CN220599761U - Overshot for well string - Google Patents

Abstract

The application relates to the technical field of petroleum and natural gas exploitation, especially, relate to a well casing string overshot that falls, it includes the main barrel, be equipped with the taper passageway that top-down internal diameter reduces in the main barrel, taper passageway downside is equipped with the slips assembly, the slips assembly is including a plurality of bosss that circumference set up, form a plurality of fore-and-aft slides between the adjacent boss, be equipped with the card tile in every slide, card tile upper end butt has elastic stop spare, elastic stop spare upper end butt has the locating part that hinders elastic stop spare and reciprocate. The well casing string falling in the well shaft is difficult to enter the overshot tool and is clamped, meanwhile, the problem that construction efficiency is affected when the fish head needs to be trimmed is solved, and the well casing string falling in the well shaft has the advantages of being simple in structure, convenient to operate, low in manufacturing cost and capable of being reused.

Description

Overshot for well string

Technical Field

The application relates to the technical field of petroleum and natural gas exploitation, in particular to a well string landing overshot.

Background

In the oil and gas well operation process, the pipe column is often corroded and broken, mishandled and the like to cause the falling of the pipe column into the well to cause the falling of the fish, and then the falling of the fish out of the well shaft is required to be salvaged, and other related operations are carried out.

At present, two processes of fishing in an oil pipe and fishing outside the oil pipe are often adopted to realize the fishing of the fish. The fishing spear that salvages to adopt in the oil pipe can be because the fish head opening shape of falling fish can not confirm when using, and the unable normal oil pipe that gets into of fishing spear leads to salvaging failure. The fishing barrel, the female cone and the like are adopted for fishing outside the oil pipe, after the fishing barrel contacts with the fish, the fishing pipe column is rotated to enable the fishing tool to rotate, the fish is forced to be screwed into the fishing tool or the outside of the fish is buckled, and the fish enters the fishing barrel to be clamped or the fish is connected with the female cone to capture the fish. In the process of screwing in and capturing the fish, in order to ensure that the fish can be caught when the fish enters the fishing tool, a gap is not reserved between a slip in the fishing tool and the fish, so that the fish is difficult to normally screw in the fishing tool; in the process of catching the fish by external buckling, the large pressure is applied to cause the fish to deform, and in addition, the falling fish shakes in the process, which can cause buckling difficulty. Therefore, the fishing success rate of currently used tools for fishing in the oil pipe and fishing outside the oil pipe is not high.

Disclosure of Invention

In order to enable the end part of the well casing string, namely the end part of the fish head, to enter the overshot more easily and be fixed by the overshot, the salvaging success rate is improved, and the well casing string overshot provided by the application adopts the following technical scheme:

including the main barrel, be equipped with the taper passageway that top-down internal diameter reduces in the main barrel, taper passageway downside is equipped with the slips assembly, and the slips assembly includes a plurality of bosss that circumference set up, forms a plurality of fore-and-aft slides between the adjacent boss, is equipped with the card tile in every slide, and card tile upper end butt has elastic stop spare, and elastic stop spare upper end butt has the locating part that hinders elastic stop spare and reciprocate.

Through adopting above-mentioned technical scheme, in the descending operation in-process of fishing tool main cylinder, well casing post that falls gets into in the main cylinder and forms upward thrust to the slips piece, the public inscribed circle diameter that multiunit slips piece formed increases, and the slips piece is gone up in the slide and is formed the extrusion to the elastic stop piece and warp upwards, and slips piece is hugged closely in well casing post outside under slip piece self gravity and elastic stop piece's reaction force at this moment, but does not form great resistance to well casing post entering spacing section, makes well casing post that falls into smoothly in the fishing tool.

After the well-falling pipe column enters the fishing tool for a certain length, slowly lifting the main cylinder body, and enabling slip sheets clung to the outer wall of the well-falling pipe column to downwards move in the slide way along with the relative downwards movement of the well-falling pipe column, wherein the diameters of common inscribed circles formed by the multiple groups of slip sheets are reduced, the slip sheets form radial clamping force on the pipe column, so that falling objects are firmly gripped, and the well-falling pipe column is gradually lifted out of a shaft.

The well dropping pipe column has the advantages that the well dropping pipe column can not encounter larger resistance in the process of gradually entering the fishing tool, the clamping tiles form strong fastening on the pipe column under the action of the conical channel, and the slip sheets are not easy to loosen the clamping of the pipe column to cause well dropping again.

Optionally, the thickness of the slip sheets gradually decreases from top to bottom.

By adopting the technical scheme, as the slip sheets on the upper side of the well falling pipe column are stressed more, the slip sheets with gradually reduced thickness from top to bottom are arranged, the strength of the upper part of the tile stack is ensured, and the clamping capacity of the slip assembly when the well falling pipe column is pulled is improved.

Optionally, the slip segments are equidistant from the main barrel axis inside.

By adopting the technical scheme, the distances from the inner sides of the slip sheets to the axis of the main cylinder body are equal, so that the slip sheets are ensured to be in contact with the well-falling pipe column sufficiently, and an anti-drop effect is achieved.

Optionally, slip teeth with upward inclination angles are arranged on the inner sides of the slip sheets.

By adopting the technical scheme, the slip teeth reduce the contact surface, improve the clamping pressure of unit area, prevent slipping, and be favorable to the slip sheet to block the well string. By the structure, the drop fish can be tightly caught when lifted up by the fishing pipe column, and the slip of the pipe column caused by the slip of the tile and the drop fish is avoided.

Optionally, an elastic mud scraping ring is arranged on the lower side of the slip sheet.

By adopting the technical scheme, the inner diameter of the elastic mud scraping ring is slightly smaller than the outer diameter of the well string, sediment and the like on the periphery of the well string can be scraped, and the well string is clamped by the slip teeth.

Optionally, the circumferential width of the inner side of the slide is greater than the circumferential width of the opening of the slide, and the slip sheets are provided with an outline matched with the slide.

By adopting the technical scheme, after the slip sheets fall into the slide way, the slip sheets are limited by the circumferential width difference between the inside of the slide way and the outlet, so that the slip sheets are prevented from falling inwards.

Optionally, a guide shoe is arranged at the lower part of the main cylinder body, and a first inner chamfer for introducing the well-falling pipe column is arranged at the lower end of the guide shoe.

By adopting the technical scheme, when the rotary overshot slowly descends, the upper end of the well-falling pipe column gradually enters the guide shoe, is guided by the guide shoe and is easier to enter the main barrel.

Optionally, a milling ring is arranged at the lower part of the main cylinder body.

On the other hand, during conventional salvage, in order to enable the fish to enter the salvage tool more easily, the end part of the head of the fish, namely the well string, must be trimmed, however, the currently commonly used salvage tool does not have a trimming function for the head of the fish, the head of the fish needs to be trimmed by being put into a corresponding tool before salvage, and then the head of the fish is put into the salvage tool for salvage operation, so that the work load of tripping in the salvage operation process is greatly improved.

Through adopting above-mentioned technical scheme, the mill that main barrel lower part set up mills the ring and carries out the repairment to it in advance before well casing post entering spacing section, has guaranteed well casing post that falls can normally get into in the fishing tool, increases fishing efficiency and success rate.

Optionally, the elastic stop piece includes the main pipe cover, main pipe cover periphery is equipped with multichannel channel, main pipe cover lower extreme is equipped with a plurality of and supports the stop ear, be equipped with the recess between the adjacent stop ear, support the stop ear butt in on the card tile, the recess with boss top lock.

Through adopting above-mentioned technical scheme, the ascending channel of elastic stop spare circumference makes it can have great deflection at the extrusion in-process that upwards, can not cause too big elastic force to the slips piece simultaneously, guarantees that the card tile can not form great frictional force at the relative in-process that goes upward of tubular column. The supporting and stopping lug at the lower end of the elastic stopping piece is in a step shape and is matched with the step at the upper part of the clamping tile, so that the supporting and stopping lug cannot slide out of the slideway in the extrusion process of elastic rubber on one hand, and cannot radially deform on the other hand.

Optionally, the limiting piece is a joint which is inscribed on the upper part of the main cylinder body and is abutted with the upper end of the elastic stop piece.

Through adopting above-mentioned technical scheme, connect and be used for connecting the pulling equipment, connect the lower part inscription in form limit structure in the main barrel, block that elastic stop piece from restricting its upward movement.

In summary, the present application includes at least one of the following beneficial technical effects: the utility model has the dual characteristics of fishing and trimming the fish head, solves the problem that the well dropping pipe column in the shaft is difficult to enter the overshot tool and be clamped, solves the problem that the construction efficiency is influenced when the trimming operation is required to be carried out on the fish head, and has the characteristics of simple structure, convenient operation, low manufacturing cost and reusability.

Drawings

Fig. 1 is a cross-sectional view of the structure of the present application.

Fig. 2 is a cross-sectional view of a tapered channel structure of the present application.

Fig. 3 is an enlarged view of a portion a in fig. 1.

Fig. 4 is a schematic view of the elastic stopper structure of the present application.

Reference numerals illustrate: 1. a joint; 2. a main cylinder; 21. a tapered channel; 3. a gasket; 4. an elastic stopper; 41. a main pipe sleeve; 42. a channel; 43. a stop lug; 44. a groove; 5. clamping tiles; 51. slip teeth; 511. an inclined section; 6. an elastic mud scraping ring; 7. a boss; 71. a slideway; 8. guiding shoes; 9. milling the ring; 91. and a second inner chamfer.

Detailed Description

The present application is described in further detail below in conjunction with figures 1-4.

Referring to fig. 1, an embodiment of the present application discloses a landing tubular string overshot, the uppermost part of which overshot is provided with a joint 1, the joint 1 being intended for threaded connection with an upper fishing tubular string. The salvaging pipe column is used for driving the salvaging barrel to lift and rotate, and plays a role in power transmission.

Referring to fig. 1, the joint 1 is screwed into the upper portion of the main cylinder 2, and a tapered passage 21 having an inner diameter gradually decreasing from top to bottom is provided in the main cylinder 2. The underside of the tapered passage 21 is provided with a slip assembly for restraining a drop string. The slip assembly is provided with a gasket 3 which is abutted with the lower end of the joint 1 from top to bottom, an elastic stop piece 4 which is abutted with the gasket 3, a plurality of clamping tiles 5 which are abutted with the elastic stop piece 4, and an elastic mud scraping ring 6 which is used for scraping mud and sand falling from the periphery of the fish is arranged at the lower part of the slip piece 5. The joint 1 acts as a stop, blocking the elastic stop 4 from moving upwards. A plurality of bosses 7 are circumferentially arranged on the limiting section of the conical channel 21, a longitudinal slideway 71 is formed between every two adjacent bosses 7, and the slideway 71 enables the clamping tile 7 to move up and down in the channel so as not to lead the slip sheets 5 to deviate from the slideway 71.

Referring to fig. 2, the circumferential width of the inside of the slips 71 is greater than the circumferential width of the opening of the slips 71, one slip sheet 5 being provided in each slip 71. The thickness of the clamping tile 5 gradually decreases from top to bottom, and the outline of the slip sheet 5 is matched with the slideway 71, namely, the outline of the clamping tile 5 is similar to and close to the outline of the shape of the inner wall of the slideway 71. A gap of 1-2mm is also left between the card tile 5 and the slideway 71, the gap being used to reduce the resistance of the card tile 5 to sliding up and down within the slideway 71. The slip sheets 5 are obliquely arranged upwards, and the distances from the inner sides of the slip sheets 5 arranged from bottom to top to the axis of the main cylinder 2 are equal in a normal state. Referring to fig. 3, the side of the clamping tile 5 near the axis of the main cylinder 2 is provided with a slip tooth 51 with an upward inclination, and the slip tooth 51 is provided with an upward inclined section 511.

Referring to fig. 4, the elastic stopper 4 includes a main tube sleeve 41, a plurality of channels 42 are provided on the outer periphery of the main tube sleeve 41, a plurality of stopping lugs 43 are provided at the lower end of the main tube sleeve 41, grooves 44 are provided between adjacent stopping lugs 43, the stopping lugs 43 are abutted on the stack, and the grooves 44 are buckled with the tops of the bosses 7. The circumferential channel 42 of the elastic stop 4 allows for a greater amount of deformation during the upward extrusion process without providing a greater elastic force to the clamping tiles 5 and thus without providing a greater friction of the slip segments 5 during the relative upward travel of the landing leg. The abutment lugs 43 at the lower end of the elastic stop piece 4 are stepped and are matched with the steps at the upper part of the clamping tile 5, so that the abutment lugs 43 cannot slide out of the slide ways 71 in the process of pressing the elastic stop piece 4, and the abutment lugs 43 cannot deform radially.

Referring to fig. 1, the lower side of the boss 7 abuts against the elastic mud scraping ring 6. The inner diameter of the elastic mud scraping ring 6 is slightly smaller than the outer diameter of the well string, so that sediment and the like on the periphery of the well string can be scraped, sediment is prevented from being accumulated on slip teeth, and the slip teeth 51 are beneficial to clamping the well string. The lower part of the main cylinder body 2 below the elastic mud scraping ring 6 is connected with a guide shoe 8 in a threaded manner, and a first inner chamfer angle for introducing a well-falling pipe column is arranged at the lower end of the guide shoe 8. The guide shoe 8 is internally provided with a milling ring 9, and the milling ring 9 is used for trimming the end part of the well-dropping pipe column, including trimming burrs, circumferential protruding parts and the like of the fish head. The inner side surface of the milling ring 9 is provided with cemented carbide particles, preferably YG cemented carbide particles. The milling ring 9 is provided at its lower part with a second inner chamfer 91, preferably an arc chamfer. The included angle between the waist line of the section of the second inner chamfer 91 and the inner side wall surface of the guide shoe 8 is 30-45 degrees. The clamping tile 5 and the milling ring 9 can be selected according to the outer diameter of the well string to be fished.

The implementation principle of the landing pipe string overshot provided by the embodiment of the application is as follows:

when the overshot tool (hereinafter referred to as tool) is lowered to the top of a fish, namely the upper end of a well-falling pipe column, the well-falling pipe column is generally clung to the inner wall of a well shaft of the well-falling well, the tool is blocked against the fish, the dead weight of the fishing pipe column in operation is displayed to be lowered, at the moment, the rotating tool is slowly driven by the rotating fishing pipe column and slowly lowered, the fish gradually enters the guide shoe 8, at the moment, the dead weight of the fishing pipe column is displayed normally, then the tool is slowly lowered, the fish head gradually enters the milling ring 9, at the moment, the dead weight of the fishing pipe column is displayed to be lowered by a small extent again, then the tool is rotated again, for example, 40-50 revolutions per minute, the lowering speed is 5-8 meters per minute, and sundries such as burrs are milled.

After finishing the fish head by the milling ring 9, the elastic mud scraping ring 6 scrapes sediment and other impurities on the outer side of the pipe column further, the tool is continuously lowered, for example, 0.8-1 meter, in the process of descending the tool, upward thrust is formed on the slip sheets 5, the diameter of a common inscribed circle formed by a plurality of groups of clamping tiles 5 is increased, the slip sheets 5 ascend in the slideway 71 to form extrusion and upward deformation on elastic rubber, at the moment, under the self gravity of the slip sheets 5 and the reaction force of the elastic stop piece 4, the slip teeth 51 of the slip sheets 5 are tightly attached to the outer side of the well-falling pipe column, but no larger resistance is formed in the well-falling pipe column entering tool, so that the well-falling pipe column smoothly enters the tool, after the well-falling pipe column enters the tool for a certain length, the tool is slowly lifted, the common inscribed circle formed by the slip sheets 5 attached to the outer wall of the well-falling pipe column is reduced along with the relative descending of the well-falling pipe column, the plurality of clamping tiles 5 form radial clamping force on the well-falling pipe column, the well-falling pipe column is firmly gripped, and the well-falling pipe column is gradually lifted. The well string that falls can not meet great resistance effect at the in-process that gets into the instrument step by step to card tile 5 has formed the strong fastening to well string that falls under the effect of taper passageway, can not cause card tile 5 to fall the not hard up of well string and lead to falling the well once more, has guaranteed simultaneously before getting into the slips assembly to the repairment of fish head in can normally getting into the instrument, and elasticity scrapes mud ring 6 and can scrape the foreign matter such as silt in the well string outside that drops, further guarantees the clamping force of slips assembly to the tubular column.

The foregoing are all preferred embodiments of the present application, and are not intended to limit the scope of the present application in any way, therefore: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.

Claims (10)

1. A well string overshot, characterized in that: including main barrel (2), be equipped with taper passageway (21) that top-down internal diameter reduces in main barrel (2), taper passageway (21) downside is equipped with the slips assembly, and the slips assembly includes a plurality of bosss (7) of circumference setting, forms a plurality of fore-and-aft slides (71) between adjacent boss (7), is equipped with card tile (5) in every slide (71), and slips piece (5) upper end butt has elastic stop piece (4), and elastic stop piece (4) upper end butt has the locating part that hinders elastic stop piece (4) to reciprocate.

2. The landing leg string overshot of claim 1, wherein: the thickness of the slip sheet (5) is gradually reduced from top to bottom.

3. The landing leg string overshot of claim 2, wherein: the inner sides of the slip sheets (5) are equal in axial distance from the main cylinder (2).

4. A landing leg string overshot according to claim 3, wherein: slip teeth (51) with upward inclination angles are arranged on the inner sides of the slip sheets (5).

5. The landing leg string overshot of claim 4, wherein: an elastic mud scraping ring (6) is arranged on the lower side of the slip sheet (5).

6. The landing leg string overshot of claim 1, wherein: the circumferential width of the inner side of the slide way (71) is larger than that of the opening of the slide way (71), and the slip sheets (5) are provided with an outline matched with the slide way (71).

7. The landing leg string overshot of claim 1, wherein: the lower end of the main cylinder body (2) is connected with a guide shoe (8), and a first inner chamfer for introducing a well-falling pipe column is arranged at the lower end of the guide shoe (8).

8. The landing leg string overshot of claim 7, wherein: milling rings (9) are arranged in the guide shoes (8).

9. The landing leg string overshot of claim 1, wherein: elastic stop piece (4) are including main pipe cover (41), be equipped with multichannel channel (42) in main pipe cover (41) periphery, main pipe cover (41) lower extreme is equipped with a plurality of and supports and stop ear (43), be equipped with recess (44) between adjacent support and stop ear (43), support and stop ear (43) butt in on slip piece (5), recess (44) with boss (7) top lock.

10. The landing leg string overshot of claim 1, wherein: the limiting piece is a joint (1) which is inscribed on the upper part of the main cylinder body (2) and is abutted against the upper end of the elastic stop piece (4).