Thermal recovery packer capable of being fished and unsealed

Abstract

The utility model discloses a thermal recovery packer capable of being fished and unsealed, which comprises a central pipe, a releasing assembly used for driving setting of the packer, a fishing assembly used for fishing and unsealing of the packer, a rubber sleeve assembly used for sealing an annular space between the packer and a casing pipe and a slip assembly used for clamping and fixing the packer in the casing pipe are sequentially arranged on the outer wall of the central pipe from top to bottom, and the rubber sleeve assembly comprises a liner pipe and a rubber sleeve base. The upper end of the rubber sleeve seat is inserted into the outer tube, a starting shear pin is arranged between the outer tube and the rubber sleeve seat, a liner tube lock spring ring groove is formed in the inner wall of the liner tube, and a liner tube lock spring is arranged in the liner tube lock spring ring groove; the slip assembly comprises an upper cone, a setting shear pin is arranged between the upper cone and the liner tube, an upper cone lock spring ring groove is formed in the inner wall of the upper cone, and an upper cone lock spring is arranged in the upper cone lock spring ring groove. The thermal recovery packer is high in slip anchoring force, large in setting pressure difference, capable of meeting the use requirement of heavy oil thermal recovery under the high-temperature and high-pressure environment, and good in setting effect.

Description

TECHNICAL FIELD

[0001] The utility model relates to a packer that can be fished and unsealed, in particular to a thermal recovery packer for heavy oil thermal recovery. BACKGROUND

[0002] During heavy oil thermal recovery, packers are needed to block the casing to meet the needs of bottom hole sealing or selective layer fracturing operation, and the packer needs to be fished and unsealed after the operation is completed. CN213087959U discloses a fishable bridge plug with a sealing function, which includes a blocking device, an anchoring device, and a sealing device. The sealing device includes an upper joint, an upper protective cap threadedly connected to the outer wall of the upper joint, an upper sleeve, a connecting sleeve threadedly connected to the inner wall of the upper joint, thereby forming a setting liquid cylinder in the annular space between the upper sleeve and the connecting sleeve, a setting piston and a push cylinder in the setting liquid cylinder, and a setting shear pin between the upper sleeve and the push cylinder. The connecting sleeve is a solid core stepped variable diameter connecting sleeve with a thin upper part and a thick lower part. An axial liquid guide blind hole is provided at the upper end of the connecting sleeve, and a liquid inlet hole is provided on the wall of the liquid guide blind hole to deliver setting high-pressure water into the setting liquid cylinder. During the setting process of the fishable bridge plug, the central tube at the lower part of the bridge plug is not under pressure, has the advantages of simple structure, high reliability, etc., and can be set with smaller water pressure and good setting effect. However, during the setting process of the fishable bridge plug with a sealing function, there is no shear pin mechanism between the upper cone and the lower compression ring of the rubber tube, so that after the slips stop moving downward during the setting process, the rubber tube is pressed and swells, blocking in the casing, and subsequent pressure will not increase the anchoring force between the slips and the casing, resulting in limited anchoring force between the slips and the casing. In addition, there is no locking device between the upper cone and the central tube, and when the downhole temperature changes significantly, the upper cone will slide along the central tube, causing the slips to loosen and affecting the setting effect of the bridge plug. Therefore, the fishable bridge plug with a sealing function cannot meet the use requirements in the high temperature and high pressure environment of heavy oil thermal recovery. SUMMARY

[0003] The technical problem to be solved by the utility model is to provide a thermal recovery packer that can be fished and unsealed, which has strong slip anchoring force, large setting pressure difference, and good setting effect, and can meet the use requirements in the high temperature and high pressure environment of heavy oil thermal recovery.

[0004] The technical scheme adopted for solving the technical problem: a hot production packer capable of being fished and unsealed, comprising a center pipe, a releasing assembly for driving the packer to set, a fishing assembly for fishing and unsealing the packer, a rubber sleeve assembly for sealing the annular space between the packer and a casing, and a slip assembly for clamping the packer in the casing are sequentially arranged on the outer wall of the center pipe from top to bottom, characterized in that: the rubber sleeve assembly comprises a liner pipe sleeved on the outer wall of the center pipe, a rubber sleeve seat is threadedly connected to the upper end of the liner pipe, the rubber sleeve seat is inserted into the outer pipe, a starting shear pin is arranged between the outer pipe and the rubber sleeve seat, an adjusting cap is sleeved on the lower end of the liner pipe, a setting rubber sleeve is sleeved on the outer wall of the liner pipe between the adjusting cap and the rubber sleeve seat, a liner pipe lock spring ring groove is formed in the inner wall of the liner pipe, and a liner pipe lock spring is arranged in the liner pipe lock spring ring groove; the slip assembly comprises an upper cone inserted into the annular space between the adjusting cap and the liner pipe, the upper cone is connected to the adjusting cap through threads, a setting shear pin is arranged between the upper cone and the liner pipe, an upper cone lock spring ring groove is formed in the inner wall of the upper cone, an upper cone lock spring is arranged in the upper cone lock spring ring groove, a lower cone is threadedly connected to the lower end of the center pipe, a slip sleeve and a connecting cap for connecting the upper cone and the lower cone are further arranged outside the center pipe, the connecting cap and the slip sleeve are fixed outside the upper cone and the lower cone through thread connection and cooperation, a slip and a slip plate spring are arranged in the annular space between the slip sleeve and the center pipe, and a cone plug is arranged in the center hole of the lower cone to block the center hole of the lower cone.

[0005] As a further improvement of the utility model: a one-way tooth ring is arranged on the outer wall of the center pipe and cooperates with the liner pipe lock spring and the upper cone lock spring.

[0006] As a further improvement of the utility model: the fishing assembly comprises a stepped pipe-shaped transition sleeve, a fishing head is inserted into the inner wall of the transition sleeve and is in sliding cooperation with the inner wall of the transition sleeve, an unsealing shear pin is arranged between the fishing head and the transition sleeve, the lower end of the transition sleeve is inserted into the center pipe and is connected to the upper end of the center pipe through threads, a connecting rod is further inserted into the transition sleeve, the upper end of the connecting rod is connected to the fishing head through threads, the lower end of the connecting rod is connected to a rod cap through threads, and an unsealing ring table is arranged on the inner wall of the lower end of the center pipe and cooperates with the rod cap to prevent the rod cap from ascending.

[0007] As a further improvement of the utility model: the releasing assembly comprises an upper connector, a piston rod hole is arranged at the center position of the upper connector, axial flow-through holes are arranged around the piston rod hole, an outer pipe is connected to the outer wall of the upper connector, radial flow-through holes are arranged on the pipe wall of the outer pipe, a piston rod is fixed in the piston rod hole, a connecting sleeve is threadedly connected to the lower end of the piston rod, the lower end of the connecting sleeve is sleeved on the outer wall of the fishing head and the transition sleeve, a releasing shear pin is arranged between the connecting sleeve and the transition sleeve, an annular setting piston is arranged in the annular space between the piston rod and the outer pipe, the annular setting piston is connected to an inner pipe through threads, and the lower end of the inner pipe abuts against the upper end of the rubber sleeve seat.

[0008] As a further improved scheme of the present utility model: the outer wall of the rod cap and the inner wall of the central pipe below the releasing ring table are in sliding fit, and a plurality of axial collapse joints are opened on the wall of the central pipe below the releasing ring table.

[0009] As a further improved scheme of the present utility model: the plug-in shaft head which is in plug-in fit with the piston rod hole is arranged on the upper end of the piston rod, the annular clamping groove is arranged on the plug-in shaft head, and the anti-dropping ring which prevents the piston shaft head from dropping out of the piston rod hole is arranged in the annular clamping groove.

[0010] As a further improved scheme of the present utility model: two sealing ring grooves are opened on the inner wall and the outer wall of the annular setting piston, and the sealing rubber rings are embedded in the sealing ring grooves.

[0011] As a further improved scheme of the present utility model: the central pipe sealing ring groove and the lower cone sealing ring groove are opened on the inner wall of the central hole of the lower cone, and the sealing rubber rings are respectively embedded in the central pipe sealing ring groove and the lower cone sealing ring groove.

[0012] As a further improved scheme of the present utility model: the inner wall of the central hole of the upper end of the liner is in sliding sealing fit with the outer wall of the central pipe, two liner sealing ring grooves are opened on the inner wall of the central hole of the upper end of the liner, and the sealing rubber rings are embedded in the liner sealing ring grooves.

[0013] Beneficial effects: the hot production packer of the utility model can be fished and unsealed, because the liner lock spring ring groove is opened on the inner wall of the liner, the liner lock spring is installed in the liner lock spring ring groove, the setting shear pin is arranged between the upper cone and the liner, the upper cone lock spring ring groove is opened on the inner wall of the upper cone, and the upper cone lock spring is installed in the upper cone lock spring ring groove, during the setting process of the packer, the slip assembly needs to be anchored completely, then the setting shear pin is broken, and the setting rubber begins to expand along the radial direction, therefore, the slip anchoring force of the packer is strong, the setting pressure difference of the packer is larger, the setting rubber expands more fully, the expansion sealing effect is better, the working pressure and temperature that can be resisted are higher, the use requirement under the high temperature and high pressure environment of the heavy oil hot production can be met, in addition, because the upper cone lock spring and the liner lock spring are adopted to lock the center tube, the length change of the center tube caused by thermal expansion and cold contraction when the downhole temperature changes greatly can be effectively prevented, the setting rubber and / or the slip are loosened, the setting effect of the hot production packer of the utility model is good, and the stability is higher. Because the one-way tooth ring matched with the liner lock spring and the upper cone lock spring is arranged on the outer wall of the center tube, the locking effect between the liner lock spring, the upper cone lock spring and the center tube is further improved, the hot production packer of the utility model can resist higher setting pressure difference and working pressure. Because the fishing assembly comprises the stepped pipe-shaped transition sleeve, the fishing head is inserted and arranged on the upper end of the transition sleeve and is in sliding fit with the inner wall of the transition sleeve, the unsealing shear pin is arranged between the fishing head and the transition sleeve, the lower end of the transition sleeve is inserted in the center tube and is connected with the upper end of the center tube through the thread, the connecting rod is further inserted in the transition sleeve, the upper end of the connecting rod is connected with the fishing head through the thread, the lower end of the connecting rod is connected with the rod cap through the thread, the unsealing ring table matched with the rod cap and preventing the rod cap from going up is arranged on the inner wall of the lower end of the center tube, the connecting rod is used instead of the inner center tube in the ordinary packer, the defects that the unsealing load is large and the fishing unsealing fails easily caused by the rust and adhesion of the inner center tube and the outer center tube when the inner center tube and the outer center tube structure are used can be overcome, the load that can be resisted by the connecting rod is larger, and the success rate of the fishing unsealing is higher. Because the releasing assembly comprises the upper joint, the piston rod hole is arranged at the center position of the upper joint, the axial flow hole is arranged around the piston rod hole, the outer tube is connected to the outer wall of the upper joint, the radial flow hole is arranged on the wall of the outer tube, the piston rod is fixed in the piston rod hole, the connecting sleeve is connected to the lower end of the piston rod through the thread, the lower end of the connecting sleeve is sleeved on the outer wall of the fishing head and the transition sleeve, the releasing shear pin is arranged between the connecting sleeve and the transition sleeve, the annular setting piston is installed in the annular space between the piston rod and the outer tube, the inner tube is connected with the annular setting piston through the thread, and the lower end of the inner tube abuts against the upper end of the rubber seat, so that the production and assembly of the packer are more convenient.The technical features of the present application are that the outer wall of the rod cap is in sliding fit with the inner wall of the central pipe below the releasing ring table, and a plurality of axial collapse joints are formed on the wall of the central pipe below the releasing ring table, which can effectively prevent the failure of the slip plate spring during releasing and the failure of the slip to release in time, and further improve the success rate of releasing. The technical features of the present application are that the upper end of the piston rod is provided with an inserted shaft head in plug fit with the hole of the piston rod, the inserted shaft head is provided with an annular clamping groove, and a anti-falling ring is arranged in the annular clamping groove to prevent the piston shaft head from falling out of the hole of the piston rod, which makes the assembly of the thermal recovery packer more convenient. The technical features of the present application are that two sealing ring grooves are formed on the inner wall and the outer wall of the annular setting piston, and sealing rubber rings are embedded in the sealing ring grooves, which makes the sealing effect of the inner wall and the outer wall of the piston better and the output power of the piston stronger. The technical features of the present application are that a central pipe sealing ring groove and a lower cone sealing ring groove are formed on the inner wall of the central hole of the lower cone, and sealing rubber rings are respectively embedded in the central pipe sealing ring groove and the lower cone sealing ring groove, which prevents the packer tail end from leaking in a high temperature and high pressure environment after setting. The technical features of the present application are that the inner wall of the central hole of the upper end of the liner is in sliding sealing fit with the outer wall of the central pipe, two liner sealing ring grooves are formed on the inner wall of the central hole of the upper end of the liner, and sealing rubber rings are embedded in the liner sealing ring grooves, which prevents slow leakage between the central pipe and the liner, and ensures the sealing effect of the thermal recovery packer in a high temperature and high pressure environment for a long time. BRIEF DESCRIPTION OF DRAWINGS

[0014] The present application will be further described in detail below with reference to the drawings.

[0015] Figure 1 is the axial cross-sectional structure of the fishing and releasing thermal recovery packer of the present application. DETAILED DESCRIPTION

[0016] As shown in Figure 1 , the fishing and releasing thermal recovery packer of the present application comprises a central pipe 12, and a releasing ring table, a rubber cylinder assembly, a slip assembly and a slipper assembly are sequentially arranged on the outer wall of the central pipe from top to bottom.

[0017] The rubber cylinder assembly comprises a liner 11 sleeved on the outer wall of the central pipe, a rubber cylinder seat 9 is threadedly connected to the upper end of the liner, the upper end of the rubber cylinder seat is inserted into the outer pipe, a starting shear pin 28 is arranged between the outer pipe and the rubber cylinder seat, an adjusting cap 14 is sleeved on the lower end of the liner, a setting rubber cylinder 10 is sleeved on the outer wall of the liner between the adjusting cap and the rubber cylinder seat, a liner lock spring ring groove is formed on the inner wall of the liner, and a liner lock spring 30 is arranged in the liner lock spring ring groove.

[0018] The slip assembly comprises an upper cone 15 inserted into the annular space between the adjusting cap and the liner, the upper cone is connected with the adjusting cap by screw thread, a setting shear 31 is arranged between the upper cone and the liner, an upper cone lock spring groove is formed on the inner wall of the upper cone, an upper cone lock spring 32 is arranged in the upper cone lock spring groove, a lower cone 19 is connected with the center tube by screw thread at the lower end of the center tube, a slip sleeve 16 connecting the upper cone and the lower cone and a connecting cap 17 are further arranged outside the center tube, the connecting cap and the slip sleeve are fixed outside the upper cone and the lower cone by screw thread connection, slips 33 and slip plate springs 34 are arranged in the annular space between the slip sleeve and the center tube, and a cone plug 20 is arranged in the central hole of the lower cone to block the central hole of the lower cone.

[0019] The fishing assembly comprises a stepped tube-shaped transition sleeve 8, a fishing head 7 is inserted into the upper end of the transition sleeve and is in sliding fit with the inner wall of the transition sleeve, a releasing shear 27 is arranged between the fishing head and the transition sleeve, the lower end of the transition sleeve is inserted into the center tube and is connected with the upper end of the center tube by screw thread, a connecting rod 13 is further inserted into the transition sleeve, the upper end of the connecting rod is connected with the fishing head by screw thread, the lower end of the connecting rod is connected with a rod cap 18 by screw thread, a releasing ring table 35 is arranged on the inner wall of the lower end of the center tube and is in fit with the outer wall of the rod cap to prevent the rod cap from going up, the outer wall of the rod cap is in sliding fit with the inner wall of the center tube below the releasing ring table. A plurality of axial collapse seams are formed on the wall of the center tube below the releasing ring table, the collapse seams are a plurality of axial notches cut at equal angles at the tail end of the center tube.

[0020] The releasing assembly comprises an upper joint 1, a piston rod hole 21 is arranged at the center position of the upper joint, axial flow hole 23 is arranged around the piston rod hole, an outer tube 2 is connected to the outer wall of the upper joint, radial flow holes 25 are arranged on the wall of the outer tube, a piston rod 5 is fixed in the piston rod hole, an insertion shaft head is arranged at the upper end of the piston rod and is in insertion fit with the piston rod hole, an annular clamping groove is arranged on the insertion shaft head, an anti-falling check ring 22 is arranged in the annular clamping groove to prevent the piston shaft head from falling out of the piston rod hole, a connecting sleeve 6 is connected to the lower end of the piston rod by screw thread, the lower end of the connecting sleeve is sleeved on the outer wall of the fishing head and the transition sleeve, a releasing shear 26 is arranged between the connecting sleeve and the transition sleeve, an annular setting piston 3 is arranged in the annular space between the piston rod and the outer tube, two sealing ring grooves 24 are respectively formed on the inner wall and the outer wall of the annular setting piston, sealing rubber rings are embedded in the sealing ring grooves, the inner tube 4 is connected with the annular setting piston by screw thread, and the lower end of the inner tube abuts against the upper end of the rubber cylinder seat.

[0021] Preferably, a one-way tooth ring 38 is arranged on the outer wall of the center tube and is in fit with the liner lock spring and the upper cone lock spring.

[0022] Preferably, a center tube sealing ring groove 36 and a lower cone sealing ring groove 37 are formed on the inner wall of the central hole of the lower cone, and sealing rubber rings are respectively embedded in the center tube sealing ring groove and the lower cone sealing ring groove.

[0023] Preferably, the inner wall of the central hole of the upper end of the liner is in sliding sealing engagement with the outer wall of the central tube, two liner sealing ring grooves 29 are formed in the inner wall of the central hole of the upper end of the liner, and sealing rubber rings are embedded in the liner sealing ring grooves.

[0024] The working process of the hot production packer capable of being fished and unsealed is as follows: setting process, the hot production packer is lowered to a specified position of the casing by using a tubing, the hot production packer is pressed by the tubing, the pressurized liquid reaches the upper surface of the annular setting piston through the axial flow hole of the upper joint, the annular setting piston pushes the inner tube and the rubber seat to move downward under the action of the pressurized liquid, the start shear pin between the outer tube and the rubber seat is broken, the rubber seat, the liner, the setting rubber, the adjusting cap and the upper cone move downward synchronously, the upper cone and the lower cone cooperate to fix the slips in the inner wall of the casing, when the upper cone cannot move downward any more, the anchor is completed, the lower cone is locked on the one-way tooth ring on the outer wall of the central tube, the liner continues to move downward, the setting shear pin between the upper cone and the liner is broken, the adjusting cap does not move downward, the liner and the rubber seat continue to move downward, the setting rubber is compressed, the setting rubber is fully expanded in the radial direction, the annular space between the casing and the liner is closed, until the setting differential pressure is reached, the liner is locked on the one-way tooth ring on the outer wall of the central tube, the pressing is stopped, and the setting is completed. After setting, the pressing is continued, at this time, the rubber seat does not move downward any more under the constraint of the setting rubber, the piston rod pulls the connecting sleeve upward, the release shear pin is broken, the tubing is pulled upward, the upper joint, the piston rod, the connecting sleeve, the piston, the outer tube and the inner tube are pulled out of the wellhead together, and the releasing is completed. The fishing tool is lowered from the wellhead, and is pulled upward after being caught by the fishing head, the unsealing shear pin between the fishing head and the transition sleeve is broken, the fishing head, the connecting rod and the rod cap move upward, the central tube moves upward in the space between the fishing head and the transition sleeve, when the rod cap at the lower end of the connecting rod moves upward to the unsealing ring table, the central tube moves upward together, the collapse seam area at the lower end of the central tube deforms inwardly, loses the support of the slips, the slips are separated from the inner wall of the casing under the action of the slip plate spring, the anchor is unfastened, the axial pressure of the setting rubber is released when the central tube continues to move upward, the setting rubber contracts in the radial direction, the sealing is released, the fishing head is continuously pulled upward until the rubber assembly and the slip assembly are pulled out of the wellhead, and the unsealing is completed.

[0025] The setting differential pressure of the hot production packer capable of being fished and unsealed can be up to 27 Mpa, the working pressure can be up to 17 Mpa, the connecting rod can bear an unsealing load of 40 KN, and the working requirements of heavy oil hot production can be met.

Claims

1. A retrievable thermal recovery packer comprising a base pipe, on the outer wall of which are arranged, from top to bottom, a release assembly for driving the packer to set, a fishing assembly for retrievable the packer, a rubber sleeve assembly for sealing the annular space between the packer and the casing, and a slip assembly for securing the packer within the casing. The packer is characterized by: The rubber sleeve assembly comprises a liner pipe sleeved outside the central pipe, the upper end of the liner pipe is connected with a rubber sleeve base through screw thread, the rubber sleeve base is inserted into the outer pipe, a starting shear pin is arranged between the outer pipe and the rubber sleeve base, the lower end of the liner pipe is sleeved with an adjusting cap, a setting rubber sleeve is sleeved outside the liner pipe between the adjusting cap and the rubber sleeve base, a liner pipe lock spring ring groove is opened in the inner wall of the liner pipe, and a liner pipe lock spring is arranged in the liner pipe lock spring ring groove.

2. The hot production packoff that can be fished unsealed according to claim 1, characterized in that: The upper end of the central pipe is connected with a lower cone through screw thread, a slip sleeve and a connecting cap are further arranged outside the central pipe, the connecting cap and the slip sleeve are connected and fixed outside the upper cone and the lower cone through screw thread, a slip and a slip plate spring are arranged in the annular space between the slip sleeve and the central pipe, and a cone plug is arranged in the central hole of the lower cone.

3. The hot production packoff that can be pulled apart according to claim 2, characterized in that: A one-way tooth ring is arranged on the outer wall of the central pipe and matched with the liner pipe lock spring and the upper cone lock spring.

4. The hot production packer that can be unblocked and fished out according to claim 3, characterized in that: The fishing assembly comprises a stepped pipe-shaped transition sleeve, a fishing head is inserted into the upper end of the transition sleeve and is in sliding fit with the inner wall of the transition sleeve, a releasing shear pin is arranged between the fishing head and the transition sleeve, the lower end of the transition sleeve is inserted into the central pipe and is connected with the upper end of the central pipe through screw thread, a connecting rod is further inserted into the transition sleeve, the upper end of the connecting rod is connected with the fishing head through screw thread, the lower end of the connecting rod is connected with a rod cap through screw thread, and a releasing ring table matched with the rod cap and preventing the rod cap from ascending is arranged on the inner wall of the lower end of the central pipe.

5. The hot production packoff that can be pulled apart according to claim 4, characterized in that: The releasing ring table is matched with the rod cap through sliding fit, and a plurality of axial collapse seams are opened on the pipe wall below the releasing ring table.

6. The hot production packoff that can be pulled apart according to claim 5, characterized in that: An insertion shaft head matched with the piston rod hole is arranged on the upper end of the piston rod, an annular clamping groove is arranged on the insertion shaft head, and an anti-falling check ring preventing the piston shaft head from falling out of the piston rod hole is arranged in the annular clamping groove.

7. The hot production packoff that can be fished unsealed according to claim 6, characterized by the fact that: Two sealing ring grooves are respectively opened on the inner wall and the outer wall of the annular setting piston, and sealing rubber rings are embedded in the sealing ring grooves.

8. The hot production packoff that can be pulled apart according to claim 7, characterized by the fact that: A central pipe sealing ring groove and a lower cone sealing ring groove are opened on the inner wall of the central hole of the lower cone, and sealing rubber rings are respectively embedded in the central pipe sealing ring groove and the lower cone sealing ring groove.

9. The retrievably unblocking thermal recovery packer according to any one of claims 1 to 8, characterized in that: The inner wall of the central hole of the upper end of the liner pipe is in sliding sealing fit with the outer wall of the central pipe, two liner pipe sealing ring grooves are opened on the inner wall of the central hole of the upper end of the liner pipe, and sealing rubber rings are embedded in the liner pipe sealing ring grooves. The inner wall of the central hole of the upper end of the liner pipe is in sliding sealing fit with the outer wall of the central pipe, two liner pipe sealing ring grooves are opened on the inner wall of the central hole of the upper end of the liner pipe, and sealing rubber rings are embedded in the liner pipe sealing ring grooves.

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