Packing type drilling-free grading hoop
By designing a sealed drill-free graded hoop, high-strength alloy steel and high-temperature and high-pressure rubber sealing cylinder, combined with a drill-free release mechanism, the existing graded hoop drilling problems are solved, and efficient downhole sealing and safe cementing operations are achieved.
Patent Information
- Application Number
- CN202510883124.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-28
- Publication Date
- 2025-08-15
AI Technical Summary
The existing graded hoops need to be drilled to remove the blocking device in cementing operations, which increases the working time and cost, and the sealing performance is poor in high-pressure and high-temperature environments, resulting in cement slurry leakage and annular flow, affecting cementing quality and safety.
A sealed drill-free graded hoop is designed, using high-strength alloy steel material and a rubber sealing cylinder that is resistant to high temperature and high pressure. Combined with a drill-free release mechanism, the automatic expansion and sealing of the rubber sealing cylinder is achieved through the cooperation of the extrusion ring and the moving ring, providing good sealing performance, and controlling the opening and closing of the circulation hole through the sliding sleeve mechanism.
No drilling operation is required, which shortens the cementing cycle, reduces costs, improves the cementing quality, ensures the downhole sealing effect, prevents cement slurry leakage and annular flow, and enhances the integrity and safety of the well body structure.
Smart Images
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Abstract
Description
Technical Field
[0001] The invention relates to the field of well cementing in oil and gas wells, in particular to an isolation type drilling-free grading collar. Background Art
[0002] Currently, after cementing stages in existing graded collars, the internal plugging devices typically need to be removed through subsequent drilling and removal operations. This not only increases operation time and costs, but can also damage the casing due to improper drilling tool operation, affecting the integrity of the wellbore structure and the safety of subsequent production operations. Furthermore, some graded collars have poor isolation performance. Under harsh downhole conditions such as high pressure and high temperature, cement slurry leakage and annular crossflow are prone to occur, resulting in substandard cementing quality and an inability to effectively isolate formation fluids, increasing safety risks and economic losses during oil well production.
[0003] Based on this, the present invention designs a sealed drill-free grading collar to solve the above problems. Summary of the Invention
[0004] The object of the present invention is to provide an isolation type drill-free grading collar to solve the problems of the existing grading collars mentioned in the above background art, such as cumbersome drilling and removal operations and poor isolation performance in cementing operations.
[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a sealed drill-free grading collar, comprising a lifting short section, wherein the outer side of the bottom of the lifting short section is connected to an upper joint by a thread, the outer side of the bottom of the upper joint is connected to a body by a thread, a retaining ring is installed inside the body, a closing sleeve is slidably connected to the inner wall of the body by a guide screw, a center tube is installed inside the closing sleeve, a locking block is provided on the center tube, a closing plug seat and an opening plug seat are installed inside the center tube, an inner tube is inserted into the inner side of the bottom of the body, a sealing mechanism is placed on the outer side of the inner tube, and a lower joint is placed on the outer side of the bottom of the inner tube.
[0006] Preferably, the body is made of high-strength alloy steel.
[0007] Preferably, the closing plug seat and the opening plug seat are both connected to the central tube via shear nails.
[0008] Preferably, the sealing mechanism includes a rubber sealing tube, and the rubber sealing tube is placed on the outside of the inner tube, and a rubber ring is fixed on the inner wall of the rubber sealing tube.
[0009] Preferably, the rubber sealing cylinder is made of a special rubber material that is resistant to high temperature and high pressure.
[0010] Preferably, an annular groove is provided in the side wall of the rubber sealing cylinder, and two movable rings are slidably connected in the extrusion ring, and the outer sides of the movable rings are connected to the extrusion ring through a connecting rod.
[0011] Preferably, an extrusion block is fixed to the inner end surface of the movable ring, and the extrusion blocks are evenly distributed on the movable ring in the circumferential direction.
[0012] Preferably, a moving block is movably connected in the annular groove, and the moving block is wedge-shaped and fits between the upper and lower extrusion blocks.
[0013] Preferably, a supporting block is fixed on the outer side of the moving block, and the supporting block is fixed on the outer wall of the rubber sealing cylinder.
[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The packer-type drill-free grading collar adopts a drill-free release mechanism, eliminating the need for subsequent drilling operations to clear blocked components inside the grading collar. This significantly shortens the cementing operation cycle, reduces the use time of drilling equipment and the consumption of related consumables, thereby reducing operating costs. 2. The isolation type drilling-free grading collar uses a high-temperature and high-pressure resistant rubber isolation rubber sleeve as its isolation component. A leather cup is installed inside the rubber isolation rubber sleeve, which can achieve good sealing effect in harsh downhole environments such as high pressure and high temperature, effectively preventing cement slurry leakage and annular channeling, ensuring that cementing quality meets standards. The good isolation performance and drilling-free function significantly improve cementing quality, effectively isolate formation fluids, reduce mutual interference between formations, and provide a strong guarantee for the long-term and stable production of oil and gas wells. 3. When the extrusion ring of the packer-type drill-free grading collar is squeezed, the extrusion ring squeezes the rubber ring, and the rubber packing tube automatically expands after being separated from the pressure cap. At the same time, the moving ring and the extrusion block move and squeeze the moving block, and the support block pulls the rubber packing tube apart. The support block plays a pulling role on the rubber packing tube, so that it can fit more tightly to the well wall more effectively. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of the front cross-sectional structure of the present invention; Figure 3 This is a schematic diagram of the connection structure of the body, pressure cap, inner tube, lower joint and sealing mechanism of the present invention; Figure 4 It is a schematic diagram of the connection structure of the connecting rod, extrusion ring, moving ring and extrusion block of the present invention.
[0016] In the figure: 1. lifting nipple; 2. center tube; 3. upper joint; 4. body; 5. closing plug seat; 6. locking block; 7. retaining ring; 8. closing sleeve; 9. opening plug seat; 10. pressing cap; 11. shear pins; 12. inner tube; 13. lower joint; 14. sealing mechanism; 1401. rubber sealing rubber tube; 1402. rubber ring; 1403. connecting rod; 1404. extrusion ring; 1405. moving ring; 1406. annular groove; 1407. extrusion block; 1408. moving block; 1409. supporting block. DETAILED DESCRIPTION
[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.
[0018] See also Figures 1 to 4 The present invention provides a technical solution: a sealing type drill-free grading collar, comprising a lifting short section 1, an upper joint 3 is connected to the outer side of the bottom of the lifting short section 1 through a threaded connection, a body 4 is connected to the outer side of the bottom of the upper joint 3 through a threaded connection, a retaining ring 7 is installed inside the body 4, a closing sleeve 8 is slidably connected to the inner wall of the body 4 through a guide screw, a center pipe 2 is installed inside the closing sleeve 8, a locking block 6 is provided on the center pipe 2, a closing plug seat 5 and an opening plug seat 9 are installed inside the center pipe 2, an inner tube 12 is inserted into the inner side of the bottom of the body 4, a sealing mechanism 14 is placed on the outer side of the inner tube 12, and a lower joint 13 is placed on the outer side of the bottom of the inner tube 12.
[0019] In this embodiment, Figure 1 、 Figure 2 and Figure 3 As shown, the body 4 is made of high-strength alloy steel, has good pressure resistance and corrosion resistance, and can withstand the complex pressure and harsh chemical environment underground.
[0020] In this embodiment, Figure 2As shown, the closing plug seat 5 and the opening plug seat 9 are both connected to the central pipe 2 by shear nails 11. When staged cementing operation is required, the opening plug collides with the opening plug seat 9 to shear the shear nails 11 at the opening plug seat 9 and the central pipe 2, so that the opening plug seat 9 moves relative to the central pipe 2 and the closing sleeve 8. The pressure is exerted through the pressure cap 10 to expand and seal the isolation mechanism 14. After expansion and sealing, the pressure is continued to be applied, and the shear nails 11 at the pressure cap 10 are cut to open the circulation hole, thereby realizing a circulation channel for the cement slurry. After the cementing operation is completed, after the closing plug reaches the position of the closing plug seat 5, the shear nails 11 at the closing plug seat 5 and the central pipe 2 are cut. By means of a component arranged at the lower end of the closing sleeve 8, the closing sleeve 8 can be locked inside the body 1, and the sliding sleeve mechanism closes the circulation hole to prevent the cement slurry from flowing back.
[0021] In this embodiment, Figure 1 、 Figure 2 and Figure 3 As shown, the sealing mechanism 14 includes a rubber sealing tube 1401, and the rubber sealing tube 1401 is placed on the outside of the inner tube 12. A rubber ring 1402 is fixed on the inner wall of the rubber sealing tube 1401. When the rubber ring 1402 expands and squeezes the rubber sealing tube 1401, the rubber sealing tube 1401 expands and adheres tightly to the well wall.
[0022] In this embodiment, Figure 1 、 Figure 2 and Figure 3 As shown, the rubber sealing cylinder 1401 is made of a special rubber material that is resistant to high temperature and high pressure and has good elasticity and sealing properties.
[0023] In this embodiment, Figure 2 、 Figure 3 and Figure 4 As shown, an annular groove 1406 is provided in the side wall of the rubber sealing cylinder 1401, and two movable rings 1405 are slidably connected in the extrusion ring 1404. The outer side of the movable ring 1405 is connected to the extrusion ring 1404 through a connecting rod 1403. The connecting rod 1403 serves to connect the extrusion ring 1404 and the movable ring 1405. When the extrusion ring 1404 is squeezed and moved, the movable ring 1405 moves accordingly.
[0024] In this embodiment, Figure 2 、 Figure 3 and Figure 4 As shown, an extrusion block 1407 is fixed to the inner end face of the moving ring 1405, and the extrusion blocks 1407 are evenly distributed circumferentially on the moving ring 1405. The movement of the moving ring 1405 will drive the extrusion blocks 1407 to move. When the two moving rings 1405 approach each other, the upper and lower extrusion blocks 1407 approach each other and cause extrusion.
[0025] In this embodiment, Figure 2 and Figure 3 As shown, a moving block 1408 is movably connected in the annular groove 1406, and the moving block 1408 is wedge-shaped and connected between the upper and lower extrusion blocks 1407. When the two moving rings 1405 approach each other, the upper and lower extrusion blocks 1407 approach each other and squeeze the moving block 1408, and the moving block 1408 moves outward, and every two extrusion blocks 1407 squeeze one moving block 1408.
[0026] In this embodiment, Figure 1 、 Figure 2 and Figure 3 As shown, a supporting block 1409 is fixed to the outside of the moving block 1408, and the supporting block 1409 is fixed on the outer wall of the rubber sealing tube 1401. When the upper and lower extrusion blocks 1407 squeeze the moving block 1408, the supporting block 1409 moves outward and expands the rubber sealing tube 1401. The supporting block 1409 plays a traction role in the process of the rubber sealing tube 1401 expanding, so that it can be better expanded and sealed.
[0027] The use method and advantages of the present invention: The working process of the packer-type drill-free grading collar is as follows: like Figures 1 to 4As shown: connect the assembled isolation type drill-free grading collar with the casing, lower it into the predetermined position in the well, carry out the first-stage cementing operation, put in the gravity opening plug, inject cement slurry according to the construction requirements, observe the expansion and sealing of the rubber tube to ensure good sealing, apply the graded opening pressure, check whether the grading collar is opened normally, carry out the second-stage cementing operation, put in the closing plug and apply the closing pressure to close the grading collar. After the cementing operation is completed, test the cementing quality to verify the working effect of the grading collar. The central pipe 2 provides a channel for the circulation of cement slurry. The function of the isolation mechanism 14 is to expand the rubber isolation rubber tube 1401 through external pressure after the grading collar is lowered into the well, and fit tightly to the grading collar. The casing is connected to the well wall to achieve a seal between the casing and the well wall, preventing cement slurry from running up or leaking down in the annulus. A plurality of circulation holes are evenly distributed on the circumference of the body 4. The function of the circulation hole is to provide a circulation channel for the cement slurry during the graded cementing operation, so that the cement slurry can smoothly enter the annulus from the casing to achieve cementing operations in different well sections. The sliding sleeve mechanism installed inside the body 4 is mainly composed of a closing sleeve 8, a central pipe 2, an opening plug seat 9 and a closing plug seat 5. The closing sleeve 8 is connected to the inner wall of the body 4 by a guide screw installed on the body 4 and can slide up and down inside the body 4. The function of the sliding sleeve mechanism is to control the opening and closing of the graded collar circulation hole. When it is needed, When performing staged cementing operations, the opening plug is pressed against the opening plug seat 9 to cut the shear nails 11 at the opening plug seat 9 and the central pipe 2, so that the opening plug seat 9 moves relative to the central pipe 2 and the closing sleeve 8. The pressure is applied to the pressure cap 10 to expand and seal the rubber packing tube 1401. When the extrusion ring 1404 is squeezed, the extrusion ring 1404 squeezes the rubber ring 1402. The rubber packing tube 1401 automatically expands after it is separated from the pressure cap 10. At the same time, the moving ring 1405 and the extrusion block 1407 move and squeeze the moving block 1408. The supporting block 1409 pulls and pulls the rubber packing tube 1401 apart, so that the rubber packing tube 1401 is more accurately and forcefully pressed against the wellbore. On the wall, continue to pressurize after expansion and sealing, and the shear nails 11 at the pressure cap 10 are cut off to open the circulation hole, thereby realizing the circulation channel of the cement slurry. After the cementing operation is completed, after the closing plug reaches the closing plug seat 5 position, the shear nails 11 at the closing plug seat 5 and the center pipe 2 are cut off. By means of the components arranged at the lower end of the closing sleeve 8, the closing sleeve 8 can be locked inside the body 4, and the sliding sleeve mechanism closes the circulation hole to prevent the cement slurry from flowing back. The drilling-free release mechanism is mainly composed of the center pipe 2, the closing plug seat 5, the opening plug seat 9 and the locking block 6. When the shear nails 11 at the closing plug seat 5 are cut off, the closing plug seat 5 moves downward, causing the locking block 6 to fall off, thereby realizing the falling off of the aluminum parts inside the grading hoop, and no drilling operation is required.
[0028] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.
[0029] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings. They are merely simplified descriptions for the convenience of describing the present invention, and do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the protection content of the present invention.
[0030] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A packer-type drill-free grading collar, comprising a lifting nipple (1), characterized in that: The outer thread of the bottom of the lifting short section (1) is connected to the upper joint (3), the outer thread of the bottom of the upper joint (3) is connected to the body (4), a retaining ring (7) is installed inside the body (4), a closing sleeve (8) is slidably connected to the inner wall of the body (4) through a guide screw, a center tube (2) is installed inside the closing sleeve (8), a locking block (6) is provided on the center tube (2), a closing plug seat (5) and an opening plug seat (9) are installed inside the center tube (2), an inner tube (12) is inserted into the inner side of the bottom of the body (4), a sealing mechanism (14) is placed on the outer side of the inner tube (12), and a lower joint (13) is placed on the outer side of the bottom of the inner tube (12).
2. The packer-type drill-free grading collar according to claim 1, characterized in that: The body (4) is made of high-strength alloy steel.
3. The packer-type drill-free grading collar according to claim 1, characterized in that: The closing plug seat (5) and the opening plug seat (9) are both connected to the central tube (2) via shear nails (11).
4. The packer-type drill-free grading collar according to claim 1, characterized in that: The sealing mechanism (14) comprises a rubber sealing tube (1401), and the rubber sealing tube (1401) is placed on the outside of the inner tube (12), and a rubber ring (1402) is fixed on the inner wall of the rubber sealing tube (1401).
5. The packer-type drill-free grading collar according to claim 4, characterized in that: The rubber sealing rubber cylinder (1401) is made of a special rubber material that is resistant to high temperature and high pressure.
6. The packer-type drill-free grading collar according to claim 4, characterized in that: An annular groove (1406) is provided in the side wall of the rubber sealing rubber cylinder (1401), and two movable rings (1405) are slidably connected in the extrusion ring (1404). The outer sides of the movable rings (1405) are connected to the extrusion ring (1404) via connecting rods (1403).
7. The packer-type drill-free grading collar according to claim 6, characterized in that: An extrusion block (1407) is fixed to the inner end surface of the movable ring (1405), and the extrusion blocks (1407) are evenly distributed on the movable ring (1405) in the circumferential direction.
8. The packer-type drill-free grading collar according to claim 6, characterized in that: A moving block (1408) is movably connected in the annular groove (1406), and the moving block (1408) is wedge-shaped and fits between the upper and lower extrusion blocks (1407).
9. The packer-type drill-free grading collar according to claim 8, characterized in that: A supporting block (1409) is fixed on the outer side of the moving block (1408), and the supporting block (1409) is fixed on the outer wall of the rubber sealing cylinder (1401).