CN112922555B

CN112922555B - Overshot and fishing tool

Info

Publication number: CN112922555B
Application number: CN201911232205.1A
Authority: CN
Inventors: 陈伟; 孙楠; 韩冬; 刘文杰; 侯万滨
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2019-12-05
Filing date: 2019-12-05
Publication date: 2022-11-04
Anticipated expiration: 2039-12-05
Also published as: CN112922555A

Abstract

The present disclosure provides an overshot and fishing tool, the overshot comprising: the barrel is provided with two axially extending connecting grooves and two circumferentially extending locking grooves, the two connecting grooves are symmetrically distributed, one end of each locking groove is communicated with the corresponding connecting groove, and a first mounting hole and the corresponding connecting groove in the barrel are spaced by 90 degrees in the circumferential direction of the barrel; a connecting part of the connecting joint is inserted into the cylinder from one end of the cylinder, the connecting part is provided with a bulge matched with the locking groove, and a second mounting hole and the bulge on the connecting joint are spaced by 90 degrees in the circumferential direction of the connecting joint; the anti-rotation pin is inserted in the first mounting hole and the second mounting hole, at least one end of the anti-rotation pin is provided with an annular groove, and the annular groove is hooped with a resistance-increasing ring positioned in the first mounting hole or the second mounting hole. This openly can be when taking out fishing tool cluster, do not use crane, lift truck, reduce the salvage cost, and receive axial strong pressure at the salvage in-process in the pit, also can not loosen easily between a fishing barrel and the logging instrument and take off.

Description

Overshot and fishing tool

Technical Field

The disclosure relates to the technical field of oilfield testing, in particular to a fishing barrel and a fishing tool.

Background

In the testing process of the water injection and polymer injection well, the condition that the well is dropped when an instrument is blocked usually occurs, and then the fishing work of the instrument is performed.

In the related technology, the fishing tool comprises a weighting rod, a jar knocker and a fishing barrel, wherein the weighting rod, the jar knocker and the fishing barrel are fixedly connected through threaded threads. After the fishing tool has successfully salvaged the dropped instruments, the fishing tool plus the salvaged instruments typically results in an entire tool string that is over 4m in length and heavy in weight. Therefore, a crane or lift truck is typically used to hoist the tool string off the wellhead. However, the cost of using a crane or a lift truck is large, and the fishing cost is increased virtually. In addition, in the related technology, the fishing barrel and the logging instrument are fixed by threads, and if the fishing barrel is pressed by axial force in the process of fishing in the well, the fishing barrel and the logging instrument are easy to loosen.

Disclosure of Invention

The embodiment of the disclosure provides a salvage cylinder and a fishing tool, which can reduce the salvage cost without using a crane and a lifting car when taking out a fishing tool string, and can not easily loosen and fall off between the salvage cylinder and a logging instrument when being pressed by strong force in the axial direction in the underground salvage process, thereby improving the reliability. The technical scheme is as follows:

the disclosed embodiment provides an overshot, which comprises: the fishing barrel comprises a barrel body and a fishing assembly, wherein the barrel body is provided with two axially extending connecting grooves, the two connecting grooves are symmetrically distributed on two sides of a central axis of the barrel body, two circumferentially extending locking grooves are arranged on the barrel body, one ends of the two locking grooves are respectively communicated with the two connecting grooves, the extending directions of the two locking grooves from the end, communicated with the connecting grooves, of the locking grooves to the other end of the locking grooves are the same, the connecting grooves and the locking grooves radially penetrate through the barrel wall of the barrel body, a first mounting hole is formed in the barrel body and is a through hole, the first mounting hole and the connecting grooves are spaced by 90 degrees in the circumferential direction of the barrel body, and the barrel body is internally provided with the fishing assembly; the connecting joint is provided with a connecting part, the connecting part is inserted into the barrel from one end of the barrel, the connecting part is provided with two protrusions, the two protrusions are matched with the corresponding locking grooves, so that the barrel and the connecting joint are detachably connected, the connecting joint is provided with a second mounting hole, and the second mounting hole and the protrusions are spaced by 90 degrees in the circumferential direction of the connecting joint; the anti-rotation pin is inserted into the first mounting hole and the second mounting hole, an annular groove is formed in at least one end of the anti-rotation pin, a resistance increasing ring is hooped on the annular groove, and the resistance increasing ring is located in the first mounting hole or the second mounting hole.

In an implementation manner of the embodiment of the present disclosure, the barrel has two first mounting holes, the two first mounting holes are distributed coaxially, the connection joint has one second mounting hole, the second mounting hole is a through hole, there are two anti-rotation pins, one anti-rotation pin passes through one first mounting hole and is inserted into the second mounting hole from one end of the second mounting hole, and the other anti-rotation pin passes through the other first mounting hole and is inserted into the second mounting hole from the other end of the second mounting hole.

In another implementation manner of the embodiment of the present disclosure, one end of one of the anti-rotation pins located in the second mounting hole has a connecting thread, and one end of the other anti-rotation pin located in the second mounting hole has a connecting hole, and the connecting thread is in threaded fit with the connecting hole.

In another enablement of an embodiment of the disclosure, a diameter of one end of the anti-rotation pin is smaller than a diameter of the other end of the anti-rotation pin.

In another implementation of the disclosed embodiment, the resistance-increasing ring is a rubber ring or an annular spring.

In another implementation manner of the embodiment of the present disclosure, an outer wall of the anti-rotation pin is provided with an external thread, and at least one of the first mounting hole and the second mounting hole is a threaded hole.

In another implementation of the disclosed embodiment, a polished rod segment is provided on the anti-rotation pin, and the polished rod segment is located at the intersection of the first mounting hole and the second mounting hole.

In another implementation manner of the embodiment of the present disclosure, a fishing assembly is disposed in the cylinder, and the fishing assembly includes: the slip piece is arranged in the barrel in a sliding mode, the slip piece is provided with a first end face and a second end face which are opposite to each other, the first end face faces to the other end of the barrel, the slip pieces are arranged on the first end face at intervals in the circumferential direction, slip teeth extending radially inwards are arranged on the slip pieces, the slip piece is located between the spring and the slip pieces, one end of the spring abuts against the second end face, and the other end of the spring abuts against a stop structure on the inner wall of the barrel.

In another implementation of an embodiment of the disclosure, the other end of the cylinder has a reduced inner diameter section.

Embodiments of the present disclosure provide a fishing tool that includes an overshot as described above.

In another implementation of the disclosed embodiment, the fishing tool further includes: the bumper comprises a first connecting piece, a second connecting piece, a jar and a weighting rod, wherein the first connecting piece is cylindrical, one end of the first connecting piece is the same as one end of the cylinder in structure, and the other end of the first connecting piece is provided with external threads; the second connecting piece is columnar, one end of the second connecting piece is the same as the connecting part in structure, and the other end of the second connecting piece is provided with a threaded hole; one end of the jar is connected with the connecting joint, and the other end of the jar is connected with the other end of the second connecting piece; one end of the weighting rod is connected with the other end of the first connecting piece.

The technical scheme provided by the embodiment of the disclosure has the following beneficial effects:

the one end of barrel has two spread grooves in this disclosure's an overshot, attach fitting's connecting portion can be adorned in the barrel, and connecting portion cartridge when in the barrel, two archs on the connecting portion can follow two spread grooves and get into in the barrel along with attach fitting together, and when two archs slide to spread groove and locking groove intercommunication department, can rotate attach fitting, make two archs block respectively into two locking inslots that extend circumferentially, cell wall and arch through the locking groove offset promptly, in order to restrict protruding removal along axial, and undertake the axial effort between barrel and the attach fitting, thereby prevent to produce between barrel and the attach fitting along axial removal. Simultaneously still install the anti-rotating pin on barrel and attach fitting, the anti-rotating pin cartridge is in first mounting hole and second mounting hole, and the arch utilizes the anti-rotating pin can lock the arch in the locking groove after getting into the locking groove promptly, prevents to produce circumferential direction between barrel and the attach fitting and makes the arch break away from the locking groove to it is more stable to make the connection between attach fitting and the barrel.

The fishing barrel provided by the embodiment of the disclosure bears axial pressure through the cooperation of the protrusion and the locking groove and the anti-rotation pin inserted in the first mounting hole and the second mounting hole when being subjected to axial pressure in the process of fishing in a well, namely, the fishing barrel is prevented from loosening from a logging instrument due to overlarge axial pressure through double protection.

When using an overshot, the other end suit of the overshot is on the cap of the rope of the instrument that falls into the well to connect the instrument that falls into the well on the overshot, because the arch of the connecting portion of attach fitting is located the locking inslot, undertakes the axial effort between barrel and the attach fitting through the cooperation in arch and locking groove, and prevent circumferential direction between barrel and the attach fitting through the anti-rotating pin, thereby ensure the connection stability of barrel and attach fitting. When lifting a fishing barrel to the well head, can take off from barrel and attach fitting with the anti-rotation pin to control attach fitting makes arch on it loop through behind locking groove, the spread groove and the barrel separation, and the tool string is separated for two parts promptly, need not to use crane, lift truck to hoist whole tool string and take out this moment, only the manual work respectively with the tool string of two parts take out can, consequently save the expense, reduce the salvage cost, and reduce the operation risk.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic structural view of an overshot provided by an embodiment of the disclosure;

FIG. 2 is a schematic view of an anti-rotation pin according to an embodiment of the disclosure;

FIG. 3 is a schematic view of an assembly of an anti-rotation pin and a second mounting hole provided by an embodiment of the disclosure;

FIG. 4 is a schematic structural view of a fishing assembly provided by embodiments of the present disclosure;

FIG. 5 is a schematic structural view of a fishing tool provided by embodiments of the present disclosure;

fig. 6 is a schematic structural diagram of a first connecting element according to an embodiment of the disclosure;

fig. 7 is a schematic structural diagram of a second connecting member according to an embodiment of the disclosure.

Detailed Description

To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of an overshot provided by the embodiment of the disclosure. As shown in fig. 1, the overshot comprises: barrel 1, attach fitting 2 and anti-rotation pin 3. The barrel 1 is provided with two axially extending connecting grooves 11, the two connecting grooves 11 are symmetrically distributed on two sides of a central axis of the barrel 1, two circumferentially extending locking grooves 13 are arranged on the barrel 1, one ends of the two locking grooves 13 are respectively communicated with the two connecting grooves 11, the extending directions of the two locking grooves 13 from the end, communicated with the connecting grooves 11, of the locking grooves 13 to the other end of the locking grooves 13 are the same, the connecting grooves 11 and the locking grooves 13 radially penetrate through the barrel wall of the barrel 1, the barrel 1 is provided with first mounting holes 12, the first mounting holes 12 are through holes, the first mounting holes 12 and the connecting grooves 11 are spaced by 90 degrees in the circumferential direction of the barrel 1, and a fishing assembly is arranged in the barrel 1; the connecting joint 2 is provided with a connecting part 21, the connecting part 21 is inserted into the cylinder body 1 from one end of the cylinder body 1, the connecting part 21 is provided with two protrusions 22, the two protrusions 22 are respectively matched with the corresponding locking grooves 13, so that the cylinder body 1 and the connecting joint 2 are detachably connected, the connecting joint 2 is provided with a second mounting hole 23, and the second mounting hole 23 and the protrusions 22 are spaced by 90 degrees in the circumferential direction of the connecting joint 2.

Fig. 2 is a schematic structural view of an anti-rotation pin provided in an embodiment of the present disclosure. Referring to fig. 1 and 2, the anti-rotation pin 3 is inserted into the first mounting hole 12 and the second mounting hole 23, at least one end of the anti-rotation pin 3 is provided with an annular groove 34, the annular groove 34 is hooped with a resistance-increasing ring 35, and the resistance-increasing ring 35 is located in the first mounting hole 12 or the second mounting hole 23.

The one end of barrel has two spread grooves in this disclosure's an overshot, attach fitting's connecting portion can be adorned in the barrel, and connecting portion cartridge when in the barrel, two archs on the connecting portion can follow two spread grooves and get into in the barrel along with attach fitting together, and when two archs slide to spread groove and locking groove intercommunication department, can rotate attach fitting, make two archs block respectively into two locking inslots that extend circumferentially, cell wall and arch through the locking groove offset promptly, in order to restrict protruding removal along axial, and undertake the axial effort between barrel and the attach fitting, thereby prevent to produce between barrel and the attach fitting along axial removal. Wherein, two spread grooves and two archs all are symmetrical arrangement to the atress between barrel and the attach fitting is balanced more stable. After the two protrusions are clamped in the two locking grooves, the axial acting force which can be born between the cylinder body and the connecting joint can be improved, and the axial sliding between the cylinder body and the connecting joint is further prevented. Simultaneously still install the anti-rotating pin on barrel and attach fitting, the anti-rotating pin cartridge is in first mounting hole and second mounting hole, and after the arch got into the locking groove promptly, utilize the anti-rotating pin can be with protruding locking in the locking groove, prevent to produce circumferential direction between barrel and the attach fitting and make the arch break away from the locking groove to make the be connected between attach fitting and the barrel more stable. And the connecting line of the first mounting hole for inserting the anti-rotation pin and the central axis of the cylinder body and the connecting line of the connecting groove and the central axis of the cylinder body are mutually vertical, and the connecting line of the second mounting hole for inserting the anti-rotation pin and the central axis of the connecting joint and the connecting line of the bulge and the central axis of the connecting joint are mutually vertical. Therefore, after the anti-rotation pin is inserted into the first mounting hole and the second mounting hole, the anti-rotation pin is perpendicular to the protrusions, so that acting force for limiting the movement of the cylinder and the connecting joint can be generated everywhere in the circumferential direction of the cylinder and the connecting joint, the stress between the cylinder and the connecting joint is more balanced, the distances between the first mounting hole and the connecting groove and between the second mounting hole and the protrusions are sufficient, and the first mounting hole and the second mounting hole are convenient to process. Meanwhile, at least one end of the anti-rotation pin is provided with an annular groove, the annular groove is hooped with a resistance increasing ring, and the anti-rotation pin is inserted into the cylinder body and the connecting joint, so that after the resistance increasing ring on the annular groove is inserted into the cylinder body and the connecting joint, the friction force between the anti-rotation pin and the cylinder body and between the anti-rotation pin and the connecting joint can be increased, and the anti-rotation pin is prevented from being easily separated from the cylinder body and the connecting joint.

When the fishing barrel provided by the embodiment of the disclosure is subjected to axial strong pressure in the underground fishing process, axial pressure is jointly borne by the protrusions, the locking grooves and the anti-rotation pins inserted into the first mounting hole and the second mounting hole, and the fishing barrel is prevented from being loosened from a logging instrument due to overlarge axial pressure through double protection.

In the embodiment of the present disclosure, the first mounting holes 12 on the cylinder 1 may be multiple, the multiple first mounting holes 12 are circumferentially arranged along the outer wall of the cylinder 1, and the second mounting holes 23 corresponding to the first mounting holes 12 may also be multiple, the multiple second mounting holes 23 are circumferentially arranged on the outer wall of the joint 2, that is, the first mounting holes 12 and the second mounting holes 23 are the same in number and are arranged in a one-to-one correspondence. The provision of the plurality of first mounting holes 12 and the second mounting holes 23 can be used to mount the plurality of rotation preventing pins 3, thereby improving the connection stability of the cylinder 1 and the joint connector 2.

The number of the first mounting holes 12 and the second mounting holes 23 on the cylinder 1 may be different.

Illustratively, as shown in fig. 1, the connection joint 2 is a column structure, and the connection portion 21 of the connection joint 2 has a second installation hole 23 penetrating through the connection portion 21, since the connection joint 2 is inserted into the barrel 1, that is, two ends of the first installation hole 12 are respectively opposite to two side walls of the barrel 1 at different positions. At this time, the first mounting holes 12 can be disposed at two positions on the cylinder 1 opposite to the first mounting holes 12, so that the rotation preventing pin sequentially passes through one first mounting hole 12, the second mounting hole 23 and the other first mounting hole 12, and the cylinder 1 and the connector 2 are fixedly connected.

In the embodiment of the present disclosure, the annular grooves 34 may be distributed at one end or both ends of the anti-rotation pin, and when the annular grooves 34 are disposed at both ends of the anti-rotation pin, resistance increasing rings 35 may be disposed in both the annular grooves 34, so as to increase the friction between the anti-rotation pin and the cylinder 1 and the connection joint 2.

Illustratively, as shown in fig. 2, one end of the anti-rotation pin has an annular groove 34, a rubber ring is sleeved in the annular groove 34, and after the anti-rotation pin is inserted into the barrel 1 and the connector 2, the rubber ring is used to expand the interference fit between the anti-rotation pin and the barrel 1 and the connector 2, so as to prevent the anti-rotation pin from loosening in the barrel 1 and the connector 2.

In other embodiments, the annular groove 34 may also be sleeved with an annular spring, as long as the interference fit between the anti-rotation pin and the cylinder 1 and the connector 2 can be increased, and the friction force can be increased, which is not limited in this embodiment.

Fig. 3 is a schematic view illustrating an assembly of an anti-rotation pin and a second mounting hole according to an embodiment of the disclosure. As shown in fig. 3, the cylinder 1 has two first mounting holes 12, the two first mounting holes 12 are coaxially distributed, the connector 2 has a second mounting hole 23, the second mounting hole 23 is a through hole, there are two anti-rotation pins 3, one anti-rotation pin 3 passes through one first mounting hole 12 and is inserted into the second mounting hole 23 from one end of the second mounting hole 23, and the other anti-rotation pin 3 passes through the other first mounting hole 12 and is inserted into the second mounting hole 23 from the other end of the second mounting hole 23. Thus, the two anti-rotation pins 3 are respectively inserted into the first mounting hole 12 and the second mounting hole 23, and compared with the case that only one anti-rotation pin 3 is used, the circumferential acting force and the axial acting force which can be borne by the anti-rotation pin can be improved. And two anti-rotation pins are arranged, which is equivalent to that a heavy protection is added on the basis of double protection functions, thereby further preventing the condition that the axial pressure is too large to force the fishing barrel and the logging instrument to be loosened.

When two anti-rotation pins 3 are provided, one end of one anti-rotation pin 3 located in the second mounting hole 23 may have a connecting thread 31, and one end of the other anti-rotation pin 3 located in the second mounting hole 23 may have a connecting hole 32, wherein the connecting hole 32 is in threaded fit with the connecting thread 31. Through being in the same place two anti-rotating pin threaded connection, compare in when setting up an anti-rotating pin, two anti-rotating pins can pin each other to prevent that the anti-rotating pin from breaking away from in first mounting hole and the second mounting hole in the course of the work, improve the connection reliability of anti-rotating pin.

For the above-described connection anti-rotation pin with the end portion screwed, in an alternative implementation, one end of the anti-rotation pin 3 (i.e., the end portion opposite to the end where the anti-rotation pin is screwed) may have a smaller diameter than the other end of the anti-rotation pin 3, i.e., the other end of the anti-rotation pin 3 may have a larger diameter than the first mounting hole 12. After the two anti-rotation pins 3 are respectively inserted into the barrel 1 and the connector 2 and one ends of the two anti-rotation pins 3 are connected by screw threads, the diameter of the other ends of the anti-rotation pins 3 is larger than the diameter of one end of the anti-rotation pins 3 and larger than the diameter of the first mounting hole 12, so that the two anti-rotation pins 3 are locked with each other to be limited in the barrel 1 and the connector 2, and the anti-rotation pins 3 are prevented from falling off.

For the connection anti-rotation pin with the threaded connection at the end part, in another optional implementation manner, a thread may be provided on the outer wall of the other end of the anti-rotation pin 3, and the thread provided on the outer wall may be in threaded connection with the first mounting hole 12 or the second mounting hole 23, so that after the two anti-rotation pins 3 are respectively inserted into the barrel 1 and the joint 2, not only one ends of the two anti-rotation pins 3 are fixed by threads, but also the two anti-rotation pins 3 are fixed by threads with the barrel 1 or the joint 2, and the anti-rotation pins 3 are more firmly locked in the barrel 1 and the joint 2 by a connection manner of double thread fixing.

In the embodiment of the present disclosure, the outer wall of the anti-rotation pin may be provided with an external thread 36, and at least one of the first mounting hole 12 and the second mounting hole 23 is a threaded hole. Through with the anti-rotation pin with first mounting hole 12 and/or second mounting hole 23 threaded connection to fix the anti-rotation pin in barrel 1 and connector, prevent that the anti-rotation pin is not hard up from barrel 1 and attach fitting 2, improve the connection reliability.

Illustratively, as shown in fig. 1 and 2, the first mounting hole 12 is a smooth hole, the second mounting hole 23 is a threaded hole, and the middle part of the anti-rotation pin is provided with an external thread 36, and the external thread 36 located in the middle part is used for being in threaded connection with the second mounting hole 23.

Optionally, the anti-rotation pin has a polished rod segment 37, and the polished rod segment 37 is located at the intersection of the first mounting hole 12 and the second mounting hole 23. The polish rod section 37 is a section without external threads on the anti-rotation pin, and the polish rod section 37 of the anti-rotation pin is arranged at the junction of the first mounting hole 12 and the second mounting hole 23, so that when the anti-rotation pin is stressed, the polish rod section 37 bears shearing force between the barrel body 1 and the connecting joint 2, the external threads 36 on the anti-rotation pin are prevented from being damaged, and the anti-rotation pin is protected.

Illustratively, as shown in fig. 1 and 2, the anti-rotation pin is inserted into the first mounting hole 12 and the two second mounting holes 23, so that the anti-rotation pin has two polished rod sections 37, the two polished rod sections 37 of the anti-rotation pin are respectively located at two ends of the anti-rotation pin, and the length of the polished rod sections 37 at the two ends is not less than the thickness of the cylinder wall of the cylinder 1, thereby ensuring that the polished rod sections 37 can be located at the junction of the first mounting hole 12 and the second mounting hole 23 after the anti-rotation pin is inserted into the cylinder 1 and the connector 2, and avoiding the external thread 36 from being damaged by an external axial force.

Optionally, there are a plurality of connecting grooves 11, a plurality of connecting grooves 11 are arranged at intervals in the circumferential direction, each connecting groove 11 is provided with a locking groove 13 communicated with the connecting groove 11, the protrusions 22 correspond to the connecting grooves 11 one to one, and the connecting grooves 11 are symmetrically distributed on two sides of the axial section of the cylinder 1. Because the protrusions 22 of the connecting joint 2 are located in the locking grooves 13, and each connecting groove 11 has the locking groove 13 corresponding to the connecting groove, the plurality of protrusions 22 can be matched with the plurality of locking grooves 13 at the same time by arranging the plurality of connecting grooves 11, so that more axial acting force can be borne between the cylinder body 1 and the connecting joint 2, and the rotation between the cylinder body 1 and the connecting joint 2 is prevented to a greater extent.

FIG. 4 is a schematic structural diagram of a fishing assembly provided by an embodiment of the disclosure. As shown in fig. 4, a fishing assembly is arranged in the cylinder body 1, and comprises: a slider 41, a spring 42 and at least two card tiles 43. Slider 41 slides and sets up in barrel 1, slider 41 has relative first terminal surface and second terminal surface, first terminal surface is towards the other end of barrel 1, two at least calorie of tile 43 circumference intervals are arranged at first terminal surface, slip 44 that has radial inward extension on slip piece 43, after the cap for a rope of well instrument gets into the other end of barrel 1, can overcome the conflict effect of slip 44 on calorie of tile 43, between a plurality of calorie of tile 43 with the cartridge income, and under the restriction effect of slip 44, the buckle is between a plurality of calorie of tiles 43, in order to realize the hasp of instrument. And the slide block 41 is positioned between the spring 42 and the slip sheet 43, one end of the spring 42 is propped against the second end surface, and the other end of the spring 42 is propped against the stop structure of the inner wall of the cylinder body 1.

The stopping structure may be a spigot arranged on the inner wall of the cylinder 1 or an inner flange on the inner wall of the cylinder 1, as long as the spring can be abutted against the stopping structure, and the embodiment is not limited.

As shown in fig. 4, the other end of the cylinder 1 may further have an inner diameter-reduced section 14, and the inner diameter-reduced section 14 may prevent the slip sheets 43 from expanding radially outward, and may increase the relative distance between the slip teeth 44, so as to prevent the string cap of the instrument from falling off the limit of the slip teeth 44 and falling off the slip sheets 43, thereby improving the connection stability.

When the fishing assembly is used, when the other end of the cylinder body 1 of the fishing cylinder impacts a rope cap at the upper end of an apparatus to be fished in a well, under the action of downward inertial acting force and the reduced inner diameter section 14 at the other end of the cylinder body 1, the rope cap of the apparatus enters the cylinder body 1, the plurality of clamping pieces 43 are forced to expand radially outwards, after the rope cap at the upper end of the apparatus passes through the clamping teeth 44 of the clamping pieces 43, the spring 42 compressed by the sliding block 41 rapidly pushes the sliding block 41 to slide and reset towards the other end of the cylinder body 1 under the action of elastic restoring force, and the relative distance between the plurality of clamping pieces 43 is reduced by matching with the extrusion action of the reduced inner diameter section 14, so that the rope cap of the apparatus is locked in the cylinder body 1, and at the moment, the fishing cylinder can be lifted to fish the apparatus up.

FIG. 5 is a schematic structural view of a fishing tool according to an embodiment of the present disclosure. As shown in fig. 5, the fishing tool includes an overshot as previously described.

Optionally, the fishing tool may further comprise: a first connector 51, a second connector 52, a jar 6, and a weighted rod 7.

Fig. 6 is a schematic structural diagram of a first connecting element according to an embodiment of the present disclosure. As shown in fig. 6, the first connector 51 has a cylindrical shape, one end of the first connector 51 has the same structure as one end of the cylinder 1, and the other end of the first connector 51 has an external thread.

Fig. 7 is a schematic structural diagram of a second connecting member according to an embodiment of the disclosure. As shown in fig. 7, the second connector 52 has a cylindrical shape, one end of the second connector 52 has the same structure as the connecting portion 21, and the other end of the second connector 52 has a screw hole.

With reference to fig. 4, 5 and 6, one end of the jar 6 is connected to the connecting joint 2, and the other end of the jar 6 is connected to the other end of the second connecting member 52; one end of the weight lever 7 is connected to the other end of the first connecting member 51. Wherein, one end of the jar 6 can be connected with the connector 2 by screw thread, and the other end of the jar 6 is screwed into the threaded hole at the other end of the second connecting piece 52 by external screw thread. One end of the weight bar 7 may be screw-coupled with the other end of the first coupling member 51 through a screw hole provided thereon.

The fishing tool provided by the embodiment of the disclosure is provided with the fishing barrel, and the first connecting piece and the second connecting piece which are connected quickly are added, so that when the structure of the original tool is not damaged, the first connecting piece and the second connecting piece which are extremely short in length are added, and the first connecting piece and the second connecting piece are convenient to be connected and detached quickly with other instruments. First connecting piece and second connecting piece all can be connected the fastening through screw thread and instrument, and the mode quick assembly disassembly through the buckle between first connecting piece and the second connecting piece to be convenient for when taking out fishing tool from the well head, divide fishing tool into more parts, make things convenient for the technical staff directly to take out fishing tool from the well head.

When the fishing tool provided by the embodiment of the disclosure is used for fishing, firstly, the fishing assembly is installed in the barrel; and then inserting the anti-rotation pin into the first mounting hole and the second mounting hole of the cylinder body and the connecting joint to complete the assembly of the overshot. And then, the assembled fishing barrel is used for fishing the well falling instrument in a trial manner, so that the fishing barrel can successfully catch the rope cap of the instrument at one time and cannot fall off. Then, the rope cap is taken out of the fishing barrel, the fishing barrel is reassembled, the resistance-increasing ring is sleeved into the annular groove on the anti-rotation pin, and the anti-rotation pin is fastened by using an inner hexagonal wrench so that the anti-rotation pin penetrates through the first mounting hole and the second mounting hole to be tightly matched with the barrel body and the connecting joint. And then, connecting the connecting joint of the overshot with the jar hammer through threads, connecting the first connecting piece with the weighting rod through threads, and fixedly connecting the first connecting piece and the second connecting piece together through an anti-rotation pin. And then, a steel wire penetrates through a rope cap on the weighting rod to manufacture a steel wire rope cap, and a fishing tool is lowered by utilizing the test steel wire and is controlled to fish up the instrument in the well. After the instrument is salvaged, the fishing tool is lifted, the weighting rod, the first connecting piece and the second connecting piece are all exposed out of the well mouth, and the jar and the fishing tool at the lower end of the jar are fixed at the well mouth through the tool. Then, the first connecting piece and the second connecting piece are removed, and the weighting rod is taken down. And then, continuously lifting the fishing tool to expose the jar and the fishing barrel out of the wellhead, and fixing the fished instrument on the wellhead by using the tool. The jar is then removed by separating the connector from the barrel. And continuously lifting the salvaged instrument and taking out the wellhead to finish the salvage operation.

The above description is meant to be illustrative of the principles of the present disclosure and not to be taken in a limiting sense, and any modifications, equivalents, improvements and the like that are within the spirit and scope of the present disclosure are intended to be included therein.

Claims

1. An overshot, characterized in that it comprises:

the barrel body (1) is provided with two axially extending connecting grooves (11), the two connecting grooves (11) are symmetrically distributed on two sides of a central axis of the barrel body (1), two circumferentially extending locking grooves (13) are arranged on the barrel body (1), one ends of the two locking grooves (13) are respectively communicated with the two connecting grooves (11), the extending directions of the two locking grooves (13) from one end, communicated with the connecting grooves (11), to the other end of the locking groove (13) are the same, the connecting grooves (11) and the locking grooves (13) radially penetrate through the barrel wall of the barrel body (1), a first mounting hole (12) is formed in the barrel body (1), the first mounting hole (12) is a through hole, the first mounting hole (12) and the connecting grooves (11) are spaced by 90 degrees in the circumferential direction of the barrel body (1), a fishing assembly is arranged in the barrel body (1), the barrel body (1) is provided with the two first mounting holes (12), and the two first mounting holes (12) are coaxially distributed;

the connecting joint (2) is provided with a connecting part (21), the connecting part (21) is inserted into the cylinder body (1) from one end of the cylinder body (1), the connecting part (21) is provided with two protrusions (22), the two protrusions (22) are respectively matched with the corresponding locking grooves (13) so that the cylinder body (1) and the connecting joint (2) can be detachably connected, the connecting joint (2) is provided with a second mounting hole (23), the second mounting hole (23) and the protrusions (22) are spaced by 90 degrees in the circumferential direction of the connecting joint (2), the connecting joint (2) is provided with one second mounting hole (23), and the second mounting hole (23) is a through hole;

the anti-rotation pin (3) is inserted in the first mounting hole (12) and the second mounting hole (23), at least one end of the anti-rotation pin (3) is provided with an annular groove (34), the annular groove (34) is hooped with a resistance increasing ring (35), the resistance increasing ring (35) is positioned in the first mounting hole (12) or the second mounting hole (23), two anti-rotation pins (3) are provided, one anti-rotation pin (3) passes through one first mounting hole (12) and is inserted into the second mounting hole (23) from one end of the second mounting hole (23), the other anti-rotation pin (3) passes through the other first mounting hole (12) and is inserted into the second mounting hole (23) from the other end of the second mounting hole (23), one anti-rotation pin (3) is provided with a connecting thread (31) at one end of the second mounting hole (23), the other anti-rotation pin (3) is provided with a connecting hole (32) at one end of the second mounting hole (23), the diameter of one end of the anti-rotation pin (3) at the second mounting hole (23) is not larger than the inner diameter of the other anti-rotation pin (3) at one end of the second mounting hole (23), the inner wall of the connecting hole (32) is provided with internal threads, and the connecting threads (31) are in threaded fit with the connecting hole (32).

2. Overshot according to claim 1, characterized in that the diameter of one end of the anti-rotation pin (3) is smaller than the diameter of the other end of the anti-rotation pin (3).

3. Overshot according to claim 1 or 2, characterized in that the outer wall of the anti-rotation pin is provided with an external thread (36), at least one of the first mounting hole (12) and the second mounting hole (23) being a threaded hole.

4. The overshot of claim 3, characterized in that the rotation preventing pin has a light rod segment (37), which light rod segment (37) is located at the intersection of the first mounting hole (12) and the second mounting hole (23).

5. Overshot according to claim 1 or 2, characterized in that the resistance increasing ring (35) is a rubber ring or an annular spring.

6. The overshot according to claim 1 or 2, characterized in that the fishing assembly comprises: a slide block (41), a spring (42) and at least two clamping pieces (43),

the sliding block (41) is arranged in the cylinder body (1) in a sliding mode, the sliding block (41) is provided with a first end face and a second end face which are opposite to each other, the first end face faces the other end of the cylinder body (1), at least two clamping pieces (43) are arranged on the first end face at intervals in the circumferential direction, the clamping pieces (43) are provided with clamping teeth (44) which extend inwards in the radial direction,

the sliding block (41) is located between the spring (42) and the clamping piece (43), one end of the spring (42) abuts against the second end face, and the other end of the spring (42) abuts against a stop structure on the inner wall of the barrel body (1).

7. Overshot according to claim 6, characterized in that the other end of the cylinder (1) has a reduced inner diameter section (14).

8. A fishing tool comprising an overshot according to any one of claims 1 to 7, the fishing tool further comprising: a first connecting piece (51), a second connecting piece (52), a jar (6) and a weighting rod (7),

the first connecting piece (51) is cylindrical, one end of the first connecting piece (51) is the same as one end of the barrel body (1) in structure, and the other end of the first connecting piece (51) is provided with an external thread;

the second connecting piece (52) is columnar, one end of the second connecting piece (52) is the same as the connecting part (21) in structure, and the other end of the second connecting piece (52) is provided with a threaded hole;

one end of the jar (6) is connected with the connecting joint (2), and the other end of the jar (6) is connected with the other end of the second connecting piece (52);

one end of the weighting rod (7) is connected with the other end of the first connecting piece (51).