Self-guiding type fishing spear and fishing tool string

Abstract

The utility model provides a self-leading type fishing spear and a fishing tool string, the self-leading type fishing spear comprises a guide cylinder and a solid spear rod, the guide cylinder is arranged outside the solid spear rod, the upper end of the guide cylinder is provided with a connector body, and a cylinder opening at the lower end of the guide cylinder is arranged to be a forward rotation poking opening; a spear tile sliding groove is formed in the outer circumferential surface of the solid spear rod, the spear tile sliding groove is an arc sliding groove of a structure with the outer portion smaller than the inner portion, a forward rotation sliding block spear tile is arranged in the spear tile sliding groove, and the upper end of the solid spear rod is fixed to the inner wall of the top end of the guide cylinder. The fishing tool string comprises the self-guiding type fishing spear. The fishing spear disclosed by the utility model can easily enter a fish falling water hole to fish a fish.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling engineering, specifically to a self-propelled retrieval spear and a retrieval tool string. Background Technology

[0002] With the continuous development of science and technology, the horizontal sections of shale gas wells have been continuously extended, from the initial 800-1000m, 1000-1500m, 1500-2000m, 2000-2500m, and even longer. This continuous extension of horizontal section length is attributed to the widespread application of rotary steerable tools. Despite the continuous entry of domestically produced and imported rotary steerable tools into the market, the rapidly growing demand still cannot be met. This has led to an increasing number of cases where conventional bent screws or straight screws with bent joints are used for directional drilling, or even where rotary steerable tools are simply stopped. This results in inadequate maintenance of the rotary steerable tools after they enter the market; for example, the number of times a single well needs to replace the rotary steerable tool in a 2000m horizontal section is constantly increasing, mostly due to software failures such as communication system malfunctions. In actual production, hardware failures such as flexible short sections and broken lower drive shafts of rotary steerable tools also occur frequently. In particular, after the lower drive shaft breaks, the fish with a large outer diameter and small interring diameter, short and light weight, and easy rotation with the fishing tools, as well as varying degrees of elevation difference along the fracture surface, are prone to problems. Furthermore, because the rotary steerable continuously adjusts its inclination and azimuth in the horizontal section according to the dip angle of the producing formation, the smoothness of the wellbore is poor. If the cuttings bed is not cleaned in time in the horizontal section, it can easily lead to complex downhole problems or even stuck pipe accidents. To prevent stuck pipe in the horizontal section, reverse reaming is often used to retrieve the drilling tools. Similarly, retrieval of a broken rotary steerable drive shaft requires reverse reaming to retrieve the fish. Currently, conventional external retrieval with a female cone or internal retrieval with a common male cone are used to meet the requirements of reverse reaming operations. When the axial elevation difference of the fracture surface of the rotary steerable drive shaft is large, the residual upper drive shaft body exerts a radial force on the male cone, inevitably causing the male cone to slip outwards and the combined force of drilling pressure to break and fall into the well. If the conventional retrieval spear grabs the fish and then rotates, it will cause the fish to be lost. Therefore, it is necessary to design a self-guided, reversible retrieval spear for a rotary guide drive shaft, overcoming the shortcomings of existing spears and solving the problems of loss of control during rotation and lack of torsional resistance. The aim is to maximize the tensile and torsional strength of the spear shaft and spear bearing assembly within a limited diameter, overcome the technical challenge of large axial height differences and lack of internal retrieval tools after drive shaft failure, and minimize the economic losses caused by drive shaft breakage.

[0003] Chinese patent publication number "CN202596639U" entitled "Scratching-type Reverse-locking Device" discloses a reverse-locking device for clearing collapsed blocks blocking water holes where fish have fallen in, thus enabling reverse-locking retrieval. The scratching-type reverse-locking device includes a spear body and a mandrel. The upper part of the spear body has internal threads, and a first step is fixed to the inner side of the middle part of the spear body. The upper part of the mandrel and the first step are fixedly connected together by threads and at least one radial positioning device. A through hole is axially located in the middle of the mandrel, and a retractable sleeve is fitted onto the mandrel below the first step. Through the combined use of pins and bevels, the collapsed blocks blocking water holes where fish have fallen in can be quickly cleared, achieving the purpose of reverse-locking retrieval. Unlike this patent, this utility model adjusts the structure of the guide tube, reducing the risk of the retrieval spear inserting between the fallen fish and the well wall annulus. The retrieval spear has also been adjusted based on the existing design, strengthening the connection between the spear shaft and the guide tube to avoid accidents during retrieval and enhancing the biting force. Utility Model Content

[0004] The purpose of this invention is to address at least one of the aforementioned shortcomings of the existing technology. For example, one objective of this invention is to provide a self-guiding retrieval spear that can solve the problems of loss of control during rotation and lack of anti-torsion capability. Another objective of this invention is to provide a retrieval tool with high retrieval efficiency.

[0005] To achieve the above objectives, this invention provides a self-guided retrieval spear, which may include a guide tube and a solid spear shaft. The guide tube is located outside the solid spear shaft, and a connector is provided at the upper end of the guide tube. The lower end of the guide tube is configured as a forward-rotating nozzle. A spear pad groove is provided on the outer circumferential surface of the solid spear shaft. The spear pad groove is an arc-shaped groove with a smaller outer diameter and a larger inner diameter. A forward-rotating sliding spear pad is provided in the spear pad groove. The upper end of the solid spear shaft is fixed to the inner wall of the top of the guide tube.

[0006] According to an exemplary embodiment of one aspect of the present invention, the retrieval spear may include an upper spear shaft and a lower spear shaft, wherein the diameter of the upper spear shaft is 38-40 mm and the diameter of the lower spear shaft is 34-36 mm.

[0007] Alternatively, the outer diameter of the guide tube is 190–192 mm, and the inner diameter of the guide tube is 145–148 mm.

[0008] According to an exemplary embodiment of one aspect of the present invention, a connecting joint may be provided between the retrieval spear and the guide tube, and the connecting joint is fixedly connected to the solid spear shaft.

[0009] According to an exemplary embodiment of one aspect of the present invention, a spear tile limiting block may be fixedly provided in the spear tile groove.

[0010] According to an exemplary embodiment of one aspect of the present invention, a connection port is provided on the inner side of the connector body, and a connection structure is provided in the connection port.

[0011] According to an exemplary embodiment of one aspect of the present invention, a marking groove may be provided at the connection between the connector body and the guide tube.

[0012] According to an exemplary embodiment of one aspect of the present invention, a water eye may be provided between the connector body and the guide tube.

[0013] According to an exemplary embodiment of one aspect of the present invention, a guide shoe may be provided at the lower end of the solid spear shaft.

[0014] Another aspect of this utility model provides a salvage tool string, which may include the self-drawing salvage spear described above.

[0015] Compared with the prior art, the beneficial effects of this utility model include at least one of the following:

[0016] (1) The retrieval spear provided by this utility model can be successfully lowered into different well sections to retrieve fish that have fallen into the well section;

[0017] (2) The retrieval spear provided by this utility model can be applied to well conditions where the axial height difference is large after the fish breaks, and the retrieval efficiency is higher.

[0018] (3) The retrieval spear provided by this utility model has a positive rotating mouth at the lower end of the cylinder, which is beneficial for the spear shaft to be lowered into the inclined section and the inclined section. It also plays a role in preventing wear on the spear tiles set inside and preventing the fish from snagging and cutting the well wall and wellhead device after retrieval.

[0019] (4) The diameter of the upper spear shaft of the retrieval spear provided by this utility model is larger than that of the lower spear shaft, thereby increasing the connection strength between the spear shaft and the connecting joint.

[0020] (5) The spear tile groove structure in the salvage tool string provided by this utility model can effectively retain the strength of the cylindrical metal structure to obtain the maximum torsional resistance.

[0021] Instruction manual illustrations

[0022] The above and other objects and / or features of this utility model will become clearer from the following description taken in conjunction with the accompanying drawings, wherein:

[0023] Figure 1 A schematic diagram of the structure of a self-guided retrieval spear according to an exemplary embodiment of the present invention is shown;

[0024] Figure 2 A schematic diagram of the combination structure of the chuck and the spear shaft according to an exemplary embodiment of the present invention is shown.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1-Connector body, 11-Correct snap, 12-Marking groove, 13-Water eye, 14-Connecting connector, 2-Solid spear rod, 21-Upper spear rod, 22-Lower spear rod, 23-Spear pad slide groove, 24-Spear pad limiting block, 241-Fixing component, 25-Sliding spear pad, 26-Guide shoe, 3-Guide cylinder, 31-Correct rotation dial. Detailed Implementation

[0027] In the following description, a self-propelled retrieval spear and retrieval tool of the present invention will be described in detail with reference to the accompanying drawings and exemplary embodiments. It should be noted that terms such as "first" and "second" are merely for ease of description and distinction, and should not be construed as indicating or implying relative importance. Terms such as "upper," "lower," "inner," and "outer" are merely for ease of description and to establish relative orientation or positional relationships, and do not indicate or imply that the component referred to must have that specific orientation or position.

[0028] First exemplary embodiment

[0029] This exemplary embodiment provides a self-retrieval spear.

[0030] Figure 1 A schematic diagram of the structure of the self-guided retrieval spear according to this exemplary embodiment is shown; Figure 2 A schematic diagram of the combined structure of the chuck and spear shaft according to this exemplary embodiment is shown below. Figures 1-2 This describes a self-retrieval spear in an exemplary embodiment. It should be noted that the top-to-bottom direction described in the specification is... Figure 1 The direction from left to right in the middle.

[0031] In this exemplary embodiment, as Figure 1As shown, the self-guided retrieval spear mainly comprises a guide tube 3 and a solid spear shaft 2. The upper end of the solid spear shaft 2 is fixed to the top of the inside of the guide tube 3. A connector body 1 can be provided at the upper end of the guide tube 3 for easy connection with upstream tools. The lower end of the guide tube 3 can be configured as a positive-rotation swivel swivel 31, which facilitates its insertion into the directional section and / or the increased directional section during the retrieval of a fallen fish, and provides anti-wear protection for the spear pad structure located inside the tube. At the same time, it also prevents the fish from snagling and cutting against the well wall and wellhead equipment after retrieval. A spear pad groove 23 can be provided on the outer circumferential surface of the solid spear shaft 2. The spear pad groove 23 may include an arc groove with a trapezoidal structure that is smaller on the outside and larger on the inside, which can more effectively preserve the strength of the cylindrical metal structure to obtain the maximum torsional resistance. A sliding spear pad 25 is provided in the spear pad groove 23, for example, it may include a positive-rotation sliding spear pad. The positive-rotation sliding spear pad rotates with the left side lower and the right side higher, thereby changing the original withdrawal mechanism to an insertion and tightening mechanism, realizing the reverse reaming function. The self-guided type utilizes the outer diameter of the guide tube and the outer diameter of the fish-drop joint, ensuring that the downhole retrieval tool and the fish are concentric. When the retrieval drill string is rotated, the highest point of the spiral guide tube's front section touches the outer edge of the fish, causing it to be propelled into the guide tube. Once inside, the fish is straightened, reducing concentricity errors with the spear shaft. The spear pad groove is located on the outer circumference of the solid spear shaft. Its "smaller outer, larger inner" trapezoidal structure restricts lateral movement of the spear pad within the groove, allowing only vertical movement. Further, as... Figure 2 As shown, the solid spear shaft 2 can also be combined with a chuck to improve the efficiency of retrieval of fallen fish. It should be noted that the fallen fish retrieved by the self-propelled retrieval spear and retrieval tool string of this application are driven by a rotary guide shaft.

[0032] In this exemplary embodiment, as Figure 1 As shown, the solid spear shaft 2 may include an upper spear shaft 21 and a lower spear shaft 22. The diameter of the upper spear shaft may be 38 mm, and the diameter of the lower spear shaft may be 34 mm. Here, having a larger diameter for the upper spear shaft than for the lower spear shaft can enhance the connection strength between the solid spear shaft and the guide tube. The connection strength between the solid spear shaft and the guide tube requires a tensile strength of not less than 300 kN and a torsional yield strength at the point where the spear blade engages with the fish to be not less than 5 kN·m.

[0033] In this exemplary embodiment, when the fish-catching device is a rotary drive shaft, the outer diameter of the guide tube can be equal to the outer diameter of the drive connector to reduce coaxiality errors and decrease the risk of the retrieval spear inserting between the fish-catching device and the wellbore annulus. Furthermore, the inner diameter of the guide tube can be 3-5 mm larger than the outer diameter of the drive shaft sleeve. When the drive shaft sleeve enters the guide tube, the bottom flow channel area decreases significantly, resulting in an increase in circulation pump pressure, which is more conducive to determining whether the retrieval was successful. Furthermore, the overall outer diameter of the guide tube can be uniform, ensuring a smooth, stepless connection between the fish-catching device and the guide tube during retrieval, avoiding problems such as the fish's top scraping the wellbore, rubbing against the casing shoe, or steps within the wellhead device.

[0034] In this exemplary embodiment, as Figure 1 As shown, a connecting joint 14, such as a solid female joint, can be provided between the solid spear 2 and the guide tube 3. The connecting joint 14 can be fixedly connected to the solid spear 2, for example, by a threaded connection. The thread can include a right-hand thread. Using a solid female joint eliminates the flow channel at the center of the bottom end of the female joint, and replaces the original one central flow channel with three flow channels on the side, thus ensuring the circulation of the working fluid and the connection strength between the female joint and the lower solid spear 2.

[0035] In this exemplary embodiment, as Figure 1 As shown, a spear pad limiting block 24 can be fixedly installed in the spear pad slide groove 23. For example, a fixing member 241 can be used to fix the spear pad limiting block 24 in the spear pad slide groove 23. Setting the spear pad limiting block 24 can limit the range of motion of the slider spear pad 25, making the retrieval operation more precise. Here, the fixing member 241 may include a fixing bolt. The spear pad limiting block has a fixed setting position, which is set at the point where the outer diameter of the top surface of the spear pad is 2-3 mm larger than the outer diameter of the spear rod when the spear pad slides upward, ensuring that the spear pad is always larger than the spear rod. When the drill string is lifted, the spear pad is subjected to downward force. If the spear pad retracts to the same diameter as the spear rod and the drill string is retrieved upward, the spear pad will lose its function.

[0036] In this exemplary embodiment, as Figure 1 As shown, a connection port may be provided on the inner side of the connector body 1 in the opposite direction to the opening of the guide tube 3, and a connection structure is provided in the connection port. For example, a positive thread 11, which may include a 410 positive thread. A clockwise rotation to complete the thread engagement is a positive thread, and a counterclockwise rotation is a reverse thread. This connection structure is a standard oilfield connection form, and its connection method cannot be changed; otherwise, the tool cannot be connected to the retrieval drill string.

[0037] In this exemplary embodiment, as Figure 1 As shown, a marking groove 12 can be provided at the connection between the connector body 1 and the guide cylinder 3. The function of the marking groove is: 1. to visually determine whether it is a right-hand or left-hand tool; 2. to mark the tool model, manufacturer, production time, self-number, and other information in the groove in the form of a steel stamp.

[0038] In this exemplary embodiment, as Figure 1 As shown, a water eye 13 can be provided inside the space between the connector body 1 and the guide cylinder 3. The water eye 13 can be disposed through the space between the connector body 1 and the guide cylinder 3. The purpose of providing the water eye here is to circulate the working fluid.

[0039] In this exemplary embodiment, as Figure 1 As shown, a guide shoe 26 may be provided at the lower end of the solid spear shaft 2. The guide shoe may include a pen-tip guide shoe. The guide shoe is integrated with the spear shaft and is located at the lowest end of the spear shaft.

[0040] In this exemplary embodiment, as Figure 1 As shown, the circled structure is an integrated structure of the positive spiral dial at the bottom of the guide tube and the tool.

[0041] Second exemplary embodiment

[0042] This exemplary embodiment provides a salvage tool string, which may include the self-guided salvage spear described in the first exemplary embodiment above.

[0043] In summary, the advantages of this utility model may include at least one of the following:

[0044] (1) The outer diameter of the guide tube in the retrieval spear provided by this utility model is the same as that of the fish drop joint, which reduces the coaxiality error and can fundamentally reduce the risk of the retrieval spear being inserted between the fish drop and the well wall ring.

[0045] (2) The inner diameter of the guide tube in the fishing spear provided by this utility model is larger than the outer diameter of the fish-dropping jacket. When the fish-dropping jacket enters the guide tube, the bottom flow channel area is greatly reduced, resulting in an increase in the circulation pump pressure, which is beneficial for judging whether the catching is successful.

[0046] (3) The fishing tool string provided by this utility model is different from the conventional fishing spear. The direction of the spear blade is adjusted to be lower on the left and higher on the right. When the drill string is rotated in the forward direction, the toothed thread of the spear blade is screwed into the lower part of the fallen fish, which drives the spear blade to move downward and increases the biting force.

[0047] (4) The retrieval spear provided by this utility model is equipped with a spear bearing limiting block to limit the range of movement of the spear bearing, making the retrieval operation more precise.

[0048] Although a self-guided retrieval spear and retrieval tool string of the present invention have been described above in conjunction with exemplary embodiments, those skilled in the art should understand that various modifications and changes can be made to the exemplary embodiments of the present invention without departing from the spirit and scope defined by the claims.

Claims

1. A self-propelled retrieval spear, characterized in that, The self-propelled retrieval spear includes a guide tube and a solid spear shaft, wherein... The guide tube is located outside the solid spear shaft, with a connector body at the upper end and a positive rotation port at the lower end of the guide tube. The outer circumferential surface of the solid spear shaft is provided with a spear pad groove, which is an arc groove with a structure of smaller outer and larger inner. A positive rotation slider spear pad is provided in the spear pad groove, and the upper end of the solid spear shaft is fixed to the inner wall of the top of the guide cylinder.

2. The self-propelled retrieval spear according to claim 1, characterized in that, The retrieval spear includes an upper spear shaft and a lower spear shaft, wherein the diameter of the upper spear shaft is 38-40 mm and the diameter of the lower spear shaft is 34-36 mm.

3. The self-propelled retrieval spear according to claim 1, characterized in that, The outer diameter of the guide tube is 190-192 mm, and the inner diameter of the guide tube is 145-148 mm.

4. The self-propelled retrieval spear according to claim 1, characterized in that, A connecting joint is provided between the retrieval spear and the guide tube, and the solid spear shafts are fixedly connected at the connecting joint.

5. The self-propelled retrieval spear according to claim 1, characterized in that, A spear-shaped limiting block is fixedly installed in the spear-shaped sliding groove.

6. The self-propelled retrieval spear according to claim 1, characterized in that, The connector body has a connection port on its inner side, and a connection structure is provided in the connection port.

7. The self-propelled retrieval spear according to claim 1, characterized in that, A marking groove is provided at the connection between the connector body and the guide tube.

8. The self-propelled retrieval spear according to claim 1, characterized in that, A water hole is provided between the connector body and the guide tube.

9. The self-propelled retrieval spear according to claim 1, characterized in that, The solid spear shaft is equipped with a guide shoe at its lower end.

10. A salvage tool string, characterized in that, The salvage tool string includes the self-guided salvage spear as described in any one of claims 1 to 9.

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