A floating collar float shoe for deep well cementing

Abstract

A kind of float collar float shoe for deep well cementing, relate to the technical field of oil and gas cementing tool.The upper part of the cementing valve body is provided with a tubing box thread, the cementing valve body is provided with a central hole below the tubing box thread, the outer circle of the cementing valve body is connected to the cementing valve body through thread and sealing ring, the inner side of the cementing valve body extends downward a central tube, the outer circle of the cementing valve body extends downward a downcomer, the downcomer and the central tube are gap fit, and the central hole of the cementing valve body extends downward a convex sleeve.The beneficial effects of the present application are: the cementing operation is carried out after anchoring and sealing at the bottom of the casing, avoiding the problem that the float collar float shoe cannot be removed when it is installed at the bottom of the casing for cementing operation, the cementing valve body is provided to realize the function of one-way cement injection, the cementing valve body is provided to realize the function of reverse pressure bearing after being pulled out, the cementing valve body can be reused after the cementing operation is completed, and the operation cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of oil and gas cementing tools, and in particular to a floating hoop and float shoe for deep well cementing. Background Technology

[0002] Floaters and floats are one of the important tools for cementing operations. Their reverse pressure bearing reliability is the key to ensuring that cement slurry does not flow back. As exploration and development continue to move towards ultra-deep and extra-deep wells, and drilling depths are constantly breaking records, the reverse pressure bearing requirements of floaters and floats are becoming increasingly stringent. Accompanying the high temperature, acid, alkali, and salt corrosion, as well as the high-volume high-pressure erosion construction environment, conventional cementing floaters and floats are failing more and more, leading to engineering problems such as plugging inside the pipe and cement slurry not flowing back properly outside the pipe.

[0003] The existing floats and float shoes are installed at the bottom of the casing string for cementing operations. After the grouting operation is completed in the well, they cannot be removed and eventually solidify with the cement slurry and casing to form the wellbore structure, resulting in a waste of equipment resources and high construction costs. Summary of the Invention

[0004] To address the problems of insufficient reverse pressure bearing capacity and high construction costs of existing floating hoop floats, this invention provides a floating hoop float for deep well cementing.

[0005] The technical solution provided by this invention is: a floating hoop float shoe for deep well cementing, including a ash injection valve body, an oil pipe female thread on the upper part of the ash injection valve body, a central hole at the lower part of the oil pipe female thread of the ash injection valve body, a plugging valve body connected to the outer circle of the ash injection valve body through a thread and a sealing ring, a central pipe extending downward from the inner side of the plugging valve body, a lower guide pipe extending downward from the outer circle of the ash injection valve body, the lower guide pipe and the central pipe being clearance-fitted, a protruding sleeve extending downward from the central hole of the ash injection valve body, an annular space between the protruding sleeve and the lower guide pipe, several side holes B on the pipe wall of the protruding sleeve, an upper valve seat threaded to the lower end of the inner hole of the lower guide pipe, a through-flow port A on the upper valve seat, a compression spring connected to the upper part of the upper valve seat, an upper valve head connected to the upper part of the compression spring, a sealing column A on the upper part of the upper valve head, a pressure bearing ring A on the lower part, the sealing column A being clearance-fitted to the central hole through a sealing ring, and the outer diameter of the pressure bearing ring being larger than the central hole;

[0006] The outer circle of the ash-blocking valve body extends downwards to form an outer sleeve. Inside the outer sleeve is a piston. The piston is fitted with the outer sleeve and the central tube through a sealing ring. The central tube has an inlet hole above the sealing ring of the piston. The ash-injecting valve body has an annular groove at the inlet hole. A side hole A is machined between the annular groove and the central hole. The outer sleeve has a strip groove extending upwards from the lower end. The number of strip grooves is three evenly distributed around the circumference. A slip is installed in each strip groove. The lower part of the outer circle of the piston is a conical surface with a reduced diameter. The inner side of the slip is a conical arc surface. The conical arc surface on the inner side of the slip has the same taper as the conical surface of the piston.

[0007] The central tube is fitted with spacer ring A, rubber sleeve and spacer ring B in sequence on the lower side of the slip. The lower part of the central tube is connected to the guide shoe by thread. The outer side of the guide shoe is pressed against the bottom of spacer ring B. The protruding sleeve and the upper valve head are connected by a setting pin.

[0008] A conical hole extends from the lower part of the central tube toward the axis. The diameter of the upper part of the conical hole is reduced, and the upper part of the conical hole is machined into a straight section hole. The lower part of the guide shoe is threaded to the lower valve seat. The lower valve seat has a through-flow port B. The upper part of the lower valve seat is connected to a compression spring. The upper part of the compression spring is connected to the lower valve head. The lower valve head has a sealing column B at the upper part and a pressure bearing ring B at the lower part. The diameter of the pressure bearing ring B is larger than the maximum diameter of the conical hole. The sealing column B and the straight section hole are fitted with a sealing ring through a clearance. The lower valve head has a conical head machined on the upper part of the sealing column B.

[0009] The lower part of the upper valve seat is provided with a top column. When in the installation position, the top column pushes the lower valve head downward, and the sealing column B does not contact the straight section hole.

[0010] The piston's inner bore is machined with a one-way toothed hole, and the outer circle of the central tube is machined with a one-way toothed ring. The one-way toothed hole and the one-way toothed ring work together to allow the piston to descend along the central tube but not rise.

[0011] During installation, the sealing ring of sealing column A is positioned above the side hole B.

[0012] The three locks are fitted with restraint rings on the outside, which are made of magnesium metal.

[0013] The beneficial effects of the present invention are as follows: The present invention avoids the problem that the float collar and float shoe could not be removed when cementing operations were carried out after anchoring and sealing the bottom of the casing. The present invention sets up a cement injection valve body to realize the function of unidirectional cement injection, and sets up a cement plugging valve body to realize the function of reverse pressure after the cement injection valve body is pulled out. The cement injection valve body can be pulled up and reused after the cementing operation is completed, reducing the operating cost.

[0014] The pressure ring A of the upper valve head and the pressure ring B of the lower valve head bear pressure through a planar pressure, which is different from the line seal pressure bearing of the steel ball in the previous one-way valve. The pressure rings A and B can withstand greater reverse pressure, making them suitable for deep well cementing operations. Attached Figure Description

[0015] Appendix Figure 1 This is a schematic diagram of the structure of the present invention;

[0016] Appendix Figure 2 It is attached Figure 1 Enlarged view of point A;

[0017] Appendix Figure 3 This is a schematic diagram of the ash injection valve body in this invention;

[0018] Appendix Figure 4This is a perspective view of the ash-blocking valve body in this invention;

[0019] Appendix Figure 5 This is a schematic diagram of the ash-blocking valve body in this invention;

[0020] Appendix Figure 6 This is a schematic diagram of the upper valve head in this invention;

[0021] Appendix Figure 7 This is a schematic diagram of the lower valve head in this invention;

[0022] Appendix Figure 8 This is a schematic diagram of the structure after the ash injection operation of the present invention is completed.

[0023] In the diagram: 1-Ash injection valve body, 101-Oil pipe female thread, 102-Center hole, 103-Annular groove, 104-Side hole A, 105-Protruding sleeve, 106-Side hole B, 107-Lower guide pipe, 2-Ash plugging valve body, 201-Center pipe, 202-Outer sleeve, 203-Strip groove, 204-Conical hole, 205-Straight section hole, 206-Inlet hole, 207-One-way toothed ring, 3-Piston, 301-One-way... 4-Upper valve head, 401-Sealing post A, 402-Pressure ring A, 5-Setting pin, 6-Upper valve seat, 601-Flow port A, 602-Top post, 7-Lower valve head, 701-Sealing post B, 702-Pressure ring B, 703-Conical head, 8-Guide shoe, 9-Lower valve seat, 901-Flow port B, 10-Slipper, 11-Restraint ring, 12-Spacer ring A, 13-Rubber sleeve, 14-Spacer ring B. Detailed Implementation

[0024] like Figures 1-8 As shown, a floating hoop / float shoe for deep well cementing includes an ash injection valve body 1. The upper part of the ash injection valve body 1 has a tubing female thread 101. A central hole 102 is opened at the lower part of the tubing female thread 101. The outer circumference of the ash injection valve body 1 is connected to a plugging valve body 2 via threads and a sealing ring. A central pipe 201 extends downward from the inner side of the plugging valve body 2. A lower guide pipe 107 extends downward from the outer circumference of the ash injection valve body 1, with a clearance fit between the lower guide pipe 107 and the central pipe 201. A protruding sleeve 105 extends downward from the central hole 102 of the ash injection valve body 1. There is an annular space between 105 and the lower lead pipe 107. Several side holes B106 are opened on the pipe wall of the protruding sleeve 105. The lower end of the inner hole of the lower lead pipe 107 is threaded to the upper valve seat 6. The upper valve seat 6 has a through flow port A601. The upper part of the upper valve seat 6 is connected to the upper part of the compression spring. The upper part of the compression spring is connected to the upper valve head 4. The upper part of the upper valve head 4 is provided with a sealing column A401 and the lower part is provided with a pressure bearing ring A402. The sealing column A401 is connected to the center hole 102 through the sealing ring clearance fit. The outer diameter of the pressure bearing ring A402 is larger than the center hole 102.

[0025] The outer circle of the ash-blocking valve body 2 extends downward into a sleeve 202. A piston 3 is installed inside the sleeve 202. The piston 3 is in clearance fit with the sleeve 202 and the central tube 201 through a sealing ring. The central tube 201 has an inlet hole 206 above the sealing ring of the piston 3. The ash-injecting valve body 1 has an annular groove 103 at the inlet hole 206. A side hole A104 is machined between the annular groove 103 and the central hole 102. The sleeve 202 has a strip groove 203 extending upward from the lower end. The number of strip grooves 203 is three evenly distributed around the circumference. A slip 10 is installed in each strip groove 203. The lower part of the outer circle of the piston 3 is a conical surface with a reduced diameter. The inner side of the slip 10 is a conical arc surface. The conical arc surface on the inner side of the slip 10 has the same taper as the conical surface of the piston 3.

[0026] The central tube 201 is fitted with a spacer ring A12, a rubber sleeve 13 and a spacer ring B14 in sequence on the lower side of the slip 10. The lower part of the central tube 201 is connected to the guide shoe 8 by a thread. The outer side of the guide shoe 8 is pressed against the bottom of the spacer ring B14. The protruding sleeve 105 and the upper valve head 4 are connected by a seating pin 5.

[0027] A conical hole 204 extends from the lower part of the central tube 201 toward the axis. The upper diameter of the conical hole 204 is reduced, and the upper part of the conical hole 204 is machined into a straight section hole 205. The lower part of the guide shoe 8 is threaded to the lower valve seat 9. The lower valve seat 9 has a through-flow port B901. The upper part of the lower valve seat 9 is connected to a compression spring. The upper part of the compression spring is connected to the lower valve head 7. The lower valve head 7 has a sealing column B701 on the upper part and a pressure bearing ring B702 on the lower part. The diameter of the pressure bearing ring B702 is larger than the maximum diameter of the conical hole 204. The sealing column B701 and the straight section hole 205 are fitted with a sealing ring through a clearance. The lower valve head 7 has a conical head 703 machined on the upper part of the sealing column B701.

[0028] The lower part of the upper valve seat 6 is provided with a top post 602. When in the installation position, the top post 602 pushes the lower valve head 7 downward, and the sealing post B701 does not contact the straight section hole 205.

[0029] The piston 3 has a one-way toothed hole 301 machined in its inner hole, and a one-way toothed ring 207 machined on the outer circle of the central tube 201. The one-way toothed hole 301 and the one-way toothed ring 207 work together to allow the piston 3 to descend along the central tube 201 but not to rise.

[0030] During installation, the sealing ring of sealing column A401 is positioned above the side hole B106.

[0031] The three clasps 10 are fitted with restraint rings 11, which are made of magnesium metal.

[0032] In this invention, after the casing is installed, an oil pipe is connected to the bottom of the casing via the female thread 101 of the ash-filling valve body 1. Then, water is injected into the tubing string under pressure. The water pressure enters the inlet hole 206 through the side hole A104 and the annular groove 103, pushing the piston 3 down. As the piston 3 descends, it compresses the slip 10 to expand outward, and the rubber sleeve 13 is compressed and expanded. Since the piston 3 can only descend along the central tube 201 and cannot rise, the slip 10 is anchored to the inner wall of the casing. The expansion of the rubber sleeve 13 fills the annular space between the casing and the ash-filling valve body 2. The seal is formed, the pressure inside the tubing increases, shearing the setting pin 5. The water pressure pushes the upper valve head 4 down, and water flows from the side hole B106 to the lower valve head 7. Since the lower valve head 7 is normally open at this time, the water flows directly out of the guide shoe 8 to clean the well wall outside the casing. Then, cement is injected. After the cement injection is completed, the tubing is rotated, the ash injection valve body 1 separates from the ash plugging valve body 2, the top column 602 leaves the lower valve head 7, the lower valve head 7 rises, and the sealing column B701 seals with the straight section hole 205 to prevent the injected cement from flowing out in reverse.

[0033] This invention avoids the problem of float collars and float shoes being unable to be removed when cementing operations are carried out after anchoring and sealing the bottom of the casing. The invention sets up a cement injection valve body 1 to achieve the function of unidirectional cement injection, and a cement plugging valve body 2 to achieve the function of reverse pressure bearing after the cement injection valve body 1 is lifted. The cement injection valve body 1 can be lifted up and reused after the cementing operation is completed, reducing the operating cost.

[0034] The pressure ring A402 of the upper valve head 4 and the pressure ring B702 of the lower valve head 7 are pressure-bearing through a planar structure, which is different from the line seal pressure bearing of the steel ball in the conventional one-way valve. The pressure rings A402 and B702 can withstand greater reverse pressure, making them suitable for deep well cementing operations.

Claims

1. A floating hoop and float shoe for deep well cementing, comprising an ash injection valve body (1), characterized in that: The upper part of the ash injection valve body (1) is provided with a female thread (101) for the oil pipe. The lower part of the ash injection valve body (1) has a central hole (102). The outer circle of the ash injection valve body (1) is connected to the ash plugging valve body (2) through threads and a sealing ring. A central tube (201) extends downward from the inner side of the ash plugging valve body (2). A lower guide tube (107) extends downward from the outer circle of the ash injection valve body (1). The lower guide tube (107) and the central tube (201) are in clearance fit. A protruding sleeve (105) extends downward from the central hole (102) of the ash injection valve body (1). The protruding sleeve (105) and the lower guide tube (107) are connected downward. There is an annular space between them. Several side holes B (106) are opened on the pipe wall of the protruding sleeve (105). The lower end of the inner hole of the lower lead pipe (107) is threaded to the upper valve seat (6). The upper valve seat (6) has a through flow port A (601) that runs through the upper and lower parts. The upper part of the upper valve seat (6) is connected to the compression spring. The upper part of the compression spring is connected to the upper valve head (4). The upper valve head (4) is provided with a sealing column A (401) at the top and a pressure ring A (402) at the bottom. The sealing column A (401) is connected to the center hole (102) through the gap fit of the sealing ring. The outer diameter of the pressure ring A (402) is larger than that of the center hole (102). The outer circumference of the ash-blocking valve body (2) extends downwards by a sleeve (202). A piston (3) is provided inside the sleeve (202). The piston (3) is in clearance fit with the sleeve (202) and the central tube (201) through a sealing ring. The central tube (201) has a liquid inlet hole (206) above the sealing ring of the piston (3). The ash-injecting valve body (1) has an annular groove (103) at the liquid inlet hole (206). The annular groove (103) and the central hole (106) are connected. 2) There is a side hole A (104) between them. The outer sleeve (202) has a strip groove (203) from the bottom end to the top. The number of strip grooves (203) is three evenly distributed around the circumference. A slip (10) is installed in each strip groove (203). The lower part of the outer circle of the piston (3) is a conical surface with a reduced diameter. The inner side of the slip (10) is a conical arc surface. The conical arc surface on the inner side of the slip (10) has the same taper as the conical surface of the piston (3). The central tube (201) is fitted with a spacer ring A (12), a rubber sleeve (13) and a spacer ring B (14) in sequence on the lower side of the slip (10). The lower part of the central tube (201) is connected to the guide shoe (8) by a thread. The outer side of the guide shoe (8) rests on the bottom of the spacer ring B (14). The protruding sleeve (105) and the upper valve head (4) are connected by a seated pin (5). A conical hole (204) extends from the lower part of the central tube (201) toward the axis. The upper diameter of the conical hole (204) is reduced. The upper part of the conical hole (204) is machined into a straight section hole (205). The lower part of the guide shoe (8) is threaded to the lower valve seat (9). The lower valve seat (9) has a through-flow port B (901) that runs vertically through it. The upper part of the lower valve seat (9) is connected to a compression spring. The upper part of the compression spring is connected to the lower valve head (7). The lower valve head (7) has a sealing column B (701) on the upper part and a pressure ring B (702) on the lower part. The diameter of the pressure ring B (702) is larger than the maximum diameter of the conical hole (204). The sealing column B (701) and the straight section hole (205) are fitted with a sealing ring through a clearance. The lower valve head (7) has a conical head (703) machined on the upper part of the sealing column B (701). The upper valve seat (6) is provided with a top post (602) at the lower part. When in the installation position, the top post (602) pushes the lower valve head (7) downward, and the sealing post B (701) does not contact the straight section hole (205).

2. The floating hoop and float shoe for deep well cementing according to claim 1, characterized in that: The piston (3) has a one-way toothed hole (301) in its inner hole and a one-way toothed ring (207) in its outer circle. The one-way toothed hole (301) and the one-way toothed ring (207) work together to allow the piston (3) to descend along the central tube (201) but not to rise.

3. The floating hoop and float shoe for deep well cementing according to claim 1, characterized in that: During installation, the sealing ring of sealing column A (401) is positioned above the side hole B (106).

4. The floating hoop and float shoe for deep well cementing according to claim 1, characterized in that: The three clasps (10) are fitted with restraint rings (11) on the outside, which are made of magnesium metal.

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