Mechanical pressure control type slip fisher capable of freely grabbing and releasing fallen fish

Abstract

A mechanical pressure control type slip fisher capable of freely grabbing and releasing fallen fishes relates to the field of slip fishers and comprises an upper connector, a connecting sleeve, a spring, a fishing barrel, an anti-rotation sleeve, a rotating body, a guide control sleeve and a slip sleeve, the upper connector, the connecting sleeve and the fishing barrel are connected to form a fisher body, and the rotating body, the guide control sleeve and the slip sleeve are connected to form a fisher core string. The fisher core string and the spring are arranged in the fisher body, the spring is supported between the upper connector and the rotating body, the anti-rotating sleeve is installed on the inner side wall of the connecting sleeve, a guide groove is formed in the inner circumferential face of the anti-rotating sleeve, and guide sawteeth are arranged on the upper end face of the anti-rotating sleeve. The guide control sleeve is hung at the lower end of the rotating body, an anti-rotating wedge is arranged on the outer circumferential face of the guide control sleeve, guide control protruding teeth are arranged on the upper end face of the guide control sleeve, the slip sleeve is connected to the lower end of the guide control sleeve, the fisher achieves the free grabbing and releasing function through a combined structure of the anti-rotating sleeve, the rotating body and the guide control sleeve, and the safety, stability and reliability of free grabbing and releasing of fallen fishes can be enhanced.

Description

Technical Field

[0001] The invention relates to the field of slip catching devices, and in particular to a mechanical pressure-controlled slip catching device capable of freely catching and releasing fallen fish. Background Art

[0002] The slip salvage device is a special tool for sucker rod salvage, which is suitable for salvaging tubular perforated fish such as downhole oil pipes, drill pipes, casing milling pipes, packers, water distributors and production distributors. In actual production, when salvaging fish, it is often necessary to stop the salvage operation and release the fish due to obstacles or production process requirements. The current slip salvage device mainly releases the fish by rotating the sucker rod or drill rod forward and cutting the weak current screw. The former requires that there should be no rotating short section in the sucker rod or drill rod, while the latter cannot be salvaged again after release, both of which have great functional limitations. The utility model patent with announcement number CN210622752U discloses the technical scheme of "a pressure-controlled releasable slip salvage device", which specifically "adopts a rotating body and a guide pin matching structure, and limits the movement of the rotating body relative to the cylinder through the grooves on the surface of the rotating body, thereby limiting the axial displacement and radial contraction of the slip, and realizing the reciprocating operation of salvaging, releasing, and re-salvaging the fish in the well". However, in this technical scheme, the gravity of the rotating body, the limiting body, the slip, and the fish salvaged by the slip is always borne by the guide pin, and the radial shear force is continuously applied to the guide pin through the interaction between the rotating body and the cylinder, especially during the salvage. During the interactive transformation of salvage and release, the guide pin will be subjected to a large mechanical impact when interacting with the first side guide surface, the second side guide surface, and the upper end surfaces of the long vertical groove and the short vertical groove, further increasing the radial shear force borne by the guide pin, and the radial shear force borne will also change in value and direction with the process of salvage and release transformation. In addition, the radial section of the guide pin is small, and it is very easy to produce bending fatigue under the action of such dynamic alternating loads, which often leads to damage or even breakage during use, thereby shortening the service life of the salvage device, increasing production costs, and sometimes causing production accidents, which greatly limits the promotion and application of this technical solution. Therefore, it is necessary to further study and develop a new structure of free-catch and release fish slip salvage to solve the existing technical problems. Summary of the invention

[0003] The purpose of the present invention is to provide a mechanical pressure-controlled slip catching device capable of freely catching and releasing fallen fish, so as to enhance the safety, stability and reliability of the free catching and releasing function of fallen fish.

[0004] A mechanical pressure-controlled slip salvage device capable of freely catching and releasing fallen fish comprises: an upper joint, a connecting sleeve, a spring, a salvage tube, an anti-rotation sleeve, a rotating body, a guide sleeve and a slip sleeve, wherein the upper joint, the connecting sleeve and the salvage tube are sequentially connected up and down to form a salvage device body, an inverted inner conical surface is provided at the lower end of the inner circumferential surface of the salvage tube, the rotating body, the guide sleeve and the slip sleeve are sequentially connected up and down to form a salvage device core string, and the salvage device core string and the spring are jointly arranged on the salvage device body The spring is arranged in the inner cavity of the salvage core string, supported between the upper joint and the rotating body, and applies an elastic force to the salvage core string relative to the salvage body; the anti-rotation sleeve is fixedly installed on the inner side wall of the connecting sleeve, and an axial straight guide groove is provided on the inner circumferential surface of the anti-rotation sleeve. The guide grooves are evenly arranged on the cross-sectional circumference of the anti-rotation sleeve, and are composed of deep grooves and shallow grooves of the same width arranged alternately, and the depth of the deep groove is large. According to the depth of the shallow groove, a guide sawtooth is provided on the upper end surface of the anti-rotation sleeve, which is continuously and periodically distributed along the circumference. The guide sawtooth has an inclined guiding surface and a vertical limiting surface, and the setting positions are synchronously corresponding to the guiding groove; a plurality of guide wedges are provided on the outer circumferential surface of the rotating body, and the positions are coordinated and corresponding to the axial straight line. Each of the guide wedges can be synchronously matched with the deep groove or the shallow groove provided on the anti-rotation sleeve, and the cross-sectional structure corresponds to the deep groove. When the guide wedge is matched with the deep groove, the guide wedge can be matched and inserted into the deep groove, and the rotating body is matched with the anti-rotation sleeve to guide the rotating body to move linearly relative to the anti-rotation sleeve. An inclined matching surface is provided on the lower end head of the guide wedge, and the spatial orientation of the inclined matching surface corresponds to the inclined guiding surface on the guiding sawtooth, and the inclination is the same as that of the inclined guiding surface, and can form a rotational guide match with the inclined guiding surface;The guide control sleeve is rotatably fitted and suspended and connected to the lower end of the rotating body, and a plurality of anti-rotation wedges are arranged on the outer circumferential surface, the positions of which are coordinated and correspond to the axial straight line arrangement. The cross-sectional structure of the anti-rotation wedge corresponds to the shallow groove, and they are synchronously fitted and correspondingly embedded in the guide grooves provided on the anti-rotation sleeve, so as to limit the rotational movement of the guide control sleeve relative to the anti-rotation sleeve and guide the axial movement of the guide control sleeve. Guide control convex teeth are continuously and periodically distributed along the circumference on the upper end surface of the guide control sleeve, and the guide control convex teeth have an inclined guide surface corresponding to the spatial orientation of the inclined matching surface at the lower end of the guide wedge, and the inclined guide surface has the same inclination slope corresponding to the inclined matching surface. When the rotating body is fitted in the anti-rotation sleeve, it is protected by the guide groove. The inclined guide surface and the inclined matching surface are partially overlapped and matched, so that a space stroke for relative sliding and rotation along the matching surface is maintained between the two. When the rotating body is removed from the anti-rotation sleeve and the anti-rotation limit is released, the inclined guide surface can guide the rotating body to rotate under the action of the spring; the slip sleeve is fixedly connected to the lower end of the guide sleeve, and a check groove with an axially arranged lower end opening is provided on the slip sleeve, so that the slip sleeve has radial elastic deformation ability, and an inverted outer conical surface is provided on the lower end head. The inverted outer conical surface corresponds to the inverted inner conical surface structure in the salvage tube. When the inverted inner conical surface cooperates with the inverted outer conical surface, the slip sleeve can produce radial contraction deformation to salvage fish in the well. ;

[0005] The mechanical pressure-controlled cava salvor that can freely catch and release fallen fish is preferably provided with a thrust bearing between the rotating body and the spring, and the lower end of the spring is supported on the rotating body by the thrust bearing to reduce the rotational resistance of the rotating body, while also preventing the spring from twisting as the rotating body rotates, thereby ensuring the stability of the overall operating function and structural state of the salvor.

[0006] The mechanical pressure-controlled cava salvor that can freely catch and release fallen fish is preferably provided with an outwardly extending annular flange on the outer circumferential surface of the lower part of the rotating body, and a suspension pin with a pin body extending to the inside of the sleeve body is installed on the upper side wall of the guide and control sleeve, and the suspension pins are evenly distributed along the circumference of the cross-section of the guide and control sleeve, and the upper end of the guide and control sleeve is correspondingly overlapped with the lower end of the rotating body, and the pin body of the suspension pin and the annular flange form a balanced overlapping fit, so that the guide and control sleeve is rotationally fitted and suspended on the rotating body.

[0007] The beneficial effect of the present invention is to provide a mechanical pressure-controlled cava salvage device that can freely catch and release fallen fish, adopt a corresponding combination structure of an anti-rotation sleeve, a rotating body and a guide sleeve, use the anti-rotation sleeve to limit the motion trajectory of the guiding and controlling sleeve, cooperate to limit the spatial form of the rotating body, and use the guide sleeve to drive and control the cyclic transformation of the matching form between the rotating body and the anti-rotation sleeve, and drive the cava sleeve and the salvage tube to cyclically switch between the salvage matching state and the release matching state through the rotating body, so as to realize the free catch and release function of the fish in the well during the salvage operation; in the cyclic conversion process of salvaging and releasing the fish in the well, the rotating body can Whether between the guide sleeve or the anti-rotation sleeve, axial force is always applied to each other between the end faces. Not only is the force transmitted to each other balanced and stable, but the anti-rotation sleeve, the rotating body and the guide sleeve all have sufficient bearing capacity in the axial direction, which can ensure that the conversion process is completed stably and reliably. It can completely replace the structure in the prior art that the guide pin bears the conversion force in an unbalanced state, eliminates the phenomenon of production accidents caused by damage or breakage of the guide pin, enhances the safety, stability and reliability of the free catch and release function of falling fish, and can effectively save production costs and improve production efficiency when applied in actual production. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a cross-sectional view of the release structure of a mechanical pressure-controlled cava salvor that can freely catch and release fallen fish.

[0009] Figure 2 It is a cross-sectional view of the salvaging structure of a mechanical pressure-controlled cava salvage device that can freely catch and release fallen fish.

[0010] Figure 3 for Figure 2 Sectional view of the AA section.

[0011] Figure 4 for Figure 2 Cross-sectional view of the middle BB section.

[0012] Figure 5 This is a three-dimensional structural diagram of the anti-rotation sleeve.

[0013] Figure 6 It is a three-dimensional structural diagram of the rotating body.

[0014] Figure 7 This is a three-dimensional structural diagram of the guide and control sleeve.

[0015] Among them: 1 is the upper joint, 2 is the connecting sleeve, 3 is the salvage tube, 4 is the spring, 5 is the anti-rotation sleeve, 6 is the rotating body, 7 is the guide and control sleeve, 8 is the slip sleeve, 9 is the suspension pin, 10 is the thrust bearing, 11 is the deep groove, 12 is the shallow groove, 13 is the guide serration, 14 is the guide wedge, 15 is the anti-rotation wedge, 16 is the guide and control convex tooth, 17 is the annular flange, 18 is the extension area, 19 is the downhole fish, 20 is the inclined guide surface, 21 is the inclined guide surface, 22 is the vertical limit surface, and 23 is the inclined matching surface. DETAILED DESCRIPTION

[0016] Furthermore, the technical solution claimed in the present invention is described in detail in conjunction with specific embodiments and the accompanying drawings.

[0017] A mechanical pressure-controlled slip fisher capable of freely catching and releasing fallen fish, such as Figures 1 to 4 As shown, it is composed of an upper joint 1, a connecting sleeve 2, a salvage tube 3, a spring 4, an anti-rotation sleeve 5, a rotating body 6, a guide sleeve 7, a slip sleeve 8, a suspension pin 9 and a thrust bearing 10. The upper joint 1, the connecting sleeve 2 and the salvage tube 3 are sequentially connected up and down to form a salvage device body. An inverted inner conical surface is provided at the lower end of the inner circumferential surface of the salvage tube 3. The rotating body 6, the guide sleeve 7 and the slip sleeve 8 are sequentially connected up and down to form a salvage device core string. The salvage device core string is correspondingly arranged in the inner cavity of the salvage device body. The thrust bearing 10 is arranged at the upper end of the rotating body 6, and the spring 4 is arranged at the upper end of the thrust bearing 10, supported between the upper joint 1 and the thrust bearing 10.

[0018] The anti-rotation sleeve 5 is fixedly mounted on the inner side wall of the connecting sleeve 2. Figure 5 As shown, 8 axially straight guide grooves with the same cross-sectional width are provided on the inner circumferential surface, and the guide grooves are evenly distributed along the cross-sectional circumference of the anti-rotation sleeve 5, and are composed of deep grooves 11 and shallow grooves 12 arranged alternately, and the depth of the deep grooves 11 is twice the depth of the shallow grooves 12. 8 guide serrations 13 are provided on the upper end surface of the anti-rotation sleeve 5 and are continuously and periodically distributed along the circumference. The guide serrations 13 have inclined guide surfaces 21 and vertical limit surfaces 22, which are synchronously corresponding to the opening positions of the guide grooves; the rotating body 6 is a circular cylinder, as shown Figure 6As shown, four guide wedges 14 arranged in an axial straight line are arranged in the middle of the outer circumferential surface, and the guide wedges 14 are evenly distributed along the circumference of the cross section of the rotating body 6, and the cross-sectional structure corresponds to the deep groove 12. The four guide wedges 14 can be synchronously and correspondingly embedded in the four deep grooves 12, and inclined matching surfaces 23 are respectively arranged on the lower ends of the guide wedges 14. The inclined matching surfaces 23 have the same inclination as the inclined guide surfaces 21 on the guide serrations 13. An extended area 18 relative to the guide wedges 14 is arranged at the lower end of the rotating body 6, and an annular flange 17 is further arranged on the outer circumferential surface of the extended area 18; the guide control sleeve 7 is a circular sleeve body, as shown in FIG. Figure 7 As shown, 8 anti-rotation wedges 15 arranged along the axial straight line are arranged on the outer circumferential surface, and the cross-sectional structure of the anti-rotation wedges 15 corresponds to the shallow groove 12. They are evenly arranged along the cross-sectional circumference of the guide control sleeve 7 and respectively correspond to the lower end of the anti-rotation sleeve 5 and are inserted in the guide grooves opened on the anti-rotation sleeve 5. 8 guide control convex teeth 16 distributed continuously and periodically along the circumference are arranged on the upper end surface of the guide control sleeve 7. The guide convex teeth 16 are in the shape of an umbrella cap, and one side of the tooth surface is an inclined guide surface 20. The inclined guide surface 20 has the same inclination as the inclined matching surface 23 at the lower end of the guide wedge 14. When the rotating body 6 is matched with the anti-rotation sleeve 5, the inclined guide surface 20 can be matched with the The inclined mating surface 23 maintains a local overlapping fit. Four suspension pins 9 evenly distributed along the circumference are installed on the upper side wall of the guide sleeve 7. The pin body of the suspension pin 9 extends to the inside of the guide sleeve 7. The upper end of the guide sleeve 7 is fitted and sleeved on the extended area 18 at the lower end of the rotating body 6. The suspension pin 9 is fitted and hung on the annular flange 17 to rotationally fit and hang the guide sleeve 7 on the rotating body 6; the slip sleeve 8 is threadedly fixedly connected to the lower end of the guide sleeve 7, and the sleeve body is provided with 8 axially arranged elastic check grooves with openings at the lower end, and an inverted outer conical surface is provided at the lower end, and the inverted outer conical surface corresponds to the inverted inner conical surface structure in the salvage tube 3.

[0019] The mechanical pressure-controlled slip fishing device capable of freely catching and releasing fallen fish is in a released structural state. Figure 1As shown, the four guide wedges 14 on the rotating body 6 correspond to the four shallow grooves 12 provided on the anti-rotation sleeve 5. Since the guide wedges 14 cannot be inserted into the shallow grooves 12, under the elastic force of the spring 4, the rotating body 6 is fixedly supported on the anti-rotation sleeve 5 through the corresponding cooperation of the inclined matching surface 23 at the lower end of the guide wedge 14 and the inclined guide surface 21 on the guide serration 13 and the anti-rotation limitation of the vertical limiting surface 22 on the adjacent guide serration 13. At this time, the guide control sleeve 7 suspended at the lower end of the rotating body 6 and the slip sleeve 8 connected to the guide control sleeve 7 are lifted upward with the rotating body 6, so that the inverted outer conical surface at the lower end of the slip sleeve 8 and the inverted inner conical surface in the salvage tube 3 are separated and cannot cooperate with each other, so that the slip sleeve 8 cannot catch the fish 19 fallen in the salvage well; in the salvage structure state, Figure 2 As shown, the four guide wedges 14 on the rotating body 6 correspond to the four deep grooves 11 provided on the anti-rotation sleeve 5 and are synchronously inserted into the deep grooves 11 respectively. Under the elastic force of the spring 4, the salvage core string fully descends in the salvage body, and the inverted outer conical surface at the lower end of the slip sleeve 8 forms a corresponding fit with the inverted inner conical surface in the salvage tube 3. At this time, since the rotating body 6 is rotationally limited and inserted in the anti-rotation sleeve 5, the inclined fitting surface 23 at the lower end of the guide wedge 14 can form and maintain a partial overlapping fit with the inclined guide surface 20 on the guide control convex tooth 16, and can transmit the elastic force to the guide control sleeve 7 and the slip sleeve 8 through the rotating body 6, so that the inverted outer conical surface and the inverted inner conical surface generate an interaction force, and the slip sleeve 8 can capture and salvage the fish 19 fallen in the well.

[0020] The mechanical pressure-controlled slip fishing device capable of freely catching and releasing fish described in this embodiment is used to fish out fish in a well. The method of use and its working principle are as follows: When salvaging fish in the well, the mechanical pressure-controlled slip salvage device capable of freely catching and releasing fish in the structure state is released, such as Figure 1As shown, it is connected to the drilling tool drill pipe and sent down the well. When it is sent down to the salvage depth, the overshot tube 3 introduces the fish 19 in the well into the salvage device body and enters the slip sleeve 8. The drilling tool drill pipe is continuously applied to slowly send down the well. The fish 19 in the well will abut against the lower end of the guide sleeve 7, pushing the guide sleeve 7 to move upward relative to the guide sleeve 5 until the inclined guide surfaces 20 on a group of guide convex teeth 16 on the upper end of the guide sleeve 7 respectively cooperate with the inclined lower ends of the four guide wedges 14 on the outer circumference of the rotating body 6. The surface 23 is partially overlapped, and the driving force of the fish falling 19 in the well is transmitted through the mutually matched inclined guide surface 20 and the inclined matching surface 23, so that the salvage core string as a whole moves upward relative to the salvage body. When the guide control sleeve 7 extends from the upper end of the anti-rotation sleeve 5 to the tooth root of the guide control convex tooth 16 exceeds the tooth tip height of the guide saw tooth 13 at the upper end of the anti-rotation sleeve 5, the guide wedge 14 simultaneously breaks away from the circumferential limit of the vertical limit surface 22 on the adjacent guide saw tooth 13. Under the guidance of the inclined guide surface 20 on the guide control convex tooth 16, the rotating body 6 is pushed to rotate, and the four guide wedges 14 are correspondingly guided to the inclined guide surfaces on the adjacent guide serrations 13 and re-form a guiding match therewith. Since the guide serrations 13 that have re-formed a guiding match respectively correspond to the deep grooves 11, the guide wedges 14 can be guided by the inclined guide surfaces 21 and respectively correspondingly fit into the deep grooves 11, so that the rotating body 6 is pushed by the spring 4 to move downward relative to the anti-rotation sleeve 5. After the inclined matching surface 23 at the lower end of the guide wedge 14 forms an overlapping fit with the inclined guide surface 20 on the guide control convex tooth 16 again, the salvage device core string forms a structural whole and begins to move downward relative to the salvage device body until the slip sleeve 8 drops to the bottom of the salvage tube 3, so that the inverted inner conical surface in the salvage tube 3 forms a corresponding fit with the set outer conical surface on the slip sleeve 8, as shown in FIG. Figure 2 As shown, the mechanical pressure-controlled cava salvage device that can freely catch and release fallen fish is transformed into a released structural state. At this time, the drilling tool drill pipe is lifted. Under the action of the inverted inner conical surface, the cava sleeve 8 radially elastically contracts and tightens the fallen fish 19 in the well. Continuing to lift the drilling tool drill pipe can salvage the fallen fish 19 out of the well.

[0021] When it is necessary to release the downhole fish, the above-mentioned salvage process is terminated and the downhole fish 19 is slowly returned. After the downhole fish 19 is returned and stabilized, force is continued to be applied to slowly send down the drilling tool drill pipe. When the downhole fish 19 hits the guide control sleeve 7 again, the guide control sleeve 7 and the slip sleeve 8 connected to the guide control sleeve 7 are pushed to move upward relative to the anti-rotation sleeve 5. During the movement, the outer conical surface at the lower end of the slip sleeve 8 is gradually separated from the inverted inner conical surface in the salvage tube 3, and the slip sleeve 8 is elastically deformed to recover and loosen to release the downhole fish 19, until the inclined guide surface 20 on the guide control convex tooth 16 at the upper end of the guide control sleeve 7 is partially overlapped with the inclined matching surface 23 at the lower end of the guide wedge 14 again, so that the salvage device core string as a whole moves upward relative to the salvage device body again. When the guide control sleeve 7 extends from the upper end of the anti-rotation sleeve 5 to the point where the root of the guide control convex tooth 16 exceeds the tooth tip height of the guide serration 13 at the upper end of the anti-rotation sleeve 5, the guide wedge 14 continues to be guided by the inclined guide surface 20 to the inclined matching surface 23 on the sequentially adjacent guide serration 13, so that the inclined guide surface 20 and the inclined matching surface 23 form a guiding match with each other. Since the newly introduced guide serrations 13 correspond to the shallow grooves 12 respectively, the guide wedge 1 cannot be inserted into the shallow grooves 11 to make the rotating body 6 move relative to the anti-rotation sleeve 5. Therefore, the guide wedge 14 is circumferentially limited by the vertical limiting surfaces 22 on the sequentially adjacent guide serrations 13, and is correspondingly supported on the inclined guiding surface 21 on the newly introduced guide serrations 13, so that the salvage core string is fixedly connected to the salvage body as a whole. Figure 1 As shown, the mechanical pressure-controlled slip salvage device that can freely capture and release fallen fish is transformed into a release structure state, and the drilling tool drill pipe is continuously lifted, and the downhole fish 19 will escape from the slip sleeve 8 and the salvage tube 3 and be released in the oil well.

[0022] During the above-mentioned production and use process, when salvaging, the mechanical pressure-controlled cava salvage device that can freely catch and release fallen fish is converted from the release structure state to the salvage structure state. During the conversion process, the guide control sleeve 7 transmits an axial force to the rotating body 6 through the inclined guide surface 20 on the upper guide control convex tooth 16 and the inclined matching surface 23 at the lower end of the guide wedge 14, so that the rotating body 6 changes its matching state with the anti-rotation sleeve 5; when releasing, the mechanical pressure-controlled cava salvage device that can freely catch and release fallen fish is converted from the salvage structure state to the release structure state. During the conversion process, the guide control sleeve 7 still transmits an axial force to the rotating body 6 through the inclined guide surface 20 on the upper guide control convex tooth 16 and the inclined matching surface 23, so that the rotating body 6 is fixedly supported on the anti-rotation sleeve 5 through the inclined matching surface 23 at the lower end of the guide wedge 14 and the inclined guide surface 21 on the guide serration 13 at the upper end of the anti-rotation sleeve 5, and the matching state change is realized again. It can be seen that in the cyclic transformation of the structural state of the mechanical pressure-controlled cava salvage device capable of freely catching and releasing fallen fish described in this embodiment, the rotating body always applies axial force to each other between the upper and lower end surfaces, whether between the guide and control sleeve or between the rotating body and the anti-rotation sleeve. Not only is the force balanced and stable, but the anti-rotation sleeve, the rotating body and the guide and control sleeve all have sufficient load-bearing guarantee capacity in the axial direction, thereby ensuring the safety, stability and reliability of freely catching and releasing fallen fish in the well. In addition, although the guide and control sleeve 7 is suspended and connected to the rotating body 6 by the suspension pin 9, the suspension pin 9 does not have the function of transmitting force during the transformation of the structural state of the mechanical pressure-controlled cava salvage device capable of freely catching and releasing fallen fish. It only serves to suspend and lift the guide and control sleeve 7 and the cava sleeve 8 fixedly connected thereto in the released structural state, so that the inverted outer conical surface at the lower end of the cava sleeve 8 is separated from the corresponding cooperation with the inverted inner conical surface in the salvage tube 3. In this structural state, since the fallen fish 19 in the well has been released, the suspension pin 9 It only carries the weight of the guide sleeve 7 and the cava sleeve 8. In the salvage structure state, since the inverted outer conical surface has formed an interactive fit with the inverted inner conical surface, the overall weight of the downhole fish 19 and the salvage device core string are all borne on the salvage tube 3 through the inverted inner conical surface. At this time, the suspension pin 9 does not bear any force. It can be seen that the setting of the suspension pin 9 will not have any adverse effect on the safety, stability and reliability of the free-grabbing and releasing function of the mechanical pressure-controlled cava salvage device that can freely capture and release fallen fish described in this embodiment.

Claims

1. A mechanical pressure-controlled slip catching device capable of freely catching and releasing fallen fish, characterized in that: include: An upper joint (1), a connecting sleeve (2), a salvage tube (3), a spring (4), an anti-rotation sleeve (5), a rotating body (6), a guide sleeve (7) and a slip sleeve (8); the upper joint (1), the connecting sleeve (2) and the salvage tube (3) are connected in sequence from top to bottom to form a salvage device body; an inverted inner conical surface is provided at the lower end of the inner circumferential surface of the salvage tube (3); the rotating body (6), the guide sleeve (7) and the slip sleeve (8) are connected in sequence from top to bottom to form a salvage device core string; the salvage device core string and the spring (4) are jointly arranged in the inner cavity of the salvage device body The spring (4) is arranged at the upper part of the salvage core string, supported between the upper joint (1) and the rotating body (6), and applies an elastic force to the salvage core string relative to the salvage body; the anti-rotation sleeve (5) is fixedly mounted on the inner side wall of the connecting sleeve (2), and an axially straight guide groove is provided on the inner circumferential surface of the anti-rotation sleeve (5). The guide grooves are evenly arranged on the cross-sectional circumference of the anti-rotation sleeve (5), and are composed of deep grooves (11) and shallow grooves (12) of the same width and arranged alternately. The deep grooves (11) are The depth is greater than that of the shallow groove (12); the upper end surface of the anti-rotation sleeve (5) is provided with guide saw teeth (13) which are continuously and periodically distributed along the circumference; the guide saw teeth (13) have an inclined guide surface (21) and a vertical limit surface (22), and the arrangement positions are synchronously corresponding to the guide groove; the outer circumferential surface of the rotating body (6) is provided with guide wedges (14) which are arranged in a coordinated position corresponding to the axial straight line; the guide wedges (14) can be synchronously arranged with the deep groove (11) or the shallow groove (12) provided on the anti-rotation sleeve (5). The cross-sectional structure corresponds to the deep groove (11). When the guide wedge (14) corresponds to the deep groove (11), the guide wedge (14) can be inserted into the deep groove (11). An inclined matching surface (23) is provided on the lower end of the guide wedge (14). The spatial orientation of the inclined matching surface (23) corresponds to the inclined guide surface (21) on the guide saw tooth (13). The inclined slope is the same as that of the inclined guide surface (21). The inclined matching surface (23) can form a rotational guide match with the inclined guide surface (21);The guide control sleeve (7) is rotatably connected to the lower end of the rotating body (6) in a hanging manner, and an anti-rotation wedge (15) is arranged on the outer circumferential surface in a coordinated position corresponding to the axial straight line. The cross-sectional structure of the anti-rotation wedge (15) corresponds to the shallow groove (12) and is synchronously matched and correspondingly embedded in the guide groove provided on the anti-rotation sleeve (5). The upper end surface of the guide control sleeve (7) is provided with guide control convex teeth (16) distributed continuously and periodically along the circumference. The guide control convex teeth (16) have an inclined guide surface (20) corresponding to the inclined matching surface (23) at the lower end of the guide wedge (14) in spatial orientation. The inclined guide surface (20) ) has the same inclination as that of the inclined matching surface (23); when the rotating body (6) is matched with the device in the anti-rotation sleeve (5), the inclined guide surface (20) and the inclined matching surface (23) are limited by the anti-rotation of the guide groove, and the inclined guide surface (20) and the inclined matching surface (23) maintain a partial overlap fit, so that a space stroke for relative sliding and rotation along the matching surface is maintained between the two; the slip sleeve (8) is fixedly connected to the lower end of the guide sleeve (7); a check groove with an axially arranged lower end opening is provided on the slip sleeve (8); an inverted outer conical surface is provided on the lower end, and the inverted outer conical surface corresponds to the inverted inner conical surface structure in the overshot tube (3). ; 2. A mechanical pressure-controlled slip catching device capable of freely catching and releasing fallen fish as claimed in claim 1, characterized in that: A thrust bearing (10) is provided between the rotating body (6) and the spring (4), and the lower end of the spring (4) is supported on the rotating body (6) via the thrust bearing (10).

3. A mechanical pressure-controlled slip catching device capable of freely catching and releasing fallen fish as claimed in claim 1 or 2, characterized in that: An outwardly extending annular flange (17) is provided on the outer circumferential surface of the lower part of the rotating body (6), and a suspension pin (9) is installed on the upper side wall of the guide sleeve (7), the pin body extending to the inside of the sleeve body. The suspension pins (9) are evenly distributed along the circumference of the cross section of the guide sleeve (7), the upper end of the guide sleeve (7) and the lower end of the rotating body (6) are correspondingly overlapped, and the pin body of the suspension pin (9) and the annular flange (17) form a balanced lap fit, so that the guide sleeve (7) is rotatably fitted and suspended on the rotating body (6).

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