A bypass circulation mechanism and system for semi-cementing of oil and gas wells

Abstract

The application discloses a bypass circulation mechanism and system for semi-length cementing of an oil and gas well, and belongs to the technical field of oil and gas exploitation. The bypass circulation mechanism comprises a shell assembly, a shearing sleeve and a pushing assembly. The upper joint and the lower joint of the shell assembly are fixedly assembled with an outer shell at the outer diameter end and an inner shell at the inner diameter end. The shearing sleeve is slidably sleeved at the outer diameter end of the inner shell. The pushing assembly is arranged between the lower joint and the inner shell and is used for moving and colliding the shearing sleeve to make it reach a set position. The shearing sleeve and the pushing tooth plate are arranged between the outer shell and the inner shell, and the movable bump plug assembly is arranged at the inner cavity side of the inner shell. In the process of pumping cement slurry, the position of the shearing sleeve can be adjusted through the pressure of the displacement fluid. When the shearing sleeve is stuck, the shearing sleeve can be hit through the bump plug assembly to make the shearing sleeve slide back to the original position, so that the annular space pressure imbalance caused by the bypass circulation blockage and the well blowout induced thereby can be prevented.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas extraction technology, specifically relating to a bypass circulation mechanism and system for half-stage cementing of oil and gas wells. Background Technology

[0002] The bypass circulation mechanism for partial cementing of oil and gas wells is a tool used for partial cementing operations in oil and gas wells.

[0003] After the designed amount of cement slurry has been pumped out, a pressure reducer needs to be engaged to continue the displacement operation. The function of the pressure reducer is to reduce the internal pressure of the tool or change the fluid flow path. The pressure reduction operation causes the shear screw inside the shear sleeve to reach its designed shear value and break. The downward movement of the shear sleeve opens a new flow path, namely the bypass circulation channel. This channel allows the fluid to bypass the original main channel and circulate upwards back to the surface from the annular space between the drill pipe and the wellbore.

[0004] However, in the actual application of cementing tools, there is a possibility that the shear screw may get stuck. Because the solid phase of the mud in the well is easy to deposit, metal debris or cement blocks can easily get stuck in the gap of the shear sleeve, hindering the shear screw from bearing force and the sliding of the shear sleeve. In addition, the shear screw is in long-term contact with corrosive fluids such as hydrogen sulfide, and it is also easy to rust and stick to the metal surface of the sleeve, resulting in the shear sleeve being unable to be in place. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a bypass circulation mechanism for half-stage cementing in oil and gas wells, thereby solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A bypass circulation mechanism for half-stage cementing in oil and gas wells includes a housing assembly. The housing assembly includes an upper connector, a lower connector, a lower guide hole, an outer shell, and an inner shell. The outer shell is fixedly assembled to the outer diameter ends of the upper connector and the lower connector. A lower guide hole is also provided on one side of the lower connector. The inner shell is fixedly assembled to the inner diameter ends of the upper connector and the lower connector.

[0008] A shearing assembly, comprising a shearing sleeve and shearing screws, wherein the shearing sleeve is slidably sleeved on the outer diameter end of the inner housing and arranged on the inner wall side of the outer housing, and a plurality of shearing screws are arranged on the inner diameter end of the shearing sleeve, the ends of which are fitted onto the outer wall surface of the inner housing.

[0009] A pushing component is disposed between the lower connector and the inner housing, and is used to move the collision shear sleeve to reach a set position.

[0010] As a further embodiment of the present invention, the housing assembly further includes an inner guide groove, a plurality of the inner guide grooves are arranged on the inner wall surface of the inner housing, and the inner cavity of the inner housing is set as a first cavity with opposite sides, and the gap cavity between the inner housing and the outer housing is set as a second cavity with opposite sides. The first cavity and the second cavity are in a connected state by default, and the first cavity and the lower guide hole are movably sealed by a shear sleeve.

[0011] As a further embodiment of the present invention, the pushing assembly includes a pushing toothed plate, a linkage rod, a flipping plate, a fixing pin, and a collision rod. The pushing toothed plate is slidably arranged in the second cavity and is positioned near the inner guide groove. One end of the linkage rod is fixedly connected to the pushing toothed plate, and the other end of the linkage rod is rotatably fitted with the flipping plate. The fixing pin is fixedly arranged on the outer wall of the inner shell. The collision rod is slidably arranged in the second cavity, and one end of the collision rod is movably abutting against the flipping plate, while the other end of the collision rod is movably abutting against the shearing sleeve.

[0012] As a further embodiment of the present invention, the bypass circulation mechanism and system for half-stage cementing of oil and gas wells also includes a pressure plug assembly. The pressure plug assembly includes a plug head, a conical sealing ring and a tail cylinder. The plug head is slidably arranged in the first cavity. Several conical sealing rings are coaxially arranged on the plug head. A tail cylinder is also fixedly arranged at the end of the plug head.

[0013] As a further embodiment of the present invention, the pressure plug assembly further includes a central hole, a compression rod, a slot, a side hole, and a piston rod. The central hole is disposed in the tail cylinder body, the compression rod is elastically slidably inserted into the central hole, and the outer diameter end of the compression rod is also provided with a slot. The tail cylinder body is also provided with a side hole, and the piston rod is elastically slidably inserted into the side hole.

[0014] As a further embodiment of the present invention, the pressing plug assembly further includes a locking member, a locking plate, a groove, and a driven pin. The locking member is slidably assembled between the central hole and the side hole. One end of the locking member is provided with a locking plate, which is movably snapped into a slot. The locking member is also provided with a groove. One end of the driven pin is fixedly connected to the piston rod, and the other end of the driven pin is slidably assembled in the groove.

[0015] As a further embodiment of the present invention, the impact-pressing plug assembly further includes a tail plate and a one-way push plate. The tail plate is fixedly connected to the compression rod, and a plurality of one-way push plates are rotatably mounted on the tail plate. The one-way push plates and the push toothed plates are movably abutted against each other.

[0016] In summary, the embodiments of the present invention have the following beneficial effects compared with the prior art:

[0017] This invention provides a shear sleeve and a pusher plate between the outer shell and the inner shell, and a movable impact plug assembly is provided on the inner cavity side of the inner shell. During the pumping of cement slurry, the position of the shear sleeve can be regulated by the pressure of the displacement fluid. At the same time, when the shear sleeve is stuck, the impact plug assembly can impact the shear sleeve to make it slide back into place, preventing the bypass circulation from being blocked, which would lead to annular pressure imbalance and induce a blowout. Attached Figure Description

[0018] Figure 1 This is a partial cross-sectional view of a bypass circulation mechanism for half-cementing of oil and gas wells provided in one embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the shell assembly in a bypass circulation mechanism for half-stage cementing of oil and gas wells provided in one embodiment of the present invention.

[0020] Figure 3 for Figure 2 Enlarged schematic diagram of reference numeral A in the attached figure.

[0021] Figure 4 This is a schematic diagram of the pusher tooth plate in a bypass circulation mechanism for half-cementing of oil and gas wells provided in one embodiment of the present invention.

[0022] Figure 5 for Figure 4 Enlarged schematic diagram of reference numeral B in the attached figure.

[0023] Figure 6 This is a schematic diagram of the pressure plug assembly in a bypass circulation mechanism for half-stage cementing of oil and gas wells, provided in one embodiment of the present invention.

[0024] Figure 7 This is a schematic diagram of the pressure plug assembly in a bypass circulation mechanism for half-cementing of oil and gas wells, provided in one embodiment of the present invention, from another perspective.

[0025] Figure 8 for Figure 7 Enlarged schematic diagram of the figure marked C in the attached diagram.

[0026] Reference numerals: 1-Housing assembly, 101-Upper connector, 102-Lower connector, 103-Lower guide hole, 104-Outer shell, 105-Inner shell, 106-Inner guide groove, 2-Shearing assembly, 201-Shearing sleeve, 202-Shearing screw, 3-Pushing assembly, 301-Pushing toothed plate, 302-Linkage rod, 303-Flipping plate, 304-Fixing pin, 305-Collision rod, 4-Pushing plug assembly, 401-Plug head, 402-Conical sealing ring, 403-Tail cylinder, 404-Central hole, 405-Compression rod, 406-Slot, 407-Side hole, 408-Piston rod, 409-Locking element, 410-Locking plate, 411-Slanted groove, 412-Driven pin, 413-Tail plate, 414-One-way push plate. Detailed Implementation

[0027] To more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Please see Figures 1-8 According to one embodiment of the present invention, a bypass circulation mechanism and system for half-stage cementing of oil and gas wells is provided. The bypass circulation mechanism and system for half-stage cementing of oil and gas wells has a first direction x, a second direction y, and a third direction z. The bypass circulation mechanism and system for half-stage cementing of oil and gas wells includes a housing assembly 1, which includes an upper connector 101, a lower connector 102, a lower guide hole 103, an outer shell 104, and an inner shell 105. The outer diameter ends of the upper connector 101 and the lower connector 102 are fixedly fitted with the outer shell 104. A lower guide hole 103 is also provided on one side of the lower connector 102. The inner diameter ends of the upper connector 101 and the lower connector 102 are fixedly fitted with the inner shell 105. A shearing assembly 2 is also provided, which includes a shear sleeve 201 and a shear screw 202. The shear sleeve 201 is slidably sleeved on the inner shell 105. The outer diameter end of the shear sleeve 201 is provided on the inner wall side of the outer shell 104, and the inner diameter end of the shear sleeve 201 is provided with a plurality of shear screws 202, the ends of which are fitted onto the outer wall surface of the inner shell 105; the push assembly 3 is provided between the lower connector 102 and the inner shell 105, and is used to move and collide with the shear sleeve 201 to make it reach a set position; the shell assembly 1 also includes an inner guide groove 106, a plurality of which are provided on the inner wall surface of the inner shell 105, and the inner cavity of the inner shell 105 is set as a first cavity a1 with opposite sides, and the gap cavity between the inner shell 105 and the outer shell 104 is set as a second cavity a2 with opposite sides. The first cavity a1 and the second cavity a2 are in a connected state by default, and the first cavity a1 and the lower guide hole 103 are movably sealed by the shear sleeve 201.

[0029] In practical application, the outer diameter ends of the upper connector 101 and the lower connector 102 are fixedly fitted with outer shells 104, and the inner diameter ends of the upper connector 101 and the lower connector 102 are fixedly fitted with inner shells 105. A first cavity a1 is provided in the inner cavity of the inner shell 105. A second cavity a2 is provided between the upper connector 101, the lower connector 102, the outer shell 104, and the inner shell 105. The first cavity a1 and the second cavity a2 are connected by an inner guide groove 106. A shear sleeve 201 is movably disposed between the second cavity a2 and the lower guide hole 103. When the shear sleeve 201 slides against the outer shell 104 and the inner shell 105, the second cavity a2 and the lower guide hole 103 are in a sealed state. At this time, the shear screw 202 is assembled in the fixing hole on the outer wall side of the inner shell 105. When the cement slurry is pumped along the first cavity a1 and fills the bottom of the well, the pressure plug assembly 4 is assembled into the well and the cement slurry and the displacement fluid are separated by the pressure plug assembly 4. At this time, the displacement fluid is continuously... Pressurization is achieved by continuously pressurizing the cement slurry through the pressure-pressing plug assembly 4. When the pressure reaches a set value, the movement of the pressure-pressing plug assembly 4 is obstructed. At this time, the pressure of the displacement fluid in the well continues to increase. When the displacement fluid moves through the inner guide groove 106 into the second cavity a2, the pressure on the shear sleeve 201 continuously increases until the pressure exceeds the set threshold. At this time, the shear screw 202 breaks under the pressure, causing the shear sleeve 201 to slide along the outer wall of the inner shell 105 and move to the other side of the lower guide hole 103. When cavity a2 and lower guide hole 103 are switched to a connected state, the displacement fluid can pass through the lower guide hole 103 and circulate back from the annulus space outside the well wall to the wellhead, preventing excessive downhole pressure, allowing safe displacement operations, and providing a circulation path for circulating excess drilling fluid after cementing, and checking whether the wellbore is unobstructed and whether the pressure is balanced, etc., avoiding the problem of the lower part being blocked by cement after cementing and unable to establish circulation. At the same time, it can also reduce the situation where the bypass circulation is blocked when the shear sleeve 201 is stuck.

[0030] Please see Figure 4 and Figure 5 In a preferred embodiment of the present invention, the pushing component 3 includes a pushing toothed plate 301, a linkage rod 302, a flipping plate 303, a fixing pin 304, and a collision rod 305. The pushing toothed plate 301 is slidably arranged in the second cavity a2 and is positioned near the inner guide groove 106. One end of the linkage rod 302 is fixedly connected to the pushing toothed plate 301, and the other end of the linkage rod 302 is rotatably fitted with the flipping plate 303. The fixing pin 304 is fixedly arranged on the outer wall of the inner housing 105. The collision rod 305 is slidably arranged in the second cavity a2, and one end of the collision rod 305 is movably abutting against the flipping plate 303, while the other end of the collision rod 305 is movably abutting against the shearing sleeve 201.

[0031] In practical application, the push toothed plate 301 is elastically slidably arranged in the inner guide groove 106, and the end of the push toothed plate 301 is fixedly equipped with a linkage rod 302. Since the fixed shaft pin 304 is fixedly arranged on the outer wall end of the inner shell 105, and the flip plate 303 is rotatably assembled at the end of the linkage rod 302, one end of the flip plate 303 is in movable contact with the fixed shaft pin 304, and the other end of the flip plate 303 is in movable contact with the collision rod 305. Therefore, when the push toothed plate 301 moves in the negative direction of the first direction x, the push toothed plate 301 synchronously pulls the linkage rod 302 to move during the movement. When the linkage rod 302 moves, the flip plate 303 connected to its end pushes the collision rod 305 to move in the positive direction of the first direction x during the process of contacting the fixed shaft pin 304, thereby causing the end of the collision rod 305 to collide with the shear sleeve 201.

[0032] Because the solid phase of the mud in the well is prone to deposition, metal debris or cement blocks can easily get stuck in the gap of the shear sleeve 201, hindering the shear screw 202 from bearing force and the sliding of the shear sleeve 201. In addition, the shear screw 202 is in long-term contact with corrosive fluids such as H2S and / or CO2, and is also prone to rust and adhesion to the metal surface of the sleeve, resulting in the shear sleeve 201 being unable to be in place. The collision rod 305 can further cause the shear screw 202 to break through the impact and push the shear sleeve 201 to slide, thereby preventing the bypass circulation from being blocked.

[0033] Please see Figure 5 In a preferred embodiment of the present invention, the bypass circulation mechanism and system for the half-stage cementing of the oil and gas well further includes a pressure plug assembly 4. The pressure plug assembly 4 includes a plug head 401, a conical sealing ring 402 and a tail cylinder 403. The plug head 401 is slidably arranged in the first cavity a1. A plurality of conical sealing rings 402 are coaxially arranged on the plug head 401. The tail cylinder 403 is also fixedly arranged at the end of the plug head 401.

[0034] In practical application, the plug 401, the conical sealing ring 402, and the tail cylinder 403 are slidably arranged in the first cavity a1. Several conical sealing rings 402 are used to separate the cement slurry and the displacement liquid, and under the pressure of the displacement liquid, the cement slurry is pushed into the first cavity a1 to compact the cement slurry.

[0035] Please see Figure 8 In a preferred embodiment of this embodiment, the pressure plug assembly 4 further includes a central hole 404, a compression rod 405, a groove 406, a side hole 407, and a piston rod 408. The central hole 404 is disposed in the tail cylinder 403. The compression rod 405 is elastically slidably inserted into the central hole 404, and the outer diameter end of the compression rod 405 is also provided with a groove 406. The tail cylinder 403 is also provided with a side hole 407, and the piston rod 408 is elastically slidably inserted into the side hole 407.

[0036] In practical application, the central hole 404 is located in the middle of the tail cylinder 403. The compression rod 405 is elastically and slidably disposed in the central hole 404, and the compression rod 405 has a relative locked state and a released state. The compression rod 405 is in the locked state by default, and the slot 406 on one side is locked in the central hole 404. The tail cylinder 403 is also provided with a side hole 407, in which a piston rod 408 is elastically and slidably assembled. The piston rod 408 and the side hole 407 are slidably and sealingly connected. When the plug 401 pushes the cement slurry... When the movement reaches the limit position and the shear sleeve 201 is not released, the pressure of the displacement fluid in the well continuously increases, causing the piston rod 408 to move against the elastic force under the pressure. This causes the piston rod 408 to move in the positive direction of the first direction x, and the compression rod 405 to switch from the locked state to the released state. At this time, the compression rod 405 is quickly released under the action of elastic force, and drives the push tooth plate 301 to move in the negative direction of the first direction x, thereby pushing the collision rod 305 to move, so that the collision rod 305 quickly impacts one side of the shear sleeve 201, thereby causing the shear sleeve 201 to slide to the set fracture position.

[0037] Please see Figure 7 and Figure 8 In a preferred embodiment of the present invention, the pressing plug assembly 4 further includes a locking member 409, a locking plate 410, a groove 411, and a driven pin 412. The locking member 409 is slidably assembled between the central hole 404 and the side hole 407. One end of the locking member 409 is provided with a locking plate 410, which is movably snapped into a slot 406. The locking member 409 is also provided with a groove 411. One end of the driven pin 412 is fixedly connected to the piston rod 408, and the other end of the driven pin 412 is slidably assembled in the groove 411.

[0038] In practical application, the locking member 409 is slidably assembled between the central hole 404 and the side hole 407 along the third direction z, and the locking plate 410 at one end of the locking member 409 is movably snapped into the slot 406 to restrict the movement of the compression rod 405 in the first direction x. The locking member 409 is also provided with a slanted groove 411 on one side. When the driven pin 412 moves along the positive direction of the first direction x with the piston rod 408, it can push the slanted groove 411 and the locking member 409 to move away from the slot 406, thereby switching the compression rod 405 from the locked state to the released state, thereby driving the movement of the push tooth plate 301.

[0039] Furthermore, the pressure plug assembly 4 also includes a tail plate 413 and a one-way push plate 414. The tail plate 413 is fixedly connected to the compression rod 405. The tail plate 413 is also elastically and rotatably equipped with a plurality of one-way push plates 414. The one-way push plates 414 and the push tooth plate 301 are movably abutted, so that when the compression rod 405 moves in the negative direction of the first direction x, the one-way push plates 414 on the tail plate 413 are stuck in the groove of the push tooth plate 301 and push the push tooth plate 301 to move in the negative direction of the first direction x. When the plug head 401, the conical sealing ring 402 and the tail cylinder 403 move in the positive direction of the first direction x, the one-way push plates 414 elastically abut against the push tooth plate 301 and do not interfere with the groove on the push tooth plate 301.

[0040] Furthermore, the push tooth plate 301 is configured as a strip structure so that the unidirectional push plate 414 can push the push tooth plate 301 at any position. During the pushing process, since the cement slurry at the other end of the plug 401 can no longer be compressed, the plug 401 and the inner shell 105 are assumed to be approximately stationary relative to each other. This makes the effect of the small displacement of the plug 401 on the stroke of the push tooth plate 301 negligible during the release of the compression rod 405.

[0041] The above embodiments of the present invention provide a bypass circulation mechanism and system for half-stage cementing of oil and gas wells. By providing a shear sleeve 201 and a pusher tooth plate 301 between the outer shell 104 and the inner shell 105, and providing a movable impact plug assembly 4 on the inner cavity side of the inner shell 105, the position of the shear sleeve 201 can be regulated by the pressure of the displacement fluid during the pumping of cement slurry. At the same time, when the shear sleeve 201 is stuck, the impact plug assembly 4 can impact the shear sleeve 201 to make the shear sleeve 201 slide back into place, preventing the bypass circulation from being blocked, which would lead to annular pressure imbalance and induce a blowout.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A bypass circulation mechanism for half-stage cementing in oil and gas wells, characterized in that, The bypass circulation mechanism for half-stage cementing in oil and gas wells includes: A housing assembly, comprising an upper connector, a lower connector, a lower guide hole, an outer shell, and an inner shell, wherein the outer shell is fixedly assembled to the outer diameter ends of the upper and lower connectors, a lower guide hole is provided on one side of the lower connector, and the inner shell is fixedly assembled to the inner diameter ends of the upper and lower connectors. A shearing assembly, comprising a shearing sleeve and shearing screws, wherein the shearing sleeve is slidably sleeved on the outer diameter end of the inner housing and arranged on the inner wall side of the outer housing, and a plurality of shearing screws are arranged on the inner diameter end of the shearing sleeve, the ends of which are fitted onto the outer wall surface of the inner housing. A pushing component is provided between the lower connector and the inner housing, and is used to move the collision shear sleeve to make it reach a set position; The housing assembly further includes an inner guide groove, a plurality of the inner guide grooves are arranged on the inner wall surface of the inner housing, and the inner cavity of the inner housing is set as a relative first cavity, the gap cavity between the inner housing and the outer housing is set as a relative second cavity, the first cavity and the second cavity are in a connected state by default, and the first cavity and the lower guide hole are movably sealed by a shear sleeve. The pushing assembly includes a pushing toothed plate, a linkage rod, a flipping plate, a fixed shaft pin, and a collision rod. The pushing toothed plate is slidably arranged in the second cavity and is positioned near the inner guide groove. One end of the linkage rod is fixedly connected to the pushing toothed plate, and the other end of the linkage rod is rotatably fitted with the flipping plate. The fixed shaft pin is fixedly arranged on the outer wall of the inner shell. The collision rod is slidably arranged in the second cavity, and one end of the collision rod is movably abutting against the flipping plate, while the other end of the collision rod is movably abutting against the shearing sleeve. The bypass circulation mechanism for the half-stage cementing of the oil and gas well also includes a pressure plug assembly, which includes a plug head, a conical sealing ring, and a tail cylinder. The plug head is slidably arranged in the first cavity, and several conical sealing rings are coaxially arranged on the plug head. A tail cylinder is also fixedly installed at the end of the plug head.

2. The bypass circulation mechanism for half-stage cementing of oil and gas wells according to claim 1, characterized in that, The pressure plug assembly also includes a central hole, a compression rod, a slot, a side hole, and a piston rod. The central hole is located in the tail cylinder. The compression rod is elastically slidably inserted into the central hole, and the outer diameter end of the compression rod is also provided with a slot. The tail cylinder is also provided with a side hole, and the piston rod is elastically slidably inserted into the side hole.

3. A bypass circulation mechanism for half-stage cementing of oil and gas wells according to claim 2, characterized in that, The pressure plug assembly also includes a locking member, a locking plate, a groove, and a driven pin. The locking member is slidably assembled between the central hole and the side hole. One end of the locking member is provided with a locking plate, which is movably snapped into a slot. The locking member is also provided with a groove. One end of the driven pin is fixedly connected to the piston rod, and the other end of the driven pin is slidably assembled in the groove.

4. A bypass circulation mechanism for half-stage cementing of oil and gas wells according to claim 2, characterized in that, The pressure plug assembly also includes a tail plate and a one-way push plate. The tail plate is fixedly connected to the compression rod, and a number of one-way push plates are also rotatably mounted on the tail plate. The one-way push plates and the push tooth plate are in movable contact.

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