A downhole cable capture and release device and method of use thereof

Abstract

The application discloses a downhole cable capturing and separating device and a use method thereof and belongs to the technical field of oil logging. The downhole cable capturing and separating device comprises a long-throwing rod and a clamping and shearing body, the clamping and shearing body is internally sequentially provided with a pressing sliding block, a pressing cone sleeve, a power-assisted sliding block and a cable shearing device, a cavity for the cable to pass through is arranged on the central axis direction of the long-throwing rod, the pressing sliding block, the pressing cone sleeve, the power-assisted sliding block and the cable shearing device, the inner side of the pressing sliding block is designed in a taper, and the outer side of the pressing cone sleeve is designed in a taper matched with the pressing sliding block; the long-throwing rod is used for pushing the pressing sliding block to impact the pressing cone sleeve, the pressing cone sleeve is shrunk and clamps the cable, the power-assisted sliding block impacts the cable shearing device, and the cable shearing device shears the cable. The device can clamp the cable automatically while cutting off the cable, the cable can be pulled out of the well mouth, the device is convenient to use, has high practicability, improves work efficiency and reduces production cost.

Description

Technical Field

[0001] This invention belongs to the field of oil well logging technology, specifically relating to a downhole cable capture and separation device and its usage method. Background Technology

[0002] Currently, the complexity of well logging operations is on the rise due to cables and instruments getting stuck. The principle for handling complex well logging operations is to first clear the cables from the wellbore before retrieving the instruments. However, because cables are often stuck to the wellbore wall or buried by debris, blindly pulling the cable makes it impossible to control the break point and remove all cables, increasing the difficulty of subsequent retrieval. Therefore, during well logging operations, a cable cutter needs to be used to cut the cables and retrieve them all from the wellhead, creating a favorable wellbore environment for the subsequent retrieval of radioactive and high-value logging instruments. However, the current cable cutters cannot automatically retrieve the cutter from the wellhead after cutting the cable; the retrieval instruments must be lowered again to retrieve the cable cutter from the well. This complicates the project. As time goes on, the mud performance deteriorates, the wellbore becomes unstable, and the number of drilling trips increases, all of which are unfavorable factors that increase the difficulty of retrieval. At the same time, there are many uncertainties in using retrieval tools to retrieve the cable cutter during drilling. If the retrieval fails, it will cause a secondary accident, increase the difficulty of subsequent retrieval, and lead to serious consequences such as uncontrolled radioactive sources and damage to high-value logging instruments. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, the present invention aims to provide a downhole cable capture and separation device and its usage method, which solves the problem that the cable cutter cannot automatically retrieve the cable from the wellhead after cutting the cable during logging operations.

[0004] To achieve the above objectives, the present invention employs the following technical solution:

[0005] This invention discloses a downhole cable capture and separation device, comprising a long throwing rod and a clamping and shearing body. The clamping and shearing body contains, in sequence, a pressing slider, a pressing cone sleeve, an assisting slider, and a cable cutting device. Each of the long throwing rod, pressing slider, pressing cone sleeve, assisting slider, and cable cutting device has a coaxial cavity for cable passage. The pressing slider has an inner conical surface, and the pressing cone sleeve has an outer conical surface that mates with the inner conical surface of the pressing slider. The outer conical surface of the pressing cone sleeve has an adjustable-diameter opening at its cone angle for cable passage and clamping. The pressing slider is connected to the assisting slider, the pressing cone sleeve is fixed within the clamping and shearing body, and a gap exists between the assisting slider and the cable cutting device.

[0006] Preferably, the inner conical surface of the pressing slider is provided with opposing axial slots, and the outer conical surface of the pressing cone sleeve is provided with two protrusions that cooperate with the axial slots of the pressing slider.

[0007] Preferably, the clamping and shearing body is composed of an upper outer shell, a short-connecting outer shell, and a short-section body connected in sequence. The upper outer shell has a cavity for accommodating the long throwing rod. The clamping slider and the assisting slider are connected by threads and can move within the short-connecting outer shell.

[0008] More preferably, the short section body has a protruding key on the side near the cable cutting device, and the protruding key has a through hole.

[0009] More preferably, the cable cutting device includes a cutting blade, a fixing pin, a torsion spring, and a cotter pin. The cutting blade has a U-shaped groove at one end near the short section body, and a through hole in the vertical direction of the U-shaped groove. The fixing pin is perpendicular to the cutting blade and passes through the through hole of the cutting blade, the through hole of the key of the short section body, and the torsion spring connected to the key of the short section body. It is then fixed by the cotter pin. The U-shaped groove, the key of the short section body, the torsion spring, and the cotter pin together form a hinge structure.

[0010] Preferably, a flow pin is also provided on the upper outer casing.

[0011] Preferably, the assist slider is fixed inside the shorting housing by a weak point pin.

[0012] Preferably, the long throwing rod is bullet-shaped, with an annular groove with a slanted opening on the rear half end face of the bullet, and a limiting part on the inner wall of the upper outer shell that engages with the annular groove with the slanted opening of the long throwing rod.

[0013] Preferably, the shorting shell has a radial inner hole, and the inner hole has an axial slot, so that the clamping cone sleeve is fixedly connected to the axial slot of the shorting shell.

[0014] This invention also discloses a method for using the aforementioned downhole cable capture and separation device. First, the clamping and shearing body is slipped over the cable and inserted into the drill string's water hole. Simultaneously, the pump is turned on to pressurize the device, causing the clamping and shearing body to descend into the position of the cable to be cut. Then, a long drop bar is dropped from the wellhead, increasing the pump pressure. The impact force of the long drop bar as it falls strikes the clamping slider, causing it to approach the clamping cone sleeve. The inner diameter of the clamping cone sleeve contracts and clamps the cable. The assisting slider connected to the clamping slider strikes the cable cutting device and cuts the cable. After the cable cutting operation is completed, the cable is lifted, and the downhole cable capture and separation device is retrieved from the wellhead.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This invention provides a downhole cable capture and separation device. The impact force of a long drop bar striking a clamping slider near a clamping cone sleeve causes the opening of the clamping cone sleeve to tighten and clamp the cable. Simultaneously, the impact force of the long drop bar drives an assist slider connected to the clamping slider to move, striking a cable cutting device, thus achieving the cable cutting function. The tapered design of the clamping slider and clamping cone sleeve ensures that the inner diameter of the clamping slider contracts upon contact, thereby achieving the cable clamping function. A gap is left between the assist slider and the cable cutting device to allow space for the movement of the assist slider. This downhole cable capture and separation device can clamp the cable while cutting it. As the cable is retrieved from the wellhead, the device can be pulled out along with it, eliminating the need to retrieve the cable cutter, reducing the number of drilling trips and various uncertainties, creating a better wellbore environment for subsequent instrument retrieval, and improving the efficiency and success rate of complex logging operations. This device is easy to use and highly practical. It does not affect the efficiency of handling complex engineering problems. During the salvage operation, it can effectively reduce the risk of secondary accidents, improve operational efficiency, reduce production costs, and enable rapid and safe handling of complex engineering accidents, thereby reducing well occupation time and improving the ability to prevent and handle complex downhole engineering problems.

[0017] Furthermore, the protrusions and slots allow the clamping cone sleeve and the clamping slider to fit together, thereby clamping the cable.

[0018] Furthermore, the design of the short-circuit flow pin allows for the reservation of mud circulation channels based on well conditions and drilling fluid properties after the cable is cut.

[0019] Furthermore, the long baton is designed in a bullet shape to reduce air resistance, thereby increasing the impact force when the long baton descends.

[0020] Furthermore, the engagement between the annular groove and the limiting part allows the long baton to be fixed after its descent.

[0021] The present invention provides a method for using a downhole cable capture and separation device. The method is simple and highly operable. By inserting a long drop bar into the wellhead, the clamping slider, the clamping cone sleeve and the assisting slider are linked together, and the cable is cut by touching the cable cutting device. This method can quickly solve the problem that the cable cutter cannot automatically retrieve the cable from the wellhead after cutting it during logging operations. Attached Figure Description

[0022] Figure 1 This is an overall design drawing of the downhole cable capture and separation device of the present invention;

[0023] Figure 2 for Figure 1 Enlarged view of the A-A' region.

[0024] Wherein: 1-Short section body; 2-Short-connection outer shell; 3-Weak point pin; 4-Upper outer shell; 5-Flow pin; 6-Long casting rod; 7-Assist slider; 8-Pressure slider; 9-Pressure cone sleeve; 10-Shearing blade; 11-Fixing pin; 12-Torsion spring; 13-Cotter pin; 14-O-ring seal. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings:

[0028] This invention provides a downhole cable capture and separation device, comprising a long drop bar 6 and a clamping and shearing body. The long drop bar 6 is bullet-shaped, which reduces resistance during its descent, thereby increasing impact force. A cavity penetrating the body of the long drop bar 6 is provided along its central axis for cable passage. An annular groove with a slanted opening is provided on the rear half of the bullet's end face. This groove increases fluid assistance during pumping and lowering, providing acceleration and increasing the downward thrust of the long drop bar 6. The long drop bar 6 provides propulsion for the movement of various components within the clamping and shearing body. The clamping and shearing body consists of an upper outer shell 4, a short-connecting outer shell 2, and a short section body 1 connected sequentially. The short-connecting outer shell 2 is threadedly connected to both the upper outer shell 4 and the short section body 1. Inside the clamping and shearing body, from the upper outer shell 4 to the short section body 1, are sequentially arranged a clamping slider 8, a clamping cone sleeve 9, an assisting slider 7, and a cable cutting device. The upper outer casing 4 has a cavity inside to accommodate the long casting rod 6, and the inner wall of the upper outer casing 4 has a retrieval groove; the short-connecting outer casing 2 has a radial inner hole with an axial slot; the short section body 1 has a key on the side near the cable cutting device, and the key has a through hole. The clamping slider 8, clamping cone sleeve 9, assisting slider 7, cable cutting device, and the central axis of the short section body 1 all have cavities to accommodate the cable, allowing the cable to be fitted inside the cable capture and separation device. The long casting rod 6 is inside the upper outer casing 4 and extends to the outside of the upper outer casing 4. The clamping slider 8 and the assisting slider 7, connected by threads, can move inside the short-circuit housing 2. The clamping slider 8 has an inner conical surface at one end near the clamping cone sleeve 9, with two axial slots distributed opposite each other at the top and bottom of the clamping slider 8. The clamping cone sleeve 9 has an outer conical surface at one end near the clamping slider 8 that mates with the inner conical surface of the clamping slider 8. The cone angle of the outer conical surface has an adjustable opening for the cable to pass through. The opening at the cone angle of the clamping cone sleeve 9 has two protrusions distributed at the top and bottom of the opening. The protrusions are fixed to the axial slots designed in the inner hole of the short-circuit housing 2 and also mate with the two axial slots of the clamping slider 8. The adjustable design of the protrusions, the axial slots, and the cone angle of the clamping cone sleeve 9 allows the inner diameter of the clamping cone sleeve 9 to shrink, tighten, and clamp the cable when the clamping slider 8 moves (the axial slot of the clamping slider 8 approaches the protrusion of the clamping cone sleeve 9) and approaches the clamping cone sleeve 9. The outer circumference of the assist slider 7 is provided with an annular groove. The weak point pin 3 is screwed into the annular groove of the assist slider 7 through the radial threaded hole on the short section housing 2, fixing the assist slider 7 inside the short section housing 2. The assist slider 7 is a certain distance away from the cable cutting device. The impact force generated by the long throwing rod 6 can cut the weak point pin 3, push the pressing slider 8 and the assist slider 7 to move towards the cable cutting device, and the assist slider 7 hits the cable cutting device to open.The cable cutting device consists of a cutting blade 10, a fixing pin 11, a torsion spring 12, a cotter pin 13, and a short section body 1. The cutting blade 10 has a U-shaped groove near one end of the short section body 1, with a through hole perpendicular to the U-shaped groove. The fixing pin 11 is perpendicular to the cutting blade 10 and passes through the through hole of the cutting blade 10, the through hole of the key on the short section body 1, and the torsion spring 12 connected to the key on the short section body 1. It is then fixed by the cotter pin 13. The U-shaped groove, the key on the short section body 1, the torsion spring 12, and the cotter pin 13 together form a hinge structure, allowing the cutting blade 10 to be folded. When the assisting slider 7 collides with the cutting blade 10, the hinge structure pushes the cutting blade 10 upwards, increasing the angle at which the cutting blade 10 is lifted as the assisting slider 7 advances. The upper casing 4 is also equipped with a flow pin 5 for mud circulation. An O-ring seal 14 is installed on the flow pin 5. After the cable is cut, if mud circulation is required depending on the well conditions and drilling fluid properties, the flow pin 5 can be removed before running into the well to leave a circulation channel. If mud circulation is not required, the flow channel can be sealed with the O-ring seal 14, and the flow pin 5 can be run into the well. The downhole cable capture and separation device can operate inside the drill string water hole.

[0029] The method of using the downhole cable capture and separation device provided by this invention is as follows: When the logging instrument gets stuck during the logging process and it is necessary to cut the cable in the well, first, the clamping and shearing body is put through the cable and inserted into the water hole of the drill string. At the same time, the pump is turned on to pressurize, so that the clamping and shearing body is lowered into the position of the cable to be cut by the pump pressure. Then, the long drop bar 6 is put into the wellhead to increase the pump pressure. The impact force of the long drop bar 6 when it falls hits the clamping slider 8. The clamping slider 8 moves and approaches the clamping cone sleeve 9. The inner diameter of the clamping cone sleeve 9 contracts and clamps the cable. At the same time, the impact force generated by the long drop bar 6 hitting the clamping slider 8 cuts the weak pin 3. The assist slider 7 connected to the clamping slider 8 hits the cable cutting device. The torsion spring 12 is triggered, pushing the shearing blade 10 to lift and cut the cable. After the cable cutting operation is completed, the cable is lifted up, the clamping cone sleeve 9 clamps the cable and is fixed in place, and the downhole cable capture and separation device is pulled out of the wellhead.

[0030] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A downhole cable capture and separation device, characterized in that, The device includes a long throwing rod (6) and a clamping and shearing body. The clamping and shearing body contains, in sequence, a pressing slider (8), a pressing cone sleeve (9), an assisting slider (7), and a cable cutting device. Each of the long throwing rod (6), pressing slider (8), pressing cone sleeve (9), assisting slider (7), and cable cutting device has a coaxial cavity for cable passage. The pressing slider (8) has an inner conical surface, and the pressing cone sleeve (9) has an outer conical surface that mates with the inner conical surface of the pressing slider (8). The outer conical surface of the pressing cone sleeve (9) has an adjustable opening at its cone angle for cable passage and clamping. The slider (8) is connected to the assist slider (7), and the clamping cone sleeve (9) is fixed in the clamping shear body. There is a gap between the assist slider (7) and the cable cutting device. The clamping shear body is composed of an upper shell (4), a short-circuit shell (2) and a short section body (1) connected in sequence. The upper shell (4) has a cavity inside to accommodate the long throwing rod (6). The clamping slider (8) and the assist slider (7) are connected by threads and can move inside the short-circuit shell (2). When the clamping slider (8) and the assist slider (7) move toward the cable cutting device, the assist slider (7) hits the cable cutting device to open.

2. The downhole cable capture and separation device according to claim 1, characterized in that, The inner conical surface of the pressing slider (8) is provided with opposing axial slots, and the outer conical surface of the pressing cone sleeve (9) is provided with two protrusions that cooperate with the axial slots of the pressing slider (8).

3. The downhole cable capture and separation device according to claim 1, characterized in that, The short section body (1) has a key near the cable cutting device, and a through hole is provided on the key.

4. The downhole cable capture and separation device according to claim 3, characterized in that, The cable cutting device includes a cutting blade (10), a fixing pin (11), a torsion spring (12), and a cotter pin (13). The cutting blade (10) has a U-shaped groove at one end near the short section body (1). The U-shaped groove has a through hole in the vertical direction. The fixing pin (11) is perpendicular to the cutting blade (10) and passes through the through hole of the cutting blade (10), the through hole of the key of the short section body (1), and the torsion spring (12) connected to the key of the short section body (1). Then it is fixed by the cotter pin (13). The U-shaped groove, the key of the short section body (1), the torsion spring (12), and the cotter pin (13) together form a hinge structure.

5. The downhole cable capture and separation device according to claim 1, characterized in that, A flow pin (5) is also provided on the upper outer casing (4).

6. The downhole cable capture and separation device according to claim 1, characterized in that, The assist slider (7) is fixed inside the short-circuit housing (2) by the weak point pin (3).

7. The downhole cable capture and separation device according to claim 1, characterized in that, The long throwing rod (6) is bullet-shaped, with an annular groove with a slanted opening on the rear half end face of the bullet, and a limiting part on the inner wall of the upper shell (4) that engages with the annular groove with the slanted opening of the long throwing rod (6).

8. The downhole cable capture and separation device according to claim 1, characterized in that, The short-circuit housing (2) has an inner hole in the radial direction, and an axial slot is provided on the inner hole. The clamping cone sleeve (9) is fixedly connected to the axial slot of the short-circuit housing (2).

9. The method of using the downhole cable capture and separation device according to claim 1, characterized in that, First, the clamping shear body is passed over the cable and inserted into the water hole of the drill string. At the same time, the pump is turned on to pressurize the clamping shear body and it is lowered into the position of the cable to be cut by the pump pressure. Then, the long drop bar (6) is dropped from the wellhead to increase the pump pressure. The impact force of the long drop bar (6) when it falls hits the clamping slider (8). The clamping slider (8) approaches the clamping cone sleeve (9). The inner diameter of the clamping cone sleeve (9) shrinks and clamps the cable. The assist slider (7) connected to the clamping slider (8) hits the cable cutting device and cuts the cable. After the cable cutting operation is completed, the cable is lifted up and the downhole cable capture and separation device is brought out of the wellhead.

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