A segmented cementing device

Abstract

This invention relates to the field of cementing and completion technology, and in particular to a segmented cementing device. Multiple packer components arranged at intervals from top to bottom work in conjunction with a bottom float shoe to achieve layer-by-layer grouting from bottom to top. During the grouting process, the cement slurry first activates the sealing and anchoring mechanisms of the lowest packer component, causing it to expand and tightly adhere to the well wall, forming a stable packer layer. This not only effectively supports the upper cement slurry and prevents it from sinking, but also significantly enhances the bonding strength between the casing and the formation. Furthermore, through a perforation, stop, tension spring, and a second moving casing linkage mechanism controlled by a shear pin, the interlayer channel is automatically opened: after the lower layer of cement slurry is fully saturated, pressure pushes the second shear pin to break, causing the locking block to move upward, releasing the tension spring, and allowing the stop to reset and open the perforation. The cement slurry can then automatically flow upward to the next layer for grouting. The entire process requires no additional operational procedures.

Description

Technical Field

[0001] This invention relates to the field of cementing and completion technology, and in particular to a segmented cementing device. Background Technology

[0002] Cementing is one of the most important parts of oil and gas well drilling. Its main purpose is to seal off the oil, gas and water layers in the wellbore, protect the oil and gas well casing, increase the life of the oil and gas well and increase oil and gas production.

[0003] Currently, most cementing methods employ a one-time grouting molding method, which involves drilling, running the casing, and injecting cement slurry into the well to fill the annular space between the casing and the well wall. After the cement solidifies, the cementing is completed. However, in this one-time cementing method, the cement slurry is prone to settling under its own weight during the solidification process, resulting in poor bonding between the casing and the well wall, which further affects the cementing quality. Summary of the Invention

[0004] To alleviate the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0005] This invention provides a segmented cementing device, comprising multiple packer components connected sequentially from top to bottom to a tubing string and a float shoe disposed at the bottom of the tubing string;

[0006] Each enclosure component has a certain spacing between it;

[0007] The packer assembly includes a sealing mechanism, an anchoring mechanism, and perforations;

[0008] The cement grout allows the sealing mechanism to expand and come into contact with the well wall, and the anchoring mechanism to extend and engage with the well wall. The cement grout flows out along the float shoe and into the well. After the grouting work in the lower layer is completed, the cement grout can flow upward along the perforation to the upper layer to continue the grouting work.

[0009] Furthermore,

[0010] The sealing mechanism includes a main body, a first movable sleeve, and an elastomer;

[0011] The sidewall of the tube string has a first opening;

[0012] The main body is connected to the pipe string;

[0013] The main body has a second opening corresponding to the first opening;

[0014] The first movable sleeve is disposed on the inner wall of the tube string and is fixedly connected to the tube string by the first shearing nail. Before the first shearing nail breaks, the first movable sleeve closes the first opening.

[0015] The elastomer is fitted onto the outer wall of the main body, and there is a cavity between the elastomer and the main body;

[0016] The cavity is connected to the second opening;

[0017] A one-way valve is installed in the second opening.

[0018] Furthermore,

[0019] The one-way valve allows the liquid in the first opening to flow into the cavity.

[0020] Furthermore,

[0021] Anchoring mechanisms include anchor seats and anchor claws;

[0022] The anchoring mechanism is located above the sealing mechanism;

[0023] The anchor claw is installed inside the anchor seat, and the tip of the anchor claw points horizontally toward the well wall;

[0024] The side of the anchor seat away from the tip of the anchor claw is connected to the cavity.

[0025] Furthermore,

[0026] A stop and a tension spring are provided at the bottom of the perforation;

[0027] The tension spring is set horizontally, with one end fixedly connected to the stop block and the other end fixedly connected to the main body;

[0028] The stop block can close the lower part of the perforation.

[0029] Furthermore,

[0030] A second movable sleeve is provided inside the main body;

[0031] The second movable sleeve can be slidably connected to the main body;

[0032] A locking block is provided at the lower part of the second movable sleeve;

[0033] The locking block engages with the stop block, which restricts the stop block from moving horizontally.

[0034] Furthermore,

[0035] The second movable sleeve is fixedly connected to the main body by the second shear pin;

[0036] A sliding cavity is provided inside the main body;

[0037] A pusher block is provided at the sliding cavity corresponding to the second movable sleeve.

[0038] Furthermore,

[0039] The lower part of the main body has a third opening;

[0040] The main body has a first branch and a second branch that communicate with the third opening;

[0041] The first branch is connected to the sliding cavity;

[0042] The second branch connects to the perforation;

[0043] The stop block is installed at the connection between the second branch and the perforation.

[0044] Furthermore,

[0045] After the lower part of the arbitrary sealing component is filled with cement grout, the cement grout flows into the sliding cavity along the first branch and applies pressure to the push block to break the second shear nail, causing the second moving sleeve to drive the locking block to move upward.

[0046] The tension spring returns to its original position, allowing the second branch to connect with the perforation.

[0047] Furthermore,

[0048] The outer wall of the second movable sleeve is provided with a retaining ring;

[0049] The main body is equipped with a slot corresponding to the retaining ring;

[0050] After the second movable sleeve moves upward, the retaining ring can be engaged in the retaining groove.

[0051] The beneficial effects of the segmented cementing device for reducing downhole leakage in this invention are analyzed as follows:

[0052] This invention provides a segmented cementing device, comprising multiple packer components connected sequentially from top to bottom to a tubing string and a float shoe disposed at the bottom of the tubing string; each packer component has a certain interval between them; each packer component includes a sealing mechanism, an anchoring mechanism, and a perforation; cement grout enables the sealing mechanism to expand and abut against the well wall, and enables the anchoring mechanism to extend and engage with the well wall; the cement grout flows out along the float shoe to inject grout into the well; after completing the grouting operation of the lower layer, the cement grout can flow upward along the perforation to the upper layer to continue the grouting operation.

[0053] Multiple packer components arranged at intervals from top to bottom work in conjunction with the bottom float shoe to achieve layer-by-layer grouting from bottom to top. During the grouting process, the cement slurry first activates the sealing and anchoring mechanisms of the bottom packer component, causing it to expand and fit tightly and firmly against the well wall, forming a stable packer layer. This not only effectively supports the upper cement slurry and prevents it from sinking, but also significantly enhances the bonding strength between the casing and the formation. Through the linkage mechanism of perforation, stop, tension spring, and second moving casing controlled by shear pin, the interlayer channel is automatically opened: after the lower layer of cement slurry is fully injected, the pressure pushes the second shear pin to break, causing the locking block to move upward, releasing the tension spring, and causing the stop to reset and open the perforation. The cement slurry can then automatically flow upward to the next layer for injection. The entire process requires no complex manual intervention or additional operating procedures. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0055] Figure 1 A schematic diagram of a segmented cementing device for reducing downhole leakage provided in an embodiment of the present invention;

[0056] Figure 2 This is a half-sectional schematic diagram of the enclosure component;

[0057] Figure 3 for Figure 2 A magnified view of part A in the diagram.

[0058] icon:

[0059] 100 - Pipe string; 110 - First opening;

[0060] 200-Sealing assembly; 210-Sealing mechanism; 211-Main body; 2111-Second opening; 2112-Sliding cavity; 2113-Third opening; 2114-Slot; 212-First moving sleeve; 213-Elastomer; 214-Cavity; 215-One-way valve; 220-Anchoring mechanism; 221-Anchor seat; 222-Anchor claw; 230-Perforation; 231-Stop block; 232-Tension spring; 240-Second moving sleeve; 241-Locking block; 242-Push block; 243-Snap ring;

[0061] 300-Floating Shoes. Detailed Implementation

[0062] During the solidification process of cement slurry in a one-time cementing method, the cement slurry is prone to settling under its own gravity, resulting in poor bonding between the casing and the well wall, which further affects the cementing quality.

[0063] In view of this, such as Figures 1 to 3 As shown, this solution provides a segmented cementing device to alleviate the above-mentioned problems.

[0064] This device includes multiple sealing components 200 connected to the tube string 100 from top to bottom and a floating shoe 300 disposed at the bottom of the tube string 100;

[0065] Each enclosure component 200 has a certain interval between them;

[0066] The sealing assembly 200 includes a sealing mechanism 210, an anchoring mechanism 220, and a perforation 230;

[0067] The cement grout allows the sealing mechanism 210 to expand and come into contact with the well wall, and the anchoring mechanism 220 to extend and engage with the well wall. The cement grout flows out along the float shoe 300 and into the well. After the grouting operation of the lower layer is completed, the cement grout can flow upward along the perforation 230 to the upper layer to continue the grouting operation.

[0068] Specifically, during cementing operations, multiple packer components 200 work together to divide the well section into multiple layers, and then grouting is carried out layer by layer from bottom to top. During the cement grouting process, the cement grout starts from the packer component 200 at the bottom layer, activating the sealing mechanism 210 and the anchoring mechanism 220 to make it tightly connected to the well wall. After reaching a certain pressure, the float shoe 300 at the bottom of the tubing string opens to allow the cement grout to flow out. After the cement grout fills the layer, the cement grout flows upward along the perforation 230 in the packer component 200 at that layer to carry out cementing operations on the upper layer. At this time, the packer component 200 at the lower layer can provide support for the cement grout at the upper layer, preventing it from sinking due to its own weight.

[0069] It should be noted that there is not just one perforation 230. Since the sealing component 200 is a cylindrical object, multiple perforations 230 are configured. The multiple perforations 230 are arranged around the circumference of the sealing component 200. In other words, the use of multiple perforations 230 can ensure that the cement slurry can pass through the sealing component smoothly without clogging.

[0070] In this design, the sealing mechanism 210 includes a main body 211, a first movable sleeve 212, and an elastic body 213;

[0071] The sidewall of the tube string 100 has a first opening 110;

[0072] The main body 211 is connected to the string 100;

[0073] The main body 211 has a second opening 2111 corresponding to the first opening 110;

[0074] The first movable sleeve 212 is disposed on the inner wall of the tube string 100 and is fixedly connected to the tube string 100 by the first shearing nail. Before the first shearing nail breaks, the first movable sleeve 212 closes the first opening 110.

[0075] The elastic body 213 is sleeved on the outer wall of the main body 211, and there is a cavity 214 between the elastic body 213 and the main body 211;

[0076] Cavity 214 is connected to the second opening 2111;

[0077] A one-way valve 215 is installed in the second opening 2111;

[0078] One-way valve 215 allows liquid in the first opening 110 to flow into cavity 214;

[0079] Anchoring mechanism 220 includes anchor seat 221 and anchor claw 222;

[0080] Anchoring mechanism 220 is located on the upper part of sealing mechanism 210;

[0081] Anchor claw 222 is disposed inside anchor seat 221, and the tip of anchor claw 222 points horizontally toward well wall;

[0082] The side of the anchor seat 221 away from the tip of the anchor claw 222 is connected to the cavity 214.

[0083] Specifically, after the setting ball is inserted into the pipe string 100 before the cement grout is injected, the setting ball can engage with the first movable sleeve 212. After pressurization, the first shear nail breaks, causing the first movable sleeve 212 to move down and open the first opening 110.

[0084] During the grouting process, a portion of the grout enters the second opening 2111 through the first opening 110 and then enters the cavity 214 through the one-way valve 215. After filling the cavity 214, the grout flows upward into the anchor seat 221, causing the anchor claw 222 to extend under pressure and engage with the well wall. As filling continues, the elastic body 213 expands under pressure at the point where it contacts the well wall, allowing the packer assembly 200 to completely fill the gap between the pipe string and the well wall. The engaging action of the anchor claw 222 prevents the packer assembly 200 from loosening under pressure. Furthermore, the pressure-bearing capacity of the one-way valve 215 is much smaller than that of the float shoe 300. Therefore, before the packer assembly 200 achieves sealing, the float shoe 300 will not open prematurely, causing a pressure drop in the pipe string and resulting in incomplete sealing by the packer assembly 200.

[0085] In particular, such as Figure 3As shown, a sliding push block with an inclined pushing surface is slidably provided at the top of the first movable sleeve 212. A spring is provided between the sliding push block and the first movable sleeve 212. During the sliding process of the setting ball, it will be blocked by the sliding push block. Therefore, the setting ball will exert a pushing force on the first movable sleeve 212, causing the first shear pin to break, thereby opening the first opening 110. When the first movable sleeve 212 slides to the point where it can no longer slide, the setting ball will squeeze the sliding push block to slide back into the first movable sleeve 212. At this time, the setting ball will pass through the first movable sleeve 212 and continue to slide downward. When it slides to the bottom, all the first movable sleeves 212 will be driven to slide, that is, all the first openings 110 will be opened. In other words, after the setting ball is inserted, it will push multiple first movable sleeves 212 to slide from top to bottom.

[0086] In this design, a stop 231 and a tension spring 232 are provided at the lower part of the perforation 230;

[0087] The tension spring 232 is set in the horizontal direction, with one end fixedly connected to the stop block 231 and the other end fixedly connected to the main body 211;

[0088] The stop 231 can close the lower part of the perforation 230;

[0089] A second movable sleeve 240 is provided inside the main body 211;

[0090] The second movable sleeve 240 can be slidably connected to the main body 211;

[0091] A locking block 241 is provided at the lower part of the second movable sleeve 240;

[0092] The locking block 241 engages with the stop block 231, which can restrict the stop block 231 from moving horizontally; the second moving sleeve 240 is fixedly connected to the main body 211 by the second shear pin;

[0093] A sliding cavity 2112 is provided inside the main body 211;

[0094] A pusher 242 is provided at the sliding cavity 2112 corresponding to the second movable sleeve 240;

[0095] The lower part of the main body 211 has a third opening 2113;

[0096] The main body 211 has a first branch and a second branch that communicate with the third opening 2113;

[0097] The first branch is connected to the sliding cavity 2112;

[0098] The second branch connects to the perforation 230;

[0099] The stop block 231 is located at the connection between the second branch and the through hole 230;

[0100] After the lower part of the arbitrary sealing component 200 is filled with cement grout, the cement grout flows into the sliding cavity 2112 along the first branch and applies pressure to the push block 242 to break the second shear nail, causing the second moving sleeve 240 to drive the locking block 241 to move upward.

[0101] The tension spring 232 is reset, allowing the second branch to connect with the through hole 230.

[0102] Specifically, when the locking block 241 and the stop block 231 are engaged, the tension spring 232 is stretched and cannot return to its original position. At this time, the stop block 231 completely disconnects the passage between the second branch and the through hole 230. After the cement slurry is filled in the lower part of this layer, the cement slurry enters from the third opening 2113 and enters the sliding cavity 2112 along the first branch, putting pressure on the push block 242. After the second shear nail breaks under pressure, the second moving sleeve 240 drives the locking block 241 to move upward, releasing the restricted state of the tension spring 232, allowing the tension spring 232 to return to its original position and drive the stop block 231 to move, thereby reconnecting the second branch and the through hole 230, opening a channel for the cement slurry to flow into the upper layer.

[0103] More preferably, a retaining ring 243 is provided on the outer wall of the second movable sleeve 240;

[0104] The main body 211 is provided with a slot 2114 corresponding to the retaining ring 243;

[0105] After the second movable sleeve 240 moves upward, the retaining ring 243 can be engaged in the retaining groove 2114. The retaining ring 243 engages with the retaining groove 2114 to limit the second movable sleeve 240, thus preventing the second movable sleeve 240 from moving downward due to the pressure drop in the sliding cavity 2112 when the second branch is opened, which would make it difficult for cement slurry to enter the perforation 230.

[0106] This solution has at least the following beneficial effects:

[0107] The segmented cementing device provided in this solution effectively solves the problem of uneven annular bonding and poor cementing quality caused by gravity settling of cement slurry in traditional one-time grouting cementing through innovative structural design.

[0108] This device utilizes multiple packer components arranged at intervals from top to bottom, working in conjunction with a bottom float shoe to achieve layer-by-layer grouting from bottom to top. During the grouting process, the cement slurry first activates the sealing and anchoring mechanisms of the bottommost packer component, causing it to expand and tightly adhere to the well wall, forming a stable packer layer. This not only effectively supports the upper cement slurry and prevents it from sinking, but also significantly enhances the bonding strength between the casing and the formation. Furthermore, through a perforation, stop, tension spring, and a second moving casing linkage mechanism controlled by a shear pin, the interlayer channel is automatically opened: after the lower layer of cement slurry is fully saturated, the pressure pushes the second shear pin to break, causing the locking block to move upward, releasing the tension spring, and allowing the stop to reset and open the perforation. The cement slurry can then automatically flow upward to the next layer for grouting. The entire process requires no complex manual intervention or additional operating procedures.

[0109] This bottom-up, step-by-step segmented cementing method not only greatly reduces cement slurry loss and settlement, ensuring the compactness and uniformity of the annulus filling in each segment, and improving the overall quality and long-term sealing reliability of cementing, but also improves operational efficiency and reduces construction risks through its automated opening mechanism, providing a safe, efficient, and high-quality technical solution for cementing complex formations and deep wells.

[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A segmented cementing device, characterized in that: It includes multiple sealing components (200) connected to the tube string (100) from top to bottom and a floating shoe (300) disposed at the bottom of the tube string (100); Each of the sealing components (200) has a certain interval between it; The sealing assembly (200) includes a sealing mechanism (210), an anchoring mechanism (220), and a perforation (230). The sealing mechanism (210) includes a main body (211), a first movable sleeve (212), and an elastic body (213). The sidewall of the tube string (100) has a first opening (110); The main body (211) is sleeved with the tube string (100); The main body (211) has a second opening (2111) corresponding to the first opening (110). The first movable sleeve (212) is disposed on the inner wall of the tube string (100) and is fixedly connected to the tube string (100) by the first shearing nail. Before the first shearing nail breaks, the first movable sleeve (212) closes the first opening (110). The elastic body (213) is sleeved on the outer wall of the main body (211), and there is a cavity (214) between the elastic body (213) and the main body (211). The cavity (214) is connected to the second opening (2111); A one-way valve (215) is provided inside the second opening (2111); The cement grout can cause the sealing mechanism (210) to expand and abut against the well wall, and cause the anchoring mechanism (220) to extend and engage with the well wall. The cement grout flows out along the float (300) and is injected into the well. After the grouting operation of the lower layer is completed, the cement grout can flow upward along the perforation (230) to the upper layer to continue the grouting operation.

2. The segmented cementing device according to claim 1, characterized in that: The one-way valve (215) allows liquid in the first opening (110) to flow into the cavity (214).

3. The segmented cementing device according to claim 2, characterized in that: The anchoring mechanism (220) includes an anchor seat (221) and an anchor claw (222); The anchoring mechanism (220) is located on the upper part of the sealing mechanism (210); The anchor claw (222) is disposed within the anchor seat (221), and the tip of the anchor claw (222) points towards the well wall in the horizontal direction; The side of the anchor seat (221) away from the tip of the anchor claw (222) is connected to the cavity (214).

4. The segmented cementing device according to claim 3, characterized in that: A stop (231) and a tension spring (232) are provided at the lower part of the perforation (230). The tension spring (232) is arranged in the horizontal direction, with one end fixedly connected to the stop (231) and the other end fixedly connected to the main body (211); The stop (231) can close the lower part of the perforation (230).

5. The segmented cementing device according to claim 4, characterized in that: The main body (211) is provided with a second movable sleeve (240). The second movable sleeve (240) is slidably connected to the main body (211); A locking block (241) is provided at the lower part of the second movable sleeve (240). The locking block (241) engages with the stop block (231) to restrict the stop block (231) from moving in the horizontal direction.

6. The segmented cementing device according to claim 5, characterized in that: The second movable sleeve (240) is fixedly connected to the main body (211) by a second shear pin; A sliding cavity (2112) is provided inside the main body (211); The second movable sleeve (240) is provided with a push block (242) at the location corresponding to the sliding cavity (2112).

7. The segmented cementing device according to claim 6, characterized in that: The lower part of the main body (211) has a third opening (2113). The main body (211) has a first branch and a second branch that communicate with the third opening (2113); The first branch is connected to the sliding cavity (2112); The second branch is connected to the perforation (230); The stop (231) is located at the connection between the second branch and the perforation (230).

8. The segmented cementing device according to claim 7, characterized in that: After the lower part of any of the sealing components (200) is filled with cement slurry, the cement slurry flows into the sliding cavity (2112) along the first branch and applies pressure to the push block (242) to break the second shear nail, causing the second moving sleeve (240) to drive the locking block (241) to move upward; The tension spring (232) is reset, so that the second branch is connected to the through hole (230).

9. The segmented cementing device according to claim 8, characterized in that: The outer wall of the second movable sleeve (240) is provided with a retaining ring (243); The main body (211) is provided with a slot (2114) corresponding to the retaining ring (243). After the second movable sleeve (240) moves upward, the retaining ring (243) can be engaged in the retaining groove (2114).

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