Underground fishing tool and using method thereof

Abstract

The invention discloses an underground fishing tool and a using method thereof. The underground fishing tool comprises an upper connector, a central pipe, an anchor tile, a basket type supporting ring and a lower connector. The using method of the underground fishing tool comprises the steps that S1, the underground fishing tool and a drilling tool are connected to form a tubular column, and the tubular column is put into a well till the tubular column reaches a fish entering cavity; s2, the tubular column is lifted upwards, the fishing claw expands in the radial direction, the fishing claw and the friction claw abut against the fish cavity, and downhole falling objects are fished; if the fish is stuck, the tubular column is rotated, the fishing claw is folded, and rotation and hand release are achieved; and if the field torque transmission is difficult, the tubular column is continuously lifted until the shear pin is sheared and the fishing claw is closed up, so that lifting and hand releasing are realized. The device has the advantages that the device can be smoothly put into a fish cavity to avoid accidental hanging resistance, and the device can be rotated to slip out of the hand and lifted to slip out of the hand.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield well completion and repair, and in particular to a downhole fishing tool and a use method thereof. Background Art

[0002] Salvage is a general term for the professional technology used in the oil industry to remove objects that have fallen into the well or to deal with stuck objects. Salvage technology is the most effective way to solve accidents such as instrument falling into the well or getting stuck during logging and perforating operations. At present, the salvage tools commonly used in offshore oil fields have problems such as unexpected obstruction during lowering, difficulty in changing direction, and unreliable release.

[0003] Therefore, a downhole fishing tool that can smoothly enter the fish cavity to avoid accidental obstruction and can also be rotated and lifted to release the tool and a method of using the tool have become the key to solving the problem. Summary of the invention

[0004] The purpose of the present invention is to provide a downhole fishing tool, which is provided with an upper joint, a central tube, a basket support ring, an anchor tile and a lower joint, which can be smoothly lowered into the fish cavity to avoid accidental obstruction and can also be rotated and lifted to release.

[0005] Another object of the present invention is to provide a method for using a downhole salvage tool, which is provided with an upper joint, a central tube, a basket support ring, an anchor tile and a lower joint, which can be smoothly lowered into the fish cavity to avoid accidental obstruction, and can also be rotated to release and lifted to release.

[0006] To achieve the above object, the present invention adopts the following technical solutions, including:

[0007] Upper joint;

[0008] A central tube, the upper end of which is connected to the upper joint; the central tube is composed of a first tube body, a second tube body and a third tube body connected in sequence from top to bottom; the outer diameter of the first tube body is larger than the outer diameters of the second tube body and the third tube body, and the outer diameter of the second tube body is larger than the outer diameter of the third tube body; a pair of guide blocks are evenly distributed along the circumference of the first tube body; a lower joint is provided at the lower end of the central tube;

[0009] A basket-type support ring is sleeved on the outer periphery of the second tube body and is in gap fit with the second tube body. The basket-type support ring is fixed on the outer periphery of the second tube body by a plurality of evenly distributed shear pins; a gradually expanding first conical surface is provided on the upper part of the basket-type support ring, and a limiting peripheral edge extending outward is provided on the lower part of the basket-type support ring;

[0010] An anchor shoe, a pair of guide grooves parallel to the axial direction are provided on the inner circumference from the upper end to the middle of the anchor shoe, the guide grooves are matched with the guide blocks, and the anchor shoe is axially movably arranged on the outer circumference of the central tube; a plurality of fishing claws are evenly distributed along the circumference of the lower part of the anchor shoe, and a friction claw is provided in the middle of the fishing claw; a second conical surface that gradually expands is provided on the inner circumference of the free end of the fishing claw, and the second conical surface is matched with the first conical surface; the outer diameter of the free end of the fishing claw is larger than the outer diameter of the friction claw;

[0011] A pair of windows are respectively radially penetrated on the anchor shoe; and are opposite to the lower middle part of the guide groove; the windows are in the shape of a right-angled trapezoid, the short base of the right-angled trapezoid is parallel to the guide groove, the long base of the right-angled trapezoid coincides with the guide groove, and the hypotenuse of the right-angled trapezoid is located below the right-angled side; and are used to cooperate with the guide block to realize rotation and release.

[0012] Preferably, the lower end of the upper joint is connected to the male thread arranged at the upper end of the central tube via a female thread; and the upper end of the lower joint is connected to the male thread arranged at the lower end of the central tube via a female thread.

[0013] Preferably, a plurality of first cutting grooves extending from the upper end to the lower middle part are evenly distributed along the circumference of the basket-type support ring, and a plurality of second cutting grooves extending from the lower end to the upper middle part are evenly distributed along the circumference of the basket-type support ring, and the first cutting grooves and the second cutting grooves are spaced apart.

[0014] Preferably, the taper of the first conical surface and the second conical surface is 5°.

[0015] Preferably, the number of the first cutting grooves and the number of the second cutting grooves are 8 respectively.

[0016] Preferably, the basket-type support ring is fixed to the outer periphery of the second tube body by four evenly distributed shear pins.

[0017] Preferably, the guide block is cylindrical.

[0018] Preferably, the outer diameter of the free end of the fishing claw is 3-4 mm larger than the outer diameter of the friction claw.

[0019] A method for using the downhole fishing tool as described in any one of the above, characterized in that it comprises the following steps:

[0020] S1, connecting the downhole fishing tool with the drilling tool to form a pipe string and lowering it into the well until it reaches the fish entry cavity. During this process, the anchor shoe has no contact with the basket support ring, and the fishing claw is not opened;

[0021] S2, lift the pipe column, the center pipe moves upward relative to the anchor shoe, the second conical surface of the salvage claw cooperates with the first conical surface of the basket support ring, the salvage claw produces radial expansion, the salvage claw and the friction claw are both in contact with the fish cavity, so that the fallen objects in the well are salvaged; if the fallen fish is stuck, rotate the pipe column, due to the friction between the friction claw and the fish cavity, the anchor shoe and the center pipe produce relative rotation, the guide block escapes from the guide groove and enters the window, the anchor shoe moves upward with the center pipe under the limit of the guide block, and is separated from the basket support ring again, the salvage claw is retracted, and the rotation and release are achieved; if the torque transmission on site is difficult, continue to lift the pipe column until the shear pin is sheared, the basket support ring is separated from the second pipe body, the anchor shoe is separated from the basket support ring, and the salvage claw is retracted, so as to achieve lifting and release.

[0022] The beneficial effects of the present invention are as follows: the upper joint, the central tube, the basket support ring, the anchor tile and the lower joint are provided, which can smoothly enter the fish cavity to avoid accidental obstruction and can also realize rotation release and upward lifting release. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure is a schematic diagram of a downhole fishing tool of the present invention (in the lowered state).

[0024] Figure 2 This is a half view of a downhole fishing tool of the present invention (in the lowered state).

[0025] Figure 3 This is a half view of a downhole fishing tool of the present invention (fishing status).

[0026] Figure 4 The figure is a half view of a downhole fishing tool of the present invention (lifted up and out of the hands state).

[0027] Figure 5 It is a schematic diagram of the anchor shoe in the present invention (lowered state).

[0028] Figure 6 It is a schematic diagram of the anchor shoe in the present invention (rotating and releasing state).

[0029] Figure 7 Schematic diagram of the central tube in the present invention.

[0030] Figure 8 It is a schematic diagram of the basket-type support ring in the present invention. DETAILED DESCRIPTION

[0031] The invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement it according to the description.

[0032] It should be understood that terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or other elements or combinations thereof.

[0033] like Figure 1-8 As shown, a downhole fishing tool 1 of the present invention comprises:

[0034] Upper connector 110;

[0035] The center tube 120, the upper end of which is connected to the upper joint 110; the center tube 120 is composed of a first tube body 121, a second tube body 122 and a third tube body 123 connected in sequence from top to bottom; the outer diameter of the first tube body 121 is larger than the outer diameters of the second tube body 122 and the third tube body 123, and the outer diameter of the second tube body 122 is larger than the outer diameter of the third tube body 123; a pair of guide blocks 124 are evenly distributed along the circumference of the first tube body 121; a lower joint 130 is provided at the lower end of the center tube;

[0036] A basket-type support ring 140 is sleeved on the outer periphery of the second tube body 122 and is in clearance fit with the second tube body 122. The basket-type support ring is fixed to the outer periphery of the second tube body 122 by a plurality of evenly distributed shear pins 150; a gradually expanding first conical surface 141 is provided on the upper portion of the basket-type support ring 140, and a limiting peripheral edge 142 extending outward is provided on the lower portion of the basket-type support ring;

[0037] An anchor shoe 160, whose inner circumference is provided with a pair of guide grooves 161 arranged parallel to the axial direction from the upper end to the middle of the anchor shoe 160, the guide grooves 161 are matched with the guide block 124, and the anchor shoe 160 is axially movably arranged on the outer circumference of the central tube 120; a multi-petal fishing claw 162 is evenly distributed along the circumference of the lower part of the anchor shoe 160, and a friction claw 163 is provided in the middle of the fishing claw 162; a gradually expanding second conical surface 162a is provided on the inner circumference of the free end of the fishing claw, and the second conical surface 162a is matched with the first conical surface 141; the outer diameter of the free end of the fishing claw 162 is larger than the outer diameter of the friction claw 163;

[0038] A pair of windows 170 are respectively radially penetrated on the anchor shoe 160; and are opposite to the lower middle part of the guide groove 161; the window 170 is a right-angled trapezoid, the short base 171 of the right-angled trapezoid is parallel to the guide groove 161, the long base 172 of the right-angled trapezoid coincides with the guide groove, and the hypotenuse 173 of the right-angled trapezoid is located below the right-angled side 174; and are used to cooperate with the guide block 124 to realize rotation and release.

[0039] In another embodiment, the lower end of the upper joint 110 is connected to the male thread arranged at the upper end of the central tube 120 through a female thread; the upper end of the lower joint 130 is connected to the male thread arranged at the lower end of the central tube 120 through a female thread.

[0040] In another embodiment, a plurality of first cutting grooves 143 extending from the upper end to the lower middle portion are evenly distributed along the circumference of the basket-type support ring 140, and a plurality of second cutting grooves 144 extending from the lower end to the upper middle portion are evenly distributed along the circumference of the basket-type support ring 140, and the first cutting grooves 143 and the second cutting grooves 144 are spaced apart from each other.

[0041] In another embodiment, the taper of the first conical surface and the second conical surface is 5°.

[0042] In another embodiment, the number of the first cutting grooves 143 and the number of the second cutting grooves 144 are 8 respectively.

[0043] In another embodiment, the basket support ring 140 is fixed to the outer periphery of the second tube body 122 by four evenly distributed shear pins 150 .

[0044] In another embodiment, the guide block 124 is cylindrical.

[0045] In another embodiment, the outer diameter of the free end of the fishing claw 162 is 3-4 mm larger than the outer diameter of the friction claw 163 .

[0046] Example 1

[0047] A method for using a downhole fishing tool, characterized in that it comprises the following steps:

[0048] S1, connecting the downhole fishing tool 1 with the drilling tool to form a pipe string and lowering it into the well until it reaches the fish cavity. During this process, the anchor shoe 160 has no contact with the basket support ring 140, and the fishing claw 162 is not opened, so that it can be smoothly lowered into the fish cavity to avoid accidental obstruction;

[0049] S2. Lift the pipe string, the center pipe 120 moves upward relative to the anchor shoe 160, the second conical surface 162a of the salvage claw 162 cooperates with the first conical surface 141 of the basket support ring 140, the salvage claw 162 expands radially, and the salvage claw 162 and the friction claw 163 are both in contact with the fish cavity, so as to realize the salvage of fallen objects in the well.

[0050] Example 2

[0051] A method for using a downhole fishing tool, characterized in that it comprises the following steps:

[0052] S1, connecting the downhole fishing tool 1 with the drilling tool to form a pipe string and lowering it into the well until it reaches the fish cavity. During this process, the anchor shoe 160 has no contact with the basket support ring 140, and the fishing claw 162 is not opened, so that it can be smoothly lowered into the fish cavity to avoid accidental obstruction;

[0053] S2, lift the pipe column, the center pipe 120 moves up relative to the anchor shoe 160, the second conical surface 162a of the salvage claw 162 cooperates with the first conical surface 141 of the basket support ring 140, the salvage claw 162 expands radially, and the salvage claw 162 and the friction claw 163 are in contact with the fish cavity, so as to realize the salvage of the fallen objects in the well. When the fish is stuck, rotate the pipe column, due to the friction between the friction claw 163 and the fish cavity, the anchor shoe 160 and the center pipe 120 rotate relative to each other, the guide block 124 escapes from the guide groove 161 and enters the window 170, the anchor shoe 160 moves up with the center pipe 120 under the limit of the guide block 124, and separates from the basket support ring 140 again, the salvage claw 162 is retracted, and the rotation is realized.

[0054] Example 3

[0055] A method for using a downhole fishing tool, characterized in that it comprises the following steps:

[0056] S1, connecting the downhole fishing tool 1 with the drilling tool to form a pipe string and lowering it into the well until it reaches the fish cavity. During this process, the anchor shoe 160 has no contact with the basket support ring 140, and the fishing claw 162 is not opened, so that it can be smoothly lowered into the fish cavity to avoid accidental obstruction;

[0057] S2, lift the pipe column, the center pipe 120 moves upward relative to the anchor shoe 160, the second conical surface 162a of the salvage claw 162 cooperates with the first conical surface 141 of the basket support ring 140, the salvage claw 162 produces radial expansion, the salvage claw 162 and the friction claw 163 are both in contact with the fish cavity, and the downhole object is salvaged. When the fish is stuck and the torque transmission on site is difficult, continue to lift the pipe column until the shear pin 150 is sheared, the basket support ring 140 is separated from the second pipe body 122, the anchor shoe 160 is separated from the basket support ring 140, and the salvage claw 162 is retracted, so as to achieve lifting and release.

[0058] In summary, the present invention provides a downhole salvage tool 1, which is provided with an upper joint 110, a central tube 120, a basket support ring 140, an anchor shoe 150 and a lower joint 130. It can be smoothly lowered into the fish cavity to avoid accidental obstruction and can also be rotated and lifted to release.

[0059] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A downhole fishing tool, characterized in that: include: Upper joint; A central tube, the upper end of which is connected to the upper joint; the central tube is composed of a first tube body, a second tube body and a third tube body connected in sequence from top to bottom; the outer diameter of the first tube body is larger than the outer diameters of the second tube body and the third tube body, and the outer diameter of the second tube body is larger than the outer diameter of the third tube body; a pair of guide blocks are evenly distributed along the circumference of the first tube body; a lower joint is provided at the lower end of the central tube; A basket-type support ring is sleeved on the outer periphery of the second tube body and is in gap fit with the second tube body. The basket-type support ring is fixed on the outer periphery of the second tube body by a plurality of evenly distributed shear pins; a gradually expanding first conical surface is provided on the upper part of the basket-type support ring, and a limiting peripheral edge extending outward is provided on the lower part of the basket-type support ring; An anchor shoe, a pair of guide grooves parallel to the axial direction are provided on the inner circumference from the upper end to the middle of the anchor shoe, the guide grooves are matched with the guide blocks, and the anchor shoe is axially movably arranged on the outer circumference of the central tube; a plurality of fishing claws are evenly distributed along the circumference of the lower part of the anchor shoe, and a friction claw is provided in the middle of the fishing claw; a second conical surface that gradually expands is provided on the inner circumference of the free end of the fishing claw, and the second conical surface is matched with the first conical surface; the outer diameter of the free end of the fishing claw is larger than the outer diameter of the friction claw; A pair of windows are respectively radially penetrated on the anchor shoe; and are opposite to the lower middle part of the guide groove; the windows are in the shape of a right-angled trapezoid, the short base of the right-angled trapezoid is parallel to the guide groove, the long base of the right-angled trapezoid coincides with the guide groove, and the hypotenuse of the right-angled trapezoid is located below the right-angled side; and are used to cooperate with the guide block to realize rotation and release.

2. The downhole fishing tool according to claim 1, characterized in that: The lower end of the upper joint is connected to the male thread arranged at the upper end of the central tube through a female thread; the upper end of the lower joint is connected to the male thread arranged at the lower end of the central tube through a female thread.

3. The downhole fishing tool according to claim 1, characterized in that: A plurality of first cutting grooves extending from the upper end to the lower middle part are evenly distributed along the circumference of the basket-type support ring, and a plurality of second cutting grooves extending from the lower end to the upper middle part are evenly distributed along the circumference of the basket-type support ring, and the first cutting grooves and the second cutting grooves are spaced apart.

4. The downhole fishing tool according to claim 3, characterized in that: The taper of the first conical surface and the second conical surface is 5°.

5. The downhole fishing tool according to claim 3, characterized in that: The number of the first cutting grooves and the number of the second cutting grooves are 8 respectively.

6. The downhole fishing tool according to claim 3, characterized in that: The basket-type support ring is fixed to the outer periphery of the second tube body by four evenly distributed shear pins.

7. The downhole fishing tool according to claim 3, characterized in that: The guide block is cylindrical.

8. The downhole fishing tool according to claim 3, characterized in that: The outer diameter of the free end of the fishing claw is 3-4 mm larger than the outer diameter of the friction claw.

9. A method for using the downhole fishing tool according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, connecting the downhole fishing tool with the drilling tool to form a pipe string and lowering it into the well until it reaches the fish entry cavity. During this process, the anchor shoe has no contact with the basket support ring, and the fishing claw is not opened; S2, lift the pipe column, the center pipe moves upward relative to the anchor shoe, the second conical surface of the fishing claw cooperates with the first conical surface of the basket support ring, the fishing claw expands radially, and the fishing claw and the friction claw abut against the fish cavity to realize the salvage of the fallen objects in the well; if the fish is stuck, rotate the pipe column, due to the friction between the friction claw and the fish cavity, the anchor shoe and the center pipe rotate relative to each other, the guide block escapes from the guide groove and enters the window, the anchor shoe moves upward with the center pipe under the limit of the guide block, and separates from the basket support ring again, the fishing claw is retracted, and the rotation and release are realized; If the torque transmission on site is difficult, continue to lift the pipe column until the shear pin is sheared, the basket support ring is separated from the second pipe body, the anchor shoe is separated from the basket support ring, and the salvage claws are retracted to achieve lifting and release.

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