Recoverable packer with slotted sleeve release device

Abstract

A recoverable packer system (10) includes a packer mandrel (20), a locking ring (26), an upper cone (30), a lower cone (40), a slip device (60), a recovery mandrel (70), and a slotted recovery sleeve (80). And the locking ring (26) is fixed on the packer mandrel (20) and then respectively fixed on the upper cone (30), the slip device (60), the lower cone (40) and the recovery mandrel (70). The upper connection sleeve (92) and the lower connection sleeve (94) cover the packer mandrel (20) to form a chamber in fluid connection with the slip flow passage (65) of the slip device (60). The packer system (10) will be tripped into a wellbore when the slotted recovery sleeve (80) is in a first position relative to the lower cone (40) and the slip device (60) is in a tripped position. The packer system (10) may be seated and locked at a particular location in a wellbore. The slotted recovery sleeve (80) may return the slip device (60) to a lowered position by pushing the upper cone (30) to recover the packer system (10).

Description

[0001] Claim of priority

[0002] This application claims the benefit of the following non - provisional applications, the entire content of each of which is incorporated herein by reference:

[0003] Application No.: USN 18049188, Filed: October 24, 2022; Title: Retrievable Packer with Slotted Sleeve Release Device. Technical Field

[0004] The present invention relates to isolating production zones from non - production zones in a wellbore. More specifically, the present invention relates to a retrievable packer system that can be fixed at a specific location in a wellbore and released from that specific location. More specifically, the present invention relates to a packer system with a slotted sleeve for releasing a packer system placed in a wellbore for downhole operations from a specific location in the wellbore after completion of the downhole operations. Background Art

[0005] In a wellbore, hydrocarbons are located in rock formations at a specific depth. The rock formation at this depth can be divided into a production zone to target the flow of fluid to the location of the hydrocarbons. The flow of fluid will assist in the recovery of hydrocarbons from the wellbore. Rock formations at other depths that do not contain hydrocarbons are referred to as "non - production zones". There is no need to waste fluid flow in non - production zones that do not contain hydrocarbons. Therefore, in order to successfully recover hydrocarbons from a wellbore, the production zone should be isolated from the non - production zone.

[0006] Known downhole tools can be used to isolate the production zone from the non - production zone to ensure that fluid flow can be delivered to the production zone rather than the non - production zone. Examples of downhole tools that can be used for isolation include bridge plugs, packers, or other tools with isolation valves.

[0007] In a conventional process, a packer is run downhole into a wellbore. When it reaches the correct location in the wellbore, the packer expands against the wellbore wall to be fixed at a specific location within the wellbore. The cone assembly drives the slip device from a retracted position to an expanded position. The slip device grasps the wellbore wall in the expanded position to fix the packer at the specific location. Downhole operations can be carried out after the packer is fixed at the specific location. After completion of the downhole operations, the retrievable packer must be removed. There are various methods to release the packer from the specific location - cutting the entire or part of the slip device, forcibly pulling out the slip device, mechanically separating the slip device from its specific location using wedges and other levers. There are also various methods to release the cone assembly from the slip device - applying an external force through the cone assembly to expand the slip device to separate the cone assembly from the slip device, so that the slip device no longer supports at the specific location.

[0008] It is known that the packer can be released for recovery by removing or separating the cone assembly from the slip device. It is known that snap rings and collet pins can be used to release the cone assembly from the slip device. U.S. Patent No. 6,691,788, issued to Dearing on February 17, 2004, discloses a packer having a collet member that can be used to expand and retract a slip device. U.S. Patent No. 5,311,938, issued to Hendrickson et al. on May 17, 1994, discloses a packer that releases the slips by a locking ring. Since its bearing area is usually small, the snap ring may cause problems. If more external force is required to disengage the cone assembly and the slip device, the snap ring will break, resulting in the inability to release the slip device from its specific position.

[0009] The prior art embodiments shown in FIGS. 1 and 2 also include a packer system 1 having a packer mandrel 3 that can be inserted into a cone 4. A retrieval sleeve 5 fixed to the packer mandrel 3 will ensure that the packer mandrel 3 can slide along the cone 4 to effect the setting and release of the slips (not shown). As shown in FIGS. 1 and 2, an outer sleeve 2 having slots 6 and vent holes 7 covers the packer mandrel 3 and the retrieval sleeve 5 to form a chamber 8. The retrieval sleeve 5 will drive the packer mandrel 3 to drive fluid in and out of the chamber 8 and through the vent holes 7, and then flow through the packer system 1 (as shown by the dashed arrows). Drilling fluid becomes heavy and dirty due to carrying cuttings, debris, rocks, gas, and chemicals. The vent holes 7 are often blocked by various debris, resulting in hydraulic resistance to the movement of the retrieval sleeve 5 driving the packer mandrel 3 when releasing the packer system 1. A fluid chamber 8 without functional vent holes will block the retrieval sleeve, resulting in the inability to retrieve the packer system 1.

[0010] It is known that packer systems include slotted sleeves. Slotted sleeves and slotted pipe fittings are commonly used as flow channels to direct fluid flow through various parts of the packer system. U.S. Patent No. 8,291,976, issued to Schultz et al. on October 23, 2012, and World Intellectual Property Organization (WIPO) Publication No. WO2019100138, published by Campbell on May 31, 2019, both disclose slots, channels, and complex notches for controlling fluid flow between concentric sleeve layers. U.S. Patent No. 10,024,150, issued to Andreychuk et al. on July 17, 2018, and U.S. Publication No. 2005 / 0139362, published by Coon et al. on June 30, 2005, both disclose slotted housings used as fluid bypasses around the external seals of tools. The present invention discloses the flow path function formed by the slots in the slotted sleeve, but the various relationships with other components around the slotted sleeve need to refer to the prior art involved in specific patents. SUMMARY OF THE INVENTION

[0011] The object of the present invention is to provide a retrievable packer system for isolating a production zone from a non-production zone in a wellbore for downhole operations.

[0012] The object of the present invention is to provide a retrievable packer system that can be seated at a specific location in a wellbore and released from that specific location.

[0013] Another object of the present invention is to provide a retrievable packer that can release the packer system from a specific location through a slotted retrieval sleeve.

[0014] Another object of the present invention is to provide a retrievable packer system with a slip device having two positions: a running-in position and a setting position.

[0015] Another object of the present invention is to provide a retrievable packer system that can move the slip device from the setting position back to the running-in position through a slotted retrieval sleeve.

[0016] Another object of the present invention is to provide a retrievable packer system that can move the slip device from the setting position back to the running-in position through a lower cone that slidably engages with a slotted retrieval sleeve.

[0017] Another object of the present invention is to provide a retrievable packer system that can prevent debris from causing blockage and hydraulic resistance through a flow bypass from a retrieval mandrel to the slips.

[0018] Another object of the present invention is to provide a retrievable packer system with a slotted retrieval sleeve, wherein the retrieval sleeve has a plurality of slots that provide fluid connection to the slips and a chamber formed by a retrieval mandrel, a slotted retrieval sleeve, a lower cone, and a lower connection sleeve.

[0019] The above and other objects and advantages of the present invention will become apparent by reading the accompanying specification, drawings, and claims.

[0020] Embodiments of the present invention include a retrievable packer system that can be set and locked at a specific location in a wellbore and also unlocked and released from that specific location. The packer system of the present invention includes a release member, wherein the release member can withstand a wider range of external forces to release the packer system from the specific location and reduce the risk of fatal damage to the release member caused by external forces. The packer system also prevents hydraulic resistance from being applied to the release member by forming a flow channel between the lower cone and the packer mandrel. Previous destructive debris blockages no longer generate hydraulic resistance to release the slips. The packer system includes a packer mandrel, a locking ring, an upper cone, a lower cone, a slip device, a retrieval mandrel, a slotted retrieval sleeve, an upper connection sleeve, and a lower connection sleeve.

[0021] The locking ring has an unlocking position and a locking position on the packer mandrel relative to the lower mandrel end. The locking position is closer to the lower mandrel end than the unlocking position. When the locking ring is in the unlocking position, it can move along the packer mandrel. The locking ring can move towards the lower mandrel end to lock the packer system in a specific position.

[0022] The slip assembly has a running-in position and a setting position within the range of the distance between its outer engagement surface and the upper cone and the lower cone. The extension distance of the setting position is greater than the initial distance of the running-in position. When the extension distance is equal to the expanded diameter of the slip assembly, the packer system will be set in a specific position in the wellbore. The slip assembly has a slip flow passage for fluid to flow from the inner engagement surface through the slip assembly to the outer engagement surface.

[0023] The locking ring is linked with the slip assembly. The slip assembly sets the packer system in a specific position, while the locking ring locks the packer system in that specific position. When retrieving the packer system set and locked in that specific position, it needs to be unlocked and released. After unlocking the locking ring, the slip assembly can return to the running-in position to release the packer system. A slotted sleeve is used to release the packer system.

[0024] Embodiments of the lower cone and the slotted retrieval sleeve also disclose the relationship aimed at releasing the packer system in a specific position in the wellbore from the set and locked position. The lower cone includes a lower cone tip facing the upper cone and a lower cone base end opposite the lower cone tip. The slotted retrieval sleeve is installed on the retrieval mandrel and extends into the lower cone. The slotted retrieval sleeve has a plurality of slots that are in fluid communication with the lower cone through the slot flow passage. The slotted retrieval sleeve has three positions relative to the lower cone, especially the lower cone tip of the lower cone.

[0025] The upper connecting sleeve is placed on the packer mandrel above the locking ring. The lower connecting sleeve is placed around the packer mandrel between the lower cone and the lower mandrel end, thereby forming a chamber with the lower connecting sleeve, the lower cone, the retrieval mandrel, the slotted retrieval sleeve, and the packer mandrel. This chamber is in fluid connection with the slip flow passage of the slips.

[0026] When the slotted retrieval sleeve is in the first position, the packer system is deployed into the wellbore. The slip assembly is at the initial distance and does not engage with the wellbore wall to ensure that the packer system can pass through the wellbore. When the slotted retrieval sleeve is in the first position, the packer system is set in a specific position in the wellbore. Downhole operations can be performed when the packer system is in this set and locked position in the wellbore.

[0027] After downhole operations are completed when the packer system is in a specific position, it can be retrieved. The slotted retrieval sleeve will transition from a first position to a second position. When the slotted retrieval sleeve is in the second position relative to the tip of the lower cone, it can extend from the lower cone to contact the upper cone. The slotted retrieval sleeve can now push the upper cone.

[0028] When the slotted retrieval sleeve is in a third position, the packer system can be released from a specific position within the wellbore. The slotted retrieval sleeve has pushed the upper cone away from the lower cone to ensure that the slip assembly can be repositioned by being slid down. The packer system is no longer seated at a specific position within the wellbore. The packer system can now be released from the wellbore and then retrieved.

[0029] Embodiments of the upper and lower cones include corresponding inclined surfaces that mate with the inner slip engagement surfaces of the slip assembly. The inclined surfaces and the inner slip engagement surfaces determine the initial and extended distances of the outer slip engagement surfaces relative to the run-in and seated positions of the slip assembly. The slip assembly has a slip flow passage from the inner engagement surface to the outer engagement surface.

[0030] Embodiments of the retrieval mandrel include a connection portion, a release portion, and a cutting target between the connection portion and the release portion. The connection portion must be separated from the release portion to ensure that the slotted retrieval sleeve can move from the first position to the second position and then from the second position to the third position. The release portion must be disconnected to ensure that the connection portion can be pulled upward together with the packer mandrel to move the slotted retrieval sleeve.

[0031] Threaded or snap-fit structures are no longer solely responsible for applying an upward external force on the upper cone. The magnitude of the external force is no longer limited by the strength of these additional structures. The chambers involved in the present invention are no longer in contact with debris that may block the vent holes of the chambers. The hydraulic resistance generated by the movement of the retrieval mandrel no longer poses a risk to the operation of retrieving the packer system. There is a fluid connection between the chambers and the slip flow passage when the slotted retrieval sleeve is in each position to ensure that the chambers are never sealed and no pressure is generated that would impede the movement of the retrieval mandrel. There is no hydraulic pressure that obstructs or causes failure of the retrieval mandrel and the slotted retrieval sleeve as release components.

[0032] The present invention provides a retrievable packer system for isolating a production zone from a non-production zone within a wellbore for downhole operations. The retrievable packer system and method can seat the packer system at a specific position within the wellbore and can release the packer system from that specific position. The packer system can be seated and locked at a specific position for performing various downhole operations. After the downhole operations are completed, the packer system can be unlocked and released from the position to be retrieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a cross-sectional view of a packer system with a vent chamber that can be blocked by debris using the prior art.

[0034] Figure 2 is a partial perspective view of a packer system using the prior art, which shows the vent holes on the lower connecting sleeve.

[0035] Figure 3 is a cross-sectional view of an embodiment of the packer system of the present invention, where the locking ring is in the unlocked position, the slip device is in the running-in position, and the slotted retrieval sleeve is in the first position.

[0036] Figure 4 is a perspective view of an embodiment of the slotted retrieval sleeve of the present invention.

[0037] Figure 5 is Figure 3 a partial perspective view of an embodiment of the packer system shown, which shows the lower connecting sleeve without any vent holes.

[0038] Figure 6 is a cross-sectional view of an embodiment of the packer system of the present invention, where the locking ring is in the locked position, the slip device is in the running-in position, and the slotted retrieval sleeve is in the first position.

[0039] Figure 7 is Figure 6 a partial perspective view and cross-sectional view of an embodiment of the packer system shown, which shows the slotted retrieval sleeve in the first position and the open flow path between the chamber and the slips when in the running-in position.

[0040] Figure 8 is a cross-sectional view of an embodiment of the packer system of the present invention, where the locking ring is in the locked position, the slip device is in the set position, and the slotted retrieval sleeve is in the first position.

[0041] Figure 9 is Figure 8 a partial perspective view and cross-sectional view of an embodiment of the packer system shown, which shows the slotted retrieval sleeve in the first position and the open flow path between the chamber and the slips when in the set position.

[0042] Figure 10 is an enlarged cross-sectional view of an embodiment of the packer system of the present invention, where the locking ring is in the locked position, the slip device is in the set position, and the slotted retrieval sleeve is in the second position.

[0043] Figure 11 is a cross-sectional view of an embodiment of the packer system of the present invention, where the locking ring is in the locked position, the slip device is in the running-in position, and the slotted retrieval sleeve is in the third position.

[0044] Figure 12 isFigure 11 Partial perspective and cross-sectional views of an embodiment of the packer system shown, showing the slotted retrieval sleeve in the third position and the open flow path between the chamber and the slips in the run-in position. Detailed Description

[0045] A retrievable packer system releases the entire or part of the slip assembly from the wellbore wall or releases the slip assembly from the cone assembly to ensure that the cone assembly no longer supports the slip assembly against the wellbore wall. Without the support of the cone assembly, the slip assembly is more easily released from the wellbore wall. The external force used to initially release the slip assembly from the wellbore wall or the cone assembly may damage the release components that are pulled or pressed. Release components such as snap rings and jaw pins may break, resulting in these release components not functioning properly. In addition, a releasable packer system relies on a chamber with a vent hole to push the release components, and if the vent hole of the chamber is blocked, hydraulic pressure that may impede or cause the release components to fail may be generated. The packer may become non-retrievable and more expensive and time-consuming equipment and methods may be required to remove the packer from its position in the wellbore. The retrievable packer system 10 according to the present invention prevents the generation of hydraulic resistance through a release component with a flow bypass, has higher durability to withstand the external force required to release the slip assembly, and can reduce the risk of fatal damage to the release components.

[0046] Figures 3 to 12 An embodiment of the retrievable packer system 10 according to the present invention is shown. The retrievable packer system 10 includes a packer mandrel 20, a locking ring 26, an upper cone 30, a lower cone 40, a slip assembly 60, a retrieval mandrel 70, and a slotted retrieval sleeve 80. The packer mandrel 20 has an upper mandrel end 22 and a lower mandrel end 24, and the locking ring 26 is installed at the upper mandrel end 22 on the packer mandrel 20. The upper cone 30 is installed on the packer mandrel 20 between the locking ring 26 and the lower mandrel end 24. The lower cone 40 is installed on the packer mandrel 20 between the upper cone 30 and the lower mandrel end 24. The slip assembly 60 is located between the upper cone 30 and the lower cone 40 and is in sliding engagement with the upper cone 30 and the lower cone 40. The slip assembly 60 includes an inner engagement surface 62 facing the upper cone 30 and the lower cone 40 and an outer engagement surface 64 opposite the inner engagement surface 62. The slip assembly 60 has a slip flow channel 65 from the inner engagement surface 62 to the outer engagement surface 64 to ensure fluid connection between the slip assembly 60 and the wellbore. Fluids at the inner engagement surface 62 can flow into the wellbore through the slip flow channel 65.

[0047] The retrieval mandrel 70 is installed on the packer mandrel 20 between the lower cone 40 and the lower mandrel end 24 and has a connection end 78 facing the lower cone 40. As Figure 4As shown, the slotted recovery sleeve 80 is mounted on the recovery mandrel 70 and has an anchoring end 84 fixed on the recovery mandrel 70, a pushing end 82 opposite to the anchoring end 84, and a plurality of slots 86. Each of the plurality of slots 86 has an open slot end 88 at the pushing end 82 and a flow end 90 opposite to the open slot end 88. An upper connecting sleeve 92 is placed on the packer mandrel 20 above the locking ring 26. A lower connecting sleeve 94 is placed around the packer mandrel 20 between the lower cone 40 and the lower mandrel end 24.

[0048] The lower connecting sleeve 94 forms a chamber 97 with the lower cone 40, the recovery mandrel 70, the slotted recovery sleeve 80 and the packer mandrel 20. The chamber 97 is fluidly connected to the slip flow channel 65 through the slot 86. Since the chamber 97 has no vent hole, there is no risk of debris blocking the vent hole, thereby eliminating the risk of hydraulic pressure accumulation blocking or causing the recovery mandrel 70 drive failure. The chamber 97 is fluidly connected to the slip flow channel 65 to ensure that the fluid can flow through the lower cone 40 through the bypass. Due to the large number of slots 86, the risk of clogging all slots 86 is significantly reduced. The release components of the recovery mandrel 70 and the slotted recovery sleeve 80 can now prevent the accumulation of hydraulic pressure in the chamber 97 and provide reliable mechanical strength for achieving controlled release of the slip device 60 to complete the recovery.

[0049] Figure 3 , Figures 5 to 7 and Figures 11 to 12 The locking ring 26 is shown on the packer mandrel 20 in an unlocked position relative to the lower mandrel end 24 . Figures 8 to 10 A locking ring 26 is shown having a locked position relative to the lower mandrel end 24. The locked position is closer to the lower mandrel end 24 than the unlocked position. The locking ring 26 is movable along the packer mandrel 20 in the unlocked position, so the unlocked position is variable. The locking ring 26 is removably fixed to the packer mandrel 20 in the locked position. The locking ring 26 can be switched between the unlocked position and the locked position by conventional locking means such as friction fit, threads or clamps.

[0050] Figure 3 , Figures 5 to 7 and Figures 11 to 12 The slip assembly 60 is shown having a run-in position with the outer engagement surface 64 maintaining an initial distance from the upper cone 30 and the lower cone 40 . Figures 8 to 10Also shown is a slip device 60 having a setting position, wherein the outer engagement surface 64 maintains an extended distance from the upper cone 30 and the lower cone 40. The extended distance is greater than the initial distance to hold the packer mandrel 20 in a specific position in the wellbore. When the extended distance is equal to the expansion diameter of the slip device 60, the slip device will clamp the wellbore, wellbore or casing wall. Gripping measures such as a knurled surface, adhesive or wear-resistant coating can be taken on the outer engagement surface 64 to achieve elastic fixation on the wellbore wall. The slip device 60 holds the packer system 10 in a specific part of the wellbore. The slip device 60 has a slip flow channel 65 from the inner engagement surface 62 to the outer engagement surface 64 to ensure that the slip device 60 can achieve fluid connection with the wellbore. As shown by the arrow, the fluid at the inner engagement surface 62 can bypass to the wellbore through the slip flow channel 65. The chambers and flow paths that are fluidly connected to the space at the inner engagement surface 62 can also bypass to the wellbore through the slip flow channel 65.

[0051] The locking ring 26 and the slip device 60 are interlocked. When the slip device 60 is in the setting position, the locking ring 26 will transition from the unlocked position to the locked position. Therefore, the locking ring 26 holds the slip device 60 at the extended distance from the outer engagement surface 64 to set the packer system 20 in a specific part of the wellbore. Before the slip device 60 transitions from the setting position to the running-in position, the locking ring 26 must transition from the locked position to the unlocked position. Therefore, in one embodiment, the slip device 60 is in the setting position while the locking ring 26 is in the locked position and the unlocked position.

[0052] Figures 3 to 12 The illustrated embodiment of the present invention includes a lower cone 40 composed of a lower cone tip 46 facing the upper cone 30 and a lower cone base end 48 opposite to the lower cone tip 46. Figure 3 and Figures 5 to 12 shows Figure 4 Three positions of the illustrated slotted retrieval sleeve 80 are shown.

[0053] Figure 3 and Figures 5 to 9 and shows the slotted retrieval sleeve 80 in a first position relative to the lower cone tip 46, wherein the push end 82 is located within the lower cone 40 while the slip device 60 is simultaneously in the running-in position and the setting position. When the slotted retrieval sleeve 80 is in the first position, the packer system 10 is deployed into the wellbore. The slip device 60 is at the initial distance and does not engage with the wellbore wall. When the slotted retrieval sleeve 80 is in the first position, the packer system 10 is fixed at a specific part on the inner wellbore wall within the wellbore. The slip device 60 is at the extended distance and can be locked at this specific part by the locking ring 26. When the locking ring 26 transitions from the unlocked position ( Figure 3 and Figure 5 ) to the locked position ( Figures 6 to 9) When this occurs, the packer system 10 will be set while the slotted retrieval sleeve 80 transitions to a stable position (first position) relative to the lower cone 40. The chamber 97 will maintain fluid connection across the lower cone 40 with the slip flow passage 65 to ensure the conventional setting of the slip assembly 60 can be implemented. The slotted retrieval sleeve 80 and the retrieval mandrel 70, which are release components of the packer system 10, will not interfere with its setting in the wellbore, and these release components will not be at risk of damage due to the setting operation.

[0054] Figure 10 The slotted retrieval sleeve 80 is shown in a second position relative to the lower cone tip 46, where the push end 82 extends from the lower cone 40 and contacts the upper cone 30 when the slip assembly 60 is in the set position. The second position extends past the lower cone tip 46 and then away from the lower cone 40. After completion of the downhole operation when the packer system 10 is in this particular position, the packer system 10 can be retrieved. The slotted retrieval sleeve 80 will transition from the first position to the second position via the retrieval mandrel 70. Before completion of the downhole operation, the slotted retrieval sleeve 80 can also transition from the first position to the second position. As long as the slotted retrieval sleeve 80 is not pushing the upper cone 30, the slotted retrieval sleeve 80 can remain against the upper cone 30 during the downhole operation.

[0055] Figures 11 to 12 The slotted retrieval sleeve 80 is shown in a third position where the push end 82 extends from the lower cone 40 and contacts the upper cone 30 while the slip assembly 60 is in the run-in position. The third position is further away from the lower cone 40 than the second position. The push end 82 remains outside the lower cone 40. When the slotted retrieval sleeve 80 is in the set position, it will push the upper cone 30 away from the slip assembly 60 to ensure the slip assembly 60 can slide to the run-in position and the upper cone 30 can separate from the lower cone 40. The slip assembly 60 will return to the initial distance to disengage from the wellbore wall at a particular location within the wellbore. The packer system 10 will now be released from the wellbore for retrieval. The slotted retrieval sleeve 80 can either remain in the third position for retrieval or return to the first position for resetting.

[0056] Embodiments of the upper cone 30 and the lower cone 40 include an upper cone 30 composed of an upper inclined surface 32 angled outward toward the upper mandrel end 22, and a lower cone 40 composed of a lower inclined surface 42 angled outward toward the lower mandrel end 24. The upper inclined surface 32 includes at least one conical surface 34, and the lower inclined surface 42 includes at least one conical surface 44.

[0057] The slip device 60 includes embodiments that cooperate with the upper inclined surface 32 and the lower inclined surface 42. Embodiments of the slip device include an inner engagement surface 62 composed of an upper slip engagement surface 66 that slidably engages with the upper inclined surface 32 and a lower slip engagement surface 68 that slidably engages with the lower inclined surface 42. The slip device 60 is complementary to the inclined surfaces 32, 42 of the corresponding cones 30, 40. The tops of the conical surfaces 34, 44 that engage with the complementary conical portions of the upper slip engagement surface 66 and the lower slip engagement surface 68 determine the extension distance of the outer engagement surface 64 when the slip device 60 is in the set position. The tops of the conical surfaces 34, 44 that engage with the gaps between the complementary conical portions of the upper slip engagement surface 66 and the lower slip engagement surface 68 determine the initial distance of the outer engagement surface 64 when the slip device 60 is in the run-in position.

[0058] Figure 3 and Figures 5 to 12 in particular Figure 11 The illustrated embodiment includes a recovery mandrel 70 composed of a connection portion 72, a release portion 74, and a cutting target 76 between the connection portion 72 and the release portion 74. The connection portion 72 includes a connection end 78. Figure 3 and Figures 5 to 12 shows that the connection portion 72 has a greater wall thickness than the release portion 74. Figure 3 and Figures 5 to 12 also shows a recovery mandrel 70 having a tapered section 79, where the diameter of the tapered section increases from the release portion 74 to the connection portion 72.

[0059] The connection portion 72 can be separated from the release portion 74 to ensure that the slotted recovery sleeve 80 can move from the first position to the second position. The release portion 74 must be disconnected to ensure that the connection portion 72 can be pulled upward together with the packer mandrel 20 to move the slotted recovery sleeve 80. When the slotted recovery sleeve 80 is in the second position and when the slotted recovery sleeve 80 is in the third position, the connection portion 72 of the recovery mandrel 70 will be separated from the release portion 74. When the slotted recovery sleeve 80 is in the first position, the connection portion 72 of the recovery mandrel 70 will be integrated with the release portion 74 through the cutting target 76. When the slotted recovery sleeve 80 is in the first position, the cutting target 76 will transition from the first position to the second position to complete the cutting. The recovery mandrel 70 will drive the slotted recovery sleeve 80 to move relative to the lower cone 40 to release the slip device 60 and ultimately recover the packer system 10.

[0060] The slotted recovery sleeve 80 includes Figures 3 to 12 (including Figure 4 ) the illustrated embodiment. The slotted recovery sleeve 80 is fixed to the connection end 78. Threaded engagement, snap-fit, friction fit, integration, or other known mechanical connection methods can be used for fixation. Figure 4Also shown is that slots 86 of appropriate size and quantity can be selected for external connection with the slotted recovery sleeve 80. This arrangement can achieve uniform or non-uniform circumferential distribution.

[0061] Figure 5 、 Figure 7 、 Figure 9 and Figure 11 An additional embodiment of the lower connection sleeve 94 is shown, where the lower connection sleeve is composed of a sleeve slot 96 and a connecting portion 72 of the recovery mandrel 70 having a stud 75. Figure 5 、 Figure 7 and Figure 9 The lower connection sleeve 94 with the stud 75 located within the sleeve slot 96 is shown, where the slotted recovery sleeve 80 is in the first position. Figure 5 、 Figure 7 and Figure 9 The packer system 10 being run in and set, and the stud 75 in the same position, are shown. Figure 11 The stud 75 in different positions within the sleeve slot 96, and the recovery mandrel 70 and the slotted recovery sleeve 80 moved to the third position, are shown. Figure 10 The stud 75 with the slotted recovery sleeve 80 in the second position is not shown. When the packer mandrel 20 is pulled from above, the packer mandrel 20 can move relative to the upper connection sleeve 92 and the lower connection sleeve 94.

[0062] Embodiments of the present invention include methods that can be used for downhole operations using the packer system 10. The method includes running the packer system 10 into the wellbore, where the slip device 60 is in the running-in position, the locking ring 26 is in the unlocked position, and the slotted recovery sleeve 80 is in the first position, as Figure 3 and Figures 5 to 7 shown. The packer system 10 can move smoothly through the wellbore without engaging the wellbore wall.

[0063] The packer system 10 is placed at a specific location within the wellbore, and the upper cone 30 moves downward along the packer mandrel 20 towards the lower cone 40. The method includes sliding the slip device 60 from the running-in position to the set position while the slotted recovery sleeve 80 remains in the first position. As Figures 8 to 9 shown, the slip device 60 will be slid when the slotted recovery sleeve 80 is in the first position.

[0064] The packer system 10 in the set position will be fixed at Figures 8 to 9The indicated part. The locking ring 26 can transition from the unlocked position to the locked position. The packer system 10 is now fixed and locked at this specific part to position the packer system 10 when the slip device 60 is in the set-down position and the slotted recovery sleeve 80 is in the first position. Wellbore operations such as injection, production, and fracturing can be carried out when the packer system 10 is fixed and locked at this specific part. The method includes the step of carrying out such wellbore operations after transitioning the locking ring from the unlocked position to the locked position when the packer system is at this specific part.

[0065] After completing the wellbore operations, this method can be used to move the slotted recovery sleeve 80 from the first position to the second position while the slip device 60 is still in the set-down position. In some embodiments of this method, such wellbore operations can be carried out after transitioning the locking ring from the unlocked position to the locked position and moving the slotted recovery sleeve 80 from the first position to the second position, and during this process, the packer system will remain at this specific part. Wellbore operations can be carried out when the slotted recovery sleeve 80 is in the first position or the second position. The steps of carrying out the wellbore operations can be adjusted according to the time when the cutting recovery mandrel 70 is used to move the slotted recovery sleeve 80 outside the lower cone 40 and then onto the upper cone 30.

[0066] As Figure 10 shown, when the slotted recovery sleeve 80 is in the second position, this method can be used to transition the locking ring 26 from the locked position to the unlocked position. The upper cone 30 can now move freely along the packer mandrel 20. When the slotted recovery sleeve 80 is in this second position, it will contact the upper cone 30. When the locking ring 26 is in the unlocked position, the recovery mandrel 70 and the slotted recovery sleeve 80, which are release components, can move further.

[0067] The method includes the step of further pushing the upper cone 30 away from the lower cone 40 along the packer mandrel 20 while moving the slotted recovery sleeve 80 from the second position to the third position. The slip device 60 will slide from the set-down position to the run-in position to ensure that the packer system 10 can be released from this specific part when the slotted recovery sleeve 80 reaches the third position, as Figures 11 to 12 shown. The method now includes the step of retrieving the packer system 10 when the slip device 60 is in the run-in position and the slotted recovery sleeve 80 is in the third position (as Figures 11 to 12 shown), or when the slotted recovery sleeve 80 returns to the first position (as Figure 3 shown).

[0068] Embodiments of the method include the step of applying pressure from above the locking ring 26 in the step of pushing the upper cone 30 closer to the lower cone 40 along the packer mandrel 20. As Figure 8 and Figure 9As shown, when the upper connection sleeve 92 of the packer system 10 is placed on the packer mandrel 20 above the locking ring 26, during the process of applying pressure to the packer system 10, the step of applying pressure to the locking ring 26 and the upper cone 30 using the upper sleeve 92 will be carried out.

[0069] In another alternative embodiment, the step of moving the slotted retrieval sleeve 80 from the first position to the second and third positions further includes the following steps: As Figure 11 shown, at the cutting target 76 of the retrieval mandrel 70, separate the connecting portion 72 from the release portion 74; and pull the packer mandrel 20 without the release portion 74 towards the upper cone 30. The step of separating the connecting portion 72 includes the following steps: deploy a cutting tool to the cutting target 76; and cut the retrieval mandrel 70 at the cutting target 76. The first position can be used as the main transition point to change the relative position of the slotted retrieval sleeve 80 and the lower cone 40. At the first position, the connecting portion 72 can be separated from or integrated with the release portion 74 of the retrieval mandrel 70. The separation step can be implemented before or after the downhole operation is completed. The separation step can be implemented before or after the downhole operation of the packer system 10 according to the cutting time of the cutting target 76. The slotted retrieval sleeve 80 is capable of reaching Figure 10 the second position as shown, and then reaching Figures 11 to 12 the third position as shown.

[0070] When the slotted retrieval sleeve 80 is in the first position, the locking ring 26 may already be in the unlocked position and the locked position. When the slotted retrieval sleeve 80 is in the second position, the locking ring 26 may also already be in the unlocked position and the locked position. However, the locking ring 26 must transition to the unlocked position to ensure that the push rod 80 can move from the second position to the third position. The upper cone 30 must be released before the movement. When the slotted retrieval sleeve 80 is in the third position, the locking ring 26 must be in the unlocked position.

[0071] The method further includes the following steps: pull the packer mandrel 20 towards the upper cone 30 again, and use the slotted retrieval sleeve 80 to push the upper cone 30 until the slotted retrieval sleeve 80 reaches the third position. The step of moving the slotted retrieval sleeve 80 from the first position to the second position and then to the third position further includes the step of pulling the packer mandrel 20 without the release portion 74 further towards the upper cone. The step of pushing the upper cone 30 further away from the lower cone 40 includes the step of using the slotted retrieval sleeve 80 to push the upper cone 30.

[0072] The present invention provides a retrievable packer system for isolating a production zone from a non-production zone in a wellbore for downhole operations. The retrievable packer system and method can set the packer system at a specific location in the wellbore and can release the packer system from that specific location. The packer system can be set and locked at a specific location for performing various downhole operations. After completion of the downhole operations, the packer system can be released from the location to be retrieved through the slotted retrieval sleeve of the packer system.

[0073] The packer system includes a slotted retrieval sleeve and a retrieval mandrel as release components. The slotted retrieval sleeve cooperates with a lower cone and the retrieval mandrel to push an upper cone and return the slip assembly from the set position to the run-in position. After separating the release portion of the retrieval mandrel, the packer mandrel can be pulled upward without the release portion. The connecting portion will be pulled upward together with the packer mandrel to bring the slotted retrieval sleeve to a second position adjacent to the upper cone. After the locking ring transitions from the locked position to the unlocked position, the upper cone can move freely. When the packer mandrel can be pulled further upward, the slotted retrieval sleeve will push the upper cone further away to slide the slip assembly back to the run-in position.

[0074] The release components of the retrievable packer system now form a flow bypass from the retrieval mandrel to the slip assembly. There are no longer vent holes in the lower connecting sleeve, and no longer rely on any single vent hole to release fluid pressure from the chamber formed by the lower connecting sleeve, lower cone, retrieval mandrel, slotted retrieval sleeve, and packer mandrel. The slotted retrieval sleeve provides fluid connection between the chamber and the slip assembly through the slip flow channels leading to the wellbore. There are multiple fluid slot bypasses through the slotted retrieval sleeve in the chamber to prevent debris blockage. Blockage of any single slot no longer generates hydraulic pressure that would impede or cause failure of the retrieval mandrel and slotted retrieval sleeve drive.

[0075] The slotted retrieval sleeve can withstand different external forces to ensure that the slip assembly in the set position can return to the run-in position. The slotted retrieval sleeve and the retrieval mandrel are release components, while a snap ring or shear screw is an external force mechanical limiting device applied to the upper cone to slide the slip assembly back to the run-in position. In addition, the present invention avoids using other fragile release components, increases the external force available to push the upper cone, and reduces the risk of hydraulic resistance that would prevent reliable retrieval of the packer system.

[0076] The foregoing disclosure and description of the present invention are illustrative and explanatory of the present invention. Various changes may be made to the details of the illustrated structures, configurations, and methods without departing from the true spirit of the present invention.

Claims

1. A retrievable packer system, comprising: A packer mandrel having an upper mandrel end and a lower mandrel end; A locking ring fixed to the packer mandrel at the upper mandrel end, and having an unlocking position relative to the lower mandrel end and a locking position relative to the lower mandrel end on the packer mandrel, the locking position being closer to the lower mandrel end than the unlocking position, and the locking ring being removably fixed to the locking position of the packer mandrel; An upper cone mounted on the packer mandrel between the locking ring and the lower mandrel end; A lower cone mounted on the packer mandrel between the upper cone and the lower mandrel end; Wherein the lower cone includes: A lower cone tip facing the upper cone; A lower cone base end opposite to the lower cone tip; and Slip means slidably engaging with the upper cone and the lower cone between the upper cone and the lower cone; Wherein the slip means includes an inner engaging surface facing the upper cone and the lower cone and an outer engaging surface opposite to the inner engaging surface, and the slip means has a slip flow channel from the inner engaging surface to the outer engaging surface; and Wherein the slip means has a running-in position and a setting position, the outer engaging surface maintaining an initial distance from the upper cone and the lower cone, the outer engaging surface maintaining an extended distance from the upper cone and the lower cone, and the extended distance being greater than the initial distance to ensure that the packer mandrel can be held at a specific position in the wellbore; A retrieval mandrel mounted on the packer mandrel between the lower cone and the lower mandrel end and having a connection end facing the lower cone; and A slotted retrieval sleeve mounted on the retrieval mandrel and extending into the lower cone, and including an anchoring end fixed to the retrieval mandrel, a pushing end opposite to the anchoring end, and a plurality of slots, wherein each of the plurality of slots has an open slot end at the pushing end and a flow end opposite to the open slot end; An upper connection sleeve placed on the packer mandrel above the locking ring; and A lower connection sleeve placed around the packer mandrel between the lower cone and the lower mandrel end to ensure that a chamber can be formed with the lower connection sleeve, the lower cone, the retrieval mandrel, the slotted retrieval sleeve, and the packer mandrel, wherein the chamber is in fluid connection with the slip flow channel.

2. The packer system according to claim 1, wherein: The slotted retrieval sleeve has a first position relative to the lower cone tip, the pushing end is located within the lower cone, the slip means is in the running-in position, and the slip means is in the setting position; The slotted retrieval sleeve has a second position relative to the lower cone tip, the pushing end extends from the lower cone and contacts the upper cone when the slip means is in the setting position, and the second position extends past the lower cone tip; And The slotted retrieval sleeve has a third position where the push end extends from the lower cone and contacts the upper cone when the slip assembly is in the run-in position, and the third position is further away from the tip of the lower cone than the second position.

3. The packer system according to claim 1, wherein the upper cone includes an upper inclined surface angled outwardly towards the upper mandrel end, and the lower cone includes a lower inclined surface angled outwardly towards the lower mandrel end.

4. The packer system according to claim 3, wherein the upper inclined surface includes at least one upper conical surface, and the lower inclined surface includes at least one lower conical surface.

5. The packer system according to claim 1, wherein: the inner engagement surface includes an upper slip engagement surface 66 that slidably engages with the upper inclined surface and a lower slip engagement surface 68 that slidably engages with the lower inclined surface; the outer engagement surface maintains the initial distance from the upper inclined surface and the lower inclined surface in the run-in position; and the outer engagement surface maintains the extended distance from the upper inclined surface and the lower inclined surface.

6. The packer system according to claim 1, wherein the retrieval mandrel includes a connection portion, a release portion, and a cutting target between the connection portion and the release portion; and wherein the lower connection sleeve includes a sleeve slot, and the connection portion of the retrieval mandrel is movable within the sleeve slot.

7. The packer system according to claim 6, wherein the connection portion further includes a stud extending into the sleeve slot.

8. The packer system according to claim 6, wherein the connection portion has a greater wall thickness than the release portion.

9. The packer system according to claim 6, wherein the retrieval mandrel has a tapered section 79, and the diameter of the tapered section 79 increases from the release portion towards the connection portion.

10. The packer system according to claim 6, wherein the connection portion of the retrieval mandrel separates from the release portion when the slotted retrieval sleeve is in the second position.

11. The packer system according to claim 6, wherein the connection portion of the retrieval mandrel separates from the release portion when the slotted retrieval sleeve is in the third position.

12. The packer system according to claim 6, wherein the connection portion of the retrieval mandrel is integral with the release portion through the cutting target, and the slotted retrieval sleeve is in the first position.

13. The packer system according to claim 1, wherein the plurality of slots are circumferentially arranged around the slotted retrieval sleeve.

14. A downhole operation method, comprising the steps of: running in the packer system according to claim 1 into the wellbore, wherein the slip assembly is in the run-in position, the locking ring is in the unlocked position, and the slotted retrieval sleeve is in the first position; positioning the packer system at a specific location in the wellbore; moving the upper cone along the packer mandrel towards the lower cone; sliding the slip assembly from the run-in position to the set position; With the packer system in the said position, transition the locking ring from the unlocked position to the locked position to ensure that the packer system can be held in a specific part when the slip device is in the set-down position and the slotted recovery sleeve is in the first position; Move the slotted recovery sleeve from the first position to the second position, where the slip device is in the set-down position and the slotted recovery sleeve is in the second position; With the packer system in the said position and the slotted recovery sleeve in the second position, transition the locking ring from the locked position to the unlocked position; Move the slotted recovery sleeve from the second position to the third position; While moving the slotted recovery sleeve from the second position to the third position, further push the upper cone along the packer mandrel from the lower cone; Slide the slip device from the set-down position to the run-in position to ensure that the packer system can be released from the said position; And Recover the packer system when the slip device is in the run-in position and the slotted recovery sleeve is in the third position.

15. The downhole operation method according to claim 14 further comprises the following steps: After transitioning the locking ring from the unlocked position to the locked position, perform downhole operations with the packer system in the said position.

16. The downhole operation method according to claim 14, wherein the step of moving the upper cone along the packer mandrel towards the lower cone comprises the step of applying pressure to the packer system from above the locking ring.

17. The downhole operation method according to claim 16, wherein: The step of applying pressure to the packer system comprises the step of using the upper sleeve to apply pressure on the locking ring and the upper cone.

18. The downhole operation method according to claim 15, wherein the recovery mandrel comprises a connection part, a release part, and a cutting target between the connection part and the release part, and wherein the step of moving the slotted recovery sleeve from the first position to the second position further comprises the following steps: Separate the connection part from the release part at the cutting target; And Pull the mandrel without the release part towards the upper cone.

19. The downhole operation method according to claim 18, wherein the step of separating the connection part comprises the following steps: Deploy a cutting tool to the cutting target; And Cut the recovery mandrel at the cutting target.

20. The downhole operation method according to claim 18, wherein the step of moving the slotted recovery sleeve from the second position to the third position further comprises the step of further pulling the packer mandrel without the release part towards the upper cone, and wherein the step of further pushing the upper cone away from the lower cone comprises the step of using the slotted recovery sleeve to push the upper cone.

Images