Wellhead blowout preventer packer and use method thereof

Abstract

The present invention discloses a wellhead blowout prevention packer and a method for using the same, comprising an upper anchoring mechanism, a lower anchoring mechanism, and a supporting mechanism which are sequentially mounted on the outer wall of an outer center pipe from top to bottom; the lower end of the upper anchoring mechanism is pressed against the upper end surface of the shoulder of the outer wall of the outer center pipe, and the upper end of the upper anchoring mechanism is connected to a rotary sealing / unsealing mechanism; the lower end of the lower anchoring mechanism is connected to a supporting mechanism, and the upper end of the lower anchoring mechanism is pressed against the lower end surface of the shoulder of the outer wall of the outer center pipe. The present invention can seal casing and suspend tubing at the wellhead, and has an anti-upward function. The application of a matching plug valve in the oil pipe can complete the pressure control in the well during the process of replacing the wellhead, reduce construction risks, reduce the labor intensity of employees, and prevent the blowout from getting out of control.

Description

Technical Field

[0001] The invention relates to the technical field of wellhead packers, in particular to a wellhead blowout preventer packer and a use method thereof. Background Art

[0002] At present, during the underground well repair process, wellhead replacement is a relatively frequent construction process. Thermal well steam injection, sand control fracturing, long-term well maintenance and other special working conditions all require wellhead replacement.

[0003] The process and procedure of replacing wellhead is relatively mature, but there are the following problems:

[0004] (1) There is no control device at the wellhead during the construction process, and the wellhead is in an uncontrollable state. During the replacement of the wellhead, the pressure changes in the well cannot be measured in time and are difficult to observe. If the pressure in the well changes suddenly and overflow occurs at the wellhead, it will not be possible to control it in time or even cause a blowout accident out of control, which poses a great risk to well control;

[0005] (2) The process of replacing the wellhead is complicated, especially when replacing a large high-pressure wellhead or a well with a tubing string. There are no special auxiliary tools, so it takes a long time and is inefficient, which invisibly increases the well control and safety risks.

[0006] Existing hydraulically set packers require a series of applications such as hydraulic pipelines and pump trucks when used at the wellhead. They are relatively complicated to use and cannot be reused. Current mechanically set packers such as Y211 and Y221 cannot meet the application scenarios where there is no production string at the bottom or top of the string, and cannot achieve the anti-lifting function.

[0007] Publication (announcement) number: CN107165600B, Publication (announcement) date: 2018-04-17. It is an efficient and environmentally friendly oil well wellhead sealing device, including a blowout preventer, a packing sleeve, a packing tube and a base. The blowout preventer shell, the packing sleeve, the packing tube and the base are fixedly installed together in sequence from top to bottom. The middle part of the base is provided with a seat body through hole. A lower support ring seat is fixed to the inner side of the lower part of the packing tube. A lower packing sealing ring sleeve with the top surface against the lower support ring seat is installed below the lower support ring seat. An upper support ring seat is fixed to the inner side of the upper part of the packing sleeve. An upper packing sealing ring sleeve with the bottom surface seated on the upper support ring seat is installed above the upper support ring seat. It can avoid oil leakage and environmental pollution, ensure that the overall equipment can work normally, and there is no need to stop the machine for disassembly and maintenance. It only needs to open and close the plug, which will not cause oil production interruption, ensure production efficiency, and prevent waste. It has the characteristics of high efficiency, convenience, time saving, labor saving and high safety factor.

[0008] Publication (announcement) number: CN111411914A, Publication (announcement) date: 2020-07-14 A wellbore blowout preventer plug is disclosed, including an anchoring assembly, a plugging assembly, and an anchor sealing operation assembly. The lower end of the anchoring assembly is connected to the plugging assembly, and the anchor sealing operation assembly is inserted into the inner cavity of the anchoring assembly and the inner cavity of the plugging assembly. The anchor sealing operation assembly is connected to the anchoring fork of the anchoring assembly through its own torque tube transmission, and the anchor sealing operation assembly is connected to the lower joint of the plugging assembly through its own center pull tube. When the wellhead operation needs to be switched during the operation, the blowout preventer can be directly placed in the wellbore through the derrick lifting system without removing the blowout preventer, and the wellbore can be quickly sealed by rotating, lifting and compressing the hydraulic clamp to prevent blowout accidents.

[0009] Publication (announcement) number: CN106939777B, Publication (announcement) date: 2018-12-21 It relates to a blowout prevention packer used in oil production projects in the petroleum and natural gas industry. It solves the problems of oil and gas production layer isolation and downhole blowout prevention. Its technical solution is: the sliding pin is fixed in the pin hole at the bottom of the locking cylinder; the locking steel ball is installed in the three through holes in the middle of the locking cylinder; the upper end of the connecting cylinder and the lower end of the locking cylinder are threadedly connected, and the lower end of the connecting cylinder and the upper end of the anchoring cylinder are threadedly connected; the upper spacer ring, the sealing rubber cylinder and the lower spacer ring are integrally sleeved on the outer circle of the connecting cylinder; the anchor claws are installed in the three groups of stepped through holes on the upper part of the anchoring cylinder; the upper end of the sealing mandrel and the lower end of the oil seal mandrel are threadedly connected, and the lower end of the sealing mandrel is threadedly connected to the ball seat, the ball seat is installed on the raised step surface at the lower part of the inner cavity of the lower joint, and the sealing steel ball is installed on the spherical surface at the center of the upper end face of the ball seat. The seal is set and released by injecting liquid into the pipe column, which is convenient and simple to control. In the event of a blowout, it automatically realizes downhole high-pressure plugging to ensure production safety.

[0010] In short, the technical solutions, technical problems to be solved and beneficial effects produced by the above-disclosed technologies are different from the present invention, or are in different technical fields or application scenarios. Regarding more technical features, technical problems to be solved and beneficial effects of the present invention, the above-disclosed technical documents do not contain any technical inspiration. Summary of the invention

[0011] The purpose of the present invention is to provide a wellhead blowout preventer and a method of using the same in response to the above-mentioned defects in the prior art. The blowout preventer can seal the casing and suspend the tubing at the wellhead and has an anti-upward function. The application of a matching plug valve in the oil pipe can complete the pressure control in the well during the wellhead replacement process, reduce construction risks, reduce the labor intensity of employees, and prevent uncontrolled blowouts.

[0012] In order to achieve the above object, the present invention adopts the following technical solutions:

[0013] A wellhead blowout preventer packer comprises an upper anchoring mechanism, a lower anchoring mechanism and a supporting mechanism which are sequentially mounted on the outer wall of an outer central pipe from top to bottom;

[0014] The lower end of the upper anchor sealing mechanism is pressed against the upper end surface of the shoulder of the outer wall of the outer center tube, and the upper end of the upper anchor sealing mechanism is connected to the rotary setting / unsealing mechanism;

[0015] The lower end of the lower anchoring mechanism is connected to the supporting mechanism, and the upper end of the lower anchoring mechanism is pressed against the lower end surface of the shoulder of the outer wall of the outer center tube.

[0016] Furthermore, the anchor sealing device includes an upper slip mechanism and a rubber cylinder mechanism connected to each other. The rubber cylinder mechanism includes a single rubber cylinder or a combination of multiple rubber cylinders. When there are multiple rubber cylinders, spacer rings are provided between each two of the rubber cylinders.

[0017] Further, the lower anchoring mechanism is a lower slip mechanism, and the lower slip mechanism includes a first lower cone, a first lower slip, a first lower slip support, a first cone connecting sleeve, a sleeve, and a ball locking mechanism;

[0018] The first lower cone is sleeved on the outer wall of the first cone connecting sleeve, and the first cone connecting sleeve is sleeved on the outer wall of the outer center tube;

[0019] The first lower cone is provided with a mounting groove for mounting the first lower slip, and the bottom of the mounting groove of the first lower cone and the lower slip are connected to each other by a conical surface;

[0020] The upper end of the first lower cava support supports the first lower cava, the lower end of the first lower cava support is connected to the sheath, and a ball locking mechanism is installed inside the sheath.

[0021] Furthermore, the upper end of the first lower cone is connected to the lower cone cap, and the upper end of the lower cone cap is pressed against the lower end surface of the shoulder of the outer wall of the outer center tube; the lower end of the ball locking mechanism is connected to the upper end of the top sleeve.

[0022] Furthermore, the support mechanism is a lower slip support mechanism, and the lower slip support mechanism includes a friction block, a spring, a centralizing body, a pressure ring, a retaining ring, and a track pin;

[0023] The lower end of the top sleeve is threadedly mounted on the outer wall of the centralizing body, the pressure ring is threadedly mounted on the outer wall of the centralizing body, and the centralizing body is mounted on the outer wall of the outer center tube;

[0024] The lower end of the friction block is radially limited between the inner wall of the pressure ring and the outer wall of the centralizer body, and the upper end of the friction block is radially limited between the inner wall of the top sleeve and the outer wall of the centralizer body, and at the same time, the pressure ring and the top sleeve both axially limit the outer wall step of the friction block;

[0025] The inner end of the spring bears against the outer wall of the centralizing body, and the outer end of the spring bears against the friction block;

[0026] The lower end of the pressure ring is threadedly connected to the retaining ring, and an outwardly protruding retaining platform for axial limiting is arranged on the outer wall of the lower end of the outer center tube, that is, the outer diameter of the retaining platform is larger than the inner diameter of the retaining ring;

[0027] The inner wall of the retaining ring is provided with radial track pins, the outer wall of the outer center tube is provided with tracks, and the track pins are inserted into and run relatively to the tracks.

[0028] Furthermore, the upper slip mechanism comprises a second upper slip support, a second upper slip, and a second cone;

[0029] The second cone is sleeved on the outer wall of the outer center tube, the lower end of the second cone presses against the rubber tube mechanism, and the lower end of the rubber tube mechanism presses against the upper end surface of the shoulder of the outer wall of the outer center tube;

[0030] The second cone is provided with a mounting groove for mounting the second upper slip, and the bottom of the mounting groove of the second cone and the second upper slip are connected to each other by a conical surface;

[0031] The lower end of the second upper cava support supports the second upper slip, and the upper end of the second upper cava support is connected to the moving block of the rotary sealing / unsealing mechanism through a transmission pin.

[0032] Furthermore, the upper slip mechanism comprises a transmission sleeve, a third upper cone connecting sleeve, a third upper cone, a slip sleeve, a leaf spring, a third upper slip, and a third lower cone;

[0033] The third upper slip, the third upper cone, the third lower cone, and the third upper cone connecting sleeve are all sleeved on the outer wall of the outer center tube, the upper end of the third upper slip and the lower end of the third upper cone are connected by a conical surface, the lower end of the third upper slip and the upper end of the third lower cone are connected by a conical surface, the upper end of the third upper cone is connected to the third upper cone connecting sleeve, and the lower end of the third lower cone is pressed against the upper end surface of the shoulder of the outer wall of the outer center tube;

[0034] The leaf spring is fixed on the outer wall of the third upper slip, the slip sleeve is sleeved on the outside of the third upper slip, and a window for exposing the leaf spring is opened on the slip sleeve;

[0035] The rubber cylinder mechanism is sleeved on the outer wall of the third upper cone connecting sleeve, and the lower end of the rubber cylinder mechanism is pressed against the upper end surface of the third upper cone;

[0036] The lower end of the transmission sleeve bears against the upper end of the rubber cylinder mechanism, and the transmission sleeve is connected to the moving block of the rotary sealing / unsealing mechanism through a transmission pin.

[0037] Further, the rotary setting / unsealing mechanism includes a transmission nut, a transmission block, an inner center tube, an outer center tube, and a transmission pin;

[0038] The transmission nut is threadedly mounted on the outer wall of the inner center tube, the inner center tube extends into the outer center tube, and the inner wall of the outer center tube and the outer wall of the lower end of the inner center tube are simultaneously provided with corresponding axial limiting steps to limit the upward movement of the inner center tube;

[0039] The outer center tube is provided with a travel groove for the transmission block to move up and down. The upper end of the transmission block is provided with an inner plug, which passes through the travel groove and is inserted into the outer card groove provided on the outer wall of the transmission nut. The transmission nut and the inner center tube rotate relative to each other, and the transmission nut can drive the transmission block to move up and down in the travel groove.

[0040] In order to achieve the above object, the present invention adopts the following technical solutions:

[0041] A method for using a wellhead blowout preventer packer comprises the following steps:

[0042] By lifting and lowering the slip mechanism and the lower slip support mechanism, the first lower slip is set and released to achieve the suspension of the pipe string;

[0043] The outer center pipe is clamped by the backup hydraulic pliers, and the inner center pipe is rotated by the main hydraulic pliers to seal the second upper slip and the rubber cylinder mechanism and seal the annular space of the oil casing; the inner center pipe is rotated, and the transmission nut moves downward along the inner center pipe, and the transmission nut drives the transmission block to move downward, and the transmission block pushes the second upper slip support to move downward through the transmission pin, and the second upper slip support pushes the second upper slip, the second cone, and the rubber cylinder to move downward, and the outer center pipe is fixed, the shoulder is fixed, and the lower end of the rubber cylinder is fixed; the downward movement of the transmission nut realizes the sealing of the rubber cylinder and the slip;

[0044] The upper end of the inner center tube is connected to a plug valve to seal the inner space of the oil pipe;

[0045] Remove existing old wellheads;

[0046] Replace the wellhead with a new one;

[0047] Use the backup hydraulic pliers to clamp the outer center pipe, use the main hydraulic pliers to reversely rotate the inner center pipe, and unseal the second upper slip and the rubber cylinder mechanism;

[0048] Lift up the wellhead blowout preventer packer and release the first lower slip;

[0049] Install well plug;

[0050] The wellhead blowout preventer is removed to complete the wellhead replacement construction.

[0051] In order to achieve the above object, the present invention adopts the following technical solutions:

[0052] A method for using a wellhead blowout preventer packer comprises the following steps:

[0053] By lifting and lowering the slip mechanism and the lower slip support mechanism, the first lower slip is set and released to achieve the suspension of the pipe string;

[0054] Use the hydraulic pliers to clamp the outer center pipe, use the hydraulic pliers to rotate the inner center pipe, set the third upper slip and the rubber cylinder mechanism, and seal the annular space of the oil casing; rotate the inner center pipe, the transmission nut moves downward along the inner center pipe, the transmission nut drives the transmission block to move downward, the transmission block pushes the transmission sleeve downward through the transmission pin, and when the transmission sleeve moves downward, the rubber cylinder is compressed in turn, and the third upper slip moves downward. The lower end of the third lower cone is the shoulder of the outer center pipe. During the setting and unsealing process, the shoulder is fixed, the third upper slip is first completely set, and then the rubber cylinder is set;

[0055] The upper end of the inner center tube is connected to a plug valve to seal the inner space of the oil pipe;

[0056] Remove existing old wellheads;

[0057] Replace the wellhead with a new one;

[0058] Use the backup hydraulic pliers to clamp the outer center pipe, use the main hydraulic pliers to reversely rotate the inner center pipe, and unseal the third upper slip and the rubber cylinder mechanism;

[0059] Lift up the wellhead blowout preventer packer and release the first lower slip;

[0060] Install well plug;

[0061] The wellhead blowout preventer is removed to complete the wellhead replacement construction.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] First, without hydraulic power, the packer can be set and unsealed by mechanical means such as lifting / lowering and rotating, relying only on elevators and hydraulic clamps. It is light, easy to operate, safe and reliable.

[0064] Second, the packer can be reused many times, which makes it more operable and economical;

[0065] Third, the packer has a wide range of application occasions. When it comes to replacing the wellhead construction, it can be used with or without production tubing in the well, and its application prospects are broad. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 It is a structural schematic diagram of a wellhead blowout preventer packer;

[0067] Figure 2 yes Figure 1 A partial enlarged view of the setting / release mechanism of the blowout preventer packer at the middle wellhead;

[0068] Figure 3 yes Figure 1 A half-section view of the combined type of the middle rubber cylinder mechanism;

[0069] Figure 4 yes Figure 1 A structural schematic diagram of a transmission nut;

[0070] Figure 5 yes Figure 1 The structural diagram of the middle transmission block;

[0071] Figure 6 yes Figure 1 Schematic diagram of the structure of the central tube;

[0072] Figure 7 It is a schematic diagram of another preferred embodiment of a wellhead blowout preventer packer;

[0073] Figure 8 yes Figure 7 A partial enlarged view of the upper slip mechanism and the rubber cylinder mechanism of another preferred embodiment of the wellhead blowout preventer.

[0074] In the figure: 100 - rotary sealing / unsealing mechanism, 101 - inner center tube, 102 - outer center tube, 103 - transmission nut, 104 - transmission block, 105 - shoulder;

[0075] 200-upper slip mechanism, 201-second upper slip support, 202-second upper slip, 203-second cone, 204-shoulder;

[0076] 300-rubber cylinder mechanism; 301-rubber cylinder, 302-spacer ring;

[0077] 400-lower slip mechanism, 401-lower cone cap, 402-first lower cone, 403-first lower slip, 404-first lower slip holder, 405-first cone connecting sleeve, 406-ball locking sleeve, 407-spring, 408-ball blocking sleeve, 409-steel ball, 410-sheath, 411-top sleeve;

[0078] 500-lower slip support mechanism, 501-friction block, 502-spring, 503-centering body, 504-pressure ring, 505-track pin, 506-blocking ring;

[0079] 601-transmission sleeve, 602-spacer ring, 603-third upper cone connecting sleeve, third upper cone-604, shear pin-605, 606-slip sleeve, leaf spring-607, third upper slip-608, retaining ring-609, third lower cone-610. DETAILED DESCRIPTION

[0080] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0081] Embodiment 1:

[0082] See also Figures 1 to 6 , the present invention provides a technical solution:

[0083] A wellhead blowout preventer packer comprises an upper anchoring mechanism, a lower anchoring mechanism and a supporting mechanism which are sequentially mounted on the outer wall of an outer central pipe from top to bottom;

[0084] The lower end of the upper anchor sealing mechanism is pressed against the upper end surface of the shoulder of the outer wall of the outer center tube, and the upper end of the upper anchor sealing mechanism is connected to the rotary setting / unsealing mechanism;

[0085] The lower end of the lower anchoring mechanism is connected to the supporting mechanism, and the upper end of the lower anchoring mechanism is pressed against the lower end surface of the shoulder of the outer wall of the outer center tube.

[0086] Furthermore, the anchor sealing device includes an upper slip mechanism 100 and a rubber cylinder mechanism 300 connected to each other. The rubber cylinder mechanism includes a single rubber cylinder or a combination of multiple rubber cylinders. When there are multiple rubber cylinders, spacer rings are provided between each two of the rubber cylinders.

[0087] Further, the lower anchoring mechanism is a lower slip mechanism 400, and the lower slip mechanism includes a first lower cone 402, a first lower slip 403, a first lower slip support 404, a first cone connecting sleeve 405, a sheath 410, and a ball locking mechanism;

[0088] The first lower cone is sleeved on the outer wall of the first cone connecting sleeve, and the first cone connecting sleeve is sleeved on the outer wall of the outer center tube;

[0089] The first lower cone is provided with a mounting groove for mounting the first lower slip, and the bottom of the mounting groove of the first lower cone and the first lower slip are connected to each other by a conical surface;

[0090] The upper end of the first lower cava support supports the first lower cava, the lower end of the first lower cava support is connected to the sheath, and a ball locking mechanism is installed inside the sheath.

[0091] Furthermore, the upper end of the first lower cone is connected to the lower cone cap, and the upper end of the lower cone cap is pressed against the lower end surface of the shoulder of the outer wall of the outer center tube; the lower end of the ball locking mechanism is connected to the upper end of the top sleeve.

[0092] The lower slip mechanism is a well-known technology in the art and can be directly applied, and the more specific structural connection relationship and its operation process are not described in detail. Those skilled in the art are clear about this.

[0093] Further, the support mechanism is a lower slip support mechanism, and the lower slip support mechanism includes a friction block 501, a spring 502, a centralizing body 503, a pressure ring 504, a retaining ring 506, and a track pin 505;

[0094] The lower end of the top sleeve is threadedly mounted on the outer wall of the centralizing body, the pressure ring is threadedly mounted on the outer wall of the centralizing body, and the centralizing body is mounted on the outer wall of the outer center tube;

[0095] The lower end of the friction block is radially limited between the inner wall of the pressure ring and the outer wall of the centralizer body, and the upper end of the friction block is radially limited between the inner wall of the top sleeve and the outer wall of the centralizer body, and at the same time, the pressure ring and the top sleeve both axially limit the outer wall step of the friction block;

[0096] The inner end of the spring bears against the outer wall of the centralizing body, and the outer end of the spring bears against the friction block;

[0097] The lower end of the pressure ring is threadedly connected to the retaining ring, and an outwardly protruding retaining platform for axial limiting is arranged on the outer wall of the lower end of the outer center tube, that is, the outer diameter of the retaining platform is larger than the inner diameter of the retaining ring;

[0098] The inner wall of the retaining ring is provided with radial track pins, the outer wall of the outer center tube is provided with tracks, and the track pins are inserted into and run relatively to the tracks.

[0099] The lower slip support mechanism and the track of the outer central tube matched therewith are well-known technologies in the art and can be directly applied. The more specific structural connection relationship and its operation process will not be described in detail. Those skilled in the art will be clear about this.

[0100] Furthermore, the upper slip mechanism includes a second upper slip support 201, a second upper slip 202, and a second cone 203;

[0101] The second cone is sleeved on the outer wall of the outer center tube, the lower end of the second cone presses against the rubber tube mechanism, and the lower end of the rubber tube mechanism presses against the upper end surface of the shoulder of the outer wall of the outer center tube;

[0102] The second cone is provided with a mounting groove for mounting the second upper slip, and the bottom of the mounting groove of the second cone and the second upper slip are connected to each other by a conical surface;

[0103] The lower end of the second upper cava support supports the second upper slip, and the upper end of the second upper cava support is connected to the moving block of the rotary sealing / unsealing mechanism through a transmission pin.

[0104] Further, the rotary setting / unsealing mechanism includes a transmission nut 103, a transmission block 104, and an inner center tube 101;

[0105] The transmission nut is threadedly mounted on the outer wall of the inner center tube, the inner center tube extends into the outer center tube, and the inner wall of the outer center tube and the outer wall of the lower end of the inner center tube are simultaneously provided with corresponding axial limiting steps to limit the upward movement of the inner center tube;

[0106] The outer center tube is provided with a travel groove for the transmission block to move up and down. The upper end of the transmission block is provided with an inner plug, which passes through the travel groove and is inserted into the outer card groove provided on the outer wall of the transmission nut. The transmission nut and the inner center tube rotate relative to each other, and the transmission nut can drive the transmission block to move up and down in the travel groove.

[0107] Figure 1 This is a schematic diagram of a wellhead blowout preventer with one-way slips as the upper slips. The following is an explanation Figure 1 The wellhead blowout preventer mainly comprises a rubber sleeve mechanism 300, an upper slip mechanism 200, a lower slip mechanism 400, a rotary setting / unsealing mechanism 100 and the like.

[0108] The rubber cylinder mechanism 300 includes a rubber cylinder 301 and a spacer ring 302. The rubber cylinder can be a single rubber cylinder, a double rubber cylinder, a triple rubber cylinder, etc. Figure 3 shown.

[0109] Figure 2 It is a partial enlarged schematic diagram of the packer setting / unsealing mechanism 100, which includes an inner central pipe 101, an outer central pipe 102, a transmission nut 103, a transmission block 104, and a transmission nail 106. The inner central pipe 101 is a structure with a small upper end and a large lower end, and the shoulder 105 hangs on the reducing shoulder of the outer central pipe 102 to realize the vertical connection of the inner and outer central pipes and the transmission of the tension of the pipe string.

[0110] A bearing may be added at the shoulder between the inner center tube 101 and the outer center tube 102 to reduce the rotational friction between the inner center tube 101 and the outer center tube 102 .

[0111] The inner center tube 101 and the transmission nut 103 are threadedly connected.

[0112] The outer portion of the inner central tube 103 is designed with a relatively long transmission thread to enable the transmission nut 103 to move downward along the inner central tube 101. The transmission thread may be a triangular thread, a rectangular thread, a trapezoidal thread, or the like.

[0113] The inner center tube 101 and the transmission nut 103 may be connected by left-hand thread or right-hand thread. When the intermediate thread is left-hand thread, the outer center tube 102 is fixed by a backup clamp, the inner center tube 101 is rotated forward, and the transmission nut 103 moves downward along the inner center tube 101. When the intermediate thread is right-hand thread, the outer center tube 102 is fixed by a backup clamp, the inner center tube 101 is rotated backward, and the transmission nut 103 moves downward along the inner center tube 101.

[0114] Figure 4 The figure shows the structure of the transmission nut 103. The transmission nut 103 has four slots in the middle for connecting the transmission block 104. The number of slots in the transmission nut 103 can be 1, 2, 3, 4, 5, 6, etc. The bottom of the slot can be an arc, a flat bottom or an inclined surface. Figure 4 It is just an embodiment structure of the transmission nut.

[0115] Figure 5 The figure shows the structure of the transmission block 104. The internal structure of the transmission block 104 corresponds to the bottom structure of the slotted transmission nut 103. The number of the transmission block 104 is the same as the number of slotted transmission nut 103. The transmission block 104 is slotted outside for connecting the transmission nail 106.

[0116] The outer central tube 102 has a plurality of long grooves 205 ( Figure 6 The number of grooves is the same as the number of grooves in the transmission nut 103. The grooves are used to provide axial movement space for the transmission block 104 to move downward along the outer center tube 102. The length of the grooves is greater than the setting distance between the rubber cylinder and the upper slip.

[0117] A shoulder 204 is provided in the middle of the outer center tube 102 to support the upper rubber cylinder, slips and other structures.

[0118] The thread at the lower end of the outer central tube 102 can be connected to a downhole pipe string.

[0119] The outer central tube 102 may be formed by connecting and sealing one, two or more tubes.

[0120] The driving pin 106 connects the rotary sealing / unsealing mechanism 100 and the upper slip mechanism 200 .

[0121] The upper cava mechanism 200 includes a second upper cava support 201, a second upper cava 202, and a second cone 203. The outer center tube 102 is fixed, the inner center tube 101 is rotated, the transmission nut 103 moves downward along the inner center tube 101, the transmission nut 103 drives the transmission block 104 to move downward, the transmission block 104 pushes the second upper cava support 201 to move downward through the transmission nail 106, and the second upper cava support 201 pushes the second upper cava 202, the second cone 203, and the rubber cylinder 300 to move downward, because the lower end of the rubber cylinder is fixed to the outer wall shoulder 204 of the outer center tube 102. The downward movement of the transmission nut realizes the sealing of the rubber cylinder and the second upper cava. The second upper cava 202 is a one-way cava, and a feasible cava tooth angle is 60° and 30°. Other tooth angles that can meet the one-way cava function are still feasible.

[0122] The lower slip mechanism 400 and the lower slip supporting mechanism 500 utilize the principle of the Y211 packer to realize the setting and unsealing of the lower slip by lifting and lowering, thereby realizing the suspension of the pipe string, which will not be described in detail here.

[0123] The setting of the lower slip can realize the suspension of the tubing when there is a tubing in the well when changing the wellhead.

[0124] Figure 1 The implementation steps of the wellhead blowout prevention packer shown in the figure are:

[0125] 1. Lower the wellhead blowout preventer packer to a certain distance below the wellhead;

[0126] 2. Lift up the wellhead blowout preventer packer and replace the track pins of the lower slip support mechanism with the track;

[0127] 3. Lower the wellhead blowout preventer packer and seal the first lower slip;

[0128] 4. Use the backup hydraulic pliers to clamp the outer center pipe, use the main hydraulic pliers to rotate the inner center pipe, set the second upper slip and the rubber cylinder mechanism, and seal the annular space of the oil casing;

[0129] 5. The upper end of the inner center tube is connected to a plug valve to seal the internal space of the oil pipe;

[0130] 6. Remove the existing old wellhead;

[0131] 7. Replace the new wellhead;

[0132] 8. Use the backup hydraulic pliers to clamp the outer center pipe, use the main hydraulic pliers to reversely rotate the inner center pipe, and unseal the second upper slip and the rubber cylinder;

[0133] 9. Lift up the wellhead blowout preventer packer and release the first lower slip;

[0134] 10. Install the well plugger;

[0135] 11. Remove the wellhead blowout preventer and complete the wellhead replacement construction.

[0136] Embodiment 2:

[0137] Of course, the embodiments with more specific components are only the optimal embodiments, and the embodiments with fewer specific components are basic embodiments, but they can also achieve the basic purpose of the present invention, so all these modified embodiments are within the protection scope of the present invention.

[0138] See also Figures 1 to 6 , the present invention provides a technical solution:

[0139] A wellhead blowout preventer packer comprises an upper anchoring mechanism, a lower anchoring mechanism and a supporting mechanism which are sequentially mounted on the outer wall of an outer central pipe from top to bottom;

[0140] The lower end of the upper anchor sealing mechanism is pressed against the upper end surface of the shoulder of the outer wall of the outer center tube, and the upper end of the upper anchor sealing mechanism is connected to the rotary setting / unsealing mechanism;

[0141] The lower end of the lower anchoring mechanism is connected to the supporting mechanism, and the upper end of the lower anchoring mechanism is pressed against the lower end surface of the shoulder of the outer wall of the outer center tube.

[0142] Furthermore, the anchor sealing device includes an upper slip mechanism 100 and a rubber cylinder mechanism 300 connected to each other. The rubber cylinder mechanism includes a single rubber cylinder or a combination of multiple rubber cylinders. When there are multiple rubber cylinders, spacer rings are provided between each two of the rubber cylinders.

[0143] Furthermore, the upper slip mechanism includes a second upper slip support 201, a second upper slip 202, and a second cone 203;

[0144] The second cone is sleeved on the outer wall of the outer center tube, the lower end of the second cone presses against the rubber tube mechanism, and the lower end of the rubber tube mechanism presses against the upper end surface of the shoulder of the outer wall of the outer center tube;

[0145] The second cone is provided with a mounting groove for mounting the second upper slip, and the bottom of the mounting groove of the second cone and the second upper slip are connected to each other by a conical surface;

[0146] The lower end of the second upper cava support supports the second upper slip, and the upper end of the second upper cava support is connected to the moving block of the rotary sealing / unsealing mechanism through a transmission pin.

[0147] Further, the rotary setting / unsealing mechanism includes a transmission nut 103, a transmission block 104, and an inner center tube 101;

[0148] The transmission nut is threadedly mounted on the outer wall of the inner center tube, the inner center tube extends into the outer center tube, and the inner wall of the outer center tube and the outer wall of the lower end of the inner center tube are simultaneously provided with corresponding axial limiting steps to limit the upward movement of the inner center tube;

[0149] The outer center tube is provided with a travel groove for the transmission block to move up and down. The upper end of the transmission block is provided with an inner plug, which passes through the travel groove and is inserted into the outer card groove provided on the outer wall of the transmission nut. The transmission nut and the inner center tube rotate relative to each other, and the transmission nut can drive the transmission block to move up and down in the travel groove.

[0150] Embodiment 3:

[0151] Part of the mechanism of Example 1 is slightly modified to form Example 3.

[0152] Figure 7 The schematic diagram of the wellhead blowout preventer with the upper slips being bidirectional slips is shown, and the partial enlarged schematic diagram of the bidirectional slip mechanism and the rubber cylinder mechanism is shown as follows Figure 8The transmission sleeve 601, the rubber sleeve 300, the spacer ring 602, the third upper cone 604, the third upper slip 608, and the third lower cone 610 are arranged in order from top to bottom on the outside of the outer central tube 201.

[0153] The upper slip mechanism includes a transmission sleeve 601, a third upper cone connecting sleeve 603, a third upper cone 604, a slip sleeve 606, a leaf spring 607, a third upper slip 608, and a third lower cone 610;

[0154] The third upper slip, the third upper cone, the third lower cone, and the third upper cone connecting sleeve are all sleeved on the outer wall of the outer center tube, the upper end of the third upper slip and the lower end of the third upper cone are connected by a conical surface, the lower end of the third upper slip and the upper end of the third lower cone are connected by a conical surface, the upper end of the third upper cone is connected to the third upper cone connecting sleeve, and the lower end of the third lower cone is pressed against the upper end surface of the shoulder of the outer wall of the outer center tube;

[0155] The leaf spring is fixed on the outer wall of the third upper slip, the slip sleeve is sleeved on the outside of the third upper slip, and a window for exposing the leaf spring is opened on the slip sleeve;

[0156] The rubber cylinder mechanism is sleeved on the outer wall of the upper cone connecting sleeve, and the lower end of the rubber cylinder mechanism is pressed against the upper end surface of the third upper cone;

[0157] The lower end of the transmission sleeve bears against the upper end of the rubber cylinder mechanism, and the transmission sleeve is connected to the moving block of the rotary sealing / unsealing mechanism through a transmission pin.

[0158] On the outer side of the third upper slip 608, a leaf spring 607 and a slip sleeve 606 are arranged in sequence from inside to outside;

[0159] There are shear nails 605 between the third upper cone 604 and the slip sleeve 606.

[0160] The upper part of the third upper cone 604 is connected to the third upper cone connecting sleeve 603, and the third upper cone connecting sleeve 603 is arranged on the inner side of the transmission sleeve 601, the rubber cylinder 300 and the spacer ring 602; a retaining ring 609 is arranged on the outside of the third lower cone.

[0161] When the transmission sleeve 601 moves downward, it compresses the rubber cylinder 300 in turn, and the third upper cava 608 moves downward. The lower end of the third lower cone 610 is the shoulder 204 of the outer center tube 201. During the sealing and unsealing process, the shoulder 204 is fixed, and the third upper cava 608 is first completely sealed, and then the rubber cylinder 300 is sealed.

[0162] The third upper slip 608 is a bidirectional slip, and a feasible slip tooth angle is 45°. Other tooth angles that can satisfy the bidirectional slip function are still feasible.

[0163] Figure 7The implementation steps of the wellhead blowout prevention packer shown in the figure are:

[0164] 1. Lower the wellhead blowout preventer packer to a certain distance below the wellhead;

[0165] 2. Lift up the wellhead blowout preventer packer and replace the track pins of the lower slip support mechanism with the track;

[0166] 3. Lower the wellhead blowout preventer packer and seal the first lower slip;

[0167] 4. Use the backup hydraulic pliers to clamp the outer center pipe, use the main hydraulic pliers to rotate the inner center pipe, set the third upper slip and rubber cylinder, and seal the annular space of the oil casing;

[0168] 5. The upper end of the inner center tube is connected to a plug valve to seal the internal space of the oil pipe;

[0169] 6. Remove the existing old wellhead;

[0170] 7. Replace the new wellhead;

[0171] 8. Use the backup hydraulic pliers to clamp the outer center pipe, use the main hydraulic pliers to reversely rotate the inner center pipe, and unseal the third upper slip and rubber cylinder;

[0172] 9. Lift up the wellhead blowout preventer packer and release the first lower slip;

[0173] 10. Install the well plugger;

[0174] 11. Remove the wellhead blowout preventer and complete the wellhead replacement construction.

[0175] All parts and components not discussed in detail in this application and the connection methods of the parts and components in this application belong to the well-known technology in this technical field and will not be described in detail, such as welding, threaded connection, etc.

[0176] In the present invention, the term "plurality" refers to two or more than two, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0177] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front” and “back” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0178] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0179] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wellhead blowout preventer packer, characterized in that: It includes an upper anchoring mechanism, a lower anchoring mechanism, and a supporting mechanism which are sequentially mounted on the outer wall of the outer central tube from top to bottom; The lower end of the upper anchor sealing mechanism is pressed against the upper end surface of the shoulder of the outer wall of the outer center tube, and the upper end of the upper anchor sealing mechanism is connected to the rotary setting / unsealing mechanism; The lower end of the lower anchoring mechanism is connected to the supporting mechanism, and the upper end of the lower anchoring mechanism is pressed against the lower end surface of the shoulder of the outer wall of the outer center tube; The upper anchor seal mechanism comprises an upper slip mechanism and a rubber cylinder mechanism connected to each other; The rotary setting / unsealing mechanism comprises a transmission nut, a moving block, an inner center tube, an outer center tube, and a transmission pin; The upper slip mechanism is connected to the moving block of the rotary setting / unsealing mechanism through a transmission pin, and the moving block is used for transmission and is the transmission block; The transmission nut is threadedly mounted on the outer wall of the inner center tube, the inner center tube extends into the outer center tube, and the inner wall of the outer center tube and the outer wall of the lower end of the inner center tube are simultaneously provided with corresponding axial limiting steps to limit the upward movement of the inner center tube; The outer center tube is provided with a travel groove for the transmission block to move up and down. The upper end of the transmission block is provided with an inner plug, which passes through the travel groove and is inserted into the outer card groove provided on the outer wall of the transmission nut. The transmission nut and the inner center tube rotate relative to each other, and the transmission nut can drive the transmission block to move up and down in the travel groove.

2. A wellhead blowout preventer packer according to claim 1, characterized in that: The rubber cylinder mechanism includes a single rubber cylinder or a combination of multiple rubber cylinders. When there are multiple rubber cylinders, spacer rings are provided between each two of the rubber cylinders.

3. A wellhead blowout preventer packer according to claim 1 or 2, characterized in that: The lower anchoring mechanism is a lower slip mechanism, which includes a first lower cone, a first lower slip, a first lower slip support, a first cone connecting sleeve, a sleeve, and a ball locking mechanism; The first lower cone is sleeved on the outer wall of the first cone connecting sleeve, and the first cone connecting sleeve is sleeved on the outer wall of the outer center tube; The first lower cone is provided with a mounting groove for mounting the first lower slip, and the bottom of the mounting groove of the first lower cone and the lower slip are connected to each other by a conical surface; The upper end of the first lower cava support supports the first lower cava, the lower end of the first lower cava support is connected to the sheath, and a ball locking mechanism is installed inside the sheath.

4. A wellhead blowout preventer packer according to claim 3, characterized in that: The upper end of the first lower cone is connected to the lower cone cap, and the upper end of the lower cone cap is pressed against the lower end surface of the shoulder of the outer wall of the outer center tube; the lower end of the ball locking mechanism is connected to the upper end of the top sleeve.

5. A wellhead blowout preventer packer according to claim 4, characterized in that: The support mechanism is a lower slip support mechanism, and the lower slip support mechanism includes a friction block, a spring, a centralizing body, a pressure ring, a retaining ring, and a track pin; The lower end of the top sleeve is threadedly mounted on the outer wall of the centralizing body, the pressure ring is threadedly mounted on the outer wall of the centralizing body, and the centralizing body is mounted on the outer wall of the outer center tube; The lower end of the friction block is radially limited between the inner wall of the pressure ring and the outer wall of the centralizer body, and the upper end of the friction block is radially limited between the inner wall of the top sleeve and the outer wall of the centralizer body, and at the same time, the pressure ring and the top sleeve both axially limit the outer wall step of the friction block; The inner end of the spring bears against the outer wall of the centralizing body, and the outer end of the spring bears against the friction block; The lower end of the pressure ring is threadedly connected to the retaining ring, and an outwardly protruding retaining platform for axial limiting is arranged on the outer wall of the lower end of the outer center tube, that is, the outer diameter of the retaining platform is larger than the inner diameter of the retaining ring; The inner wall of the retaining ring is provided with radial track pins, the outer wall of the outer center tube is provided with tracks, and the track pins are inserted into and run relatively to the tracks.

6. A wellhead blowout preventer packer according to claim 5, characterized in that: The upper slip mechanism comprises a second upper slip support, a second upper slip, and a second cone; The second cone is sleeved on the outer wall of the outer center tube, the lower end of the second cone presses against the rubber tube mechanism, and the lower end of the rubber tube mechanism presses against the upper end surface of the shoulder of the outer wall of the outer center tube; The second cone is provided with a mounting groove for mounting the second upper slip, and the bottom of the mounting groove of the second cone and the second upper slip are connected to each other by a conical surface; The lower end of the second upper cava support supports the second upper slip, and the upper end of the second upper cava support is connected to the moving block of the rotary sealing / unsealing mechanism through a transmission pin.

7. A wellhead blowout preventer packer according to claim 5, characterized in that: The upper slip mechanism comprises a transmission sleeve, a third upper cone connecting sleeve, a third upper cone, a slip sleeve, a leaf spring, a third upper slip, and a third lower cone; The third upper slip, the third upper cone, the third lower cone, and the third upper cone connecting sleeve are all sleeved on the outer wall of the outer center tube, the upper end of the third upper slip and the lower end of the third upper cone are connected by a conical surface, the lower end of the third upper slip and the upper end of the third lower cone are connected by a conical surface, the upper end of the third upper cone is connected to the third upper cone connecting sleeve, and the lower end of the third lower cone is pressed against the upper end surface of the shoulder of the outer wall of the outer center tube; The leaf spring is fixed on the outer wall of the third upper slip, the slip sleeve is sleeved on the outside of the third upper slip, and a window for exposing the leaf spring is opened on the slip sleeve; The rubber cylinder mechanism is sleeved on the outer wall of the third upper cone connecting sleeve, and the lower end of the rubber cylinder mechanism is pressed against the upper end surface of the third upper cone; The lower end of the transmission sleeve is pressed against the upper end of the rubber cylinder mechanism, and the transmission sleeve is connected to the moving block of the rotary sealing / unsealing mechanism through a transmission pin.

8. A method for using a wellhead blowout preventer packer, characterized in that: Using the wellhead blowout preventer packer according to claim 6 comprises the following steps: By lifting and lowering the slip mechanism and the lower slip support mechanism, the first lower slip is set and released to achieve the suspension of the pipe string; The outer center pipe is clamped by the backup hydraulic pliers, and the inner center pipe is rotated by the main hydraulic pliers to seal the second upper slip and the rubber cylinder mechanism and seal the annular space of the oil casing; the inner center pipe is rotated, and the transmission nut moves downward along the inner center pipe, and the transmission nut drives the transmission block to move downward, and the transmission block pushes the second upper slip support to move downward through the transmission pin, and the second upper slip support pushes the second upper slip, the second upper cone, and the rubber cylinder to move downward, and the outer center pipe is fixed, the shoulder is fixed, and the lower end of the rubber cylinder is fixed; the downward movement of the transmission nut realizes the sealing of the rubber cylinder and the slip; The upper end of the inner center tube is connected to a plug valve to seal the inner space of the oil pipe; Remove existing old wellheads; Replace the wellhead with a new one; Use the backup hydraulic pliers to clamp the outer center pipe, use the main hydraulic pliers to reversely rotate the inner center pipe, and unseal the second upper slip and the rubber cylinder mechanism; Lift up the wellhead blowout preventer packer and release the first lower slip; Install well plug; The wellhead blowout preventer is removed to complete the wellhead replacement construction.

9. A method for using a wellhead blowout preventer packer, characterized in that: Using the wellhead blowout preventer packer according to claim 7 comprises the following steps: By lifting and lowering the slip mechanism and the lower slip support mechanism, the first lower slip is set and released to achieve the suspension of the pipe string; Use the hydraulic pliers to clamp the outer center pipe, use the hydraulic pliers to rotate the inner center pipe, set the third upper slip and the rubber cylinder mechanism, and seal the annular space of the oil casing; rotate the inner center pipe, the transmission nut moves downward along the inner center pipe, the transmission nut drives the transmission block to move downward, the transmission block pushes the transmission sleeve downward through the transmission pin, and when the transmission sleeve moves downward, the rubber cylinder is compressed in turn, and the third upper slip moves downward. The lower end of the third lower cone is the shoulder of the outer center pipe. During the setting and unsealing process, the shoulder is fixed, the third upper slip is first completely set, and then the rubber cylinder is set; The upper end of the inner center tube is connected to a plug valve to seal the inner space of the oil pipe; Remove existing old wellheads; Replace the wellhead with a new one; Use the backup hydraulic pliers to clamp the outer center pipe, use the main hydraulic pliers to reversely rotate the inner center pipe, and unseal the third upper slip and the rubber cylinder mechanism; Lift up the wellhead blowout preventer packer and release the first lower slip; Install well plug; The wellhead blowout preventer is removed to complete the wellhead replacement construction.

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