A packoff staged collar for cementing operations in oil and gas wells

Abstract

The application relates to the technical field of downhole tools for well cementing, in particular to a packoff type grading collar for well cementing operation of oil and gas wells. The packoff type grading collar comprises a grading collar main body and an action sliding sleeve slidingly arranged in the grading collar main body. A sliding groove is coaxially arranged on the inner wall of the grading collar main body, the action sliding sleeve is slidingly arranged in the sliding groove, a piston cavity is coaxially arranged in the grading collar main body, a communication groove is arranged on the groove bottom of the sliding groove, the communication groove is communicated with the piston cavity, an installation groove is coaxially arranged on the outer peripheral wall of the grading collar main body, the installation groove is communicated with the piston cavity through a communication flow channel, a linkage rod is slidingly arranged in the communication groove, a piston ring is slidingly arranged in the piston cavity, an expansion sealing rubber tube is arranged in the installation groove, the end of the linkage rod is fixedly connected with the piston ring, the action sliding sleeve and the linkage rod are linked through a fixing column, the expansion sealing rubber tube is matched with the installation groove, the inner peripheral wall of the expansion sealing rubber tube is open and is fixedly connected with the groove bottom of the installation groove, and the effect of reducing control steps and improving well cementing operation efficiency is achieved.

Description

Technical Field

[0001] This application relates to the field of downhole tools for cementing, and in particular to a packer-type stage collar for cementing operations in oil and gas wells. Background Technology

[0002] Currently, in oil and gas drilling projects, when a well has a long cementing section or the formation has low pressure bearing capacity, a staged cementing process is usually adopted to divide the entire well section into two or more stages for cementing operations. The packer-type staged clamp is a downhole cementing tool that integrates staged cementing tools and hydraulic expansion type external packers. It solves the industry pain points of conventional staged clamps, such as lack of annular isolation, easy well leakage during staged operations, and crossflow in multi-pressure layers. By reducing cement slurry leakage and setting time, it significantly reduces material consumption and equipment operating energy consumption, achieving economical and efficient cementing operations.

[0003] When existing packer-type staged packers are used downhole, their functionality is highly dependent on multi-stage precise control of wellhead pressure. First, a specific pressure needs to be established to open the fluid inlet channel of the hydraulic expansion packer, drive the packer to expand radially and set it against the open hole wall. Then, on the premise of ensuring effective setting of the packer, the wellhead pressure must be precisely controlled again to activate the staged cementing circulation channel, so that the secondary cement slurry can be injected into the upper annulus through the channel to complete the segmented sealing.

[0004] The existing technical solutions mentioned above have the following defects: because downhole pressure is dynamically affected by multiple factors such as temperature, mud properties and tubing friction, it is difficult to accurately match the pressure applied on the surface with the actual downhole pressure. The expansion sealing pressure and the opening pressure are prone to timing or amplitude deviations, which can lead to insufficient packer expansion sealing, annular isolation failure, premature opening of the circulation hole, direct connection between the lower leaking layer and the upper annulus, complete loss of isolation conditions for secondary cementing operations, and ultimately substandard cementing quality or even failure of the entire well cementing. Summary of the Invention

[0005] In order to reduce control steps and improve cementing operation efficiency, this application provides a sealing-type stage collar for cementing operations in oil and gas wells.

[0006] The above-mentioned technical objective of this application is achieved through the following technical solution:

[0007] A sealing-type stage collar for cementing operations in oil and gas wells includes a cylindrical stage collar body and an action sleeve slidably disposed inside the stage collar body. A sliding groove is coaxially formed on the inner wall of the stage collar body, and the action sleeve is slidably disposed within the sliding groove. A piston chamber is coaxially formed inside the stage collar body, and a connecting groove is formed at the bottom of the sliding groove, extending towards and communicating with the piston chamber. An installation groove is coaxially formed on the outer peripheral wall of the stage collar body, and the installation groove is connected to the piston chamber via a connecting flow channel. A linkage rod is slidably disposed in the connecting groove, a piston ring is slidably disposed in the piston chamber, and an expansion sealing rubber sleeve is disposed in the installation groove. The end of the linkage rod is fixedly connected to the piston ring. The action sleeve is linked to the linkage rod via a fixed column. The expansion sealing rubber sleeve is adapted to the installation groove, and its inner peripheral wall is open and fixedly connected to the bottom of the installation groove.

[0008] By adopting the above technical solution, and by setting up a graded collar body, sliding groove, working sliding sleeve, piston chamber, connecting groove, installation groove, connecting flow channel, linkage rod, piston ring, expansion sealing rubber sleeve and fixing column, the working sliding sleeve can drive the linkage rod to slide along the connecting groove through the fixing column when sliding in the sliding groove. The linkage rod drives the piston ring to slide in the piston chamber and squeezes the piston fluid into the expansion sealing rubber sleeve through the curved connecting flow channel, so that the expansion sealing rubber sleeve expands outward and seals the annulus between the graded collar body and the well wall. The entire expansion sealing process is completed synchronously by one sliding action of the working sliding sleeve, without the need to establish a separate pressure control procedure, reducing the control steps of cementing operations and improving the efficiency of cementing operations.

[0009] Optionally, a sliding hole is provided on the side wall of the end of the linkage rod away from the piston chamber, and a linkage hole is provided at the corresponding position on the outer peripheral wall of the sliding sleeve. The position of the linkage hole corresponds to the position of the connecting groove, and the wall of the linkage hole coincides with the wall of the sliding hole. The peripheral wall of the fixed column is adapted to both the linkage hole and the sliding hole, and the fixed column is slidably disposed in the linkage hole and the sliding hole. A linkage spring is provided in the linkage hole, and the two ends of the linkage spring are respectively fixed to the end face of the fixed column and the bottom of the linkage hole. A circular limiting hole is provided at the corresponding position on the bottom of the connecting groove. The limiting hole is adapted to the end of the fixed column, and the end of the fixed column can be inserted into the limiting hole. The depth of the limiting hole is consistent with the axial length of the fixed column in the linkage hole, and the length of the linkage spring in the static state is consistent with the depth of the linkage hole.

[0010] By adopting the above technical solution, and by setting a sliding hole, a linkage hole, a fixed column, a linkage spring, and a limiting hole, the sliding sleeve can drive the linkage rod to move until the piston ring abuts against the piston chamber end wall. At this point, the sliding hole and the limiting hole wall coincide, the linkage spring is released, and the end of the fixed column is pushed into the limiting hole. The fixed column separates from the linkage hole, and the expansion sealing sleeve is fully opened. After that, when the sliding sleeve continues to move, it no longer drives the linkage rod, thus realizing the time separation of the expansion sealing action and the subsequent grouting action, and avoiding interference of the linkage rod with the subsequent movement of the sliding sleeve.

[0011] Optionally, the bottom of the sliding groove is provided with a grouting hole, which connects the bottom of the sliding groove and the outer peripheral wall of the graded hoop body. The peripheral wall of the functional sleeve is provided with a connecting hole, which connects the inner and outer peripheral walls of the functional sleeve. The position of the connecting hole corresponds to the position of the grouting hole, and the wall of the connecting hole can overlap and connect with the wall of the grouting hole. The bottom of the sliding groove is provided with a first shearing pin, and the corresponding position of the outer peripheral wall of the functional sleeve is provided with a receiving hole adapted to the first shearing pin. The end of the first shearing pin is inserted into the receiving hole.

[0012] By adopting the above technical solution, and by setting up grouting holes, connecting holes, first shear pins, and receiving holes, the working sleeve can be fixed in its initial position by the first shear pin. Only after the first shear pin is cut can the working sleeve slide towards the piston cavity. When the working sleeve slides to the point where the connecting hole coincides with the wall of the grouting hole, the inner cavity of the casing is connected to the outer annulus of the stage hoop body in sequence through the inner cavity of the working sleeve, the connecting hole, and the grouting hole, thus establishing a grouting channel and realizing the injection of secondary cementing slurry.

[0013] Optionally, the inner peripheral wall of the functional sleeve is provided with a limiting member and a sealing member. The limiting member is coaxially arranged with the functional sleeve, and the sealing member is coaxially arranged with the functional sleeve. The sealing member is disposed between the limiting member and the piston cavity, and the sealing member and the limiting member are spaced apart.

[0014] By adopting the above technical solution, and by setting a limiting component and a sealing component, when the opening plug of the inserted casing moves down along the inner cavity of the casing to the corresponding graded clamp body, the end of the opening plug abuts against the limiting component and is restricted from continuing to move. At the same time, the sealing component fills the gap between the outer peripheral wall of the opening plug and the inner peripheral wall of the working sleeve, preventing fluid from leaking between the opening plug and the working sleeve when pressurized, and ensuring that the pressure is effectively applied to the end face of the working sleeve to drive its sliding.

[0015] Optionally, sealing rings are provided at both ends of the outer peripheral wall of the functional sleeve and at the opening of the connecting hole. The sealing rings at both ends of the functional sleeve are coaxially arranged with the functional sleeve, and the sealing ring at the opening of the connecting hole is coaxially arranged with the connecting hole.

[0016] By adopting the above technical solution and setting sealing rings, the sealing rings at both ends can fill the gap between the outer peripheral wall of the working sleeve and the bottom of the sliding groove, preventing fluid from entering the sliding groove from both ends of the working sleeve. The sealing ring at the orifice of the connecting hole fills the gap around the orifice of the connecting hole when the connecting hole and the grouting hole do not coincide, preventing fluid from leaking from the connecting hole before the grouting channel is opened.

[0017] Optionally, a second shearing pin is further provided at the bottom of the sliding groove. The second shearing pin is disposed between the first shearing pin and the piston chamber, and is spaced apart from the end wall of the sliding groove. The shearing pressure required by the second shearing pin is greater than the shearing pressure of the first shearing pin.

[0018] By adopting the above technical solution and setting a second shearing pin, the sliding sleeve can slide towards the piston cavity after the first shearing pin is cut. When the expansion sealing sleeve is fully opened and the connecting hole and the grouting hole have not yet overlapped, the sliding sleeve continues to move until the end face abuts against the peripheral wall of the second shearing pin. The second shearing pin temporarily positions the sliding sleeve. At this position, the expansion sealing sleeve remains fully expanded and the grouting hole is opened, realizing the operation sequence of completing the expansion sealing first and then opening the grouting hole.

[0019] Optionally, the outer peripheral wall of the sliding sleeve is provided with a sealing hole, which is spaced apart from the receiving hole. A sealing post is slidably disposed in the sealing hole, and a sealing spring is disposed in the sealing hole. The two ends of the sealing spring are respectively fixed to the end face of the sealing post and the bottom of the sealing hole. A positioning hole is provided at the end of the bottom of the sliding groove away from the grouting hole. The positioning hole is adapted to the end of the sealing post, and the end of the sealing post can be inserted into the positioning hole. The positioning hole is located on the side of the second shear pin away from the first shear pin.

[0020] By adopting the above technical solution, and by setting a sealing hole, a sealing column, a sealing spring, and a positioning hole, the working sleeve can continue to slide until the sealing hole and the positioning hole wall coincide after the second shear pin is sheared. At this time, the sealing spring is released and the end of the sealing column is pushed into the positioning hole to fix the position of the working sleeve. At this time, the connecting hole and the grouting hole are staggered and the outer peripheral wall of the working sleeve seals the grouting hole, so that the grouting channel is irreversibly closed, preventing the grouting hole from being reconnected after the cementing operation is completed.

[0021] Optionally, a limiting groove is provided at the bottom of the sliding groove corresponding to the closing column. The limiting groove, the connecting groove, and the second shear pin are all provided at intervals. The end of the closing column is adapted to the limiting groove and is slidably disposed in the limiting groove.

[0022] By adopting the above technical solution and setting a limiting groove, the end of the closing column can always be located in the limiting groove and slide along the length of the limiting groove during the sliding process of the working sleeve. The limiting groove constrains the sliding direction of the closing column, thereby constraining the sliding path of the working sleeve along the axis of the graded hoop body, reducing the possibility of the working sleeve circumferentially deflecting around the axis during the sliding process, and ensuring that the connecting hole and the grouting hole are accurately aligned or misaligned at the predetermined position.

[0023] Optionally, the edge of the limiting hole is chamfered.

[0024] By adopting the above technical solution and setting a chamfer on the edge of the limiting hole, the end of the fixed column can slide into the limiting hole along the chamfered slope when it moves towards the limiting hole under the push of the linkage spring, reducing the jamming between the end of the fixed column and the edge of the limiting hole and improving the smoothness of the fixed column entering the limiting hole.

[0025] Optionally, the opening of the positioning hole is machined to be chamfered.

[0026] By adopting the above technical solution and setting a chamfer at the positioning hole, the end of the sealing column can slide into the positioning hole along the chamfered slope when it moves towards the positioning hole under the push of the sealing spring, reducing the jamming between the end of the sealing column and the edge of the positioning hole and improving the smoothness of the sealing column entering the positioning hole.

[0027] In summary, this application has the following technical effects:

[0028] 1. By setting up a graded collar body, sliding groove, working sliding sleeve, piston chamber, connecting groove, installation groove, connecting flow channel, linkage rod, piston ring, expansion sealing rubber sleeve and fixed column, the working sliding sleeve can drive the linkage rod to slide along the connecting groove through the fixed column when sliding in the sliding groove. The linkage rod drives the piston ring to slide in the piston chamber and squeezes the piston fluid into the expansion sealing rubber sleeve through the curved connecting flow channel, so that the expansion sealing rubber sleeve expands outward and seals the annulus between the graded collar body and the well wall. The entire expansion sealing process is completed synchronously by one sliding action of the working sliding sleeve. There is no need to establish a separate pressure control process, reducing the control steps of cementing operation and improving the efficiency of cementing operation.

[0029] 2. By setting up sliding holes, linkage holes, fixed columns, linkage springs, and limiting holes, the sliding sleeve can drive the linkage rod to move until the piston ring abuts against the piston chamber end wall. At this point, the sliding hole and the limiting hole wall coincide, the linkage spring is released, and the end of the fixed column is pushed into the limiting hole. The fixed column separates from the linkage hole, and the expansion sealing sleeve is fully opened. After that, when the sliding sleeve continues to move, it will no longer drive the linkage rod, thus realizing the time separation of the expansion sealing action and the subsequent grouting action, and avoiding interference of the linkage rod with the subsequent movement of the sliding sleeve.

[0030] 3. By setting a second shearing pin, the sliding sleeve can slide towards the piston cavity after the first shearing pin is cut. When the expansion sealing sleeve is fully opened and the connecting hole and the grouting hole have not yet overlapped, the sliding sleeve continues to move until the end face abuts against the peripheral wall of the second shearing pin. The second shearing pin temporarily positions the sliding sleeve. At this position, the expansion sealing sleeve remains fully expanded and the grouting hole is opened, realizing the operation sequence of completing the expansion sealing first and then opening the grouting hole. Attached Figure Description

[0031] Figure 1 This is a structural diagram of the object of this application;

[0032] Figure 2 This is an internal structural diagram of the main body of the graded hoop in this application;

[0033] Figure 3 This is a structural diagram of the internal structure of the graded hoop body from another angle in this application;

[0034] Figure 4yes Figure 3 Enlarged structural diagram at point A in the middle;

[0035] Figure 5 This is a structural diagram of the internal structure of the sliding sleeve used in this application;

[0036] Figure 6 yes Figure 5 Enlarged structural diagram at point B in the middle.

[0037] Explanation of reference numerals in the attached drawings: 1. Graded hoop body; 11. Sliding groove; 12. Grouting hole; 13. Connecting groove; 131. Limiting hole; 14. Piston chamber; 141. Connecting flow channel; 15. Positioning hole; 16. Mounting groove; 17. Limiting groove; 2. Sliding sleeve assembly; 21. Actual sliding sleeve; 22. Connecting hole; 23. Linkage hole; 24. Limiting element; 25. Receiving hole; 26. Sealing hole; 27. Sealing element; 28. Sealing ring; 3. Expansion sealing assembly; 31. Linkage rod; 311. Sliding hole; 32. Fixing column; 321. Linkage spring; 33. Piston ring; 34. Expansion sealing rubber sleeve; 4. Positioning assembly; 41. First shearing pin; 42. Second shearing pin; 43. Sealing column; 431. Sealing spring; 44. Limiting baffle. Detailed Implementation

[0038] The present application will be further described in detail below with reference to the accompanying drawings.

[0039] This application discloses a sealing-type staged collar for cementing operations in oil and gas wells. It is installed between two casings and extends into the well with the casings during operations. (Refer to...) Figure 1 and Figure 2 The classifier collar includes a classifier collar body 1, a sliding sleeve assembly 2 slidably disposed inside the classifier collar body 1, an expansion sealing assembly 3 disposed on the classifier collar body 1, and a positioning assembly 4 that fixes the position of the sliding sleeve assembly 2. The sliding sleeve assembly 2 can be linked with the expansion sealing assembly 3. Before the sliding sleeve assembly 2 connects to the outside of the classifier collar body 1, the expansion sealing assembly 3 seals the annulus between the classifier collar body 1 and the well wall. The positioning assembly 4 can accurately fix the position of the sliding sleeve assembly 2, so that the sliding sleeve assembly 2 accurately connects to the outside of the classifier collar body 1, increases the fault tolerance of the sliding sleeve assembly 2 for driving pressure, and improves the efficiency of cementing using the classifier collar.

[0040] Combination Figures 1 to 4 The grader clamp body 1 is cylindrical, and its two ends are connected to the ends of two sleeves, respectively. An annular sliding groove 11 is coaxially formed on the inner wall of the grader clamp body 1, and the sliding groove 11 is close to one end face of the grader clamp body 1. An annular piston cavity 14 is coaxially formed inside the grader clamp, and the piston cavity 14 is close to the other end face of the grader clamp body 1 and spaced apart from it.

[0041] Combination Figures 1 to 4The sliding groove 11 has circular grouting holes 12 at its bottom, which connect the bottom of the sliding groove 11 to the outer peripheral wall of the grader body 1. Multiple grouting holes 12 are evenly spaced around the axis of the grader body 1 at the bottom of the sliding groove 11. Connecting grooves 13 are provided on opposite sides of the bottom of the sliding groove 11. The length of the connecting grooves 13 is parallel to the axis of the grader body 1, and the bottom of the connecting grooves 13 is flush with the outer wall of the piston cavity 14. The connecting grooves 13 are spaced apart from the grouting holes 12 and located between the grouting holes 12 and the piston cavity 14. The connecting grooves 13 extend towards the piston cavity 14 from the sliding groove 11 and connect with the piston cavity 14.

[0042] Combination Figures 1 to 4 The outer peripheral wall of the graded hoop body 1 is coaxially provided with an annular mounting groove 16. The mounting groove 16 is located on the side of the piston cavity 14 away from the sliding groove 11. The bottom of the mounting groove 16 is connected to the end face of the piston cavity 14 away from the sliding groove 11 through an annular connecting channel 141.

[0043] Combination Figures 1 to 4 The sliding sleeve assembly 2 includes an active sliding sleeve 21 slidably disposed in the sliding groove 11, a limiting member 24 disposed on the inner wall of the active sliding sleeve 21, a sealing member 27 disposed on the inner wall of the active sliding sleeve 21, and a sealing ring 28 disposed on the outer peripheral wall of the active sliding sleeve 21. The active sliding sleeve 21 is cylindrical and is coaxially disposed with the grader clamp body 1. The outer peripheral wall of the active sliding sleeve 21 is slidably fitted with the bottom of the sliding groove 11, and the inner peripheral wall of the active sliding sleeve 21 is flush with the inner peripheral wall of the grader clamp body 1.

[0044] Combination Figures 1 to 4 The peripheral wall of the sliding sleeve 21 is provided with a connecting hole 22, which connects the inner and outer peripheral walls of the sliding sleeve 21. Multiple connecting holes 22 are evenly provided in the peripheral wall of the sliding sleeve 21 with the axis of the sliding sleeve 21 as the center. The position of the connecting hole 22 corresponds to the position of the grouting hole 12, and the wall of the connecting hole 22 can overlap and connect with the wall of the grouting hole 12.

[0045] Combination Figures 1 to 4 The limiting member 24 is annular and is located on the inner peripheral wall of the working sleeve 21 and is coaxial with the working sleeve 21. The limiting member 24 is located on the side of the connecting hole 22 near the piston chamber 14. The limiting member 24 has a triangular cross section and the surface of the limiting member 24 facing away from the piston chamber 14 is a concave arc surface. When cementing is performed, the opening plug is inserted into the casing. When the opening plug moves to the corresponding stage clamp, it abuts against the limiting member 24. The limiting member 24 restricts the opening plug from continuing to move, which facilitates the movement of the working sleeve 21 by pressure.

[0046] Combination Figures 1 to 4The sealing element 27 is annular and coaxially arranged with the actuating sleeve 21. The sealing element 27 is positioned between the limiting element 24 and the piston chamber 14, with a gap between it and the limiting element 24. The sealing element 27 seals the opening plug. A linkage hole 23 is provided at a corresponding position on the outer peripheral wall of the actuating sleeve 21. The linkage hole 23 is a circular blind hole, and two linkage holes 23 are symmetrically provided on the outer peripheral wall of the actuating sleeve 21. The positions of the linkage holes 23 correspond to the positions of the connecting groove 13.

[0047] Combination Figures 1 to 4 Sealing rings 28 are provided at both ends of the outer peripheral wall of the sliding sleeve 21 and at the opening of the connecting hole 22. The sealing rings 28 are O-shaped and made of high-temperature resistant rubber. The sealing rings 28 at both ends of the sliding sleeve 21 are coaxially arranged with the sliding sleeve 21 to fill the gap between the sliding sleeve 21 and the bottom of the sliding groove 11. The sealing ring 28 at the opening of the connecting hole 22 is coaxially arranged with the connecting hole 22.

[0048] Combination Figures 3 to 6 The expansion sealing assembly 3 includes a linkage rod 31 slidably disposed in the connecting groove 13, a piston ring 33 slidably disposed in the piston cavity 14, a fixing post 32 slidably disposed in the linkage rod 31, and an expansion sealing sleeve 34 disposed in the mounting groove 16. The linkage rod 31 is adapted to the linkage groove, and the side wall of the linkage rod 31 slides against the groove wall of the connecting groove 13. The end of the linkage rod 31 can be located in the piston cavity 14. A circular sliding hole 311 is opened on the side wall of the end of the linkage rod 31 away from the piston cavity 14. When the end face of the linkage rod 31 abuts against the end wall of the connecting groove 13, and the end face of the sliding sleeve 21 away from the piston cavity 14 abuts against the end wall of the sliding groove 11, the wall of the linkage hole 23 coincides with the wall of the sliding hole 311.

[0049] Combination Figures 3 to 6 The peripheral wall of the fixed column 32 is adapted to both the linkage hole 23 and the sliding hole 311, and the fixed column 32 is slidably disposed in the linkage hole 23 and the sliding hole 311. A linkage spring 321 is provided in the linkage hole 23. The linkage spring 321 is a high-temperature resistant compression spring. The two ends of the linkage spring 321 are respectively fixed to the end face of the fixed column 32 and the bottom of the linkage hole 23. When the end of the linkage rod 31 abuts against the end wall of the connecting groove 13, the end face of the fixed column 32 away from the linkage spring 321 abuts against the bottom of the connecting groove 13.

[0050] Combination Figures 3 to 6 A circular limiting hole 131 is provided at the corresponding position of the bottom of the connecting groove 13. The limiting hole 131 is a blind hole. The limiting hole 131 is adapted to the end of the fixing post 32, and the end of the fixing post 32 can be inserted into the limiting hole 131. The edges of the opening of the limiting hole 131 are all chamfered. The depth of the limiting hole 131 is consistent with the axial length of the fixing post 32 located in the linkage hole 23. The length of the linkage spring 321 in the static state is consistent with the depth of the linkage hole 23.

[0051] Combination Figures 3 to 6 The piston ring 33 is coaxially arranged with the graded clamp body 1 and the piston chamber 14. The surface of the piston ring 33 is fixedly connected to the end face of the linkage rod 31. When the end face of the linkage rod 31 abuts against the end wall of the connecting groove 13, the surface of the piston ring 33 abuts against the end wall of the piston chamber 14 near the sliding groove 11, and the linkage rod 31 drives the piston ring 33 to slide.

[0052] Combination Figures 3 to 6 The expansion sealing tube 34 is annular, hollow inside, and has an open inner circumferential wall. The expansion sealing tube 34 is a high-temperature resistant tube. The expansion sealing tube 34 is adapted to the mounting groove 16, and the inner circumferential wall of the expansion sealing tube 34 is fixed to the bottom of the mounting groove 16. The bottom of the mounting groove 16 seals the expansion sealing tube 34. The piston chamber 14 is filled with a high-temperature resistant, flame-retardant, and highly stable piston fluid. When the piston ring 33 slides away from the sliding groove 11, it squeezes the piston fluid into the expansion sealing tube 34, causing the expansion sealing tube 34 to expand outward.

[0053] Combination Figures 3 to 6 The positioning component 4 includes a first shear pin 41 and a second shear pin 42 disposed on the wall of the sliding groove 11, and a closed post 43 slidably disposed inside the working sleeve 21. The end face of the first shear pin 41 is fixedly connected to the bottom of the sliding groove 11. The first shear pin 41 is disposed between the grouting hole 12 and the piston chamber 14, and the first shear pin 41 and the grouting hole 12 are spaced apart circumferentially and axially at the bottom of the sliding groove 11. A receiving hole 25 adapted to the first shear pin 41 is opened at a corresponding position on the outer peripheral wall of the working sleeve 21, and the end of the first shear pin 41 is inserted into the receiving hole 25.

[0054] Combination Figures 3 to 6 The first shear pin 41 fixes the initial position of the action sleeve 21, so that the end face of the action sleeve 21 away from the piston cavity 14 abuts against the end wall of the sliding groove 11, and the end of the linkage rod 31 abuts against the end wall of the connecting groove 13. The action sleeve 21 and the linkage rod 31 are linked by the fixed column 32.

[0055] Combination Figures 3 to 6 The second shear pin 42 is disposed between the first shear pin 41 and the piston chamber 14. The end of the second shear pin 42 is disposed inside the bottom of the sliding groove 11. The second shear pin 42 is spaced apart from the end wall of the sliding groove 11. The second shear pin 42 is close to the end wall of the sliding groove 11 away from the grouting hole 12. The shearing pressure required by the second shear pin 42 is greater than the shearing pressure of the first shear pin 41.

[0056] Combination Figures 3 to 6The outer peripheral wall of the sliding sleeve 21 has a circular closed hole 26, which is a blind hole. The closed hole 26 is located on the side of the linkage hole 23 opposite to the connecting hole 22, and is spaced apart from the receiving hole 25. The closing post 43 is adapted to the closed hole 26 and is slidably disposed within the closed hole 26. A closing spring 431 is disposed within the closed hole 26. The closing spring 431 is a high-temperature resistant compression spring, and its two ends are fixedly connected to the end face of the closing post 43 and the bottom of the closed hole 26, respectively.

[0057] Combination Figures 3 to 6 The bottom of the sliding groove 11 is provided with a strip-shaped limiting groove 17 corresponding to the closing column 43. The length direction of the limiting groove 17 is parallel to the axis of the graded hoop body 1. The limiting groove 17, the connecting groove 13 and the second shear pin 42 are all spaced apart. The end of the closing column 43 is adapted to the limiting groove 17 and is slidably disposed in the limiting groove 17.

[0058] Combination Figures 3 to 6 The bottom of the limiting groove 17 is provided with a positioning hole 15 at the end away from the grouting hole 12. The positioning hole 15 is adapted to the end of the sealing column 43, and the end of the sealing column 43 can be inserted into the positioning hole 15. The positioning hole 15 is opened on the side of the second shear pin 42 away from the first shear pin 41.

[0059] Combination Figures 2 to 6 When the closed-type graded clamp is in use, the opening plug is inserted into the sleeve. The opening plug moves to the corresponding graded clamp body 1 and is locked with the limiting member 24. The sleeve is continuously pressurized. The opening plug pushes the sliding sleeve 21 to move towards the piston chamber 14 until the first shear pin 41 is cut off and moved. The linkage rod 31 is driven to slide along the connecting groove 13 through the fixed column 32, thereby driving the piston ring 33 to move and squeezing the piston fluid into the expansion sealing tube 34.

[0060] Combination Figures 2 to 6 The piston ring 33 moves to abut against the end face of the piston chamber 14 away from the sliding groove 11. The expansion sealing sleeve 34 is fully opened to close the annular space between the outer peripheral wall of the graded hoop body 1 and the well wall. At this time, the wall of the sliding hole 311 coincides with the wall of the limiting hole 131. The linkage spring 321 is released, pushing the end of the fixing column 32 into the limiting hole 131. The fixing column 32 is completely separated from the linkage hole 23, and the linkage spring 321 is completely located in the linkage hole 23, so as not to interfere with the movement of the subsequent action sleeve 21. At this time, the connecting hole 22 is offset from the grouting hole 12, and the end face of the action sleeve 21 is spaced apart from the peripheral wall of the second shear pin 42.

[0061] Combination Figures 2 to 6The sliding sleeve 21 continues to move until its end face abuts against the circumferential wall of the second shear pin 42. At this point, the connecting hole 22 coincides with the wall of the grouting hole 12, and cementing operation is performed. After the cementing operation is completed, a closing plug is inserted into the casing. The closing plug abuts against the opening plug, and at the same time, the circumferential wall of the closing plug fits against the inner circumferential wall of the sliding sleeve 21 on the side of the connecting hole 22 away from the sealing hole 26. Pressure is continuously applied into the casing, and the pressure pushes the closing plug. The closing plug, the opening plug, and the limiting member 24 push the sliding sleeve 21 to move towards the piston chamber 14 until the second shear pin 42 is sheared, and the sliding sleeve 21 moves.

[0062] Combination Figures 2 to 6 During the movement of the sliding sleeve 21, the sealing column 43 always slides in the limiting groove 17. The limiting groove 17 reduces the possibility of the sliding sleeve 21 rotating circumferentially. When the sliding sleeve 21 moves to the point where the sealing hole 26 coincides with the hole wall of the positioning hole 15, the sealing spring 431 is released and inserts the end of the sealing column 43 into the positioning hole 15, fixing the position of the sliding sleeve 21. At this time, the connecting hole 22 is offset from the grouting hole 12, and the outer peripheral wall of the sliding sleeve 21 seals the grouting hole 12.

[0063] Combination Figures 2 to 6 When the closing post 43 is inserted into the positioning hole 15, the end face of the sliding sleeve 21 is spaced apart from the end wall of the sliding groove 11 near the piston cavity 14. The end wall of the sliding groove 11 near the piston cavity 14 is coaxially provided with an annular limiting baffle 44. The side wall of the limiting baffle 44 is annular and is located at the outer edge of the end wall of the sliding groove 11. The inner peripheral wall of the limiting baffle 44 is flush with the inner peripheral wall of the graded hoop body 1, and the outer peripheral wall of the limiting baffle 44 is spaced apart from the bottom of the sliding groove 11. When the closing post 43 is inserted into the positioning hole 15, the end face of the sliding sleeve 21 abuts against the side wall of the limiting baffle 44. The limiting baffle 44 is used to accommodate the second shearing pin 42 part after shearing.

[0064] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A packer-type staged collar for cementing operations in oil and gas wells, characterized in that: The system includes a cylindrical grading hoop body (1) and an action sleeve (21) slidably disposed inside the grading hoop body (1). A sliding groove (11) is coaxially formed on the inner wall of the grading hoop body (1), and the action sleeve (21) is slidably disposed in the sliding groove (11). A piston cavity (14) is coaxially formed inside the grading hoop body (1). A connecting groove (13) is formed at the bottom of the sliding groove (11), extending towards and communicating with the piston cavity (14). An installation groove (16) is coaxially formed on the outer peripheral wall of the grading hoop body (1). The mounting groove (16) and the piston chamber (14) are connected through a connecting channel (141). A linkage rod (31) is slidably arranged in the connecting groove (13). A piston ring (33) is slidably arranged in the piston chamber (14). An expansion sealing tube (34) is arranged in the mounting groove (16). The end of the linkage rod (31) is fixedly connected to the piston ring (33). The action sleeve (21) is linked to the linkage rod (31) through a fixed column (32). The expansion sealing tube (34) is adapted to the mounting groove (16). The inner peripheral wall of the expansion sealing tube (34) is open and fixedly connected to the bottom of the mounting groove (16).

2. The packer-type stage collar for cementing operations in oil and gas wells according to claim 1, characterized in that: A sliding hole (311) is provided on the end side wall of the linkage rod (31) away from the piston chamber (14), and a linkage hole (23) is provided on the corresponding position of the outer peripheral wall of the sliding sleeve (21). The position of the linkage hole (23) corresponds to the position of the connecting groove (13), and the wall of the linkage hole (23) coincides with the wall of the sliding hole (311). The peripheral wall of the fixing post (32) is adapted to both the linkage hole (23) and the sliding hole (311), and the fixing post (32) is slidably disposed in the linkage hole (23) and the sliding hole (311). A linkage spring is provided in the linkage hole (23). Spring (321), the two ends of the linkage spring (321) are respectively fixed to the end face of the fixed column (32) and the bottom of the linkage hole (23). A circular limiting hole (131) is opened at the corresponding position of the bottom of the connecting groove (13). The limiting hole (131) is adapted to the end of the fixed column (32), and the end of the fixed column (32) can be inserted into the limiting hole (131). The depth of the limiting hole (131) is consistent with the axial length of the fixed column (32) in the linkage hole (23). The length of the linkage spring (321) in the static state is consistent with the depth of the linkage hole (23).

3. A packer-type staged collar for cementing operations in oil and gas wells according to claim 1, characterized in that: The bottom of the sliding groove (11) is provided with a grouting hole (12), which connects the bottom of the sliding groove (11) and the outer peripheral wall of the graded hoop body (1). The peripheral wall of the function sleeve (21) is provided with a connecting hole (22), which connects the inner and outer peripheral walls of the function sleeve (21). The position of the connecting hole (22) corresponds to the position of the grouting hole (12), and the wall of the connecting hole (22) can overlap and connect with the wall of the grouting hole (12). The bottom of the sliding groove (11) is provided with a first shearing pin (41), and the corresponding position of the outer peripheral wall of the function sleeve (21) is provided with a receiving hole (25) adapted to the first shearing pin (41). The end of the first shearing pin (41) is inserted into the receiving hole (25).

4. A packer-type staged collar for cementing operations in oil and gas wells according to claim 3, characterized in that: The inner peripheral wall of the functional sleeve (21) is provided with a limiting member (24) and a sealing member (27). The limiting member (24) is coaxially arranged with the functional sleeve (21), and the sealing member (27) is coaxially arranged with the functional sleeve (21). The sealing member (27) is arranged between the limiting member (24) and the piston chamber (14), and the sealing member (27) and the limiting member (24) are spaced apart.

5. A packer-type staged collar for cementing operations in oil and gas wells according to claim 4, characterized in that: Sealing rings (28) are provided at both ends of the outer peripheral wall of the functional sleeve (21) and at the opening of the connecting hole (22). The sealing rings (28) at both ends of the functional sleeve (21) are coaxially arranged with the functional sleeve (21), and the sealing rings (28) at the opening of the connecting hole (22) are coaxially arranged with the connecting hole (22).

6. A packer-type staged collar for cementing operations in oil and gas wells according to claim 5, characterized in that: The bottom of the sliding groove (11) is also provided with a second shearing pin (42), which is located between the first shearing pin (41) and the piston chamber (14). The second shearing pin (42) is spaced from the end wall of the sliding groove (11), and the shearing pressure required by the second shearing pin (42) is greater than the shearing pressure of the first shearing pin (41).

7. A packer-type staged collar for cementing operations in oil and gas wells according to claim 6, characterized in that: The outer peripheral wall of the sliding sleeve (21) is provided with a sealing hole (26). The sealing hole (26) is spaced apart from the receiving hole (25). A sealing post (43) is slidably arranged in the sealing hole (26). A sealing spring (431) is provided in the sealing hole (26). The two ends of the sealing spring (431) are respectively fixed to the end face of the sealing post (43) and the bottom of the sealing hole (26). A positioning hole (15) is provided at the end of the sliding groove (11) away from the grouting hole (12). The positioning hole (15) is adapted to the end of the sealing post (43), and the end of the sealing post (43) can be inserted into the positioning hole (15). The positioning hole (15) is opened on the side of the second shear pin (42) away from the first shear pin (41).

8. A packer-type staged collar for cementing operations in oil and gas wells according to claim 7, characterized in that: The bottom of the sliding groove (11) is provided with a limiting groove (17) corresponding to the closing column (43). The limiting groove (17) is provided at intervals with the connecting groove (13) and the second shear pin (42). The end of the closing column (43) is adapted to the limiting groove (17) and is slidably disposed in the limiting groove (17).

9. A packer-type staged collar for cementing operations in oil and gas wells according to claim 2, characterized in that: The edge of the limiting hole (131) is chamfered.

10. A packer-type staged collar for cementing operations in oil and gas wells according to claim 7, characterized in that: The opening of the positioning hole (15) is chamfered.

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