A variable gauge sucker rod fishing socket and working method

Abstract

The present application relates to oil well unjamming fishing tool technical field, especially to a variable rail type sucker rod fishing socket and working method. The variable rail type sucker rod fishing socket comprises an upper joint and a fishing socket, the upper end of the upper joint is provided with an internal thread, the lower end of the upper joint is provided with an external thread, the upper joint is threadedly connected with the fishing socket, the fishing socket is internally provided with a slope variable rail joint and a fishing assembly, the slope variable rail joint is arranged on the inner wall of the fishing socket and is used for guiding the lateral translation of the sucker rod entering the fishing socket, the fishing assembly is arranged at the lower end of the slope variable rail joint, the fishing assembly is detachably installed on the inner wall of the fishing socket through bolts, and the fishing assembly is convenient for adjusting according to actual conditions, and the lower end of the fishing socket is provided with a semicircular fish collecting baffle which is integrally formed and is used for guiding the sucker rod to enter the fishing assembly. The variable rail type sucker rod fishing socket effectively improves the fishing success rate and reduces the construction cost by utilizing the elasticity of the sucker rod, cooperating with the variable rail structure composed of the slope variable rail joint and the fishing assembly, and adjusting the in-out running track of the sucker rod.

Description

Technical Field

[0001] This invention relates to the field of oil well unblocking and retrieval tools, and in particular to a variable-track sucker rod retrieval cylinder and its working method. Background Technology

[0002] Currently, the success rate of retrieving sucker rods during well workover operations in oilfields is low. This problem seriously affects the efficiency and safety of workover operations. Among the existing retrieval tools, each tool has varying degrees of defects, as detailed below: Loose-leaf retrieval tube: The main drawback of this tool is that its spring elasticity is weak, which makes the hinge easy to deform or even break. The load-bearing capacity of the loose-leaf retrieval tube is limited, making it difficult to cope with complex downhole environments. Due to these defects, the reusability of the loose-leaf retrieval tube is low, which increases the cost of well workover operations. Three-ball retrieval tube: Although the three-ball retrieval tube can effectively retrieve sucker rods in some situations, it also has obvious shortcomings. Once the sucker rod is broken after being retrieved, the upward rebound force will cause the three balls to move upward, which can easily lead to the loss of the object. Especially in waxy wells, the three balls often cannot return to their original position after moving upward, which greatly reduces the success rate of retrieval. Slips and scoops: Slips and scoops often break during use, resulting in a low reuse rate. Due to the high manufacturing cost of slips and scoops, this defect further increases the overall cost of well workover operations. Summary of the Invention

[0003] (a) Technical problems to be solved This invention provides a variable-track sucker rod retrieval cylinder and its working method to overcome the problems of low success rate and high construction cost in existing technologies for sucker rod retrieval.

[0004] (II) Technical Solution To achieve the above objectives, the present invention provides a variable-track sucker rod retrieval tube, comprising: an upper connector and a retrieval tube; The upper connector is provided with a retrieval cylinder at its lower end, and the upper end of the upper connector is provided with an internal thread and the lower end with an external thread. The retrieval cylinder is a hollow cylindrical structure, and a ramp-type rail changer is provided inside the retrieval cylinder. The ramp-type rail changer is located on the inner wall of the retrieval cylinder. The salvage cylinder is equipped with a salvage assembly, which is located at the lower end of the inclined rail change joint. The lower outer wall of the retrieval tube is provided with two opposing through holes, which are perpendicular to the retrieval assembly. Bolts are embedded in the two through holes, and the bolts are connected to the salvage assembly. The lower end of the retrieval tube is equipped with a semi-circular fish-collecting baffle.

[0005] Preferably, the upper connector consists of two parts: the upper end of the upper connector is a hollow cylindrical structure, and the lower end of the upper connector is a hollow cylindrical structure. The outer diameter of the hollow cylindrical structure at the upper end of the upper connector is larger than the outer diameter of the hollow cylindrical structure at the lower end.

[0006] Preferably, the connection between the upper hollow cylindrical structure and the lower hollow cylindrical structure is provided with an outer step, which limits the positioning of the retrieval cylinder.

[0007] Preferably, the upper end of the retrieval cylinder is provided with an internal thread, and the retrieval cylinder is threadedly connected to the upper connector.

[0008] Preferably, the left end face of the ramp changeover joint is integral with the retrieval cylinder, and the ramp changeover joint is a right-angled trapezoidal prism structure, with the inclined side of the ramp changeover joint facing the lower end of the retrieval cylinder.

[0009] Preferably, the right end face of the inclined track changer is provided with an arc-shaped groove, the center of which is collinear with the axis of the retrieval cylinder.

[0010] Preferably, the inclined side of the ramp-type rail changer is used to guide the sucker rod into the retrieval cylinder into the arc-shaped groove, and the arc-shaped groove limits the position of the sucker rod.

[0011] Preferably, the salvage assembly consists of two parts: a trapezoidal prism groove on one side and a semi-circular groove on the other side. The trapezoidal prism groove and the semi-circular groove are arranged opposite to each other and are integrated. The trapezoidal prism groove is a trapezoidal prism structure, and a semi-circular groove is provided on the right end face of the trapezoidal prism structure.

[0012] Preferably, the upper surface of the semi-annular groove is provided with an inwardly extending step, and the inner edge of the step is rounded.

[0013] Preferably, the salvage assembly has threaded holes on both sides that communicate with the through holes on the lower outer wall of the salvage cylinder. The threaded holes are used to engage with bolts, and the salvage assembly can be installed on the inner wall of the salvage cylinder by means of bolts.

[0014] On the other hand, the present invention also provides a method for operating a variable-track sucker rod retrieval cylinder, including: Step S1: Select the appropriate retrieval assembly according to the required specifications of the sucker rod to be retrieved, and install it inside the retrieval tube with bolts. Connect the upper connector to the retrieval tube with threads to ensure a firm connection. Connect the entire variable-rail sucker rod retrieval tube to the wellbore string through the internal thread of the upper connector. Step S2: Use the insertion string to send the variable-track sucker rod retrieval tube into the well until it reaches the target position, that is, the position where the fallen sucker rod is located. Step S3: When the variable-track sucker rod retrieval tube reaches the target position, the fallen sucker rod will be guided by the fish retrieval baffle and positioned at the lower end of the retrieval assembly. At this time, the variable-track sucker rod retrieval tube will be lowered again, and the sucker rod will enter the interior of the retrieval tube under the guidance of the retrieval assembly. Step S4: The sucker rod enters the inclined area of ​​the ramp changer joint and, guided by the ramp, gradually slides towards the right end face of the ramp changer joint. During the sliding process, the sucker rod will enter the arc-shaped groove on the right end face of the ramp changer joint. Step S5: After confirming that the lower end shoulder of the sucker rod passes through the center of the salvage assembly and enters the salvage cylinder, the sucker rod shoulder will also move to the right along with the sucker rod due to the guidance of the upper end of the sucker rod by the inclined rail changer joint. Step S6: Since the sucker rod shoulder has shifted to the right, the sucker rod moves downwards relative to the top when the variable-rail sucker rod is lifted for retrieval. When the sucker rod shoulder moves to the top of the retrieval assembly, it is blocked by the step extending inward from the top of the retrieval assembly. Continue lifting the variable-rail sucker rod to complete the retrieval of the sucker rod.

[0015] (III) Beneficial Effects This invention provides a variable-track sucker rod retrieval cylinder and its working method, which can effectively capture falling objects by utilizing the elasticity of the sucker rod itself and combining it with a unique internal structure. By setting up a ramp variable-track joint and retrieval assembly inside the retrieval cylinder to form a variable-track route, the entry and exit trajectory of the falling object is changed through a one-time variable-track design. This design can capture falling objects more effectively, thereby significantly improving the retrieval success rate. The salvage assembly is detachably mounted on the inner wall of the salvage cylinder by bolts. This design allows operators to flexibly adjust the salvage assembly according to the actual situation, thereby improving the salvage success rate and reducing construction costs. Attached Figure Description

[0016] Figure 1 This diagram shows a front sectional view of the variable-track sucker rod retrieval cylinder of the present invention. Figure 2 This diagram shows a side sectional view of the structure of a variable-track sucker rod retrieval cylinder according to the present invention. Figure 3 The diagram illustrates the working process of a variable-track sucker rod retrieval cylinder according to the present invention.

[0017] The components are: 1: upper connector; 2: retrieval cylinder; 3: inclined rail changer connector; 4: retrieval assembly; 5: bolt; 6: fish catching baffle. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described. 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 are within the scope of protection of the present invention.

[0019] In the description of this invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "inner," "outer," "top," and "bottom" are based on the orientations or positional relationships shown in the accompanying drawings. They are intended only to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the components referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] like Figure 1-2 As shown, the present invention provides a variable-track sucker rod retrieval tube, comprising: an upper connector 1 and a retrieval tube 2; The upper connector 1 consists of two parts, each with specific functions and structural features. The upper end of the upper connector 1 is designed as a hollow cylindrical structure with an outer diameter larger than that of the lower end. The upper end has an internal thread, which is used to connect the entire variable-track sucker rod retrieval tube to the well tubing, thereby facilitating the insertion of the variable-track sucker rod retrieval tube into the well at the designated working position. The lower end of the upper connector 1 is also a hollow cylindrical structure, but its outer diameter is smaller than that of the upper part. The lower part is provided with external threads, which are used to make threaded connections with the salvage cylinder 2. A stepped outer edge is provided between the upper and lower ends of the upper connector 1. This step limits the positioning of the retrieval tube 2. When installing the retrieval tube 2, the step can be used to ensure that the installation position of the retrieval tube 2 is accurate.

[0021] The lower end of the upper connector 1 is provided with a retrieval cylinder 2, which is a hollow cylindrical structure. Its main function is to accommodate and catch the fallen sucker rod. The upper end of the retrieval cylinder 2 is provided with internal threads, which match the external threads at the lower end of the upper connector 1, thereby achieving a firm connection between the two.

[0022] The upper section of the salvage cylinder 2 is equipped with a ramp rail changer 3. The ramp rail changer 3 is located on the inner wall of the salvage cylinder 2. The left end face of the ramp rail changer 3 is integrated with the salvage cylinder 2 to ensure the stability and durability of its structure. The inclined rail changer 3 is a right-angled trapezoidal prism structure. The inclined side of the inclined rail changer 3 is set towards the lower end of the retrieval cylinder 2. The purpose of this inclined side design is to guide the sucker rod entering the retrieval cylinder 2 to slide smoothly into the right end face of the inclined rail changer 3, so as to realize the parallel rail change of the sucker rod. The right end face of the ramp changeover joint 3 is provided with an arc-shaped groove. The center of the arc-shaped groove is collinear with the axis of the retrieval cylinder 2. This can prevent the sucker rod from shaking as it moves along the ramp changeover joint 3, thereby ensuring that the sucker rod can be accurately positioned and fixed after entering the groove. When the variable-track sucker rod retrieval tube is sent into the well and reaches the target position, the fallen sucker rod will enter the interior of the retrieval tube 2. Due to the presence of the inclined variable-track joint 3, the sucker rod will be guided by the inclined side and gradually slide towards the right end face of the inclined variable-track joint 3. Finally, the sucker rod will enter the arc-shaped groove.

[0023] The salvage cylinder 2 is equipped with a salvage assembly 4, which is located at the lower end of the inclined rail change joint 3. The salvage assembly 4 is mainly used to guide and fix the sucker rod to ensure the smooth progress of the salvage operation. The salvage assembly 4 consists of two parts. One side of the salvage assembly 4 is a trapezoidal prism groove, and the other side is a semi-circular groove. The trapezoidal prism groove and the semi-circular groove are arranged opposite to each other and are integrated to form a complete salvage assembly 4. The trapezoidal groove is a trapezoidal prism structure. The right end face of the trapezoidal prism structure is provided with a semi-circular groove. The semi-circular groove ensures that the sucker rod can be accurately positioned and fixed after entering the salvage assembly 4. The upper surface of the semi-circular groove is provided with an inwardly extending step, and the inner edge of the step is rounded to prevent the sucker rod from getting stuck when it enters.

[0024] The lower end of the retrieval tube 2 is provided with a semi-circular fish-collecting baffle 6, which is integrated with the lower end of the retrieval tube 2. The fish-collecting baffle 6 is used to guide the sucker rod into the center of the retrieval assembly 4.

[0025] When the variable-track sucker rod retrieval tube is sent into the well by the well string and reaches the target position, the retrieval assembly 4 is used to guide the upper end of the sucker rod into the retrieval tube 2. After the sucker rod enters the retrieval tube 2, it is moved to the side by the action of the inclined variable-track joint 3. After the translation and track change is completed, the variable-track sucker rod retrieval tube is lifted. At this time, under the action of track change, the shoulder of the lower end of the sucker rod can be locked on the step extending inward from the upper end of the semi-annular groove in the retrieval assembly 4, thereby achieving effective fixation of the sucker rod and retrieving the sucker rod from the well. To ensure the stable installation of the salvage assembly 4 inside the salvage cylinder 2, two opposing through holes are provided on the lower outer wall of the salvage cylinder 2. These two through holes are perpendicular to the salvage assembly 4, and bolts 5 are embedded in each of the two through holes. The side wall of the groove is provided with a threaded hole that communicates with the through hole on the lower outer wall of the salvage cylinder 2. This threaded hole is used to mate with the bolts 5. By tightening the bolts 5, the salvage assembly 4 can be installed on the inner wall of the salvage cylinder 2. This not only makes the salvage assembly 4 firmly fixed inside the salvage cylinder 2, but also greatly simplifies the installation and disassembly process of the salvage assembly 4. The salvage assembly 4 can be easily put into and taken out by removing and installing the bolts 5, which makes the maintenance of the salvage assembly 4 easier and more convenient. It should be noted that the operator can remove and install the salvage assembly 4 by removing and installing bolt 5. That is, the operator can select the corresponding salvage assembly 4 according to the specifications of the sucker rod to be salvaged. Since the salvage assembly 4 is replaceable, the operator does not need to replace the entire variable rail sucker rod salvage cylinder, but only needs to replace the suitable salvage assembly 4. This not only improves the flexibility of the equipment, but also greatly reduces the operating cost.

[0026] The following is a detailed description of the actual working scenario of a variable-track sucker rod retrieval tube.

[0027] like Figure 3 As shown, the variable-track sucker rod retrieval tube includes the following steps in actual operation: Step S1: Select the appropriate retrieval assembly 4 according to the required specifications of the sucker rod to be retrieved, and install it inside the retrieval tube 2 with bolts 5. Connect the upper connector 1 and the retrieval tube 2 together with threads to ensure a firm connection. Connect the entire variable-rail sucker rod retrieval tube to the wellbore string through the internal thread of the upper connector 1. Step S2: Use the insertion string to send the variable-track sucker rod retrieval tube into the well until it reaches the target position, that is, the position where the fallen sucker rod is located. Step S3: When the variable-track sucker rod retrieval cylinder reaches the target position, the fallen sucker rod will be guided by the fish retrieval baffle 6 and placed at the lower end of the retrieval assembly 4. At this time, the variable-track sucker rod retrieval cylinder is lowered again, and the sucker rod will enter the interior of the retrieval cylinder 2 under the guidance of the retrieval assembly 4. In step S4, the sucker rod enters the inclined area of ​​the ramp changer joint 3 and, guided by the ramp, gradually slides towards the right end face of the ramp changer joint 3. During the sliding process, the sucker rod will enter the arc-shaped groove on the right end face of the ramp changer joint 3. Step S5: After confirming that the lower end shoulder of the sucker rod passes through the center of the salvage assembly 4 and enters the salvage cylinder 2, the sucker rod shoulder will also move to the right along with the sucker rod due to the guidance of the upper end of the sucker rod by the inclined rail changer 3. Step S6: Since the sucker rod shoulder has shifted to the right, the sucker rod moves downwards relative to the upper end of the retrieval assembly 4 when the sucker rod shoulder is lifted for retrieval. When the sucker rod shoulder moves to the upper end of the retrieval assembly 4, it is blocked by the step extending inward from the upper end of the retrieval assembly 4. Continue to lift the sucker rod to complete the retrieval of the sucker rod.

[0028] It is understood that the various embodiments mentioned above in this invention can be combined with each other to form combined embodiments without violating the principle and logic. Due to space limitations, this invention will not elaborate further.

[0029] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0030] The present invention provides a variable-track sucker rod retrieval cylinder and working method. By utilizing the elasticity of the sucker rod itself and combining it with a unique internal structure, it can effectively capture falling objects. By setting a ramp variable-track joint 3 and a retrieval assembly 4 in the retrieval cylinder 2 to form a variable-track route, the trajectory of falling objects is changed by a one-time variable-track design. This design can capture falling objects more effectively, thereby significantly improving the retrieval success rate. The salvage assembly 4 is detachably mounted on the inner wall of the salvage cylinder 2 via bolts 5. This design allows operators to flexibly adjust the salvage assembly 4 according to the actual situation, thereby improving the salvage success rate and reducing construction costs.

[0031] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A variable-track sucker rod retrieval cylinder, characterized in that, include: Upper connector (1) and retrieval tube (2); The upper connector (1) is provided with a retrieval tube (2) at its lower end, and the upper connector (1) is provided with an internal thread at its upper end and an external thread at its lower end; The salvage cylinder (2) is a hollow cylindrical structure, and a ramp change rail connector (3) is provided in the salvage cylinder (2). The ramp change rail connector (3) is located on the inner wall of the salvage cylinder (2). The salvage cylinder (2) is provided with a salvage assembly (4), which is located at the lower end of the inclined rail change joint (3); The lower outer wall of the retrieval tube (2) is provided with two opposite through holes, which are perpendicular to the retrieval assembly (4); Bolts (5) are embedded in the two through holes respectively, and the bolts (5) are connected to the salvage assembly (4); The lower end of the fishing tube (2) is provided with a semi-circular fish-collecting baffle (6).

2. The variable-track sucker rod retrieval cylinder according to claim 1, characterized in that, The upper connector (1) consists of two parts: the upper end of the upper connector (1) is a hollow cylindrical structure, and the lower end of the upper connector (1) is a hollow cylindrical structure. The outer diameter of the upper hollow cylindrical structure is larger than the outer diameter of the lower hollow cylindrical structure.

3. The variable-track sucker rod retrieval cylinder according to claim 2, characterized in that, The upper hollow cylindrical structure and the lower hollow cylindrical structure are connected by an outer step, which limits the positioning of the retrieval cylinder (2).

4. The variable-track sucker rod retrieval cylinder according to claim 1, characterized in that, The upper end of the retrieval cylinder (2) is provided with an internal thread, and the retrieval cylinder (2) is threadedly connected to the upper connector (1).

5. The variable-track sucker rod retrieval cylinder according to claim 1, characterized in that, The left end face of the inclined rail changer (3) is integrated with the retrieval cylinder (2). The inclined rail changer (3) is a right-angled trapezoidal prism structure, and the inclined side of the inclined rail changer (3) faces the lower end of the retrieval cylinder (2).

6. The variable-track sucker rod retrieval cylinder according to claim 5, characterized in that, The right end face of the inclined rail changer (3) is provided with an arc-shaped groove, the center of which is collinear with the axis of the retrieval cylinder (2).

7. The variable-track sucker rod retrieval cylinder according to claim 6, characterized in that, The inclined side of the ramp changeover joint (3) is used to guide the sucker rod into the retrieval cylinder (2) into the arc-shaped groove, which limits the position of the sucker rod.

8. The variable-track sucker rod retrieval cylinder according to claim 1, characterized in that, The salvage assembly (4) consists of two parts. One side of the salvage assembly (4) is a trapezoidal prism slot, and the other side is a semi-circular slot. The trapezoidal prism slot and the semi-circular slot are arranged opposite to each other and are integrated. The trapezoidal prism slot is a trapezoidal prism structure, and the right end face of the trapezoidal prism structure is provided with a semi-circular groove.

9. The variable-track sucker rod retrieval cylinder according to claim 8, characterized in that, The upper surface of the semi-annular slot is provided with an inwardly extending step, and the inner edge of the step is rounded.

10. The variable-track sucker rod retrieval cylinder according to claim 9, characterized in that, The salvage assembly (4) has threaded holes on both sides that are connected to the through holes on the lower outer wall of the salvage cylinder (2). The threaded holes are used to cooperate with bolts (5). The salvage assembly (4) can be installed on the inner wall of the salvage cylinder (2) by means of bolts (5).

11. The working method of the variable-track sucker rod retrieval cylinder according to any one of claims 1-10, characterized in that, include: Step S1: Select the appropriate fishing assembly (4) according to the specifications of the sucker rod to be fished, and install it inside the fishing tube (2) with bolts (5). Connect the upper connector (1) and the fishing tube (2) together with threads to ensure a firm connection. Connect the entire variable rail sucker rod fishing tube to the well string through the internal thread of the upper connector (1). Step S2: Use the insertion string to send the variable-track sucker rod retrieval tube into the well until it reaches the target position, that is, the position where the fallen sucker rod is located. Step S3: When the variable-track sucker rod retrieval tube reaches the target position, the fallen sucker rod will be guided by the fish catching baffle (6) and placed at the lower end of the retrieval assembly (4). At this time, the variable-track sucker rod retrieval tube will be lowered again, and the sucker rod will enter the interior of the retrieval tube (2) under the guidance of the retrieval assembly (4). Step S4, the sucker rod enters the inclined area of ​​the ramp changer joint (3), and guided by the ramp, it gradually slides towards the right end face of the ramp changer joint (3). During the sliding process, the sucker rod will enter the arc-shaped groove on the right end face of the ramp changer joint (3). Step S5: When it is confirmed that the lower end shoulder of the sucker rod passes through the center of the retrieval assembly (4) and enters the retrieval tube (2), the sucker rod shoulder will also move to the right along with the sucker rod due to the guidance of the upper end of the sucker rod by the inclined rail changer joint (3). Step S6: Since the sucker rod shoulder has moved to the right, the sucker rod moves downwards when the variable-track sucker rod is lifted for retrieval. When the sucker rod shoulder moves to the upper end of the retrieval assembly (4), it is blocked by the step extending inward from the upper end of the retrieval assembly (4). Continue to lift the variable-track sucker rod to complete the retrieval of the sucker rod.

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