Removable bridge plug and bridge plug setting tool

Abstract

The invention relates to a removable bridge plug and a bridge plug setting tool, and relates to the technical field of oil exploitation equipment. The upper end of the mandrel assembly is connected with a bridge plug setting tool; the inner central pipe is arranged on the periphery of the mandrel assembly in a sleeving manner; the balance pipe is arranged on the periphery of the mandrel assembly in a sleeving mode, one end of the balance pipe is fixedly connected with one end of the inner center pipe, and the other end of the balance pipe is fixed to the periphery of the mandrel assembly; the balance sliding sleeve valve is arranged on the periphery of the balance pipe in a sleeving manner and is in sliding connection with the balance pipe; the balance sliding sleeve valve shear pin is arranged on the peripheries of the balance sliding sleeve valve and the balance pipe in a penetrating manner; and the sealing mechanism is arranged on the periphery of the inner center pipe in a sleeving mode and fixed to the other end of the inner center pipe, and a communication channel is formed between the inner center pipe and the balance pipe and the mandrel assembly. According to the balance sliding sleeve valve, the other end of the communication channel can be communicated with the upper annulus. Therefore, the lower entrapment pressure can be released to the upper channel through the communication channel before the removable bridge plug is salvaged.

Description

Technical Field

[0001] The invention relates to the technical field of oil production equipment, in particular to a removable bridge plug and a bridge plug setting tool. Background Art

[0002] Bridge plug is an important tool for sealing oil layer in casing. Its main component is rubber tube, which expands and seals the annular space between oil pipe and casing through hydraulic or mechanical action, and separates the upper and lower oil layers, so as to achieve the construction purpose. This is the main function of bridge plug. There are many types of bridge plugs, which can be divided into two types according to their removal methods, namely removable bridge plugs and permanent bridge plugs.

[0003] There are many removable bridge plug structures currently used on site. When the bridge plug isolates the lower oil and gas layer for a period of time, there will be a trapped pressure under the bridge plug. When the bridge plug needs to be unsealed, the trapped pressure under the bridge plug cannot be released. In the process of salvaging the bridge plug, the trapped pressure may push up the unsealing string, causing the unsealing string to move upward, thus causing a safety accident.

[0004] That is to say, in the prior art, there is a problem of the unsealing pipe column moving upward when salvaging the bridge plug. Summary of the invention

[0005] The invention provides a retrievable bridge plug and a bridge plug setting tool, which are used to solve the problem of upward movement of an unsealed pipe column when salvaging the bridge plug.

[0006] The present invention provides a removable bridge plug, which is used for setting and sealing an oil pipe and comprises:

[0007] a mandrel assembly, the upper end of which is connected to a bridge plug setting tool; and

[0008] an inner center tube sleeved on the outer circumference of the mandrel assembly; and

[0009] A balance tube, which is sleeved on the outer circumference of the core shaft assembly, one end of which is fixedly connected to one end of the inner center tube, and the other end of the balance tube is fixed on the outer circumference of the core shaft assembly; and

[0010] A balanced sleeve valve is sleeved on the outer periphery of the balanced pipe, close to the end where the balanced sleeve valve is fixed to the core shaft assembly, and the balanced sleeve valve is slidably connected to the balanced pipe; and

[0011] Balance sleeve valve shear pins, which are inserted into the outer periphery of the balance sleeve valve and the balance pipe and are used to fix the balance sleeve valve;

[0012] A sealing mechanism is sleeved on the outer circumference of the inner center tube and fixed to the other end of the inner center tube;

[0013] Among them, when the sealing mechanism is seated in the oil pipe, it separates the central hole channel of the oil pipe into an upper channel and a lower channel which are not connected to each other. A connecting channel is provided between the inner center pipe, the balancing pipe and the core shaft assembly, and one end of the connecting channel is connected to the lower channel. Pressing down the balancing sleeve valve can shear off the shear pins of the balancing sleeve valve and make the balancing sleeve valve slide toward the sealing mechanism in a first direction. When the balancing sleeve valve slides to contact with the sealing mechanism, the balancing sleeve valve connects the other end of the connecting channel with the upper annulus.

[0014] In one embodiment, a balanced drain hole is provided on the outer periphery of the balanced sleeve valve, one end of the balanced drain hole is connected to the upper channel, and when the balanced sleeve valve slides to contact with the sealing mechanism, the other end of the balanced drain hole is connected to the other end of the connecting channel.

[0015] In one embodiment, the sealing mechanism comprises:

[0016] a driving bushing assembly, which is sleeved on the outer circumference of the inner center tube and is slidably connected to the inner center tube; and

[0017] a slip anchor assembly, which is sleeved on the outer circumference of the drive bushing assembly and is slidably connected to the drive bushing assembly; and

[0018] an adjusting assembly, one end of which is threadedly connected to one end of the slip anchor assembly, and the other end of which is fixed to the other end of the inner center tube and is capable of pressing the other end of the inner center tube onto the mandrel assembly; and

[0019] A rubber cartridge assembly is sleeved on the outer periphery of the drive bushing assembly and is placed on the slip anchor assembly;

[0020] The driving bushing assembly can drive the slip anchor assembly to be locked in the oil pipe by sliding downward, and can squeeze the rubber cylinder assembly to expand and seal it in the oil pipe.

[0021] In one embodiment, the drive bushing assembly comprises:

[0022] A setting push cylinder is sleeved on the balance pipe and the inner center pipe and is slidably connected with the balance pipe and the inner center pipe; and

[0023] The outer center tube is sleeved on the outer circumference of the inner center tube and is slidably connected to the inner center tube. One end of the outer center tube is connected to the setting push tube.

[0024] A locking assembly is arranged in a mounting groove formed between the setting push tube and the outer center tube;

[0025] An adjusting bearing cap is threadedly connected to the setting push cylinder, and the adjusting bearing cap can push the rubber cylinder assembly to slide;

[0026] Among them, the outer center tube is arranged in the annular gap between the cava anchor assembly and the rubber cartridge assembly and the inner center tube. When the bearing cap is adjusted to drive the cava anchor assembly to be locked in the oil pipe, and the rubber cartridge assembly is squeezed to expand and seal in the oil pipe, the locking assembly is locked on the outer periphery of the inner center tube.

[0027] In one embodiment, locking teeth are provided on the outer circumference of the inner central tube, and the locking assembly comprises:

[0028] A locking ring sleeve is sleeved in the mounting groove; and

[0029] A lock ring, which is sleeved on the outer circumference of the lock ring sleeve;

[0030] The locking ring can be locked on the locking teeth, and the locking ring sleeve contacts the locking ring to limit the position where the setting push cylinder slides upward.

[0031] In one embodiment, the mandrel assembly comprises:

[0032] a release bolt, one end of which is threadedly connected to the bridge plug setting tool; and

[0033] a positioning mandrel having one end connected to the other end of the release bolt; and

[0034] A mandrel, one end of which is threadedly connected to the other end of the positioning mandrel;

[0035] Among them, there is an annular space channel between the positioning core shaft and the balancing pipe, and a drainage channel is provided between the positioning core shaft and the inner center pipe, one end of the drainage channel is connected with one end of the annular space channel, and the other end of the drainage channel is connected with the lower channel; when the balancing sleeve valve slides to contact with the rubber cartridge assembly, the other end of the balancing drainage hole is connected with the other end of the drainage channel; when the cava anchoring assembly is locked in the oil pipe and the rubber cartridge assembly is expanded and sealed in the oil pipe, the lifting bridge plug sealing tool can cut off the release bolt to realize the release of the bridge plug sealing tool and the removable bridge plug.

[0036] In one embodiment, a slide groove is provided on the core shaft, a slide hole corresponding to the slide groove is provided on the inner center tube, a screw pin is provided in the rubber cylinder assembly, the screw pin passes through the slide hole and extends into the slide groove, the screw pin is slidably connected to the slide hole and the slide groove, the other end of the balance tube is detachably fixed to the outer periphery of the positioning core shaft, and the other end of the inner center tube is detachably fixed to the outer periphery of the core shaft.

[0037] In one embodiment, a first annular positioning groove is provided on the positioning core shaft, and the other end of the balancing tube is provided as an elastic claw which is inserted into the first annular positioning groove. A second annular positioning groove is provided on the other end of the adjusting assembly, and the other end of the inner center tube is provided as an elastic claw which is inserted into the second annular positioning groove. The adjusting assembly can press the other end of the inner center tube against the outer periphery of the core shaft. The removable bridge plug also includes a salvage and unsealing sleeve which is fixed to the positioning core shaft by unsealing shear pins. The salvage and unsealing sleeve can press the other end of the balancing tube into the first annular positioning groove.

[0038] In one embodiment, a card slot connected to the unsealing pipe column is provided on the outer periphery of the salvage unsealing sleeve, and the retrievable bridge plug also includes a reverse nut, which is threadedly connected to one end of the positioning core shaft, and a release bolt is passed through the reverse nut, wherein lifting the salvage unsealing sleeve can shear off the unsealing shear pin, and the salvage unsealing sleeve can slide upward and come into contact with the reverse nut, and continuing to lift the salvage unsealing sleeve can drive the core shaft assembly to slide upward to recover the retrievable bridge plug.

[0039] The present invention further provides a bridge plug setting tool, which is used to drive the removable bridge plug according to any one of claims 1 to 9 to be set in an oil pipe, and the bridge plug setting tool comprises:

[0040] A mandrel bushing, one end of which is connected to the delivery column, and the other end of which is connected to the upper end of the mandrel assembly, the mandrel bushing having a central pressure chamber; and

[0041] a stop piston fixed to the outer periphery of the spindle bushing; and

[0042] an outer bushing which is sleeved on the outer circumference of the stop piston and is slidably connected with the stop piston; and

[0043] A driving piston slidably disposed on the outer periphery of the spindle bushing;

[0044] Among them, the core shaft bushing, the stop piston, the external bushing and the removable bridge plug are arranged to form an annular cavity, and the driving piston divides the annular cavity into a first cavity and a second cavity. A punching hole is arranged on the first cavity, and the punching hole is connected with the central punching cavity. The first cavity can be pressed through the central punching cavity and the punching hole, so that the driving piston pushes the external bushing downward to slide.

[0045] Compared with the prior art, the advantage of the present invention is that before the removable bridge plug is salvaged, the balanced sleeve valve is pressed down to cut off the shear pins of the balanced sleeve valve, and the balanced sleeve valve is pressed down continuously, so that the balanced sleeve valve slides downward until it contacts with the sealing mechanism, and the sealing mechanism realizes the sliding positioning of the balanced sleeve valve, thereby ensuring that when the balanced sleeve valve slides to the positioning position, the balanced sleeve valve can connect the other end of the connecting channel with the upper annulus. Thus, it is ensured that the lower trapped pressure of the removable bridge plug can be released to the upper channel through the connecting channel before the removable bridge plug is salvaged. Thus, when the removable bridge plug is salvaged, the lower trapped pressure has been completely released and will not push up to unseal the pipe column. Thus, the potential safety hazards of on-site operations are reduced, thereby ensuring the safety of on-site operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Hereinafter, the present invention will be described in more detail based on embodiments and with reference to the accompanying drawings.

[0047] Figure 1 1 is a schematic diagram of the structure of a removable bridge plug in the first embodiment of the present invention (showing the oil pipe);

[0048] Figure 2 yes Figure 1 Schematic diagram of the center positioning mandrel;

[0049] Figure 3 yes Figure 1 Schematic diagram of the balanced sleeve valve;

[0050] Figure 4 yes Figure 1 Schematic diagram of the balance pipe;

[0051] Figure 5 yes Figure 1 Schematic diagram of the central axis;

[0052] Figure 6 yes Figure 1 Schematic diagram of the central tube in the middle;

[0053] Figure 7 yes Figure 1 Schematic diagram of the central tube in China and abroad;

[0054] Figure 8 yes Figure 1 Schematic diagram of adjusting the guide head;

[0055] Fig. 9 yes Figure 1 Schematic diagram of the middle locking ring;

[0056] Fig.10 yes Fig. 9 Side view of the middle lock ring;

[0057] Fig.11 yes Figure 1 Schematic diagram of the release flow of the medium trap pressure (the direction of the arrow is the flow direction of the trap pressure, and the balance drain hole is connected to the connecting channel at this time);

[0058] Fig.12 Schematic diagram of the structural composition of the bridge plug setting tool in the second embodiment of the present invention (showing a part of the removable bridge plug);

[0059] Fig.13 yes Fig.12 Schematic diagram of the connection relationship between the bridge plug setting tool and the removable bridge plug in Example 1 (showing a portion of the removable bridge plug).

[0060] Reference numerals:

[0061] 10. Mandrel assembly; 11. Release bolt; 12. Positioning mandrel; 121. First annular positioning groove; 13. Mandrel; 131. Slide groove; 132. Milling groove; 20. Inner center tube; 21. Slide hole; 30. Balance pipe; 40. Balance sleeve valve; 41. Balance drain hole; 50. Balance sleeve valve shear pin; 60. Sealing mechanism; 61. Drive bushing assembly; 611. Setting push cylinder; 612. Outer center tube; 613. Locking assembly; 6131. ​​Locking ring sleeve; 6132. Locking ring; 614. Adjusting bearing cap; 615. Setting shear pin; 62. Slip anchor assembly; 621. Slip support; 622. Slip; 623. Upper wedge; 624. Lower wedge; 625. Screw pin; 63. Adjusting assembly; 631. Second Annular positioning groove; 632, adjustment sleeve; 633, adjustment guide head; 634, set screw; 64, rubber cartridge assembly; 70, connecting channel; 71, annular space channel; 72, drainage channel; 80, unsealing shear nail; 90, reverse thread nut; 100, removable bridge plug; 110, salvage unsealing sleeve; 111, slot; 200, casing; 300, bridge plug setting tool; 301, core shaft bushing; 3011, upper connector; 3012, lower connector; 3013, connecting pipe; 302, external bushing; 3021, first pipe sleeve; 3022, second pipe sleeve; 3023, connecting pipe sleeve; 303, driving piston; 304, stop piston; 305, driving bushing; 306, first pressure hole; 307, second pressure hole. DETAILED DESCRIPTION

[0062] The present invention will be further described below in conjunction with the accompanying drawings.

[0063] Embodiment 1

[0064] The present invention provides a removable bridge plug 100 , which is used for setting a casing 200 .

[0065] Combine the following Figures 1 to 11The removable bridge plug 100 in this embodiment is described below. The removable bridge plug 100 includes a mandrel assembly 10, an inner center pipe 20, a balance pipe 30, a balance sleeve valve 40 and a balance sleeve valve shear pin 50. A core shaft assembly 10, the upper end of which is connected to a bridge plug sealing tool 300; an inner center pipe 20, which is sleeved on the outer circumference of the core shaft assembly 10; a balancing pipe 30, which is sleeved on the outer circumference of the core shaft assembly 10, one end of which is fixedly connected to one end of the inner center pipe 20, and the other end of the balancing pipe 30 is fixed to the outer circumference of the core shaft assembly 10; a balancing sleeve valve 40, which is sleeved on the outer circumference of the balancing pipe 30, and is close to the end of the balancing sleeve valve 40 fixed to the core shaft assembly 10, and the balancing sleeve valve 40 is slidably connected to the balancing pipe 30; a balancing sleeve valve shear pin 50, which is penetrated on the outer circumference of the balancing sleeve valve 40 and the balancing pipe 30, and is used to fix the balancing sleeve valve 40; a sealing mechanism 60, which is sleeved on the outer circumference of the inner center pipe 20 and fixed to the other end of the inner center pipe 20.

[0066] When the sealing mechanism 60 is set in the casing 200, it separates the central hole channel of the casing 200 into an upper channel and a lower channel that are not connected to each other. A communication channel 70 is provided between the inner center tube 20 and the balance tube 30 and the core shaft assembly 10. One end of the communication channel 70 is connected to the lower channel. Pressing down the balance sleeve valve 40 can shear off the balance sleeve valve shear pin 50 and make the balance sleeve valve 40 move in the first direction ( Figure 1 When the balanced sleeve valve 40 slides to contact with the sealing mechanism 60, the balanced sleeve valve 40 connects the other end of the communication channel 70 with the upper annulus.

[0067] In the above arrangement, before the removable bridge plug 100 is salvaged, the balanced sleeve valve 40 is pressed down to cut off the balanced sleeve valve shear pin 50, and the balanced sleeve valve 40 is pressed down continuously, so that the balanced sleeve valve 40 slides downward until it contacts and abuts against the sealing mechanism 60, that is, the sealing mechanism 60 realizes the sliding positioning of the balanced sleeve valve 40, so that when the balanced sleeve valve 40 slides to the positioning position, the balanced sleeve valve 40 can connect the other end of the connecting channel 70 with the upper annulus. Thus, it is ensured that the lower trapped pressure of the removable bridge plug 100 can be released to the upper channel through the connecting channel 70 before the removable bridge plug 100 is salvaged. In this way, when the removable bridge plug 100 is salvaged, the lower trapped pressure has been released completely and will not push up to unseal the pipe column. Thus, the potential safety hazards of on-site operations are reduced, thereby ensuring the safety of on-site operators.

[0068] It should be noted that, since the removable bridge plug 100 is in the casing 200, a lower trapped pressure is formed in the lower channel. When the connecting channel 70 is connected to the upper channel, the lower trapped pressure can be released to the upper channel through the connecting channel 70, that is, the pressure of the upper channel and the lower channel is balanced. This ensures that the unsealing string can salvage the removable bridge plug 100 without the action of pressure. This avoids the occurrence of the unsealing string running up during the process of salvaging the bridge plug.

[0069] Specifically, in one embodiment, a balanced leakage hole 41 is provided on the outer periphery of the balanced sleeve valve 40, one end of the balanced leakage hole 41 is connected to the upper channel, and when the balanced sleeve valve 40 slides to contact with the sealing mechanism 60, the other end of the balanced leakage hole 41 is connected to the other end of the connecting channel 70.

[0070] Specifically, in one embodiment, the sealing mechanism 60 includes a driving bushing assembly 61, a slip anchor assembly 62, an adjustment assembly 63, and a rubber cartridge assembly 64. The driving bushing assembly 61 is sleeved on the outer periphery of the inner center tube 20 and is slidably connected to the inner center tube 20; the slip anchor assembly 62 is sleeved on the outer periphery of the driving bushing assembly 61 and is slidably connected to the driving bushing assembly 61; one end of the adjustment assembly 63 is threadedly connected to one end of the slip anchor assembly 62, and the other end of the adjustment assembly 63 is fixed on the other end of the inner center tube 20, and can press the other end of the inner center tube 20 onto the mandrel assembly 10; the rubber cartridge assembly 64 is sleeved on the outer periphery of the driving bushing assembly 61 and placed on the slip anchor assembly 62; the driving bushing assembly 61 can drive the slip anchor assembly 62 to be locked in the casing 200 by sliding downward, and can squeeze the rubber cartridge assembly 64 to expand and seal it in the casing 200.

[0071] Specifically, in one embodiment, the driving bushing assembly 61 includes a setting push cylinder 611, an outer center pipe 612, a locking assembly 613 and an adjusting bearing cap 614. The setting push cylinder 611 is sleeved on the balance pipe 30 and the inner center pipe 20 and is slidably connected with the balance pipe 30 and the inner center pipe 20; the outer center pipe 612 is sleeved on the outer periphery of the inner center pipe 20 and is slidably connected with the inner center pipe 20, and one end of the outer center pipe 612 is connected with the setting push cylinder 611; the locking assembly 613 is arranged in the installation groove formed between the setting push cylinder 611 and the outer center pipe 612; the adjusting bearing cap 614 is threadedly connected with the setting push cylinder 611, and the adjusting bearing cap 614 can push the rubber cylinder assembly 64 to slide.

[0072] Among them, the outer center tube 612 is arranged in the annular gap between the cava anchor assembly 62 and the rubber cartridge assembly 64 and the inner center tube 20. When the bearing cap 614 is adjusted to drive the cava anchor assembly 62 to be locked in the casing 200, and the rubber cartridge assembly 64 is squeezed to expand and seal in the casing 200, the locking assembly 613 is locked on the outer periphery of the inner center tube 20.

[0073] Specifically, in one embodiment, the setting push cylinder 611 is fixed to the outer periphery of the balance pipe 30 by the setting shear pins 615. Since the adjusting bearing cap 614 is threadedly connected to the setting push cylinder 611, downward pressure is applied to the adjusting bearing cap 614, and the setting push cylinder 611 can shear off the setting shear pins 615 and slide synchronously with the adjusting bearing cap 614.

[0074] Specifically, in one embodiment, a locking tooth is provided on the outer circumference of the inner center tube 20, and the locking assembly 613 includes a locking ring sleeve 6131 and a locking ring 6132. The locking ring sleeve 6131 is sleeved in the installation groove; the locking ring 6132 is sleeved on the outer circumference of the locking ring sleeve 6131; the locking ring 6132 can be locked on the locking tooth, and the locking ring sleeve 6131 and the locking ring 6132 are in abutting contact with each other to limit the position where the setting push cylinder 611 slides upward.

[0075] Specifically, in one embodiment, the mandrel assembly 10 includes a release bolt 11, a positioning mandrel 12 and a mandrel 13. Among them, the release bolt 11, one end of which is threadedly connected to the bridge plug setting tool 300; the positioning mandrel 12, one end of which is connected to the other end of the release bolt 11; the mandrel 13, one end of which is threadedly connected to the other end of the positioning mandrel 12. An annular space channel 71 is provided between the positioning mandrel 12 and the balance pipe 30, and a drainage channel 72 is provided between the positioning mandrel 12 and the inner center pipe 20, one end of the drainage channel 72 is connected to one end of the annular space channel 71, and the other end of the drainage channel 72 is connected to the lower channel.

[0076] It should be noted that, in order to ensure that the trapped pressure can be released from the drain channel 72 , a milling groove 132 is provided on the outer circumference of the core shaft 13 so that the drain channel 72 has a sufficient flow area, thereby ensuring that the trapped pressure can flow through the drain channel 72 .

[0077] When the balanced sleeve valve 40 slides to contact with the rubber sleeve assembly 64 , the other end of the balanced drain hole 41 is communicated with the other end of the drain channel 72 .

[0078] When the slip anchor assembly 62 is locked in the casing 200 and the rubber cartridge assembly 64 is expanded and set in the casing 200 , the bridge plug setting tool 300 can be lifted up to shear off the release bolt 11 , so that the bridge plug setting tool 300 and the removable bridge plug 100 can be released.

[0079] Specifically, in one embodiment, a slide groove 131 is provided on the core shaft 13, a slide hole 21 corresponding to the slide groove 131 is provided on the inner center tube 20, a screw pin 625 is provided in the rubber cartridge assembly 64, the screw pin 625 passes through the slide hole 21 and extends into the slide groove 131, the screw pin 625 is slidably connected with the slide hole 21 and the slide groove 131, the other end of the balance tube 30 is detachably fixed to the outer periphery of the positioning core shaft 12, and the other end of the inner center tube 20 is detachably fixed to the outer periphery of the core shaft 13.

[0080] Specifically, in one embodiment, a first annular positioning groove 121 is provided on the positioning core shaft 12, and the other end of the balancing tube 30 is provided as an elastic claw, which is inserted into the first annular positioning groove 121. The other end of the adjusting component 63 is provided with a second annular positioning groove 631, and the other end of the inner center tube 20 is provided as an elastic claw, which is inserted into the second annular positioning groove 631. The adjusting component 63 can press the other end of the inner center tube 20 against the outer periphery of the core shaft 13. The removable bridge plug 100 also includes a salvage and unsealing sleeve 110, which is fixed to the positioning core shaft 12 by an unsealing shear pin 80. The salvage and unsealing sleeve 110 can press the other end of the balancing tube 30 into the first annular positioning groove 121.

[0081] In the above configuration, the salvage unsealing sleeve 110 is lifted to cut off the unsealing shear nail 80, and the salvage unsealing sleeve 110 slides upward, and the other end of the balance pipe 30 (the end provided with the elastic claw) is not limited in the first annular positioning groove 121. In this way, by lifting the positioning mandrel 12, the other end of the balance pipe 30 can be completely disengaged from the first annular positioning groove 121. Thus, the connection between the balance pipe 30 and the positioning mandrel 12 is released. In this way, it is ensured that the mandrel assembly 10 can slide upward on the inner center pipe 20 as a whole, so that the other end of the inner center pipe 20 is not limited in the second annular positioning groove 631. The mandrel 13 continues to slide upward and contacts the limiting step of the inner center pipe 20, and then the positioning mandrel 12 is lifted. The mandrel 13 will drive the inner center pipe 20 and the balance pipe 30 to slide upward. At this time, the inner center pipe 20 slides upward on the outer center pipe 612, and the other end of the inner center pipe 20 (the end provided with the elastic claw) can be disengaged from the second annular positioning groove 631. This releases the connection between the adjustment assembly 63 and the other end of the inner center tube 20. The inner center tube 20 continues to slide upward, and when the lower end of its sliding hole 21 contacts the screw pin 625, the positioning mandrel 12 continues to be lifted, and the screw pin 625 supports and pushes the sealing mechanism 60 and the balanced sliding sleeve valve 40 to slide upward in the casing 200, thereby fishing the removable bridge plug 100 out of the casing 200 as a whole.

[0082] Specifically, in one embodiment, a card groove 111 connected to the unsealing pipe column is provided on the outer periphery of the salvage unsealing sleeve 110, and the retrievable bridge plug 100 also includes a buckle nut 90, which is threadedly connected to one end of the positioning core shaft 12, and the release bolt 11 is passed through the buckle nut 90, wherein, lifting the salvage unsealing sleeve 110 can shear off the unsealing shear pin 80, and the salvage unsealing sleeve 110 can slide upward and come into contact with the buckle nut 90, and continuing to lift the salvage unsealing sleeve 110 can drive the core shaft assembly 10 to slide upward to recover the retrievable bridge plug 100.

[0083] Specifically, in one embodiment, the adjustment assembly 63 includes an adjustment sleeve 632, an adjustment guide head 633, and a set screw 634. The inner hole wall of the adjustment guide head 633 is provided with a second annular positioning groove. One end of the adjustment guide head 633 is threadedly connected to the adjustment sleeve 632, the adjustment sleeve 632 is threadedly connected to the slip anchor assembly 62, and the set screw 634 is used to position the adjustment guide head 633 and the adjustment sleeve 632.

[0084] It should be noted that the position of the lower wedge 624 can be adjusted by rotating the adjusting sleeve 632 to ensure that the outer diameter of the upper and lower slips is not greater than the outer diameter of the slip holder 621 and the upper and lower wedges. The adjusting guide head 633 has a guiding function and presses the other end of the inner center tube 20 against the outer periphery of the core shaft 13.

[0085] Specifically, in one embodiment, the slip anchor assembly 62 includes a slip holder 621, two slips 622, an upper wedge 623, and a lower wedge 624. The slip holder 621 is sleeved on the outer central tube 612, the two slips 622 are respectively arranged on both sides of the slip holder 621, and the upper and lower wedges are respectively located on one side of the corresponding slip 622. The screw is fixed on the upper wedge 623. The upper and lower wedges slide toward the slip holder 621 to open the corresponding slips 622 to lock them on the inner wall of the casing.

[0086] It should be noted that the rubber cylinder assembly 64 in this embodiment is an existing structure, which includes a rubber cylinder and a rubber cylinder spacer ring, and will not be described in detail here.

[0087] It should be noted that when the adjusting bearing cap 614 slides downward, the outer central tube 612 and the rubber cylinder assembly 64 are driven to move downward together. First, the upper wedge-shaped body 623 is pushed downward to open the upper slip 622 and bite it on the casing, and then the outer central tube 612 is driven downward to continue to compress the rubber cylinder assembly 64 under the thrust of the adjusting bearing cap 614, so that its outer diameter is deformed and expanded to seal the casing. The adjusting assembly 63 and the lower wedge-shaped body 624 are pulled upward through the inner central tube 20, and the lower wedge-shaped body 624 moves upward to open the lower slip 622 and bite it on the casing, and the setting and anchoring process of the slip anchor assembly 62 is completed.

[0088] The following is an explanation of the salvaging method of the removable bridge plug in this application. The specific steps are as follows:

[0089] Step 1: lower the unblocking string into the well and close to the retrievable bridge plug;

[0090] Step 2: Use the unsealed pipe string to press down the balanced sleeve valve to release the trapped pressure in the lower channel;

[0091] Step 3: lift up the unsealing pipe column. At this time, the unsealing pipe column is connected to the card slot, so that the salvage unsealing sleeve slides up to the position where it contacts the reverse thread nut;

[0092] Step 3: Continue to lift up the unsealed pipe column, and the mandrel assembly can slide upward on the inner center pipe as a whole to release the connection between the positioning mandrel and the balance pipe;

[0093] Step 4: Continue to lift the unsealed pipe column, the mandrel will drive the inner center pipe and the balance pipe to slide upward and release the connection between the adjustment assembly and the other end of the inner center pipe;

[0094] Step 5, continue to lift the unsealed pipe column until the lower end of the sliding hole contacts the screw pin;

[0095] Step six, continue to lift the unsealed pipe column, the screw pin supports and pushes the sealing mechanism (driving bushing assembly, slip anchor assembly, adjustment assembly and rubber cartridge assembly) and the balanced sleeve valve to slide upward in the casing until the removable bridge plug is salvaged as a whole.

[0096] Embodiment 2

[0097] like Fig.12 and Fig.13 As shown, the present invention provides a bridge plug setting tool 300, which is used to drive the above-mentioned removable bridge plug 100 to be set in the casing 200. The bridge plug setting tool 300 includes a mandrel bushing 301, a stop piston 304, an external bushing 302, and a driving piston 303. Among them, the mandrel bushing 301, one end of which is connected to the delivery string, and the other end of the mandrel bushing 301 is connected to the upper end of the mandrel assembly 10, and the mandrel bushing 301 has a central pressure chamber; the stop piston 304 is fixed on the outer periphery of the mandrel bushing 301; the external bushing 302 is sleeved on the outer periphery of the stop piston 304 and is slidably connected to the stop piston 304; the driving piston 303 is slidably arranged on the outer periphery of the mandrel bushing 301. The core shaft sleeve 301, the stop piston 304, the external sleeve 302 and the removable bridge plug 100 are arranged to form an annular cavity. The driving piston 303 divides the annular cavity into a first cavity and a second cavity. A punching hole is provided on the first cavity, and the punching hole is connected to the central punching cavity. The first cavity can be pressurized through the central punching cavity and the punching hole (first pressure hole 306) so that the driving piston 303 pushes the external sleeve 302 downward to slide.

[0098] In the above arrangement, by pressing the central pressing cavity and the pressing hole, the driving piston 303 can push the outer bushing 302 downward to slide, so that the outer bushing 302 can drive the adjusting bearing cap 614 to slide downward. Thus, the slip anchor assembly 62 is driven to be locked in the casing 200, and the rubber cylinder assembly 64 is expanded and set in the casing 200. Thus, the setting function of the removable bridge plug 100 is realized.

[0099] It should be noted that before pressing the central pressing cavity and the pressing hole, a plugging ball needs to be put into the central pressing cavity, and the plugging ball seat is placed on the upper conical surface of the lower connecting head 3012.

[0100] It should be noted that when the removable bridge plug 100 is seated in the casing 200, pressure is continuously applied to the first cavity, the pressure in the first cavity is accumulated, and an upward thrust is applied to the stop piston 304. When the upward thrust reaches a preset value, the release bolt 11 is pulled off, thereby achieving the release of the bridge plug setting tool 300 and the removable bridge plug 100.

[0101] Specifically, Fig.12 and Fig.13 As shown, in one embodiment, the stop piston 304 is connected to the driving piston 303 via a shear pin. When the pressure in the first chamber reaches a preset value, the driving piston 303 shears off the shear pin and slides downward. This achieves the initial fixation of the stop piston 304. This prevents the driving piston 303 from shaking in the first chamber and being damaged.

[0102] Specifically, Fig.12 and Fig.13 As shown, in one embodiment, the mandrel bushing 301 includes an upper connector 3011, a lower connector 3012 and a connecting pipe 3013, and the upper connector 3011 and the lower connector 3012 are respectively provided at both ends of the connecting pipe 3013. The upper connector 3011 is connected to the delivery pipe string, and the lower connector 3012 is connected to the release bolt 11. The stop piston 304 and the driving piston 303 are both provided on the outer periphery of the connecting pipe 3013. The stop piston 304 is fixed on the connecting pipe 3013, and the driving piston 303 is slidably connected to the connecting pipe 3013. The connecting pipe 3013 is provided with a punching hole.

[0103] Specifically, Fig.12 and Fig.13As shown, in one embodiment, the bridge plug setting tool 300 further includes a driving bushing 305, which is slidably disposed on the connecting pipe 3013, and another pressure hole is disposed on the connecting pipe 3013. A pressure cavity is provided between the driving bushing 305 and the upper connector 3011, and the pressure cavity is communicated with another pressure hole (second pressure hole 307). The pressure cavity can be pressed through the central pressure cavity and the other pressure hole, so that the driving bushing 305 pushes the outer bushing 302 downward to slide.

[0104] In the above arrangement, by pressing the central pressing cavity and the two pressing holes, the driving piston 303 and the driving bushing 305 can push the outer bushing 302 downward to slide, thus ensuring that the outer bushing 302 can drive the adjusting bearing cap 614 to slide downward. Thus, the slip anchor assembly 62 is driven to be locked in the casing 200, and the rubber cylinder assembly 64 is expanded and set in the casing 200. Thus, the setting function of the removable bridge plug 100 is realized. In this way, the dual piston drive of the outer bushing 302 is realized. Thus, the stability and reliability of the use of the bridge plug setting tool 300 are improved.

[0105] It should be noted that when the removable bridge plug 100 is seated in the casing 200, pressure is continued to be applied to the pressure chamber to build up pressure, and an upward thrust is applied to the upward connector 3011. When the upward thrust reaches a preset value, the release bolt 11 is pulled off, thereby achieving the release of the bridge plug seating tool 300 and the removable bridge plug 100.

[0106] Specifically, Fig.12 and Fig.13 As shown, in one embodiment, the outer sleeve 302 includes a first sleeve 3021 , a second sleeve 3022 and a connecting sleeve 3023 , the driving sleeve 305 is in abutment contact with the first sleeve 3021 , and the driving piston 303 is in abutment contact with the connecting sleeve 3023 .

[0107] The following is an explanation of the setting method of the bridge plug setting tool in this application. The specific steps are as follows:

[0108] Step 1: Place the removable bridge plug to a seating position in the casing;

[0109] Step 2: Pressurize the central pressing cavity of the mandrel bushing until the slip anchor assembly is locked in the casing and the rubber sleeve assembly is expanded in the casing;

[0110] Step three, continue to pressurize the center pressing cavity of the core shaft bushing until the release bolt is pulled off.

[0111] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A removable bridge plug, characterized in that: The removable bridge plug is used for setting the oil pipe, and comprises: a mandrel assembly, the upper end of which is connected to a bridge plug setting tool; and an inner center tube, which is sleeved on the outer circumference of the core shaft assembly; and a balance tube, which is sleeved on the outer circumference of the mandrel assembly, one end of which is fixedly connected to one end of the inner center tube, and the other end of the balance tube is fixed on the outer circumference of the mandrel assembly; and a balanced sleeve valve, which is sleeved on the outer circumference of the balanced pipe, close to one end of the balanced sleeve valve fixed to the core shaft assembly, and the balanced sleeve valve is slidably connected to the balanced pipe; and Balance sleeve valve shear pins, which are inserted through the outer periphery of the balance sleeve valve and the balance pipe and are used to fix the balance sleeve valve; A sealing mechanism, which is sleeved on the outer circumference of the inner center tube and fixed to the other end of the inner center tube; Wherein, when the sealing mechanism is seated in the oil pipe, it separates the central hole channel of the oil pipe into an upper channel and a lower channel which are not connected to each other, and a connecting channel is provided between the inner center pipe, the balancing pipe and the core shaft assembly, and one end of the connecting channel is connected to the lower channel; pressing down the balancing sleeve valve can shear off the shear pins of the balancing sleeve valve and make the balancing sleeve valve slide toward the sealing mechanism in a first direction, and when the balancing sleeve valve slides to contact with the sealing mechanism, the balancing sleeve valve connects the other end of the connecting channel with the upper annulus.

2. The removable bridge plug according to claim 1, characterized in that: A balanced drain hole is provided on the outer periphery of the balanced sleeve valve, one end of the balanced drain hole is communicated with the upper channel, and when the balanced sleeve valve slides to contact with the sealing mechanism, the other end of the balanced drain hole is communicated with the other end of the connecting channel.

3. The removable bridge plug according to claim 2, characterized in that: The sealing mechanism comprises: a drive bushing assembly, which is sleeved on the outer circumference of the inner center tube and is slidably connected to the inner center tube; and a slip anchor assembly, which is sleeved on the outer circumference of the drive bushing assembly and is slidably connected to the drive bushing assembly; and an adjusting assembly, one end of which is threadedly connected to one end of the slip anchor assembly, and the other end of the adjusting assembly is fixed to the other end of the inner center tube and is capable of pressing the other end of the inner center tube onto the mandrel assembly; and A rubber cartridge assembly, which is sleeved on the outer circumference of the drive bushing assembly and placed on the slip anchor assembly; The drive bushing assembly can drive the slip anchor assembly to be locked in the oil pipe by sliding downward, and can squeeze the rubber sleeve assembly to expand and seal it in the oil pipe.

4. The removable bridge plug according to claim 3, characterized in that: The drive bushing assembly comprises: a setting push cylinder, which is sleeved on the balance pipe and the inner center pipe and is slidably connected with the balance pipe and the inner center pipe; and An outer center tube is sleeved on the outer circumference of the inner center tube and is slidably connected to the inner center tube, and one end of the outer center tube is connected to the setting push tube; A locking assembly, which is arranged in a mounting groove formed between the setting push tube and the outer center tube; An adjusting bearing cap is threadedly connected to the setting push cylinder, and the adjusting bearing cap can push the rubber cylinder assembly to slide; Wherein, the outer center tube is arranged in the annular gap between the cava anchor assembly and the rubber cartridge assembly and the inner center tube. When the adjusting bearing cap drives the cava anchor assembly to be locked in the oil pipe and squeezes the rubber cartridge assembly to expand and seal it in the oil pipe, the locking assembly is locked on the outer periphery of the inner center tube.

5. The removable bridge plug according to claim 4, characterized in that: The outer periphery of the inner center tube is provided with locking teeth, and the locking assembly comprises: A locking ring sleeve, which is sleeved in the mounting groove; and A locking ring, which is sleeved on the outer circumference of the locking ring sleeve; Wherein, the locking ring can be locked on the locking teeth, and the locking ring sleeve is in abutment contact with the locking ring to limit the position of the setting push cylinder sliding upward.

6. The removable bridge plug according to claim 4, characterized in that: The spindle assembly comprises: a release bolt, one end of which is threadedly connected to the bridge plug setting tool; and a positioning mandrel, one end of which is connected to the other end of the release bolt; and A mandrel, one end of which is threadedly connected to the other end of the positioning mandrel; Among them, an annular space channel is provided between the positioning core shaft and the balancing pipe, and a drainage channel is provided between the positioning core shaft and the inner center pipe, one end of the drainage channel is communicated with one end of the annular space channel, and the other end of the drainage channel is communicated with the lower channel; when the balancing sleeve valve slides to contact with the rubber cartridge assembly, the other end of the balancing drainage hole is communicated with the other end of the drainage channel; when the slip anchor assembly is locked in the oil pipe and the rubber cartridge assembly is expanded and sealed in the oil pipe, lifting the bridge plug sealing tool can shear off the release bolt to realize the release of the bridge plug sealing tool and the removable bridge plug.

7. The removable bridge plug according to claim 6, characterized in that: The core shaft is provided with a slide groove, the inner center tube is provided with a slide hole corresponding to the slide groove, the rubber cylinder assembly is provided with a screw pin, the screw pin passes through the slide hole and extends into the slide groove, the screw pin is slidably connected with the slide hole and the slide groove, the other end of the balance tube is detachably fixed to the outer periphery of the positioning core shaft, and the other end of the inner center tube is detachably fixed to the outer periphery of the core shaft.

8. The removable bridge plug according to claim 7, characterized in that: The positioning mandrel is provided with a first annular positioning groove, the other end of the balancing tube is provided with an elastic claw which is inserted into the first annular positioning groove, the other end of the adjusting assembly is provided with a second annular positioning groove, the other end of the inner center tube is provided with an elastic claw which is inserted into the second annular positioning groove, the adjusting assembly can press the other end of the inner center tube onto the outer periphery of the mandrel, the removable bridge plug also includes a salvage and unsealing sleeve which is fixed to the positioning mandrel by unsealing shear pins, and the salvage and unsealing sleeve can press the other end of the balancing tube into the first annular positioning groove.

9. The removable bridge plug according to claim 8, characterized in that: A card slot connected to the unsealing pipe column is arranged on the outer periphery of the salvage unsealing sleeve, and the retrievable bridge plug also includes a reverse threaded nut, and the reverse threaded nut is threadedly connected to one end of the positioning core shaft, and the release bolt is passed through the reverse threaded nut, wherein, lifting the salvage unsealing sleeve can shear off the unsealing shear nail, and the salvage unsealing sleeve can slide upward and come into contact with the reverse threaded nut, and continuing to lift the salvage unsealing sleeve can drive the core shaft assembly to slide upward to recover the retrievable bridge plug.

10. A bridge plug setting tool, characterized in that: The bridge plug setting tool is used to drive the removable bridge plug according to any one of claims 1 to 9 to be set in the oil pipe, and the bridge plug setting tool comprises: A mandrel bushing, one end of which is connected to the delivery column, the other end of which is connected to the upper end of the mandrel assembly, and the mandrel bushing has a central pressure chamber; and a stop piston fixed to the outer periphery of the spindle bushing; and an outer bushing, which is sleeved on the outer circumference of the stop piston and is slidably connected to the stop piston; and A driving piston slidably disposed on the outer periphery of the core shaft bushing; Among them, the core shaft bushing, the stop piston, the external bushing and the removable bridge plug are arranged to form an annular cavity, and the driving piston divides the annular cavity into a first cavity and a second cavity. A punching hole is provided on the first cavity, and the punching hole is connected with the central punching cavity. The first cavity can be pressed through the central punching cavity and the punching hole, so that the driving piston pushes the external bushing downward to slide.

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