A new type of fishing tool for downhole ropes and cables

Abstract

The utility model discloses a novel fishing tool of downhole rope and cable, wherein the upper central pipe and the lower central pipe are connected through the central pipe joint installed in the outer tube joint; the upper outer tube and the lower outer tube are connected at the outside of the outer tube joint, the upper end of the upper outer tube is connected with the connecting tube equipped with the limit ring and the zigzag buckle ring, the limit ring is connected with the connecting tube, the zigzag buckle ring is connected with the upper central pipe through the zigzag buckle thread, the lower part of the lower outer tube is connected with the outside of the lower central pipe; the body of the central pipe joint is equipped with the pressure transmission hole, the high pressure liquid flow entering through the pressure transmission hole can push the outer tube joint and drive the connecting tube equipped with the zigzag buckle ring, the upper outer tube and the lower outer tube to go down along the zigzag buckle thread outside the upper central pipe. The anti-falling mechanism in the tool has the non-return and the anti-back function, the anti-falling mechanism can guarantee the effective pressure and lock the rope or the cable fish, effectively improves the fishing success rate of the falling object, and significantly improves the economic benefit of the fishing operation.

Description

Technical Field

[0001] This utility model relates to a tool for retrieving fallen objects from wells in the petroleum industry, and in particular to a new type of tool for retrieving ropes and cables from wells. Background Technology

[0002] With the expansion and development of offshore oil fields, the intensity of offshore production capacity development has been increasing year by year, leading to a growing workload of offshore drilling and workover operations, with the number of wells drilled and worked over annually increasing. Due to limitations imposed by ocean currents, wind direction, and construction costs, offshore oil production platforms have small well spacing and limited platform space. Stringent requirements regarding platform space and environmental regulations necessitate the use of submersible electric pumps (SAPs) or self-flowing pumps for fluid lift in production wells. Furthermore, according to offshore production well control regulations, well control tools must be installed in the annulus and outside the tubing string. Therefore, offshore SSP wells require well control tools according to well control regulations, resulting in cables being uniformly distributed outside the production tubing string. Because of these cables, retrieving these cables has become a routine procedure during maintenance or maintenance operations in the production process.

[0003] Currently, the retrieval of downhole cables or wires is still carried out using conventional tools such as internal hooks, external hooks, and grabbers, which have poor retrieval results. Often, the "fish" (lost objects) is lost when lifting the retrieval string, resulting in a low success rate. Other electric retrieval tools have complex structures, are prone to various problems during downhole operations, and are also quite expensive. Therefore, there is an urgent need to develop an economical and reliable downhole rope and cable retrieval tool to solve these problems.

[0004] To address this, technicians have undertaken extensive work and developed the following downhole cable retrieval tool: Patent application number CN201520685451.3 discloses a downhole object retrieval cylinder, belonging to the technical field of small-item and rope-type object retrieval tools for oilfield well workover operations. It consists of an upper connector, a milling sleeve, and a punch pipe. The upper connector is threaded to the milling sleeve, and the lower inner wall of the milling sleeve is equipped with hook teeth. The upper end of the punch pipe is threaded to the upper connector and installed inside the milling sleeve cavity. Hook teeth are located on the outer wall of the punch pipe at positions corresponding to the lower inner wall of the milling sleeve. The beneficial effects of this utility model are that the effective combination of the milling sleeve and the punch tip, combined with the elastic characteristics of the wire rope, ensures that small objects enter the cylinder. A hinged baffle fixes the small objects inside the cylinder, and the hook teeth retrieve rope-type objects. The operation is convenient, achieving sand flushing, milling, and retrieval in one operation, improving retrieval efficiency and saving operating costs.

[0005] However, due to the hardness, toughness, and weight of the 1 / 4-inch ferrule tube (comprising a ferrule and a cap) and the No. 4 round lead cable of the submersible pump, the success rate of retrieval is low. Furthermore, the simple connection between the upper connector, the milling sleeve, and the punch in the aforementioned utility model cannot guarantee a secure retrieval of the fallen object, leaving the possibility of it falling back into the well. Therefore, it cannot meet the retrieval requirements for cables in offshore or onshore wells.

[0006] CN202211509587.X describes a guided, automatically telescopic, internally clamped wellbore retrieval hook. Its structure includes a guide cylinder, hook body, pin, telescopic hook, spring, hook, and latch. The hook is connected to the guide cylinder via the hook. The hook body is mounted on the hook, and the telescopic hook is mounted on the hook body via the pin. The spring applies elastic force to the telescopic hook. This hook is capable of retrieving soft materials such as pumping pipes, injection pipes, and sealing tubes of sealing cables. However, due to the hardness, high toughness, and heavy weight of 1 / 4-inch tubing cable clamps and #4 round lead cables for submersible pumps, the retrieval success rate is low, thus failing to meet the technical requirements for retrieving cables in offshore or onshore wells.

[0007] CN201921445857.9 describes a segmented internal hook-tooth retrieval cylinder. Its structure includes a retrieval cylinder body and an upper connector that connects to a weighted rod. The bottom of the upper connector is fixed to the top of the retrieval cylinder body. Several slots are spaced circumferentially along the sidewall of the retrieval cylinder body, with the bottom of each slot extending to the lower end face of the retrieval cylinder body. Flexible internal hook teeth are provided on the lower inner wall of the retrieval cylinder body, with the bottom ends of the flexible internal hook teeth fixedly connected to the inner wall of the retrieval cylinder body. The flexible internal hook teeth are inclined from bottom to top towards the inner side of the retrieval cylinder body. This design allows for the retrieval of some irregular and unconventional objects that have fallen into the well, utilizing the slots and flexible internal hook teeth. However, due to the high hardness and strength of materials such as the 1 / 4-inch clamping tube (comprising a clamping sleeve and a pressure cap) and the heavy weight of the No. 4 round lead cable of the submersible pump, the retrieval success rate is low, thus failing to meet the technical requirements for retrieval of cables in offshore or onshore wells.

[0008] In summary, current retrieval tools are limited in their simple structure and are unable to retrieve hard and heavy cables from underground. Electric retrieval tools are also unreliable due to their complex structure and unreliable operation. Therefore, the tools for retrieving cables from underground still need improvement. Summary of the Invention

[0009] The purpose of this invention is to provide a novel tool for retrieving ropes and cables from wells, improving upon existing tools by making them simpler in structure and stronger in load-bearing capacity. This tool can retrieve not only softer tubing such as pumping pipes and injection pipes, but also clamped tubing composed of clamps and caps, as well as heavy, hard, and tough round lead cables from submersible electric pump wells. This improves retrieval efficiency and success rate, reduces operational costs, and increases economic benefits.

[0010] The technical solution of this utility model is: a new type of downhole rope and cable retrieval tool, including a lower central tube with a flushing channel and a retrieval hook, wherein: the upper central tube and the lower central tube are connected by a central tube joint installed in the outer cylinder joint;

[0011] Both the upper and lower outer cylinders are connected to the outside of the outer cylinder joint; the upper end of the upper outer cylinder is connected to the connecting cylinder equipped with a limit ring and a toothed snap ring, the limit ring is connected to the connecting cylinder, and the toothed snap ring is connected to the upper central tube through a toothed thread; the lower part of the lower outer cylinder is connected to the outside of the lower central tube; the body of the central tube joint is provided with a pressure transmission hole, and the high-pressure liquid flow entering through the pressure transmission hole can push the outer cylinder joint and drive the connecting cylinder equipped with the toothed snap ring, the upper outer cylinder and the lower outer cylinder to move downward along the toothed thread outside the upper central tube.

[0012] Preferably, the inner cavity of the connecting cylinder is a non-uniform diameter inner cavity and the outer circle is a non-uniform diameter outer circle. The inner cavity of the connecting cylinder, from top to bottom, consists of a limiting ring mounting cavity, a toothed buckle mounting cavity, and a sliding cavity. The inner diameters of the limiting ring mounting cavity, the toothed buckle mounting cavity, and the sliding cavity decrease sequentially from top to bottom.

[0013] Preferably, the limiting ring mounting cavity has an internal thread and can be threadedly connected to the limiting ring; the inner diameter of the toothed buckle mounting cavity is larger than the outer diameter of the toothed buckle; the inner diameter of the sliding cavity is larger than the outer diameter of the upper central tube and the outer circle has an external thread and can be threadedly connected to the upper outer cylinder.

[0014] Preferably, the toothed buckle is a broken ring with an oblique through groove, the inclination angle of which is set between 30 and 50 degrees; both ends of the body of the toothed buckle are chamfered and the inner diameter is provided with toothed threads.

[0015] Preferably, the two ends of the upper central tube are respectively provided with internal threads and external threads, and the internal thread at the upper end is a tubing thread that can be connected to the salvage string; the external thread at the lower end of the upper central tube can be threadedly connected to the central tube joint, and one or more sealing elements are installed on the outside of the tube body below the external thread, which cooperate with the sealing cavity in the central tube joint 6 through the sealing element.

[0016] Preferably, the inner and outer circles of the central tube connector are non-equal diameter structures. The two ends of the inner circle of the central tube connector are an upper central tube connecting cavity and a lower central tube connecting cavity with internal threads, respectively, and the middle inner circle is a sealing cavity that mates with the sealing element in the upper central tube. The pressure transmission hole is located in the body between the sealing cavity and the lower central tube connecting cavity. A sealing step is provided on the outer circle corresponding to the upper central tube connecting cavity, and one or more sealing elements are provided in the sealing step.

[0017] Preferably, the outer cylinder connector has an outer cylinder threaded connection section on its outer circumference and a central tube connector mounting cavity on its upper inner circumference that is larger than the inner diameter of its lower inner circumference; the outer cylinder threaded connection section can be threadedly connected to the upper and lower outer cylinders, and a central tube connector can be installed in the central tube connector mounting cavity; both the upper outer circumference and the lower inner circumference of the outer cylinder connector are equipped with sealing elements; the outer cylinder connector after the central tube connector is installed is located exactly below the sealing step on the outer circumference of the upper central tube connection cavity.

[0018] Preferably, the upper inner circle of the lower outer cylinder is provided with an internal thread and can be threadedly connected to the outer cylinder connector; the lower inner circle of the lower outer cylinder is provided with an anti-detachment step, which is composed of a small inner diameter section larger than the outer diameter of the fishing hook and a tapered guide section connected to both ends of the small inner diameter section; the small diameter end of the tapered guide section is arranged facing the two ends of the small inner diameter section.

[0019] Preferably, the lower central tube is further provided with a jet cavity and a squeezing cone communicating with the flushing channel. The jet cavity is an inverted conical inner cavity. The maximum inner diameter of the jet cavity is equal to the upper inner diameter of the lower central tube and the minimum inner diameter is equal to the aperture of the flushing channel. The outer circle of the lower central tube is a non-uniform diameter outer circle, and the outer circles of the tubes at both ends are larger than the outer circle of the tube in the middle where the fishing hook is set. The upper outer circle of the lower central tube is provided with an external thread that can be threadedly connected to the central tube connector. The squeezing cone is set at the lower end of the middle tube body.

[0020] Preferably, the retrieval hook is a barb that is set on the outer circle of the middle part of the lower central tube with the hook body facing upward, and at least one set of retrieval hooks is set and evenly distributed on the outside of the middle tube above the extrusion cone; the extrusion cone has a spindle-shaped external structure.

[0021] Compared with the prior art, the present invention has the following advantages: (1) The retrieval tool provided by the present invention adopts the anti-detachment technology of winding the retrieval hook inside the cylinder and pressing it with hydraulic pressure. Compared with the conventional retrieval tools with inner and outer hooks, the anti-detachment step set at the lower end of the lower outer cylinder of the present invention can effectively prevent rope and cable objects from falling off, while not cutting the cable or wire, which greatly improves the retrieval efficiency of rope and cable objects or fish. At the same time, the structure of the tool is simple, the working principle is safe and reliable, and it will not increase the risk of new downhole accidents; (2) The retrieval tool provided by the present invention has an anti-detachment mechanism composed of a connecting cylinder, a toothed buckle and a limiting ring, which has the functions of anti-reverse and anti-backward. Its anti-detachment mechanism can effectively press and lock the rope or cable fish, solve the problem of hooking off and losing fish during the retrieval and lifting process, effectively improve the retrieval success rate of such objects, avoid repeated retrieval and repeated operations, and significantly improve the economic benefits of retrieval operations.

[0022] Compared with conventional rope-based fishing tools, the fishing tool provided by this utility model is safer and more reliable in operation. It effectively solves the problem of fish detachment in rope and cable fishing operations, greatly reduces the time spent in the well, has significant effects, and can generate good economic and social benefits. It has huge potential for promotion. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0024] Figure 1 This is a schematic diagram of the structure of this utility model.

[0025] Figure 2 yes Figure 1 A schematic diagram of the structure of the toothed buckle.

[0026] Figure 3 yes Figure 1 A schematic diagram of the middle connecting cylinder.

[0027] Figure 4 yes Figure 1 A schematic diagram of the central tube connector.

[0028] Figure 5 yes Figure 1 Schematic diagram of the inner and outer cylinder joint.

[0029] Figure 6 yes Figure 1 Schematic diagram of the lower outer cylinder.

[0030] Figure 7 yes Figure 1 A schematic diagram of the structure of the lower central tube.

[0031] In the diagram: 1. Upper central tube; 2. Limiting ring; 3. Toothed buckle; 4. Connecting cylinder; 4-1. Limiting ring mounting cavity; 4-2. Toothed buckle mounting cavity; 4-3. Sliding cavity; 5. Upper outer cylinder; 6. Central tube connector; 6-1. Pressure transmission hole; 6-2. Sealing cavity; 6-3. Upper central tube connecting cavity; 6-4. Lower central tube connecting cavity; 7. Outer cylinder connector; 7-1. Threaded connecting section of outer cylinder; 7-2. Central tube connector mounting cavity; 8. Lower outer cylinder; 8-1. Anti-detachment step; 9. Lower central tube; 9-1. Jet cavity; 9-2. Retrieval hook; 9-3. Extrusion cone. Detailed Implementation

[0032] The accompanying drawings are for reference and illustration only and are not intended to limit the scope of protection of this utility model. The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0033] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0034] In the description of this utility model, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, in the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0035] See Figures 1-7 A novel downhole rope and cable retrieval tool includes a lower central tube 9 with a flushing channel and a retrieval hook 9-2. The upper central tube 1 and lower central tube 9 are connected by a central tube connector 6 installed in an outer tube connector 7. The upper outer tube 5 and lower outer tube 8 are both connected to the outside of the outer tube connector 7. The upper end of the upper outer tube 5 is connected to a connecting tube 4 equipped with a limiting ring 2 and a toothed buckle 3. The limiting ring 2 is connected to the connecting tube 4, and the toothed buckle 3 is connected to the upper central tube 1 via a toothed thread. The lower part of the lower outer tube 8 is connected to the outside of the lower central tube 9. The central tube connector 6 has a pressure transmission hole 6-1 in its body. High-pressure fluid entering through the pressure transmission hole 6-1 can push the outer tube connector 7 and drive the connecting tube 4 equipped with the toothed buckle 3, the upper outer tube 5, and the lower outer tube 8 downwards along the toothed thread outside the upper central tube 1.

[0036] This invention incorporates a pressure-transmitting hole 6-1 within the body of the central tube connector 6, enabling it to function as a hydraulic cylinder. This strengthens the squeezing and retrieval force of the lower outer cylinder 8, compressing and gathering ropes and cables into the annular space between the lower central tube 9 and the lower outer cylinder 8, where they are hooked by the retrieval hook 9-2. Simultaneously, the toothed buckle 3 installed in the connecting cylinder 4 is threadedly connected to the upper central tube 1. The toothed buckle 3 provides a locking function for the connecting cylinder 4, upper outer cylinder 5, and lower outer cylinder 8, preventing them from moving upwards or backwards, and firmly locking the object between the lower central tube 9 and the lower outer cylinder 8. This invention provides a locking function and prevents objects from falling back into the well after retrieval, enabling successful retrieval of hard, tough, and heavy round lead cables without them detaching, effectively solving the problem of difficult retrieval of round lead cables.

[0037] This invention significantly improves the success rate of retrieving rope and cable objects, effectively shortens the time of retrieval operations, reduces the labor intensity of workers, avoids repeated retrieval procedures, significantly reduces construction costs, and improves economic benefits. It has significant practical effects and promotional application value.

[0038] Based on the above embodiment one, the present invention also has the following embodiments:

[0039] In a preferred embodiment, the inner cavity of the connecting cylinder 4 is a non-uniform diameter inner cavity and the outer circle is a non-uniform diameter outer circle. The inner cavities of the connecting cylinder 4, from top to bottom, are a limiting ring mounting cavity 4-1, a toothed buckle mounting cavity 4-2, and a sliding cavity 4-3. The inner diameters of the limiting ring mounting cavity 4-1, the toothed buckle mounting cavity 4-2, and the sliding cavity 4-3 decrease sequentially from top to bottom.

[0040] In a preferred embodiment: the limiting ring mounting cavity 4-1 is provided with an internal thread and can be threadedly connected to the limiting ring 2, thereby preventing the toothed buckle 3 from disengaging from the connecting cylinder 4; the inner diameter of the toothed buckle mounting cavity 4-2 is larger than the outer diameter of the toothed buckle 3 to accommodate the up-and-down movement, contraction, and expansion of the toothed buckle 3; the inner diameter of the sliding cavity 4-3 is larger than the outer diameter of the upper central tube 1, allowing the connecting cylinder 4 to slide smoothly outside the toothed thread of the upper central tube 1; the outer circle of the sliding cavity 4-3 is provided with an external thread and can be threadedly connected to the upper outer cylinder 5.

[0041] In a preferred embodiment: the toothed buckle 3 is a broken ring with an oblique through groove, the inclination angle of which is set between 30 and 50 degrees; both ends of the toothed buckle 3 body are chamfered and the inner diameter is threaded with a toothed thread. The chamfered ends of the toothed buckle 3 body facilitate its installation in the connecting cylinder 4.

[0042] In a preferred embodiment: the two ends of the upper central tube 1 are respectively provided with internal threads and external threads, and the internal thread at the upper end is a tubing thread that can be connected to the salvage string; the external thread at the lower end of the upper central tube 1 can be threadedly connected to the central tube joint 6, and one or more sealing elements are installed on the outside of the tube body below the external thread, which cooperate with the sealing cavity 6-2 in the central tube joint 6 through the sealing element.

[0043] In a preferred embodiment: the inner and outer circles of the central tube connector 6 are both non-equal diameter structures. The two ends of the inner circle of the central tube connector 6 are an upper central tube connecting cavity 6-3 and a lower central tube connecting cavity 6-4, each with internal threads. The middle inner circle is a sealing cavity 6-2 that mates with the sealing element in the upper central tube 1. The pressure transmission hole 6-1 is located in the body between the sealing cavity 6-2 and the lower central tube connecting cavity 6-4. A sealing step is provided on the outer circle corresponding to the upper central tube connecting cavity 6-3, and one or more sealing elements are provided in this sealing step. The sealing elements in this sealing step mate with the inner circle of the upper outer cylinder 5, ensuring a seal between them and preventing leakage of the high-pressure liquid in the pressure transmission hole 6-1.

[0044] In a preferred embodiment: the outer cylinder connector 7 has an outer cylinder threaded connection section 7-1 on its outer circumference and a central tube connector mounting cavity 7-2 on its upper inner circumference that is larger than the inner diameter of its lower inner circumference; the outer cylinder threaded connection section 7-1 can be threadedly connected to the upper outer cylinder 5 and the lower outer cylinder 8, and a central tube connector 6 can be installed in the central tube connector mounting cavity 7-2; both the upper outer circumference and the lower inner circumference of the outer cylinder connector 7 are equipped with sealing elements; the outer cylinder connector 7 after the central tube connector 6 is installed is located exactly below the sealing step on the outer circumference of the upper central tube connection cavity 6-3.

[0045] In a preferred embodiment: the upper inner circle of the lower outer cylinder 8 is provided with an internal thread and can be threadedly connected to the outer cylinder connector 7; the lower inner circle of the lower outer cylinder 8 is provided with an anti-detachment step 8-1, which is composed of a small inner diameter section larger than the outer diameter of the retrieval hook 9-2 and a tapered guide section connected to both ends of the small inner diameter section; the small diameter end of the tapered guide section is arranged facing the two ends of the small inner diameter section. Thus, when the high-pressure liquid entering through the pressure transmission hole 6-1 causes the outer cylinder connector 7 to detach from the central pipe connector 6, and drives the toothed buckle 3, connecting cylinder 4, upper outer cylinder 5 and lower outer cylinder 8 to descend together, squeezing and retrieving ropes and cables at the bottom of the well, the debris can be first introduced into the anti-detachment step 8-1 along the tapered guide section at the lower end of the anti-detachment step 8-1, and then introduced between the lower outer cylinder 8 and the lower central pipe 9 by the upper tapered guide section and firmly fixed by the retrieval hook 9-2, preventing it from falling off again, thus successfully retrieving the heavy cable to the ground.

[0046] In a preferred embodiment: the lower central pipe 9 is further provided with a jet cavity 9-1 and a squeeze cone 9-3 communicating with the flushing channel. The jet cavity 9-1 is an inverted conical inner cavity. The maximum inner diameter of the jet cavity 9-1 is equal to the upper inner diameter of the lower central pipe 9, and the minimum inner diameter is equal to the aperture of the flushing channel. The outer diameter of the lower central pipe 9 is a non-uniform diameter outer diameter, and the outer diameters of the two ends of the pipe are larger than the outer diameter of the pipe with the retrieval hook 9-2 in the middle. The upper outer diameter of the lower central pipe 9 is provided with an external thread that can be threadedly connected to the central pipe connector 6. The squeeze cone 9-3 is located at the lower end of the middle pipe body. During the retrieval process, the bottom of the well can be flushed simultaneously, small objects can be flushed up, and cables, ropes, and other small objects such as ferrules and caps or scattered ferrule tubes can be retrieved together.

[0047] In a preferred embodiment, the retrieval hook 9-2 is a barb positioned on the outer circumference of the lower central tube 9 with the hook body facing upwards. At least one set of retrieval hooks 9-2 is provided and evenly distributed on the outer side of the central tube above the extrusion cone 9-3. The extrusion cone 9-3 has a spindle-shaped structure. The outer circumferences at both ends of the extrusion cone 9-3 are smaller than the outer circumference at the center, making it easier to enter or penetrate the object at the bottom of the well and guide it upwards into the lower outer cylinder 8, where it is retrieved by the retrieval hook 9-2. The retrieval hooks 9-2 in this invention are provided in several sets, allowing for better retrieval of fallen objects.

[0048] During the salvage operation, this utility model is connected to the lower end of the salvage string and lowered into the well. The salvage operation can then be carried out according to the normal salvage procedures and methods.

[0049] The embodiments described above are merely typical examples, but the present invention is not limited to these embodiments. Those skilled in the art can make modifications without departing from the spirit and teachings of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the inventive spirit and concept of the present invention should be included within the protection scope of the present invention. Therefore, the protection scope is not limited to the above description.

Claims

1. A novel tool for retrieving downhole ropes and cables, comprising a lower core tube equipped with a flushing channel and a retrieval hook, characterized in that: The upper and lower center tubes are connected by a center tube connector installed in the outer cylinder connector; both the upper and lower outer cylinders are connected to the outside of the outer cylinder connector; the upper end of the upper outer cylinder is connected to the connecting cylinder equipped with a limit ring and a toothed snap ring, the limit ring is connected to the connecting cylinder, and the toothed snap ring is connected to the upper center tube by a toothed thread; the lower part of the lower outer cylinder is connected to the outside of the lower center tube; the body of the center tube connector is provided with a pressure transmission hole, and the high-pressure liquid flow entering through the pressure transmission hole can push the outer cylinder connector and drive the connecting cylinder equipped with the toothed snap ring, the upper outer cylinder, and the lower outer cylinder to move downward along the toothed thread outside the upper center tube.

2. The novel downhole rope and cable retrieval tool as described in claim 1, characterized in that, The inner cavity of the connecting cylinder is a non-uniform diameter inner cavity and the outer circle is a non-uniform diameter outer circle. The inner cavity of the connecting cylinder, from top to bottom, consists of a limiting ring mounting cavity, a toothed buckle mounting cavity, and a sliding cavity. The inner diameters of the limiting ring mounting cavity, the toothed buckle mounting cavity, and the sliding cavity decrease sequentially from top to bottom.

3. The novel downhole rope and cable retrieval tool as described in claim 2, characterized in that, The limiting ring mounting cavity has an internal thread and can be threadedly connected to the limiting ring; the inner diameter of the toothed buckle mounting cavity is larger than the outer diameter of the toothed buckle; the inner diameter of the sliding cavity is larger than the outer diameter of the upper central tube and the outer circle has an external thread and can be threadedly connected to the upper outer cylinder.

4. A novel retrieval tool for downhole ropes and cables as described in claim 1 or 3, characterized in that, The toothed buckle is a broken ring with an oblique through groove, the inclination angle of which is set between 30 and 50 degrees; both ends of the body of the toothed buckle are chamfered and the inner diameter is provided with toothed threads.

5. A novel downhole rope and cable retrieval tool as described in claim 4, characterized in that, The upper central tube has internal and external threads at both ends, and the internal thread at the upper end is a tubing thread that can be connected to the salvage string; the external thread at the lower end of the upper central tube can be threaded to the central tube connector, and there is one or more sealing elements installed on the outside of the tube body below the external thread, which cooperates with the sealing cavity in the central tube connector (6).

6. A novel downhole rope and cable retrieval tool as described in claim 5, characterized in that, The inner and outer circles of the central tube joint are both non-equal diameter structures. The two ends of the inner circle of the central tube joint are the upper central tube connecting cavity and the lower central tube connecting cavity, which are respectively provided with internal threads. The middle inner circle of the central tube joint is a sealing cavity that mates with the sealing element in the upper central tube. The pressure transmission hole is set in the body between the sealing cavity and the lower central tube connecting cavity. A sealing step is provided on the outer circle corresponding to the upper central tube connecting cavity, and one or more sealing elements are provided in the sealing step.

7. A novel retrieval tool for downhole ropes and cables as described in claim 6, characterized in that, The outer cylinder connector has an outer cylinder threaded connection section on its outer circumference and a central tube connector mounting cavity on its upper inner circumference that is larger than the inner diameter of its lower inner circumference. The outer cylinder threaded connection section can be threadedly connected to the upper and lower outer cylinders, and a central tube connector can be installed in the central tube connector mounting cavity. Sealing elements are installed in both the upper outer circumference and the lower inner circumference of the outer cylinder connector. After the central tube connector is installed, the outer cylinder connector is located exactly below the sealing step on the outer circumference of the upper central tube connection cavity.

8. A novel downhole rope and cable retrieval tool as described in claim 4, characterized in that, The upper inner circle of the lower outer cylinder is provided with an internal thread and can be threadedly connected to the outer cylinder connector; the lower inner circle of the lower outer cylinder is provided with an anti-detachment step, which is composed of a small inner diameter section larger than the outer diameter of the fishing hook and a tapered guide section connected to both ends of the small inner diameter section; the small diameter end of the tapered guide section is arranged facing the two ends of the small inner diameter section.

9. A novel retrieval tool for downhole ropes and cables as described in claim 8, characterized in that, The lower central tube is also provided with a jet cavity and a squeezing cone that communicate with the flushing channel. The jet cavity is an inverted conical inner cavity. The maximum inner diameter of the jet cavity is equal to the upper inner diameter of the lower central tube and the minimum inner diameter is equal to the aperture of the flushing channel. The outer circle of the lower central tube is a non-uniform diameter outer circle, and the outer circles of the tubes at both ends are larger than the outer circle of the tube in the middle where the fishing hook is set. The upper outer circle of the lower central tube is provided with an external thread that can be threaded to the central tube connector. The squeezing cone is set at the lower end of the middle tube.

10. A novel downhole rope and cable retrieval tool as described in claim 9, characterized in that, The retrieval hook is a barb that is set on the outer circle of the middle part of the lower central tube with the hook body facing upward. At least one set of retrieval hooks is set and evenly distributed on the outside of the middle tube above the extrusion cone. The extrusion cone has a spindle-shaped structure.

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