scraping disc of the blowout preventer device for tripping the sucker rod in the work well according to Embodiment 2 of the present invention;

[0022] Figure 5 FIG. is a usage state diagram of the blowout preventer device for tripping the sucker rod in the work well according to Embodiment 3 of the present invention;

[0023] Figure 6 FIG. is a structural schematic diagram of the elastic oil scraping sheet of the blowout preventer device for tripping the sucker rod in the work well according to Embodiment 3 of the present invention;

[0024] Among them, 1 - sleeve, 2 - outer shell, 3 - upper end cover, 4 - oil scraping disc, 41 - central hole, 42 - dividing seam, 43 - anti - cracking hole, 44 - bolt hole, 45 - first extension part, 46 - second extension part, 5 - bolt, 6 - cylinder body, 7 - end flange, 8 - lower joint, 9 - upper opening, 10 - top surface groove, 11 - connection port, 12 - T - shaped tee joint, 13 - bottom surface groove, 14 - sucker rod body, 15 - coupling, 16 - joint, 17 - tapered surface. Detailed implementation mode

[0025] The technical solution of the present invention will be further described below in conjunction with the specific implementation mode.

[0026] During the workover operation, when lifting the sucker rod out of the wellbore and lowering the sucker rod into the wellbore using a elevating bail, the situation of the sucker rod tilting often occurs. In this case, during the continuous lifting or lowering of the sucker rod, it is easy to cause eccentric wear to the oil scraping component of the blowout preventer device, shorten the replacement time of the oil scraping component, and affect the workover operation efficiency. Based on this, the workover well sucker rod lifting and lowering blowout preventer device of the present invention is proposed. The blowout preventer device includes a sleeve, an oil scraping disc is arranged on the sleeve, a through - hole for the sucker rod to pass through is arranged on the oil scraping disc, an outer shell is arranged outside the sleeve, an upper opening for the sucker rod to pass through is arranged on the outer shell, a lower joint for connecting to the wellhead is arranged at the bottom of the outer shell, and an activity space is arranged between the inner walls of the sleeve and the outer shell. By using the activity space arranged between the inner wall of the sleeve and the outer shell, the oil scraping disc arranged on the outer sleeve can rotate driven by the movement of the outer sleeve during the process of lifting or lowering the sucker rod into or out of the wellbore to avoid excessive wear of the fixed position of the oil scraping disc by the sucker rod for a long time, and the oil scraping disc can also generate a certain displacement in the horizontal direction driven by the sucker rod following the inner sleeve, reducing the friction force of the sucker rod on the oil scraping disc and further prolonging the service life of the oil scraping component.

[0027] Embodiment 1

[0028] The workover well sucker rod lifting and lowering blowout preventer device of this embodiment, as Figure 1 shown, includes a sleeve 1, an outer shell 2 arranged outside the sleeve 1, a circular oil scraping disc 4 arranged on the sleeve 1, and a T - shaped tee joint 12. An activity space is arranged between the inner walls of the sleeve 1 and the outer shell 2.

[0029] Connection flanges are arranged at both ends of the sleeve 1, and the connection flanges at each end are connected to the end flanges through bolts. The oil scraping disc 4 is fixedly arranged between the end flange 7 and the corresponding connection flange. A through - hole for the sucker rod to pass through is arranged on the oil scraping disc 4, and the central hole of the end flange 7 allows the sucker rod to pass through. The diameters of the connection flanges at both ends of the sleeve 1, the oil scraping disc 4, and the end flange 7 are the same.

[0030] The oil scraping disc 4 is a circular elastic oil scraping sheet, as Figure 2As shown, a central hole 41 and six dividing slits 42 evenly distributed around the central hole 41 are provided on the elastic oil scraping blade. Each dividing slit 42 extends from the central hole 41 along the radial edge and has a crack prevention hole at the end far from the central hole. The part of the elastic oil scraping blade 4 between two adjacent dividing slits 42 can be deformed. The central hole 41 of the elastic oil scraping blade 4 forms a through hole on the oil scraping disc 4, and bolt holes 44 for bolts used to connect the connecting flange and the end flange are also provided at the edge of the elastic oil scraping blade. The apertures of the central holes of the end flange 7 and the connecting flange are both larger than the through hole on the elastic oil scraping blade. The elastic oil scraping blade used is a rubber plus wire gasket, which has good wear resistance, oil resistance and tear resistance. In other embodiments of the blowout preventer device for an operating well of the present invention, each dividing slit can also be an arc-shaped slit extending outward from the central hole 41.

[0031] The housing 1 includes a cylinder body 6, an upper end cover 3 provided at the upper end of the cylinder body 6, and a lower joint 8 provided at the lower end of the cylinder body 6. The upper end of the cylinder body 6 is provided with an internal thread, and the upper end cover 3 is threadedly connected to the cylinder body 6 through this internal thread. The upper end cover 3 is a compression cap. An upper opening 9 for the sucker rod to pass through is provided on the upper end cover 3. The upper opening 9 includes an equal-diameter section and a flared section from bottom to top. The flared section is located above the equal-diameter section, and the side wall of the flared section extends to the upper surface of the upper end of the upper end cover 3. The flared section of the upper opening can reduce the force of the joint and the coupling hitting the upper end cover vertically during the process of the sucker rod being lowered into the wellbore, and extend the service life of the blowout preventer device.

[0032] A top surface groove 10 with a circular cross-section is opened at the lower end of the upper end cover 3, and the upper opening 9 of the upper end cover 3 communicates with the bottom of the top surface groove 10; the top surface groove 10 includes an equal-diameter section and a flared section sequentially arranged from the bottom to the direction away from the bottom;

[0033] The lower joint 8 is integrally provided with the cylinder body 6. A connection port 11 is provided on the lower joint 8. The lower joint 8 is connected to the wellhead through the connection port 11. The connection port 11 also serves as a through hole for the sucker rod. The inner wall surface of the connection port 11 is provided with an internal thread throughout. The T-shaped three-way joint 12 includes a straight-through main pipe and a branch pipe. One end interface of the straight-through main pipe is threadedly connected to the lower joint 11 through the internal thread provided in the connection port 11. The other end interface of the straight-through main pipe is used to be directly connected to the wellhead, and the interface of the branch pipe is used to be connected to the wellhead overflow liquid collection device; a bottom surface groove 13 with a circular cross-section is opened at the upper end of the lower joint 8. The bottom surface groove 13 includes an equal-diameter section and an enlarged diameter section sequentially arranged from the bottom to the direction away from the bottom.

[0034] The diameters of the equal-diameter segments of the top surface groove 10 formed on the upper end cap 3 and the equal-diameter segments of the bottom surface groove 13 formed on the lower joint 8 are the same and larger than the diameter of the oil scraping disc 4; the heights of the equal-diameter segments of the top surface groove 10 and the bottom surface groove 13 in the up and down direction are the same and less than the total thickness of the connecting flange and the flange plate 7; the heights of the enlarged-diameter segments of the bottom surface groove 13 and the top surface groove 10 in the up and down direction are also the same, the minimum diameters of the flared segments of the bottom surface groove 13 and the top surface groove 10 are both the diameter of the equal-diameter segment of the bottom surface groove 13 and the maximum diameters of the flared segments of the bottom surface groove 13 and the top surface groove 10 are the same, and at the same time, the diameters of the flared segments of the bottom surface groove 13 and the top surface groove 10 change linearly; the bottoms of the bottom surface groove 13 and the top surface groove 10 are planes perpendicular to the direction of the pumping rod being lowered or retrieved. The equal-diameter segments of the top surface groove and the bottom surface groove can accommodate bolts and end flanges, which is beneficial to reducing the volume of the blowout preventer device.

[0035] The distance between the oil scraping discs 4 provided at both ends of the sleeve 1 is 1.5 times the total length of the pumping rod middle coupling and the joints extending from both sides of the coupling beyond the coupling. In this way, the situation where the oil scraping discs at the upper and lower ends of the sleeve 1 simultaneously contact the coupling or the joints extending from the coupling beyond the coupling will not occur, and it is better to prevent the oil and water from splashing. Of course, due to the presence of the oil scraping discs 4 provided at both ends of the sleeve 1, in other embodiments, the distance between the flanges at both ends of the sleeve 1 may also be not greater than the total length of the pumping rod middle coupling and the joints extending from both sides of the coupling beyond the coupling, but the effect of preventing the oil and water from splashing is not as good as the former.

[0036] The distance between the outer side surfaces of the end flanges connected to both ends of the sleeve 1 is less than the distance between the bottoms of the bottom surface groove 13 and the top surface groove 10, and an annulus can be formed between the sleeve 1 and the inner wall of the outer casing 2 in the direction of the pumping rod being lowered or retrieved vertically, that is to say, there is a movable space between the sleeve 1 and the inner wall of the outer casing 2. In this way, before the sleeve 1 is driven by the pumping rod to move up or down to the end point, it can rotate following the rotation of the pumping rod, and when the pumping rod tilts and deviates from the central axis of the wellbore, it can move in the horizontal direction following the pumping rod.

[0037] When performing the operation of pulling out and lowering the sucker rod in an oil well, the two ends of the straight main pipe of the T-shaped three-way joint 12 are respectively connected to the connection port 11 arranged on the lower joint 8 and the wellhead. The sleeve 1 is placed inside the housing 2, and the sucker rod passes through the upper opening arranged on the upper end cover 3, the central hole of the end flange 7 fixed at the upper end of the sleeve 1, the through hole on the scraping oil disc 4 fixed at the upper end of the sleeve 1, the connection flange at the upper end of the sleeve 1, the connection flange at the lower end of the sleeve 1, the through hole on the scraping oil disc 4 fixed at the lower end of the sleeve 1, the central hole of the end flange 7 fixed at the lower end of the sleeve 1, the connection port 11 arranged on the lower joint 8, and the interface at one end of the straight main pipe of the T-shaped three-way joint 12 connected to the connection port 11 from top to bottom. Along with the rotation generated during the process of pulling out or lowering the sucker rod into the wellbore, the sleeve rotates around the sucker rod during the upward or downward movement following the sucker rod. This rotation can reduce the eccentric wear of the elastic scraping oil piece when the sucker rod tilts and deviates from the central axis of the wellbore, extend the service life of the elastic scraping oil piece, and the sleeve can also generate a certain displacement synchronously with the sucker rod when the sucker rod deviates from the central axis of the wellbore, thereby further reducing the eccentric wear of the sucker rod on the elastic scraping oil piece; and the elastic scraping oil pieces fixed at the upper and lower ends of the sleeve 1 can effectively fit on the sucker rod (including the sucker rod body 14, coupling 15, and joint 16) during the process of lowering or pulling out the sucker rod into the wellbore, scrape off the oil and water, and flow into the wellhead overflow liquid collection device through the interface of the branch pipe of the T-shaped three-way joint 12.

[0038] Embodiment 2

[0039] The blowout prevention device for pulling out and lowering the sucker rod in the working well of this embodiment is only different from the blowout prevention device for pulling out and lowering the sucker rod in the working well of Embodiment 1 in that: in this embodiment, the scraping oil disc 4 includes three layers of stacked elastic scraping oil pieces, and the dividing slits 42 on any two adjacent elastic scraping oil pieces 4 are arranged with a circumferential stagger. The structures of the three layers of elastic scraping oil pieces are respectively shown in Figures 2 to 4 . Arranging the dividing slits of the stacked multi-layer elastic scraping oil pieces axially staggered can further improve the blowout prevention effect of the blowout prevention device on oil and water splashing.

[0040] Embodiment 3

[0041] The blowout prevention device for pulling out and lowering the sucker rod in the working well of this embodiment, as Figure 5 shown, is only different from the blowout prevention device for pulling out and lowering the sucker rod in the working well of Embodiment 2 in that: in this embodiment, the diameter of the scraping oil disc 4 (i.e., the diameter of the elastic scraping oil piece) between the connection flange and the end flange fixed at both ends of the sleeve 1 is larger than that of the connection flange and the end flange 7, and the part of the scraping oil disc 4 extending out of the end flange 7 forms an extension part, where the upper end forms a first extension part 45 and the lower end forms a second extension part 46, as Figure 6As shown. The diameter of the oil scraping disc 4 is greater than the minimum diameter of the enlarged diameter section of the top surface groove 10 formed on the upper end cover 3 and less than the maximum diameter of the enlarged diameter section. The groove wall surface of the flared section of the top surface groove 10 and the groove wall surface of the enlarged diameter section of the bottom surface groove 13 are both conical surfaces 17, and respectively form the abutting sealing surfaces of the first extension 45 when the sleeve 1 moves upward and the abutting sealing surfaces of the second extension 46 when the sleeve 1 moves downward. During the process of pulling and lowering the sucker rod, after the first extension 45 of the oil scraping disc 4 moves upward with the sleeve 1 and fits onto the conical surface of the top surface groove 10 or the second extension 46 moves downward with the sleeve 1 and fits onto the conical surface of the bottom surface groove 13, a sealing structure can be formed, further preventing the pressurized gas in the wellbore from flowing upward and splashing outwards.

[0042] Embodiment 4

[0043] The blowout preventer device for pulling and lowering the sucker rod in the working well of this embodiment is different from the blowout preventer device for pulling and lowering the sucker rod in Embodiment 1 only in that: in this embodiment, the lower joint 8 is connected to the interface at one end of the straight main pipe of the Y-shaped tee joint by welding, and the interface of the branch pipe of the Y-shaped tee joint is arranged obliquely downward for connecting to the wellhead overflow liquid collection device. When the lower joint and the Y-shaped tee joint are welded together, the connection between the Y-shaped tee joints is more firm, which can improve the stability of the device during use.

[0044] Embodiment 5

[0045] The blowout preventer device for pulling and lowering the sucker rod in the working well of this embodiment is different from the blowout preventer device for pulling and lowering the sucker rod in Embodiment 1 only in that: in this embodiment, the cylinder body 6 of the outer shell 2 and the lower joint 8 are separately arranged and connected by a flange; on the inner wall of the cylinder body 6, there are convex blocks for blocking the connecting flange at the lower end of the sleeve when the sleeve 1 is driven by the sucker rod to move upward and blocking the connecting flange at the upper end of the sleeve when the sleeve 1 is driven by the sucker rod to move downward. The blowout preventer device of this embodiment uses the convex blocks to prevent the sleeve from moving out of the outer shell when the sucker rod drives the sleeve to move upward or downward, which can reduce the pressure on the upper end cover and the lower joint when pulling out or lowering the sucker rod into the wellbore, and improve the stability of the device connection.

[0046] Embodiment 6

[0047] The blowout preventer device for pulling and lowering the sucker rod in the working well of this embodiment is different from the blowout preventer device for pulling and lowering the sucker rod in Embodiment 1 only in that: in this embodiment, the enlarged diameter sections of the top surface groove 10 and the bottom surface groove 13 formed on the upper end cover 3 are omitted, and the diameters of the equal diameter sections of the top surface groove 10 and the bottom surface groove 13 formed on the upper end cover 3 are greater than the diameters of the connecting flanges at both ends of the sleeve; only setting the equal diameter sections can reduce the processing difficulty of the device while not changing the prevention of oil and water splashing.

[0048] Embodiment 7

[0049] The blowout preventer for pulling and lowering sucker rods in the working well of this embodiment is only different from that of Embodiment 1 in that: in this embodiment, the distance between the end faces of the connecting flanges provided at both ends of the cylinder body of the sleeve 1 is less than the total length of the sucker rod coupling and the joints extending from both sides of the coupling, so as to reduce the volume of the blowout preventer and make it convenient for transportation and installation.

[0050] Embodiment 8

[0051] The blowout preventer for pulling and lowering sucker rods in the working well of this embodiment is only different from that of Embodiment 1 in that: in this embodiment, the aperture of the through hole of the oil scraping disc 4 adopted is slightly larger than the rod body diameter of the sucker rod, so as to reduce the resistance of pulling and lowering the sucker rod, and also generate deformation following the sizes of the centralizer, joint and coupling when the joint and coupling of the sucker rod pass through, so that the aperture of the through hole increases, and then the centralizer, joint and coupling can pass through.

[0052] Embodiment 9

[0053] The blowout preventer for pulling and lowering sucker rods in the working well of this embodiment is only different from that of Embodiment 1 in that: in this embodiment, the number of split seams on the elastic oil scraping sheet is 3, and no anti-cracking holes are provided in each split seam. Since the elastic oil scraping sheet adopted is a rubber plus wire gasket, the elastic oil scraping sheet has a good anti-cracking effect even without setting anti-cracking holes.

[0054] Embodiment 10

[0055] The blowout preventer for pulling and lowering sucker rods in the working well of this embodiment is only different from that of Embodiment 1 in that: in this embodiment, no connecting flanges are provided at the upper and lower ends of the sleeve 1, and no end flanges are fixed, and no bolt holes are provided on the oil scraping disc 4; a plurality of circular annular grooves are circumferentially formed inside the sleeve 1, the diameter of the oil scraping disc 4 matches the diameter of the ring formed by the bottom of the circular annular grooves, and the oil scraping disc 4 is fixedly connected in each circular annular groove. During the process of pulling and lowering the sucker rod, the elastic oil scraping sheet can also generate deformation to enable the centralizer, joint and coupling on the sucker rod to pass through smoothly.

Claims

1. A blowout preventer for pulling and lowering sucker rods in a working well, comprising a sleeve, a scraping disk is arranged on the sleeve, and a through hole for the sucker rod to pass through is arranged on the scraping disk. Characterized in that: An outer shell is arranged outside the sleeve, an upper opening for the sucker rod to pass through is arranged on the outer shell, a lower joint for connecting to the wellhead is arranged at the bottom of the outer shell, and an activity space is arranged between the inner walls of the sleeve and the outer shell.

2. The blowout preventer for pulling and lowering sucker rods in a working well according to claim 1, Characterized in that: The scraping disk comprises elastic scraping blades, the through hole is formed by a central hole arranged on the elastic scraping blades, at least two dividing slits extending from the central hole to the edge are arranged on the elastic scraping blades, at least two layers of elastic scraping blades are stacked, and the dividing slits on at least two layers of elastic scraping blades are arranged circumferentially staggered.

3. The blowout preventer for pulling and lowering sucker rods in a working well according to claim 1, Characterized in that: The scraping disk comprises elastic scraping blades, the through hole is formed by a central hole arranged on the elastic scraping blades, at least two dividing slits extending from the central hole to the edge are arranged on the elastic scraping blades, and anti-cracking holes are arranged at one ends of the dividing slits far away from the central hole of the scraping blades.

4. The blowout preventer for pulling and lowering sucker rods in a working well according to claim 1, Characterized in that: Scraping disks are arranged at both the upper and lower ends of the sleeve; the distance between the scraping disks arranged at the upper and lower ends of the sleeve is greater than the total length of the central coupling of the sucker rod and the joints extending from both sides of the coupling beyond the coupling; the scraping disk comprises elastic scraping blades, the through hole is formed by a central hole arranged on the elastic scraping blades, and at least two dividing slits extending from the central hole to the edge are arranged on the elastic scraping blades.

5. The blowout preventer for pulling and lowering sucker rods in a working well according to any one of claims 2 to 4, Characterized in that: The diameter of the through hole on the scraping disk is smaller than the rod body diameter of the sucker rod.

6. The blowout preventer for pulling and lowering sucker rods in a working well according to any one of claims 1 to 4, Characterized in that: The scraping disk is fixedly arranged at the upper end of the sleeve through a flange, and the scraping disk arranged at the upper end of the sleeve extends beyond the flange to form a first extension part; a conical surface is arranged on the inner wall of the upper end of the outer shell for providing an abutting sealing surface for the first extension part when the sleeve moves upward.

7. The blowout preventer for pulling and lowering sucker rods in a working well according to claim 6, Characterized in that: The outer shell comprises an upper end cover, the upper end cover is detachably connected to the top of the shell body, the upper opening is arranged on the upper end cover, and the conical surface at the upper end of the outer shell is arranged on the upper end cover.

8. The blowout preventer for pulling and lowering sucker rods in a working well according to any one of claims 1 to 4, Characterized in that: The scraping disk is fixedly arranged at the lower end of the sleeve through a flange, and the scraping disk arranged at the lower end of the sleeve extends beyond the flange to form a second extension part; a conical surface is arranged on the inner wall of the lower end of the outer shell for providing an abutting sealing surface for the second extension part when the sleeve moves downward.

9. The blowout preventer for pulling and lowering sucker rods in a working well according to any one of claims 1 to 4, Characterized in that: The housing includes an upper end cover which is detachably connected to the top of the housing, and the upper opening is provided on the upper end cover.

10. The blowout prevention device for tripping sucker rods in a working well according to any one of claims 1 to 4, characterized in that: it further includes a three-way joint which includes a straight-through main pipe and a branch pipe. The lower joint is connected to the interface at one end of the straight-through main pipe of the three-way joint. The interface at the other end of the straight-through main pipe is used for connection to the wellhead, and the interface of the branch pipe is used for connection to the wellhead overflow liquid collection device.

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