Multifunctional packer with pressure dragging fracturing and its construction method

Abstract

The present application belongs to the technical field of oil and gas reservoir reconstruction, and relates to a multifunctional packer for pressure drag fracturing and a construction method thereof. The multifunctional packer for pressure drag fracturing comprises, from top to bottom, an upper joint, a hydraulic lance, a releasing mechanism, a connecting structure, a pressure balancing mechanism, a reverse anchoring mechanism, a sealing unit and a lower joint, wherein the outer wall of the sealing unit is sleeved with a forward anchoring mechanism. In the process of well killing after pressure drag fracturing, the multifunctional packer is released and the well killing sealing function is started, the formation pressure is blocked by the packer for well killing, the wellhead zero-pressure tripping is realized, the wellhead testing equipment is removed, the problem of pressure stagnation of the testing equipment under pressure is effectively solved, the wellhead zero-pressure tripping effectively reduces the well control safety risk, the operation is convenient, and it is conducive to the large-scale popularization and application of the conventional tubing transmission pressure drag fracturing construction process.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field reservoir stimulation technology, specifically relating to a multi-functional packer for pressurized fracturing and its construction method. Background Technology

[0002] Currently, the conventional tubing-transported live-drive fracturing process cannot retrieve the entire well tubing string under pressure after fracturing. Due to the need for well shut-in procedures after fracturing, the wellhead live-drive equipment cannot be dismantled and transferred for use in the next well, resulting in a long pressure stagnation time for the oil testing equipment. Therefore, the large-scale application of the conventional tubing-transported live-drive fracturing process is restricted.

[0003] Patent CN103912257A discloses a pressurized drag-driven stratified fracturing device, which enables conventional workover rigs to drag fracturing tubing strings under pressure. After fracturing, a single-flow valve is used to seal the tubing annulus, along with a blowout preventer and a slugless tubing system. Under pressurized conditions at the wellhead and during positive well washing, the fracturing tubing string can be directly lifted under high load by the workover rig, achieving the function of lifting tubing under pressure. It can be seen that although this pressurized drag-driven stratified fracturing device achieves pressurized transfer fracturing, the wellhead remains pressurized when the tubing string is lifted. Summary of the Invention

[0004] The purpose of this invention is to provide a multifunctional packer for live-pulled fracturing and its construction method, so as to overcome the above-mentioned technical defects.

[0005] To solve the above-mentioned technical problems, the present invention provides a multi-functional packer for live-pulled fracturing, comprising: The components connected sequentially from top to bottom are: upper connector, water jet gun, release mechanism, connecting structure, pressure balancing mechanism, reverse anchoring mechanism, sealing unit, and lower connector. The outer wall of the sealing unit is fitted with a positive anchoring mechanism.

[0006] According to a multi-functional packer for pressurized fracturing, the release mechanism includes: Inner liner; The glove is fitted onto the outer wall of the inner liner. The inner liner and the glove are axially matched by a shoulder, and the inner liner and the glove are radially matched by a hole shaft. A locking ring is fitted onto the outer wall of the inner liner and is located below the lost glove. The inner liner and the locking ring are connected by scissor pins. A hand-drop connector is fitted onto the outer wall of the hand-drop glove, and the hand-drop glove is connected to the hand-drop connector by threads. A sleeve is fitted onto the outer wall of the drop glove and the locking ring.

[0007] According to a multi-functional packer for live fracturing, the pressure balancing mechanism includes: A balance bar has an axially hollow through cavity. A locking rod, a locking core, and a spindle are inserted into the axially hollow through cavity from top to bottom. A connecting sleeve and a balance sleeve are fitted onto the outer wall of the locking rod from top to bottom. The connecting sleeve and the balance bar are connected by threads, and the balance bar and the spindle are connected by threads. The locking rod is threaded to the lower part of the inner bushing, and the locking rod and the balance bar are connected by a locking claw to form a shoulder connection; A push sleeve is fitted onto the outer wall of the connecting sleeve, and the push sleeve and the sleeve are connected by threads; A serrated sleeve is fitted onto the outer wall of the push sleeve; A serrated ring is fitted onto the outer wall of the balance sleeve, and the serrated ring and the serrated sleeve are connected by serrations.

[0008] According to a multi-functional packer for live fracturing, the sealing unit includes: The track tube has an upper rubber sleeve seat, a rubber sleeve, a lower rubber sleeve seat, a backstop ring, and a cone sequentially mounted on its outer wall from top to bottom. The lower rubber sleeve seat is connected to the cone by a thread, and the backstop ring is connected to the track tube by a thread.

[0009] According to a multi-functional packer for pressurized fracturing, the positive anchoring mechanism includes: The slip assembly, the stabilizer, the slip ring sleeve, and the sand guard are located below the cone and sequentially fitted onto the outer wall of the track tube from top to bottom, wherein the slip ring sleeve and the sand guard are connected by threads; A gap is left between the slip ring sleeve and the track tube. A switching ring is sleeved in the gap. A switching pin is installed in the inner wall hole of the switching ring. The slip ring sleeve can drive the switching pin to move linearly in the track groove of the track tube, so as to realize the switching groove action, the long groove is set and the short groove is unsealed.

[0010] According to a multi-functional packer for pressurized fracturing, the slip assembly includes slips, slip retaining rings, springs, and slip seats; The slip seat is fitted onto the outer wall of the track tube, the slip is installed in the groove of the outer wall of the slip seat, and the slip retaining ring is fitted into the groove of the outer wall of the slip; The slip is connected to the slip seat by a shoulder limit via the slip retaining ring; The lower section of the slip has multiple first hollow protrusions spaced circumferentially. The spring is installed inside the first hollow protrusions. When the slip loses the constraint of the cone, the slip tiles contract under the preload of the spring, releasing the anchor.

[0011] According to a multi-functional packer for live fracturing, the centralizer comprises: The upper section of the straightening block is fitted onto the outer wall of the slip seat and the two are connected by threads, while the lower section is fitted tightly against the outer wall of the track tube. The straightening block has multiple second hollow protrusions spaced circumferentially around the outer wall of the straightening block seat. The second hollow protrusions serve as the straightening block. A flat-diameter spring is built into the second hollow protrusion. Under the preload of the flat-diameter spring, the straightening block is made to fit against the sleeve wall for straightening. A straightening block pressure ring is fitted onto the outer wall of the straightening block seat, and the straightening block seat and the straightening block pressure ring are connected by welding; The straightening block seat is connected to the slip ring sleeve by threads to fix the straightening block and the flat diameter spring inside the straightening block seat.

[0012] According to a multi-functional packer for pressurized fracturing, barbs are provided on the outer wall of the sleeve, which are suitable for assisting in the retrieval and grabbing of the remaining part of the drill string in the well after it has been lost.

[0013] This invention also provides a construction method for a multi-functional packer for live-drive fracturing, suitable for a multi-functional packer for live-drive fracturing, comprising: Step 101: Connect the upper connector of the pressurized drag fracturing multi-functional packer using tubing to form the target tubing string, and lower the target tubing string into the target wellbore; Step 102: After the target tubing is lowered to the first designed position, the target tubing is lifted and lowered, and the forward anchoring mechanism is activated to anchor the target tubing inside the target wellbore, setting the sealing unit and sealing the annular channel. Step 103: Start the hydraulic spray gun to perform spraying and perforation operation according to the designed displacement. At this time, the pressure balancing mechanism is activated, so that the pressure balancing channel in the pressure balancing mechanism is closed and the sealing unit effectively seals. Step 104, fracturing operation; Step 105: Lift the target tubing, open the pressure balance channel of the pressure balance mechanism, balance the upper and lower pressures of the sealing unit, lift and lower the target tubing, unseal the sealing unit, and at the same time, release the anchoring function of the positive anchoring mechanism, and the multi-functional packer for fracturing under pressure is in a free state. Step 106: Activate the wellhead pressurized device to seal the annulus, and drag the target tubing string to the next designed position under pressure to complete the pressurized transfer of the target tubing string. At this time, the tubing is in a sealed state. Step 107: Repeat steps 102-106 to complete the fracturing construction at all designed locations.

[0014] According to a construction method for a multi-functional packer for pressurized fracturing, it also includes: Step 108: Activate the wellhead pressurized device to seal the annulus, and drag the target tubing string under pressure to the designed position of all sections; Step 109: After the target tubing is lowered to the first designed position, the target tubing is lifted and lowered, and the forward anchoring mechanism is activated to anchor the target tubing inside the target wellbore, set the sealing unit, and seal the annular channel. At this time, the reverse anchoring mechanism is activated to form bidirectional anchoring of the sealing unit. Step 110: Throw a ball into the target tube column. The ball is located in the inner cavity of the hydraulic spray gun. Pump and pressurize the water to start the release mechanism and realize the release function. Step 111: At this point, there is no pressure at the wellhead. Pull out the target tubing string described above. Step 112: Initiate well shut-in operation; Step 113: Open the blowout channel by pumping water into the wellhead; Step 114: Lower the drilling and retrieval tool, connect it with the barbs reserved in the connecting structure, and retrieve the remaining part of the drilling tool in the well.

[0015] This invention relates to the well shut-in process after live fracturing. By releasing a multi-functional packer and activating the well shut-in function, the formation pressure is sealed through the packer, achieving zero-pressure wellhead tripping and disassembling the wellhead testing equipment. This effectively solves the problem of pressure stagnation in live testing equipment. Zero-pressure wellhead tripping significantly reduces well control safety risks, is easy to operate, and is conducive to the large-scale promotion and application of conventional tubing-transported live fracturing construction technology.

[0016] To make the above description of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is the assembly drawing of a multi-functional packer for pressurized fracturing.

[0018] Figure 2 This is a schematic diagram of the dropping mechanism.

[0019] Figure 3 This is a schematic diagram of a pressure balancing mechanism.

[0020] Figure 4 This is an assembly diagram of the sealing unit and the positive anchoring mechanism.

[0021] Explanation of reference numerals in the attached figures: 1. Oil pipeline; 2. Connector; 3. Water-powered spray gun; 4. Dropping mechanism; 401. Inner liner; 402. Dropping glove; 403. Locking ring; 404. Dropping glove connector; 405. Sleeve; 5. Connection structure; 6. Pressure balancing mechanism; 601. Locking rod; 602. Balance bar; 603. Lock cylinder; 604. Spindle; 605. Connecting sleeve; 606. Balance sleeve; 607. Push sleeve; 608. Serrated sleeve; 609. Serrated ring; a. Pressure balancing channel; 7. Reverse anchoring mechanism; 8. Sealing unit; 801. Track tube; 802. Upper glue sleeve seat; 803. Glue sleeve; 804. Lower glue sleeve seat; 805. Anti-reverse ring; 806. Cone; 9. Positive anchoring mechanism; 901. Slip seat; 902. Slip ring sleeve; 903. Sandproof ring; 904. Switching ring; 905. Switching pin; 961. Slip; 962. Slip retaining ring; 963. Spring; 964. Slip seat; 971. Centralizing block seat; 972. Centralizing block pressure ring; 973. Centralizing block; 974. Flat diameter spring; 10. Lower connector; 11. Valve seat. Detailed Implementation

[0022] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0023] It should be noted that, in this invention, the upper, lower, left, and right in the figure are regarded as the upper, lower, left, and right of the multi-functional packer with pressure drag fracturing described in this specification.

[0024] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0025] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0026] This embodiment relates to a multi-functional packer for live fracturing. Please refer to [link / reference].Figure 1 ,include: The components connected in sequence from top to bottom are: upper connector 2, water jet gun 3, release mechanism 4, connecting structure 5, pressure balancing mechanism 6, reverse anchoring mechanism 7, sealing unit 8, and lower connector 10. The outer wall of the sealing unit 8 is fitted with a forward anchoring mechanism 9.

[0027] During perforation, the hydraulic spray gun 3 provides a channel for the sand-carrying fluid, and through throttling, forms a high-speed jet that abrades the casing, thus completing the hydraulic jet perforation.

[0028] After the fracturing operation of the entire well section is completed, the release mechanism 4 is activated, allowing the retrieval of all tools and tubing above release mechanism 4. Please refer to [link / reference]. Figure 2 The dropping mechanism 4 includes an inner liner 401, a dropping glove 402, a locking ring 403, a dropping glove connector 404, and a sleeve 405.

[0029] The glove 402 is fitted onto the outer wall of the inner liner 401. The axial fit between the inner liner 401 and the glove 402 is limited by a shoulder, and the radial fit between the inner liner 401 and the glove 402 is through a hole shaft.

[0030] The locking ring 403 is fitted onto the outer wall of the inner liner 401 and is located below the glove 402. The inner liner 401 and the locking ring 403 are connected by scissor pins.

[0031] The dropper 404 is fitted onto the outer wall of the dropper 402, and the dropper 402 and the dropper 404 are connected by threads.

[0032] Sleeve 405 is fitted onto the outer wall of the drop glove 402 and locking ring 403.

[0033] A pressure transmission channel is left in the gap between the inner liner 401, the drop glove 402 and the sleeve 405 to transmit pressure when the locking ring 403 is activated, forming a pressure difference at the upper and lower ends, and shearing the shear pin to release the glove.

[0034] When the release mechanism 4 needs to be activated, a ball is dropped into the tubing string. During pumping pressure, a pressure difference is created at the upper and lower ends of the locking ring 403, pushing it downwards. The release sleeve 402 releases and retracts under the lifting action, disengaging from the sleeve 405, thus achieving the release function. After release, the sleeve 405 and locking ring 403 remain in the well, while other parts are retrieved from the well with the tubing.

[0035] The outer wall of the sleeve 405 is provided with barbs, which are suitable for retrieval and grabbing the remaining part of the drill string in the well after it has been lost.

[0036] Please see Figure 3The pressure balancing mechanism 6 includes a locking rod 601, a balance rod 602, a lock core 603, a spindle 604, a connecting sleeve 605, a balance sleeve 606, a push sleeve 607, a serrated sleeve 608, and a serrated ring 609, the specific structure of which is as follows.

[0037] The balance bar 602 has an axially hollow through cavity. In the axially hollow through cavity, a locking bar 601, a locking cylinder 603, and a spindle 604 are inserted sequentially from top to bottom. A connecting sleeve 605 and a balance sleeve 606 are sequentially fitted on the outer wall of the locking bar 601 from top to bottom. The connecting sleeve 605 and the balance bar 602 are connected by threads, the balance bar 602 and the spindle 604 are connected by threads, and the locking cylinder 603 and the balance bar 602 are connected by a locking claw to form a shoulder connection.

[0038] The locking rod 601 is threaded to the lower part of the inner bushing 401, and the locking rod 601 and the balance bar 602 are connected by a locking claw to form a shoulder connection.

[0039] The push sleeve 607 is fitted onto the outer wall of the connecting sleeve 605, and the push sleeve 607 and the sleeve 405 are connected by threads.

[0040] The serrated sleeve 608 is fitted onto the outer wall of the push sleeve 607.

[0041] The serrated ring 609 is fitted onto the outer wall of the balance sleeve 606, and the serrated ring 609 and the serrated sleeve 608 are connected by serrations.

[0042] During sandblasting and perforation, the pressure balancing mechanism 6 presses down on the mandrel 604 through the sealing unit 8, ensuring the mandrel 604 is sealed and guaranteeing smooth sandblasting and perforation. When transferring to the next layer under pressure after the next layer's pressure is exhausted, the pressure balancing mechanism 6 activates as the tubing string is lifted, balancing the pressure above and below the packer and thus successfully completing the tubing string transfer under pressure. When the reverse temporary plug is released after the well is sealed, the pressure balancing mechanism 6 activates, locking the balance rod 602 and lifting the tubing string to release the reverse temporary plug.

[0043] For details, please continue reading Figure 3 During construction, the pressure below sealing unit 8, i.e., the pump stop pressure of the previous layer, is transmitted through the pressure balance channel a of balance bar 602 to its inner chamber with balance sleeve 606, keeping mandrel 604 in a downward-pressurized sealing state. When the fracturing operation ends, the mandrel 604 can be moved upward by lifting the tubing string to disengage from the valve seat 11 of the multi-functional packer, achieving pressure balance between the upper and lower parts of the packer and completing the pressurized drag transfer. When the reverse temporary plugging is released after the well is closed, the sawtooth ring 609 is engaged with the sawtooth sleeve 608 by pressing down the tubing string, locking balance bar 602. Lifting the tubing string causes locking rod 601 to move upward, and locking claw of locking core 603 loses its restraint. After applying a certain hydraulic pressure at the upper end, it disengages from the inner shoulder of balance bar 602, thereby releasing the reverse temporary plugging effect.

[0044] During pressurized well blockage construction, the reverse anchoring mechanism 7 is activated to anchor the packer, achieving pipe string anchoring during temporary well blockage.

[0045] The sealing unit 8 is used to seal the lower constructed layers during sandblasting and fracturing operations.

[0046] Please see Figure 4 The sealing unit 8 includes a track tube 801. From top to bottom, an upper glue tube seat 802, a glue tube 803, a lower glue tube seat 804, a backstop ring 805, and a cone 806 are sequentially mounted on the outer wall of the track tube 801. The lower glue tube seat 804 is connected to the cone 806 by a thread, and the backstop ring 805 is connected to the track tube 801 by a thread.

[0047] That is, the track tube 801 and the upper glue tube seat 802 are connected to the packer part of the mechanism by threads, the glue tube 803 is placed between the upper glue tube seat 802 and the lower glue tube seat 804, the lower glue tube seat 804 is connected to the cone 806 by threads, and the anti-reverse ring 805 is connected to the track tube 801 by threads.

[0048] When the sealing unit 8 is activated and set, the positive anchoring mechanism 9 provides a positive anchoring force to achieve compression sealing of the sealing unit 8 and anchors the tubing string during injection and fracturing operations.

[0049] Please continue reading. Figure 4 The positive anchoring mechanism 9 includes a slip assembly, a stabilizer, a slip ring sleeve 902, and a sand guard 903, which are located below the cone 806 and are sequentially fitted onto the outer wall of the track tube 801 from top to bottom. The slip ring sleeve 902 and the sand guard 903 are connected by threads.

[0050] A gap is left between the slip ring sleeve 902 and the track tube 801. A switching ring 904 is sleeved in the gap. A switching pin 905 is installed in the inner wall hole of the switching ring 904. The slip ring sleeve 902 can drive the switching pin 905 to move linearly in the track groove of the track tube 801, so as to realize the switching groove action, the long groove is set and the short groove is unsealed.

[0051] That is, the switching pin 905 is placed in the hole of the switching ring 904 and installed between the slip ring sleeve 902 and the sandproof ring 903. When the construction pipe column is lifted and lowered, the slip ring sleeve 902 will drive the switching pin 905 to move linearly in the track groove of the track tube 801, realizing the switching groove action, the long groove is set and the short groove is unsealed.

[0052] Please continue reading. Figure 4The slip assembly includes slip 961, slip retaining ring 962, spring 963, and slip seat 964. Slip seat 964 is fitted onto the outer wall of track tube 801. Slip 961 is installed in a groove on the outer wall of slip seat 964. Slip retaining ring 962 is fitted into a groove on the outer wall of slip 961. Slip 961 and slip seat 964 are connected by a shoulder for limiting. Multiple first hollow protrusions are formed circumferentially at intervals on the lower section of slip 961. Spring 963 is installed within the first hollow protrusions. When slip 961 loses the constraint of cone 806, the slip sheet retracts under the preload of spring 963, releasing the anchor.

[0053] Please continue reading. Figure 4 The straightener includes a straightening block seat 971, a straightening block pressure ring 972, a straightening block 973, and a flat diameter spring 974.

[0054] The upper section of the straightening block seat 971 is fitted onto the outer wall of the slip seat 964 and the two are connected by threads, while the lower section is fitted tightly onto the outer wall of the track tube 801.

[0055] The straightening block 973 has multiple second hollow protrusions spaced circumferentially around the outer wall of the straightening block seat 971. The second hollow protrusions serve as the straightening blocks 973. A flat diameter spring 974 is installed inside the second hollow protrusion. That is, the flat diameter spring 974 is placed in the spring groove of the straightening block 973. Under the preload of the flat diameter spring 974, the straightening block 973 is made to fit against the sleeve wall for straightening.

[0056] The straightening block pressure ring 972 is fitted onto the outer wall of the straightening block seat 971, and the straightening block seat 971 and the straightening block pressure ring 972 are connected by welding.

[0057] The straightening block seat 971 is connected to the slip ring sleeve 902 by threads to fix the straightening block 973 and the flat diameter spring 974 inside the straightening block seat 971.

[0058] The centering block 973 contacts the inner wall of the casing and generates a certain frictional force. The upward or downward movement of the forward anchoring mechanism 9 can be controlled by lifting or lowering the tubing. When the slip 961 contacts the cone 806, it can be anchored to the inner wall of the casing under the weight of the tubing. The lower rubber sleeve seat 804 and the cone 806 move upward under the action of the forward anchoring mechanism 9 to compress the rubber sleeve 803, thereby achieving a seal with the inner wall of the rubber sleeve. The anti-reverse ring 805 serves to constrain the compression distance of the rubber sleeve. The outer circumference of the trajectory tube 801 is provided with a trajectory groove formed by controlling the action of the forward anchoring mechanism 9. During the lifting and lowering of the tubing, the sealing unit 8 is set and unsealed.

[0059] This embodiment also provides a construction method for a multi-functional packer for live fracturing, suitable for the aforementioned multi-functional packer for live fracturing. The construction method includes: Step 101: Connect the upper connector 2 of the pressurized drag fracturing multi-functional packer to the tubing 1 to form the target tubing string, and lower the target tubing string into the target wellbore.

[0060] Oil pipe 1 and upper connector 2 are connected by threads. Oil pipe 1 is an oil pipe with a coupling chamfer taper of less than 1:2. Each oil pipe 1 is connected to the other by a threaded seal.

[0061] Step 102: After the target tubing is lowered to the first designed position, the target tubing is lifted and lowered, and the forward anchoring mechanism 9 is activated to anchor the target tubing inside the target wellbore. The tubing is then pressed down to set the sealing unit 8 and seal the annular passage.

[0062] Step 103: Start the hydraulic spray gun 3 according to the designed displacement to perform spraying and perforation operation. At this time, the pressure balancing mechanism 6 is activated, so that the pressure balancing channel a inside the pressure balancing mechanism 6 is closed and the sealing unit 8 is effectively sealed.

[0063] The purpose of this step is to perform sandblasting and perforation. The oil pipe 1 is pumped with jet liquid according to the designed displacement, and the jetting and perforation operation is carried out through the water jet gun 3. At this time, the pressure balance mechanism 6 is activated, so that the mandrel 604 is kept in a downward sealing state, the pressure balance channel a is in a closed state, and the sealing unit 8 is effectively sealed.

[0064] Step 104, fracturing operation.

[0065] The fracturing operation is carried out according to the normal fracturing procedure, with an additional displacement of a certain amount of fluid on top of the conventional displacement fluid volume.

[0066] Step 105: Lift the target tubing, open the pressure balance channel a of the pressure balance mechanism 6, balance the upper and lower pressures of the sealing unit 8, lift and lower the target tubing, unseal the sealing unit 8, and at the same time, release the anchoring function of the positive anchoring mechanism 9, and the multi-functional packer for fracturing under pressure is in a free state.

[0067] Step 106: Activate the wellhead pressurized device to seal the annulus, and drag the target tubing to the next designed position under pressure to complete the pressurized transfer of the target tubing. At this time, the tubing 1 is in a sealed state.

[0068] Step 107: Repeat steps 102-106 to complete the fracturing construction at all designed locations, or in other words, until the fracturing construction at all construction layers is completed.

[0069] Step 108: Activate the wellhead pressurized device to seal the annulus, and drag the target tubing string under pressure to all designed positions, that is, drag the target tubing string under pressure to adjust the drill string to all construction layers.

[0070] Step 109: The purpose of this step is to set the sealing unit 8. After the target tubing is lowered to the first designed position, the target tubing is lifted and lowered, and the forward anchoring mechanism 9 is activated to anchor the target tubing inside the target wellbore. The target tubing is then pressed down to set the sealing unit 8 (i.e., the sealing unit 8 is compressed and in a sealed state), sealing the annular channel. At this time, the formation pressure at the lower end of the packer activates the reverse anchoring mechanism 7, thereby forming a bidirectional anchoring of the sealing unit 8.

[0071] Step 110: Throw the ball into the target tube. The ball is located in the inner cavity of the water jet gun 3. Pump and pressurize to start the release mechanism 4 and realize the release function.

[0072] Specifically, the ball is thrown into the tubing and located inside the hydraulic spray gun 3. The pump pressurizes and creates a pressure difference between the upper and lower ends of the locking ring 403 in the dropping mechanism 4, which pushes it downward. The dropping glove 402 is released and retracts under the lifting action, thus realizing the dropping function.

[0073] Step 111: At this point, there is no pressure at the wellhead. Pull out the target tubing above the release point.

[0074] The purpose of this step is to pull the drill string.

[0075] At this point, under the action of sealing unit 8, the target wellbore is sealed, there is no pressure at the wellhead, the tubing above the packer is pulled out, and the wellhead testing equipment is removed.

[0076] Step 112: Initiate the well sealing operation and carry out the well sealing operation according to the construction design.

[0077] Step 113: Open the venting channel by pumping water into the wellhead.

[0078] The purpose of this step is to release the spray.

[0079] By pumping water into the wellhead, the lock core 603 was removed, and the blowout channel was opened.

[0080] Step 114: Lower the drilling and retrieval tool, connect it with the barbs reserved in the connecting structure 5, and retrieve the remaining part of the drilling tools in the well.

[0081] The multi-functional packer for live fracturing has multiple functions, including hydraulic jet fracturing, live-draft formation transfer, post-fracturing release, and temporary well plugging. After the packer is drilled to the target formation, the sealing unit 8 is set and sealed by lifting and lowering the packer. Hydraulic jet perforation and fracturing of the formation are then performed using the hydraulic jet gun 3. After completion, the tubing string is lifted and lowered to release the sealing unit 8. In conjunction with the live-draft fracturing wellhead device, the tubing string is dragged to the next formation under pressure. The tubing string is then lifted and lowered again to set the sealing unit 8, and hydraulic jet perforation and fracturing of the formation are performed using the hydraulic jet gun 3. This process is repeated to complete the fracturing of all formations. After completion, a ball is dropped into the tubing string to pressurize it, the release mechanism 4 is activated, and the release mechanism 7 is activated through the pressure balancing mechanism 6 to form a reverse sealing state, with the wellhead fracturing at atmospheric pressure. Zero-pressure tripping is achieved, and the wellhead device is disassembled. After well plugging, the wellhead pump removes the lock core 603, opening the venting channel to begin venting. After the blowout, the drill string is lowered, and the barbs in the connecting sleeve grab the remaining drill string in the well.

[0082] The construction method of the multi-functional packer for live fracturing provided in this embodiment can solve the technical problem of pressure stagnation in the well testing equipment after live fracturing is completed, where the equipment is temporarily plugged and sealed under pressure. This method enables hydraulic jet fracturing, live-draft layer replacement, and release of the packer after fracturing to temporarily seal and seal the well, allowing for drilling at normal pressure at the wellhead. The live fracturing equipment can then be dismantled and transferred to the next well, effectively improving the operational efficiency of the live fracturing equipment, reducing construction costs, and facilitating the large-scale application of conventional tubing-transported live-draft jet fracturing technology.

[0083] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A multi-functional packer for pressurized fracturing, characterized in that, include: The components connected in sequence from top to bottom are: upper connector (2), water jet gun (3), release mechanism (4), connection structure (5), pressure balancing mechanism (6), reverse anchoring mechanism (7), sealing unit (8), and lower connector (10). The outer wall of the sealing unit (8) is fitted with a positive anchoring mechanism (9).

2. The multi-functional packer for fracturing under pressure as described in claim 1, characterized in that, The dropping mechanism (4) includes: Inner liner (401); The glove (402) is fitted onto the outer wall of the inner liner (401). The inner liner (401) and the glove (402) are axially fitted by a shoulder limiter, and the inner liner (401) and the glove (402) are radially fitted by a hole shaft. A locking ring (403) is fitted onto the outer wall of the inner liner (401), and the locking ring (403) is located below the drop glove (402). The inner liner (401) and the locking ring (403) are connected by scissor pins. The hand-drop connector (404) is fitted onto the outer wall of the hand-drop glove (402), and the hand-drop glove (402) and the hand-drop connector (404) are connected by threads; A sleeve (405) is fitted onto the outer wall of the drop glove (402) and the locking ring (403).

3. The multi-functional packer for live fracturing according to claim 2, characterized in that, The pressure balancing mechanism (6) includes: The balance bar (602) has an axially hollow through cavity. A locking rod (601), a locking core (603), and a spindle (604) are sequentially inserted into the axially hollow through cavity from top to bottom. A connecting sleeve (605) and a balance sleeve (606) are sequentially fitted onto the outer wall of the locking rod (601) from top to bottom. The connecting sleeve (605) and the balance bar (602) are connected by threads, and the balance bar (602) and the spindle (604) are connected by threads. The locking rod (601) is threaded to the lower part of the inner bushing (401), and the locking rod (601) and the balance bar (602) are connected by a locking claw to form a shoulder connection; A push sleeve (607) is fitted onto the outer wall of the connecting sleeve (605), and the push sleeve (607) and the sleeve (405) are connected by threads; A serrated sleeve (608) is fitted onto the outer wall of the push sleeve (607); A serrated ring (609) is fitted onto the outer wall of the balance sleeve (606), and the serrated ring (609) and the serrated sleeve (608) are connected by serrations.

4. The multi-functional packer for live fracturing according to claim 1, characterized in that, The sealing unit (8) includes: The track tube (801) has an upper rubber sleeve seat (802), a rubber sleeve (803), a lower rubber sleeve seat (804), a backstop ring (805), and a cone (806) sequentially mounted on its outer wall from top to bottom. The lower rubber sleeve seat (804) is connected to the cone (806) by a thread, and the backstop ring (805) is connected to the track tube (801) by a thread.

5. The multi-functional packer for live fracturing according to claim 4, characterized in that, The positive anchoring mechanism (9) includes: The slip assembly, the stabilizer, the slip ring sleeve (902) and the sand guard (903) are located below the cone (806) and are sequentially fitted onto the outer wall of the track tube (801) from top to bottom, wherein the slip ring sleeve (902) and the sand guard (903) are connected by threads; A gap is left between the slip ring sleeve (902) and the track tube (801). A switching ring (904) is sleeved in the gap. A switching pin (905) is installed in the inner wall hole of the switching ring (904). The slip ring sleeve (902) can drive the switching pin (905) to move linearly in the track groove of the track tube (801) to realize the switching groove action, the long groove is set and the short groove is unsealed.

6. The multi-functional packer for live fracturing according to claim 5, characterized in that, The slip assembly includes a slip (961), a slip retaining ring (962), a spring (963), and a slip seat (964). The slip seat (964) is fitted onto the outer wall of the track tube (801), the slip (961) is installed in the groove of the outer wall of the slip seat (964), and the slip retaining ring (962) is fitted into the groove of the outer wall of the slip (961). The slip (961) is connected to the slip seat (964) by a shoulder limit via the slip retaining ring (962); The lower section of the slip (961) has a plurality of first hollow protrusions spaced circumferentially. The spring (963) is installed in the first hollow protrusions. When the slip (961) loses the constraint of the cone (806), the tiles of the slip (961) contract under the preload of the spring (963), thus releasing the anchor.

7. The multi-functional packer for live fracturing according to claim 6, characterized in that, The stabilizer includes: The upper section of the straightening block (971) is fitted onto the outer wall of the slip seat (964) and the two are connected by threads, while the lower section is fitted tightly against the outer wall of the track tube (801). The straightening block (973) has multiple second hollow protrusions spaced circumferentially around the outer wall of the straightening block seat (971). The second hollow protrusions serve as the straightening block (973). A flat diameter spring (974) is built into the second hollow protrusion. Under the preload of the flat diameter spring (974), the straightening block (973) is made to fit against the sleeve wall for straightening. The straightening block pressure ring (972) is fitted onto the outer wall of the straightening block seat (971), and the straightening block seat (971) and the straightening block pressure ring (972) are connected by welding. The straightening block seat (971) is connected to the slip ring sleeve (902) by threads to fix the straightening block (973) and the flat diameter spring (974) inside the straightening block seat (971).

8. The multi-functional packer for live fracturing according to claim 2, characterized in that, The outer wall of the sleeve (405) is provided with barbs, which are suitable for retrieving the remaining part of the drill string in the well after it has been dropped.

9. A method for constructing a multi-functional packer for live fracturing, suitable for the multi-functional packer for live fracturing as described in any one of claims 1-8, characterized in that, include: Step 101: Connect the upper connector (2) of the pressurized drag fracturing multi-functional packer using the tubing (1) to form the target tubing string, and lower the target tubing string into the target wellbore; Step 102: After the target tubing is lowered to the first designed position, the target tubing is lifted and lowered, and the forward anchoring mechanism (9) is activated to anchor the target tubing in the target wellbore, and the sealing unit (8) is set to seal the annular channel. Step 103: Start the hydraulic spray gun (3) according to the designed displacement to perform spraying and perforation operation. At this time, the pressure balancing mechanism (6) is activated, so that the pressure balancing channel (a) in the pressure balancing mechanism (6) is closed, and the sealing unit (8) is effectively sealed. Step 104, fracturing operation; Step 105: Lift the target tubing, open the pressure balance channel (a) of the pressure balance mechanism (6), balance the upper and lower pressures of the sealing unit (8), lift and lower the target tubing, unseal the sealing unit (8), and at the same time, release the anchoring function of the positive anchoring mechanism (9), and the multi-functional packer for fracturing under pressure is in a free state. Step 106: Start the wellhead pressurized device to seal the annulus, drag the target tubing string to the next designed position under pressure, and complete the pressurized transfer of the target tubing string. At this time, the tubing (1) is in a sealed state. Step 107: Repeat steps 102-106 to complete the fracturing construction at all designed locations.

10. The construction method of the multi-functional packer for pressurized fracturing according to claim 9, characterized in that, Also includes: Step 108: Activate the wellhead pressurized device to seal the annulus, and drag the target tubing string under pressure to the designed position of all sections; Step 109: After the target tubing is lowered to the first designed position, the target tubing is lifted and lowered, and the forward anchoring mechanism (9) is activated to anchor the target tubing in the target wellbore, set the sealing unit (8), and seal the annular channel. At this time, the reverse anchoring mechanism (7) is activated to form bidirectional anchoring of the sealing unit (8). Step 110: Throw a ball into the target column. The ball is located in the inner cavity of the water jet gun (3). Pump and pressurize to start the release mechanism (4) to realize the release function. Step 111: At this point, there is no pressure at the wellhead. Pull out the target tubing string described above. Step 112: Initiate well shut-in operation; Step 113: Open the blowout channel by pumping water into the wellhead; Step 114: Lower the drilling and retrieval tool and connect it with the barbs reserved in the connecting structure (5) to retrieve the remaining part of the drilling tool in the well.

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