Device for removing cuttings bed

Abstract

The invention belongs to the field of downhole tools in the petroleum industry, and particularly relates to a device for removing a cuttings bed. The device for removing the cuttings bed comprises a main body, a drainage groove and a rotational flow groove, wherein the rotational flow groove comprises an inrush current generating surface. The drainage groove and the rotational flow groove are jointly constructed into an asymmetric opposite-hook-shaped structure, and the inrush current generating face is constructed to be capable of impacting drilling fluid guided into the rotational flow groove through the drainage groove so as to generate inrush current facing the well wall. According to the device for removing the cuttings bed, the structure is simple, operation is convenient, the cuttings bed located on the well wall can be effectively removed, and the device has good application prospects in the field.

Description

Technical Field

[0001] The present invention belongs to the field of downhole tools in the oil industry, and particularly relates to a device for removing a cuttings bed. Background Art

[0002] In the build-up section and horizontal section of drilling operations such as directional wells, highly deviated wells, and horizontal wells, due to the action of gravity in the vertical direction, cuttings particles are prone to settle on the bottom of the wellbore to form a cuttings bed. The presence of the cuttings bed can cause problems such as obstruction of the lowered testing tools or logging instruments, difficult tripping, decreased operation success rate, and the risk of pipe sticking. At the same time, it will lead to an increase in the friction resistance of the drill string, and in severe cases, it may even break the downhole drilling tools in the well. Although there are desanders applicable to removing the cuttings bed in the prior art, these devices also have disadvantages such as inability to form a surge flow, small impact force, and inability to clean the cuttings that are caked or adhered to the wellbore wall, and cannot well complete the cleaning operation of the cuttings bed accumulated on the bottom of the wellbore. Summary of the Invention

[0003] In view of the problems existing in the prior art, the present invention provides a device for removing a cuttings bed.

[0004] The device for removing a cuttings bed includes:

[0005] A main body, configured as a hollow cylinder;

[0006] A drainage groove, formed on the side wall of the main body in a manner that gradually inclines left / right in the direction from bottom to top; and

[0007] A swirl groove, formed on the side wall of the main body in a manner that gradually inclines right / left in the direction from bottom to top, which is connected to the drainage groove through its lower end, and includes a surge generation surface provided on the left / right side,

[0008] wherein, the drainage groove and the swirl groove together are configured as an asymmetric hook-shaped structure, and the surge generation surface is configured to be able to impact the drilling fluid introduced into the swirl groove via the drainage groove to generate a surge flow towards the wellbore wall.

[0009] As an expansion of the above technical solution, the present invention also provides the following embodiments:

[0010] The length of the drainage groove is set to be greater than the length of the swirl groove.

[0011] The included angle between the drainage groove and the swirl groove is an obtuse angle.

[0012] A number of cutting teeth are provided at the junction of the side surface of the swirl groove opposite to the surge generation surface and the outer side surface of the main body.

[0013] A number of grinding particles are provided on the outer side surface of the main body.

[0014] A ball is provided in the middle of the grinding particles.

[0015] It includes a diversion groove fixedly arranged at the lower end of the main body.

[0016] A number of groups of the hook-shaped structures are provided in the circumferential direction of the main body.

[0017] A first connector configured to be hollow is connected to the upper end of the main body.

[0018] A second connector configured to be hollow is connected to the lower end of the main body.

[0019] The advantages of the present invention compared with the prior art are as follows:

[0020] (1) Thanks to the asymmetric hook-shaped structure formed by the diversion groove and the swirl groove, a surge flow that has an impact on the wellbore can be effectively formed, so that efficient cleaning operation of the cuttings bed can be realized;

[0021] (2) The hook-shaped structure formed by the combination of the diversion groove and the swirl groove is designed based on the main body, with high structural stability, strong erosion resistance, and high safety;

[0022] (3) By providing cutting teeth and grinding particles on the main body, the purpose of effectively breaking the cuttings bed in a compacted or adhered state can be achieved without damaging the wellbore;

[0023] (4) A ball is provided in the middle of the grinding particles, reducing the torque friction during the cleaning operation and reducing the risk of downhole operations. Brief Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the device for clearing the cuttings bed according to the present invention.

[0025] All the drawings in the present invention are schematic diagrams for illustrating the structure and principle, and are not necessarily drawn according to the actual size and proportion.

[0026] The specific meanings of the reference numerals in the drawings are as follows:

[0027] 1. Main body; 2. Diversion groove; 3. Swirl groove; 4. Cutting teeth; 5. Grinding particles; 6. Ball; 7. Diversion groove; 8. First connector; 81. First transition groove; 9. Second connector; 91. Second transition groove; 92. Connection part; 100. Device for clearing the cuttings bed. Detailed Description of the Embodiment

[0028] The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0029] Figure 1 It is a schematic structural diagram of a device 100 (hereinafter referred to as "device 100" for short) for clearing a cuttings bed according to the present invention. As shown in the figure, the device 100 includes a main body 1, a drainage groove 2, and a swirl groove 3. The main body 1 is configured as a hollow cylinder, and the drainage groove 2 is opened on the outer side of the side wall of the main body 1 in a manner that gradually inclines to the left / right in the direction from bottom to top. The swirl groove 3 is opened on the outer side of the side wall of the main body 1 in a manner that gradually inclines to the right / left in the direction from bottom to top, and it includes a surge generating surface 31 provided on the left / right side. The swirl groove 3 is also configured to communicate with the drainage groove 2 through the lower end. Moreover, the drainage groove 2 and the swirl groove 3 together are configured as a longitudinally distributed asymmetric hook-shaped structure, and the surge generating surface 31 is configured to be able to impact the drilling fluid introduced into the swirl groove 3 via the drainage groove 2 to generate a surge towards the wellbore wall.

[0030] During specific operations, the staff connects the device 100 to a lowering tool (not shown, the same hereinafter) and lowers it into the well. After the drilling fluid flows out inside the device 100 in the direction from top to bottom, through the reflection effect at the bottom of the wellbore, it then flows through the outside of the device 100 in the direction from bottom to top. As a result, part of the drilling fluid enters the drainage groove 2 and is guided by the drainage groove 2 into the swirl groove 3. Since the drainage groove 2 is connected to the swirl groove 3 and is configured as a longitudinally distributed asymmetric hook-shaped structure, and since the device 100 is in a rotating state during this process, when the drilling fluid turns in the drainage groove 2 and enters the swirl groove 3, it will generate a surge towards the wellbore wall under the impact of the surge generating surface 31 located on the left / right side, thereby playing a role in clearing the cuttings bed accumulated on the side wall of the wellbore.

[0031] In addition, it should be noted that the implementation manner in which the surge generating surface 31 is a plane provided on the left side in the swirl groove 3 is applicable to the case when the device 100 rotates forward underground. The implementation manner in which the surge generating surface 31 is a plane provided on the right side in the swirl groove 3 is applicable to the case when the device 100 rotates reversely underground. That is, during operation, it is necessary to ensure that the surge generating surface 31 can act as an active acting surface to apply force to the drilling fluid in order to form a surge.

[0032] Through the design of the drainage groove 2 and the swirl groove 3, the two are combined into a longitudinally distributed asymmetric hook-shaped structure, so that during the operation of the device 100, it can impact the drilling fluid flowing through the drainage groove 2 and entering the swirl groove 3 and generate a surge towards the wellbore wall, thereby realizing an efficient cleaning operation of the cuttings bed accumulated on the wellbore wall. In addition, the hook-shaped structure formed by the combination of the drainage groove 2 and the swirl groove 3 is designed based on the main body 1 as the structural foundation, with high structural stability, strong erosion resistance, and high safety performance.

[0033] As Figure 1 shown, in an embodiment of the present invention, the length of the drainage groove 2 is set to be greater than the length of the swirl groove 3. Through this design, the length of the surge generation surface 31 is controlled within a range shorter than that of the drainage groove 2, so that the acting surface of the surge generation surface 31 and the drilling fluid introduced by the drainage groove 2 is small, which is conducive to generating a rapid and powerful impact on the drilling fluid, thereby enhancing the cleaning strength of the surge on the cuttings bed on the wellbore wall and being beneficial to improving the removal effect of the device 100 on the cuttings bed.

[0034] As Figure 1 shown, in an embodiment of the present invention, the included angle between the drainage groove 2 and the swirl groove 3 is an obtuse angle. This design helps to reduce the resistance when the drilling fluid flows from the drainage groove 2 into the swirl groove 3, so that the surge generated after the action of the surge generation surface 31 has a strong scouring ability, improving the removal effect of the device 100 on the cuttings bed.

[0035] As Figure 1 shown, in an embodiment of the present invention, a number of cutting teeth 4 are provided at the junction of the side surface of the swirl groove 3 opposite to the surge generation surface 31 and the outer side surface of the main body 1. The cutting teeth 4 are configured to protrude from the outer surface of the main body 1, but the protruding dimension is set so as not to contact the wellbore wall. Through the design of the cutting teeth 4, the device 100 can have the function of mechanically removing the cuttings bed without damaging the wellbore wall, especially has an efficient removal operation for the stubborn cuttings bed adhered to or caked on the wellbore wall, and improves the removal effect of the device 100 on the cuttings bed.

[0036] Preferably, the cutting teeth 4 are selected as negative angle cutting teeth. Through this design, on the one hand, it can achieve precise crushing and removal of irregular and larger cuttings on the wellbore wall, and on the other hand, the negative angle cutting teeth have the characteristic of not being easily worn, thereby reducing the replacement frequency of the cutting teeth 4 and reducing the operation burden of the staff.

[0037] In an embodiment of the present invention, for the purpose of facilitating processing and ensuring firm connection, the cutting teeth 4 are fixedly connected by welding at the junction of the side surface of the swirl groove 3 opposite to the surge generation surface 31 and the outer side surface of the main body 1.

[0038] As Figure 1 shown, in an embodiment of the present invention, a number of grinding particles 5 are provided on the outer side surface of the main body 1. The grinding particles 5 are also small protrusions protruding from the outer surface of the main body 1, and they are arranged on a relatively large range of the outer side surface of the main body 1, which is beneficial to enhancing the cleaning of the cuttings bed by the mechanical force of the device 100 and improving the removal effect of the device 100 on the stubborn cuttings bed.

[0039] Preferably, in order to minimize the possibility of the device 100 damaging the wellbore during the cleaning operation, the height by which the grinding particles 5 protrude from the outer surface of the main body 1 is less than the height value by which the cutting teeth 4 protrude from the outer surface of the main body 1.

[0040] Preferably, in order to enhance the cleaning effect of the device 100, the grinding particles 5 are evenly distributed over the outer surface of the main body 1.

[0041] In one embodiment of the present invention, for the purpose of facilitating processing and ensuring firm connection, the grinding particles 5 are fixedly connected to the outer side of the main body 1 by welding.

[0042] As Figure 1 shown, in one embodiment of the present invention, a ball 6 is provided in the middle of the grinding particle 5. With this design, due to the rolling action of the ball 6, the torque and frictional resistance during the rotation operation of the device 100 are reduced, thereby greatly reducing the risk of the drill tool and the device 100 getting stuck and breaking down in the well, and improving the safety of the operation of the device 100.

[0043] Preferably, for the purpose of facilitating processing, the ball 6 is arranged in the middle of the grinding particle 5 by inlaying. Specifically, first, a hole adapted to the size of the ball 6 is machined on the grinding particle 5, and the hole is machined using the groove circumferential ball locking process, and then the ball 6 is embedded in the hole, so that the ball 6 can roll while being connected to the grinding particle 5.

[0044] As Figure 1 shown, in one embodiment of the present invention, the device 100 includes a diversion groove 7 provided at the lower end of the main body 1. The diversion groove 7 is configured as an annular structure that is narrower than the main body 1 in the circumferential direction. With this design, the drilling fluid moving upward can more easily enter the drainage groove 2 to finally form a surge flow. That is, the design of the diversion groove 7 helps to improve the ability of the device 100 to form a surge flow, thereby improving its cleaning effect on the cuttings bed.

[0045] As Figure 1 shown, in one embodiment of the present invention, a number of longitudinally distributed asymmetric hook-shaped structures composed of the drainage groove 2 and the swirl groove 3 are provided in the circumferential direction of the main body 1. This design enables the device 100 to simultaneously generate multiple surge flows that scour the wellbore, improving the overall cleaning effect of the device 100 on the cuttings bed.

[0046] As Figure 1 shown, in one embodiment of the present invention, a first connector 8 configured as a hollow shape is connected to the upper end of the main body 1. Through the design of the first connector 8, it is convenient to connect the device 100 to the running tool.

[0047] Preferably, in an embodiment of the present invention, the first connector 8 includes a first transition groove 81, and the main body 1 is connected to the first connector 8 by being connected to the first transition groove 81. The first transition groove 81 is configured as a chamfered structure that gradually extends outward and inwardly recesses in the direction from bottom to top. Through this design, on the one hand, the connection between the main body 1 and the first connector 8 becomes smoother and more natural; on the other hand, the drilling fluid flowing out of the swirl groove 3 can be guided by the transition groove 81 to flow towards the wellbore again to scour the cuttings bed, thereby further improving the cleaning effect of the device 100 on the cuttings bed.

[0048] Preferably, in an embodiment of the present invention not shown, in order to conveniently and firmly connect the device 100 to the running tool, internal threads (not shown) are provided on the inner surface of the first connector 8.

[0049] As Figure 1 shown, in an embodiment of the present invention, a second connector 9 configured as a hollow shape is connected to the lower end of the main body 1. Through the design of the second connector 9, it is convenient to connect the device 100 to other downhole tools.

[0050] Preferably, in an embodiment of the present invention, the second connector 9 includes a second transition groove 91, and the main body 1 is connected to the second connector 9 by being connected to the second transition groove 91. The second transition groove 91 is configured as a chamfered structure that gradually extends inward and inwardly recesses in the direction from bottom to top. Through this design, on the one hand, the connection between the main body 1 and the second connector 9 becomes smoother and more natural; on the other hand, the drilling fluid flowing in the direction from bottom to top can more easily enter the diversion groove 7, which is beneficial to ensuring the smooth generation of the surge flow of the device 100 and the realization of the cleaning effect on the cuttings bed.

[0051] Preferably, in an embodiment of the present invention, the second connector 9 includes a connecting portion 92 provided at the lowermost end with a frustum shape having a larger outer diameter at the upper part and a smaller outer diameter at the lower part, and external threads (not shown, the same below) are provided on the outer surface of the connecting portion 92. Through this design, it is convenient to quickly and firmly connect other downhole tools to the lower end of the device 100, and the application range of the device 100 is broadened.

[0052] In an application embodiment of the present invention, according to the actual situation of downhole operations, the device 100 is designed to have a smaller size, and its upper end is connected to the rotary steering tool, so that it can be used as a dedicated cuttings bed cleaning device for the rotary steering tool.

[0053] According to the device 100 of the present invention, through the design of parts such as the drainage groove 2 and the swirl groove 3, it is possible to achieve a strong and efficient cleaning of the cuttings bed, effectively improving the working efficiency and safety during the cuttings bed cleaning operation. The device 100 has a simple structure and is convenient to operate, and has good application prospects in the technical field.

[0054] In this application, "forward rotation" means that when an operator observes from a top-down perspective, the state where an object rotates in a counterclockwise direction, and "reverse rotation" means that when an operator observes from a top-down perspective, the state where an object rotates in a clockwise direction.

[0055] In this application, the specific meanings of terms such as "up", "down", "inside", "outside", "middle", "edge" when indicating orientation are based on Figure 1 the drawing state of the device 100 in

[0056] Finally, it should be noted that although the present invention has been described in detail with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present invention. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A device for clearing a cuttings bed, comprising: The main body (1) is constructed as a hollow cylinder; A drainage groove (2) is provided on the side wall of the main body (1) in a manner of gradually tilting leftward / rightward in a direction from bottom to top; and The swirl groove (3) is opened on the side wall of the main body (1) in a manner of gradually tilting to the right / left in a direction from bottom to top, is connected to the drainage groove (2) through the lower end, and includes a surge generating surface (31) arranged on the left / right side, The drainage groove (2) and the swirl groove (3) are jointly constructed as an asymmetric hook-shaped structure, and the surge generating surface (31) is constructed to be able to impact the drilling fluid introduced into the swirl groove (3) through the drainage groove (2) to generate a surge toward the well wall.

2. The device for removing a cuttings bed according to claim 1, characterized in that: The length of the drainage groove (2) is set to be greater than the length of the swirl groove (3).

3. The device for removing a cuttings bed according to claim 2, characterized in that: The angle between the drainage groove (2) and the swirl groove (3) is an obtuse angle.

4. The device for removing a cuttings bed according to claim 3, characterized in that: A plurality of cutting teeth (4) are provided at the junction of the side surface of the swirl groove (3) opposite to the surge generating surface (31) and the outer side surface of the main body (1).

5. The device for removing a cuttings bed according to claim 4, characterized in that: A plurality of grinding particles (5) are arranged on the outer side surface of the main body (1).

6. The device for clearing a cuttings bed according to claim 5, characterized in that: A ball (6) is arranged in the middle of the grinding particles (5).

7. The device for clearing a cuttings bed according to claim 6, characterized in that: It comprises a diversion groove (7) fixedly arranged at the lower end of the main body (1).

8. The device for clearing a cuttings bed according to any one of claims 1 to 7, characterized in that: A plurality of groups of the hook-shaped structures are arranged in the circumferential direction of the main body (1).

9. The device for clearing a cuttings bed according to claim 8, characterized in that: A first connecting head (8) having a hollow structure is connected to the upper end of the main body (1).

10. The device for clearing a cuttings bed according to claim 8, characterized in that: A second connecting head (9) having a hollow structure is connected to the lower end of the main body (1).

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