A retrievable packer service tool and method of use

Abstract

The application relates to a cuttable and retrievable packer running service tool and a use method thereof, which are used for oil and gas well completion. An anchoring sealing mechanism is connected between an upper joint and a lower joint of the application, and the anchoring sealing mechanism comprises a supporting sleeve, a central pipe, a sealing nipple, a split threaded claw and a sealing assembly. A cylindrical body of the split threaded claw is longitudinally slotted to form a threaded claw, and the threaded claw is provided with a first shoulder lower surface and a key groove. A torque transmission key is arranged on the supporting sleeve and matched with the key groove, a first shoulder upper surface is arranged on the supporting sleeve, and an outer circumferential surface of a lower part of the supporting sleeve is matched with an inner surface of a lower part of the split threaded claw. An outer pipe and a hanger ring are sleeved on the outside of the central pipe, and the outer pipe is connected with the hanger ring and the sealing nipple respectively. A step is arranged on the outer wall of the central pipe to form a second shoulder upper surface and a third shoulder lower surface. The distance between the third shoulder lower surface and the upper end surface of the sealing nipple is not less than 0.2 m. Since the central pipe and the outer pipe are arranged, the central pipe can be cut and the pipe string can be tripped when the pipe string tripping is unsuccessful.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of downhole packer in oilfield development, in particular to a cuttable and recyclable packer running service tool and its using method, which is used for permanent packer completion service in oil and gas well. BACKGROUND

[0002] In the oilfield completion process, there is a permanent packer completion process. The permanent packer is placed at the uppermost part of the completion string, and a set of running service tool is connected to the packer during completion to send the completion packer and other string components connected below it downhole. After the packer is set, the running service tool is released from the well. The running service tool is generally released by rotation, hydraulic pressure or a combination of the two. These release processes sometimes fail to release or release prematurely in field applications, resulting in completion failure and increasing operation cost. SUMMARY

[0003] In order to solve the above technical problems, a cuttable and recyclable packer running service tool and its using method are invented, which solves the problem of premature release or unsuccessful release of the running service tool in the current permanent packer completion process.

[0004] To achieve the above purpose, the present application adopts the following technical scheme:

[0005] A cuttable and recyclable packer running service tool, comprising an upper joint and a lower joint, an anchoring and sealing mechanism connected between the upper joint and the lower joint, the anchoring and sealing mechanism comprising a support sleeve, a central pipe, a sealing nipple, and a split thread claw sleeved on the outside of the support sleeve and a sealing assembly sleeved on the outer periphery of the sealing nipple; the split thread claw is a cylindrical body, the cylindrical wall is longitudinally slotted to form a thread claw, a first shoulder lower surface is arranged at the upper part of the cylinder, and a key groove is arranged on the split thread claw; a torque transmission key is arranged on the support sleeve and matched with the key groove arranged on the split thread claw, a first shoulder upper surface is arranged on the support sleeve, and the outer periphery of the lower part of the support sleeve is matched with the inner surface of the lower part of the split thread claw, and the matched surfaces are cylindrical or conical; an outer pipe and an upper hanging ring are sleeved on the outside of the central pipe, and the outer pipe is connected with the upper hanging ring and the sealing nipple respectively; a step is arranged on the outer wall of the central pipe to form a second shoulder upper surface and a third shoulder lower surface, the second shoulder upper surface is opposite to the second shoulder lower surface arranged on the upper part of the inner periphery of the upper hanging ring, and the third shoulder lower surface is opposite to the upper end surface of the sealing nipple; the distance between the third shoulder lower surface and the upper end surface of the sealing nipple is not less than 0.2m.

[0006] As a preferred embodiment, the distance between the third shoulder lower surface and the upper end surface of the sealing nipple is 0.4-0.7m.

[0007] Further, the key groove on the split threaded claw is located above the first shoulder, the torque transmission key is torque transmission key one, which is arranged above the first shoulder on the outer periphery of the support sleeve, the key groove is matched with the torque transmission key one, and the length of the torque transmission key one is greater than that of the key groove. Alternatively, the torque transmission key is torque transmission key two, which is arranged on the cylindrical surface or the conical surface matched with the split threaded claw on the lower part of the support sleeve, and the torque transmission key two is arranged in the longitudinal slot of the split threaded claw.

[0008] Further, the upper joint is threadedly connected with the shear pin sleeve at the outer periphery of the lower part, the shear pin is arranged in the lower part in the radial direction, and the outer end of the shear pin extends into the shear pin hole of the insertion sealing cylinder. The releasing thread on the split threaded claw is a conical thread, and the thread taper is 1:16.

[0009] A method for using a cuttable and retrievable packer running-in service tool, comprising the following steps:

[0010] a. The cuttable and retrievable packer running-in service tool is connected with the packer, and the completion string is lowered into the well at a predetermined position by tubing;

[0011] b. The hydraulic setting packer is set in the tubing;

[0012] c. One of the following two releasing modes is selected for releasing:

[0013] (a) The releasing thread on the split threaded claw is withdrawn from the packer by rotating the string in the positive direction;

[0014] (b) The cutting tool is lowered into the tubing to a position below the third shoulder of the central pipe, the central pipe is cut off, the cutting tool is withdrawn, and the string is lifted to release the releasing thread from the inner support of the support sleeve.

[0015] Compared with the prior art, the packer running-in service tool has the following advantages:

[0016] The releasing process of the packer running-in service tool is reliable, and the problems of early releasing or unsuccessful releasing in the prior art are solved.

[0017] There are two cases of early releasing, one is that the hydraulic pressure in the tubing is too large when the tool is lowered into the well, and the releasing piston is released early due to the action of the excessive hydraulic pressure; the other is that the lower part of the completion string is rotated during the lowering process, so that the connecting thread of the running-in tool is released early due to the reverse buckling. The two problems of early releasing are solved by the packer running-in service tool, one is that the hydraulic releasing scheme is no longer used, thereby avoiding the problem of early releasing of the hydraulic mechanism, and the other is that the anti-reverse buckling shear pin is arranged between the upper joint and the insertion sealing cylinder, thereby solving the problem of early reverse buckling of the connecting thread.

[0018] There are many reasons for unsuccessful releasing, and the prior art is often difficult to solve after unsuccessful releasing, and can only re-complete the well. The scheme of the present application can use downhole cutting releasing process to release again after unsuccessful back-off. When unsuccessful back-off occurs, a mechanical, hydraulic or chemical cutting tool is lowered into the tubing, the central pipe is cut off, and then the tubing is pulled up or rotated to pull up the tubing for releasing again.

[0019] The technical scheme of the present application will be further described below in combination with the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0020] When considered in combination with the accompanying drawings, the present application can be more completely understood and readily ascertained by reference to the following detailed description, many of which accompanying advantages will be more fully understood and appreciated by reference to the following detailed description, taken in conjunction with the accompanying drawings, which are included as a part hereof, and by reference to the representative embodiments, to explain the present application and, which do not limit the present application.

[0021] Figure 1 is a structure diagram of a cuttable and recoverable packer running-in service tool of the present application.

[0022] Figure 2 is a structure diagram of a split thread claw.

[0023] Figure 3 is Figure 1 is a cross-sectional structure diagram at A-A in the middle.

[0024] Figure 4 is a structure diagram of the assembly of the support sleeve and the split thread claw, and the structure of the second torque key is shown in the figure.

[0025] In the figure: 1 - upper joint, 2 - shear pin sleeve, 3 - support sleeve, 3-1 first torque key, 3-2 upper surface of first shoulder, 3-3 outer conical surface, 3-4 second torque key, 4 - shear pin, 5 - split thread claw, 5-1 key groove, 5-2 inner conical surface, 5-3 releasing thread, 5-4 lower surface of first shoulder, 6 - insertion sealing cylinder, 7 - upper hanging ring, 7-1 lower surface of second shoulder, 8 - central pipe, 8-1 upper surface of second shoulder, 8-2 lower surface of third shoulder, 9 - outer pipe, 10 - sealing short section, 11 - sealing assembly, 12 - lower joint. DETAILED DESCRIPTION

[0026] In the present application specification and claims, "upper" and "lower" in the positional relationship are described in the state of use of the tool, and the sealing ring is shown in the figure, and will not be described one by one in the following description.

[0027] In the permanent or semi-permanent packer completion string, the permanent or semi-permanent packer is placed at the top of the completion string as a hanging packer. For the hydraulic permanent or semi-permanent packer, a running service tool is needed to complete the string running, packer setting and releasing. An insertion sealing cylinder is generally arranged at the upper part of the packer for connection and sealing with the running service tool. For the large inner diameter packer, the insertion sealing cylinder can be omitted and the running service tool is directly sealed with the inner wall of the central pipe. Figure 1 The insertion sealing cylinder 6 is shown in Figure 1 The insertion sealing cylinder 6 is shown in

[0028] Referring to Figure 1 , Figure 2 and Figure 3 , a cuttable and recoverable packer running service tool of the present application is connected between the upper joint 1 and the lower joint 12, and the anchoring sealing mechanism comprises a support sleeve 3, a central pipe 8, a sealing nipple 10 connected in sequence, and a split thread claw 5 sleeved on the outside of the support sleeve and a sealing assembly 11 sleeved on the outer periphery of the sealing nipple.

[0029] The split thread claw is a cylindrical body, the cylindrical wall is longitudinally slotted to form the thread claw, and a first shoulder upper surface 5-4 is arranged at the upper part of the inner cavity of the cylindrical body. A key groove is arranged on the split thread claw, and a torque transmission key is arranged on the support sleeve to match the key groove of the split thread claw to realize torque transmission.

[0030] A first shoulder lower surface 3-2 is arranged on the support sleeve, and the outer periphery of the lower part of the support sleeve matches the inner surface of the lower part of the split thread claw, and the matching surface is cylindrical or conical, Figure 1 The outer conical surface 3-3 is shown in Figure 2 The inner conical surface 5-2 is shown in. When the split thread claw is subjected to a radial inward thrust in the state shown in Figure 1 , the split thread claw will not release. When the support sleeve is lifted and the split thread claw loses internal support, the split thread claw will release when subjected to a radial inward thrust.

[0031] An outer pipe 9 and an upper hanging ring 7 are sleeved on the outside of the central pipe, and the upper and lower parts of the outer pipe are connected with the upper hanging ring and the sealing nipple respectively. A step is arranged on the outer wall of the central pipe to form a second shoulder upper surface 8-1 and a third shoulder lower surface 8-2, the second shoulder upper surface matches a second shoulder lower surface 7-1 arranged on the inner periphery of the upper part of the upper hanging ring, and the third shoulder lower surface matches the upper end surface of the sealing nipple. The distance L between the third shoulder lower surface and the upper end surface of the sealing nipple is not less than 0.2 m, and in order to facilitate positioning of the cutting operation, the distance L between the third shoulder lower surface and the upper end surface of the sealing nipple is preferably 0.4-0.7 m. The cutting operation of the central pipe should be such that the cutting tool is located between the third shoulder lower surface and the upper end surface of the sealing nipple.

[0032] The keyway and keyway can be matched as follows: the keyway 5-1 is located above 5-4 below the first shoulder. The keyway is keyway 3-1, which is located above 3-2 above the first shoulder on the outer circumference of the support sleeve. The keyway 5-1 and keyway 3-1 are matched. In order to ensure that the support sleeve can still transmit the torque to the split thread claw when the pipe column is lifted and torque is applied after cutting the center pipe, the length of keyway 3-1 should be greater than the length of keyway 5-1.

[0033] The interaction between the key and the keyway can also be achieved in the following way: See Figure 4 As shown, the key for transmitting torque is key two 3-4. Key two is disposed on the cylindrical or conical surface of the lower part of the support sleeve that mates with the split threaded claw. Key two is placed in the longitudinal groove of the split threaded claw cylinder wall. Here, the longitudinal groove of the split threaded claw cylinder wall serves as a keyway.

[0034] Furthermore, in order to prevent the split threaded claws from disengaging during the installation of the completion tubing, the lower outer periphery of the upper connector is threadedly connected to the shearing pin sleeve 2, and the lower part of the shearing pin sleeve is radially provided with shearing pins 4. The insert sealing cylinder 6 is provided with shearing pin holes, and the outer end of the shearing pin extends into the shearing pin holes of the insert sealing cylinder 6.

[0035] The drop-off thread 5-3 on the split threaded claw can be any known left-hand thread, with a thread profile angle greater than 29°. Its thread profile can be trapezoidal, triangular, or any other thread with a thread profile angle greater than 29°. For ease of drop-off, the drop-off thread 5-3 on the split threaded claw is preferably a tapered thread with a taper of 1:16.

[0036] The method of using the tool of this invention includes the following steps:

[0037] a. The cuttable and recyclable packer is sent into the service tool and connected to the packer. The completion string is then lowered into the well to the predetermined position using tubing.

[0038] b. Install a hydraulic packer inside the oil pipe;

[0039] c. Choose one of the following two ways to drop your hand:

[0040] (a) Rotate the tubing forward to disengage the release thread 5-3 on the split threaded claw from the packer;

[0041] (b) Lower the cutting tool into the tubing to a position 8-2 below the third shoulder of the central tube, cut the central tube, remove the cutting tool, and lift the tubing string so that the slip thread loses the inner support of the support sleeve and slips.

[0042] The current tubing cutting process mainly includes chemical cutting, mechanical cutting and hydraulic cutting. In field operation, generally, the tubing string is first selected to rotate in the positive direction to release the string, and if unsuccessful, the cutting release is selected.

[0043] After the central pipe is cut, the tubing string is pulled up, the upper joint, the support sleeve and the upper central pipe are pulled up together, the 3-2 on the upper surface of the first shoulder is hung on the 5-4 on the lower surface of the first shoulder, at this time, the split thread claw loses internal support, and the pulling force makes the split thread claw be subjected to a radial inward thrust to release the string; the tubing string is continuously pulled up, the 8-1 on the upper surface of the second shoulder is hung on the 7-1 on the lower surface of the second shoulder, and the outer pipe and the connected sealing nipple, the lower central pipe and the lower joint are pulled out of the wellbore.

[0044] If the tubing string cannot be released after the central pipe is cut, the tubing string can be rotated in the positive direction, the split thread claw is rotated through the torque key, and the release is realized by causing the split thread claw to be loose.

[0045] Obviously, many modifications and changes made by those skilled in the art based on the purpose of the present application belong to the protection scope of the present application.

Claims

1. A retrievable packer running service tool, comprising an upper sub (1) and a lower sub (12), characterized in that, The anchor sealing mechanism is connected between the upper joint and the lower joint, and comprises a support sleeve (3), a central pipe (8), a sealing nipple (10) connected in sequence, a split thread claw (5) sleeved outside the support sleeve, and a sealing assembly (11) sleeved outside the sealing nipple; the split thread claw is a cylindrical body, a thread claw is formed by longitudinally slotting the cylindrical wall, a first shoulder lower surface (5-4) is arranged at the upper part of the cylinder, a key groove is arranged on the split thread claw; a torque transmission key is arranged on the support sleeve and matches the key groove arranged on the split thread claw, a first shoulder upper surface (3-2) is arranged on the support sleeve, the outer peripheral surface of the lower part of the support sleeve matches the inner surface of the lower part of the split thread claw, and the matching surfaces are cylindrical or conical; an outer pipe (9) and a hanger ring (7) are sleeved outside the central pipe, the outer pipe is connected with the hanger ring and the sealing nipple respectively; steps are arranged on the outer wall of the central pipe to form a second shoulder upper surface (8-1) and a third shoulder lower surface (8-2), the second shoulder upper surface is opposite to a second shoulder lower surface (7-1) arranged on the upper inner periphery of the hanger ring, and the third shoulder lower surface is opposite to the upper end surface of the sealing nipple; The distance between the third shoulder lower surface and the upper end surface of the sealing nipple is 0.4-0.7 m; The key groove (5-1) arranged on the split thread claw is located above the first shoulder lower surface, the torque transmission key is torque transmission key one (3-1), torque transmission key one (3-1) is arranged on the outer periphery of the support sleeve above the first shoulder upper surface (3-2), the key groove (5-1) matches torque transmission key one (3-1), and the length of torque transmission key one (3-1) is greater than the length of the key groove (5-1); The lower part of the outer periphery of the upper joint is threadedly connected with a shear pin sleeve (2), a shear pin (4) is arranged radially on the lower part of the shear pin sleeve, and the outer end of the shear pin extends into a shear pin hole of a sealing cylinder (6); The release thread (5-3) on the split thread claw is a conical thread, and the thread taper is 1:

16.

2. A retrievable packer running service tool, comprising an upper sub (1) and a lower sub (12), characterized in that, The anchor sealing mechanism is connected between the upper joint and the lower joint, and comprises a support sleeve (3), a central pipe (8), a sealing nipple (10) connected in sequence, a split thread claw (5) sleeved outside the support sleeve, and a sealing assembly (11) sleeved outside the sealing nipple; the split thread claw is a cylindrical body, a thread claw is formed by longitudinally slotting the cylindrical wall, a first shoulder lower surface (5-4) is arranged at the upper part of the cylinder, a key groove is arranged on the split thread claw; a torque transmission key is arranged on the support sleeve and matches the key groove arranged on the split thread claw, a first shoulder upper surface (3-2) is arranged on the support sleeve, the outer peripheral surface of the lower part of the support sleeve matches the inner surface of the lower part of the split thread claw, and the matching surfaces are cylindrical or conical; an outer pipe (9) and a hanger ring (7) are sleeved outside the central pipe, the outer pipe is connected with the hanger ring and the sealing nipple respectively; steps are arranged on the outer wall of the central pipe to form a second shoulder upper surface (8-1) and a third shoulder lower surface (8-2), the second shoulder upper surface is opposite to a second shoulder lower surface (7-1) arranged on the upper inner periphery of the hanger ring, and the third shoulder lower surface is opposite to the upper end surface of the sealing nipple; The distance between the third shoulder lower surface and the upper end surface of the sealing nipple is 0.4-0.7 m; The torque transmission key is a torque transmission key two (3-4), the torque transmission key two is arranged on the cylindrical surface or the conical surface of the lower part of the support sleeve and cooperates with the split thread claw, and the torque transmission key two is arranged in the longitudinal slot of the split thread claw cylinder wall; The outer periphery of the lower part of the upper joint is threadedly connected with the shear pin sleeve (2), the shear pin sleeve is radially provided with a shear pin (4) at the lower part, and the outer end of the shear pin extends into the shear pin hole of the insertion sealing cylinder (6); The release thread (5-3) on the split thread claw is a conical thread, and the thread taper is 1:

16.

3. The use method of the cuttably-retrievable packer running service tool according to claim 1 or 2, comprising the following steps: a. The cuttably-retrievable packer running service tool is connected with the packer, and the completion string is lowered into the well to the predetermined position by the tubing; b. The hydraulic pressure is pumped into the tubing to set the packer; c. One of the following two release modes is selected to release: (a) The positive rotation of the string makes the release thread (5-3) on the split thread claw exit from the packer; (b) The cutting tool is lowered into the tubing to the position below the third shoulder (8-2) of the center tube, the center tube is cut, the cutting tool is pulled out, the string is pulled up, the release thread loses the inner support of the support sleeve, and the release is achieved.

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