CN-121827726-B - Retractable salvaging device and salvaging method thereof

CN121827726BCN 121827726 BCN121827726 BCN 121827726BCN-121827726-B

Abstract

The invention discloses a retractable salvaging device and a salvaging method thereof, and relates to the technical field of petroleum drilling. The retractable fishing device comprises an overshot, a drill bit, an inner supporting sleeve and a plurality of conical petals, wherein an upper joint is arranged on the overshot, the drill bit is fixed at the lower end of the overshot, the inner supporting sleeve is sleeved in the overshot and is axially and slidably connected with the inner wall of the overshot, at least two conical petals are circumferentially distributed at the lower end of the inner supporting sleeve, and the conical petals are enclosed to form a frustum structure. The guide hole is drilled in advance through the drill bit, the operation mode that the traditional male cone or split male cone directly bites the inner wall of the fish is changed, the guide hole is utilized to provide accurate axial guide and circumferential positioning for the introduction of the cone-split assembly, and the accuracy and consistency of the cut-in position of the buckling thread are ensured, so that the starting success rate of the salvaging operation and the buckling quality are remarkably improved, and the short frustum structure formed by enclosing the cone-split is matched with the drill bit, so that the buckling depth is reduced, and the method also has applicability to some fish with thinner wall thickness.

Inventors

GAO YUNDONG
BAI DONG
QIAN CHENGMING
Chu Liangyun
SONG WENJIE
WANG XIAOQIANG

Assignees

东营市昌瑞石油机械配件有限责任公司

Dates

Publication Date: 20260512
Application Date: 20260313

Claims (5)

1. The utility model provides a retractable fishing device, includes overshot (1), is equipped with top connection (2) on it, its characterized in that still includes: the drill bit (5) is fixed at the lower end of the overshot (1); The inner support sleeve (10) is sleeved in the overshot (1) and is axially and slidably connected with the inner wall of the overshot (1), at least two cone petals (4) are circumferentially distributed at the lower end of the inner support sleeve (10), a plurality of cone petals (4) are enclosed to form a cone table structure, and the inner diameter of an opening formed at the lower end of the cone table structure is matched with the maximum outer diameter of the drill bit (5); A gap (20) is arranged between two adjacent cone petals (4), an inner supporting cylinder (16) is axially and slidably connected in the inner supporting sleeve (10), and the inner supporting cylinder (16) is downwards used for radially supporting the gap (20) so as to enhance the connection strength between the cone petals (4) and the inner wall of the fish; the inner support sleeve (10) is fixedly provided with a first piston (8) which is in sliding connection with the cavity, and a closed space between the first piston (8) and the top end of the cavity forms a first oil pressure cavity (9); a connecting pipe (6) is fixed in the middle of the inside of the overshot (1), the lower end of the connecting pipe (6) is fixedly connected with the upper end of the drill bit (5), and a first oil guide hole (7) communicated with the top end area inside the first oil pressure cavity (9) is formed in the side wall of the connecting pipe (6); the sealed space between the top end of the inner supporting cylinder (16) and the first piston (8) forms a second oil pressure cavity (17); The fishing socket is characterized in that a lifting cavity (11) is formed in the fishing socket (1) and above the cavity, a lifting pipe (12) is arranged in the lifting cavity (11), a second piston (13) is fixed at the upper end of the lifting pipe (12), the lower end of the lifting pipe (12) extends to the inside of a second oil pressure cavity (17), and a second oil guide hole (14) is formed in the position, close to the upper end, of the outer side of the lifting pipe (12) and used for communicating the first oil pressure cavity (9) with the second oil pressure cavity (17) during fishing of the fish; When the lifting pipe (12) descends to the lowest stroke point, the height position of the second oil guide hole (14) is lower than that of the first oil guide hole (7); The outer surface of the cone valve (4) is provided with a buckling thread, and the lower end of the cone valve (4) is provided with a cutter head (15) for cutting; A limiting ring (19) is fixed at the lower end inside the inner support sleeve (10); The upper end of the inner supporting cylinder (16) is provided with a third piston which is in sliding connection with the inner wall of the inner supporting sleeve (10), and a reset spring (18) is arranged between the third piston and the limiting ring (19) outside the inner supporting cylinder (16).
2. The retractable fishing device according to claim 1, wherein the wall of the overshot (1) is provided with a balance hole (3), and the balance hole (3) communicates the lower part of the cavity with the outside of the overshot (1).
3. The retractable fishing device according to claim 2, wherein an inclined plane (21) with the outer diameter gradually decreasing from top to bottom is arranged at the lower end of the outer side of the inner supporting cylinder (16), and the inclined plane (21) is abutted against the inner wall of the cone valve (4); the inner supporting cylinder (16) descends, and the inclined surface (21) radially supports the conical valve (4) to increase the cross section area of the frustum structure formed by surrounding the conical valve (4).
4. A method of salvaging a retractable salvage device of any of claims 1-3, comprising the steps of: step one, preparing for tripping, namely connecting the fishing device to the lower end of a drill string, tripping the fishing device to the top of a fish in a well, pumping flushing fluid to clean the fish head of the fish; Step two, drilling operation, namely continuously lowering a drill string to enable the drill bit (5) to drill a guide hole in the center of the top surface of the fish; Pumping a hydraulic medium into a drill string to drive an inner supporting sleeve (10) and a cone valve (4) to descend, and simultaneously rotating the drill string to enable the cone valve (4) to mechanically buckle on the inner wall of the guide hole; step four, locking enhancement, namely continuously pumping pressure, pushing the inner supporting cylinder (16) to descend so as to radially support the cone valve (4) and enable the cone valve to be tightly buckled with the inner wall of the fish; And fifthly, lifting the drill string, and if the fish moves along with the drill string, continuing lifting to fish out the fish.
5. The method of claim 4, wherein if the fish cannot be lifted when the fish is caught during the step five, lowering the pump pressure in the drill string and rotating the drill string in the opposite direction; At the moment, the inner supporting cylinder (16) moves upwards, so that the inner supporting cylinder (16) is separated from the cone valve (4), the cone valve (4) is withdrawn from the fish thread under the rotating action after losing radial support, and therefore separation of the fishing device and the fish is realized, and the fishing device is safely started.

Description

Retractable salvaging device and salvaging method thereof Technical Field The invention relates to the technical field of petroleum drilling, in particular to a retractable salvaging device and a salvaging method thereof. Background The male cone is the most commonly used inner hole buckling and salvaging tool in the existing drilling or well repairing engineering, buckling and salvaging can be realized through simple pressurization rotation, and the tool has the advantages of simple structure, easiness in operation and wide salvaging range, can be matched with a forward and a reverse buckling drill rod, is suitable for complex salvaging under different conditions, can salvage as long as the fish has an inner hole (cavity) and certain strength, and is the most effective and economical salvaging tool and means for salvaging the fish. The Chinese patent application CN109083610B discloses a retractable overshot male cone which has a retractable function, prevents the underground environment from being more complicated due to accidents caused by the failure of salvaging, and the male cone adopts a three-split male cone, so that the clearance formed between every two split bodies is convenient for cutting, buckling and chip removing. However, the cone is easy to break and crush due to the large length, high hardness and high brittleness of the cone, and the cone is large in length, so that the cone always needs to go deep into the inner cavity of the fish when being buckled, and the cone has low applicability to some equipment with thinner wall thickness. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a retractable fishing device and a fishing method thereof, which solve the problems proposed by the background technology. The retractable fishing device comprises a fishing barrel, a drill bit, an inner supporting sleeve, at least two conical petals and a gap, wherein the upper connector is arranged on the fishing barrel, the drill bit is fixed at the lower end of the fishing barrel, the inner supporting sleeve is sleeved in the fishing barrel and is axially and slidably connected with the inner wall of the fishing barrel, the conical petals are circumferentially distributed at the lower end of the inner supporting sleeve and form a conical platform structure in a surrounding mode, the inner diameter of an opening formed at the lower end of the conical platform structure is matched with the maximum outer diameter of the drill bit, the gap is arranged between two adjacent conical petals, the inner supporting sleeve is axially and slidably connected with the inner supporting barrel, and the inner supporting barrel is downwards used for radially supporting the gap to enhance the connection strength of the conical petals and the inner wall of the fish. Further, a cavity is formed in the overshot, a first piston which is connected with the cavity in a sliding mode is fixed at the upper end of the inner supporting sleeve, a first oil pressure cavity is formed in a closed space between the first piston and the top end of the cavity, a connecting pipe is fixed in the middle of the overshot, the lower end of the connecting pipe is fixedly connected with the upper end of the drill bit, and a first oil guide hole which is communicated with the top end area inside the first oil pressure cavity is formed in the side wall of the connecting pipe. The inner support cylinder is characterized in that a first oil pressure cavity is formed in the inner support cylinder, a second piston is fixedly arranged at the upper end of the inner support cylinder, a second oil guide hole is formed in the outer side of the inner support cylinder, close to the upper end, of the inner support cylinder, a second oil pressure cavity is formed in the sealing space between the top end of the inner support cylinder and the first piston, a lifting cavity is formed in the inner side of the overshot, a lifting pipe is arranged in the lifting cavity, the second piston is fixedly arranged at the upper end of the lifting pipe, the lower end of the lifting pipe extends into the second oil pressure cavity, and a second oil guide hole is formed in the outer side of the lifting pipe, close to the upper end, and is used for communicating the first oil pressure cavity with the second oil pressure cavity when the fish is salvaged. Further, when the lifting pipe descends to the lowest stroke point, the height position of the second oil guide hole is lower than that of the first oil guide hole. Further, the outer surface of the cone valve is provided with a buckling thread, and the lower end of the cone valve is provided with a cutter head for cutting. Further, a balance hole is formed in the wall of the overshot, and the balance hole is used for communicating the lower portion of the cavity with the outside of the overshot. Further, a limiting ring is fixed at the lower end inside the inner support sleeve, a third piston which