A hydraulic release mechanism for connecting drill pipe and large-diameter fly pipe

Abstract

This invention provides a hydraulic release mechanism for connecting drill pipe and large-diameter fly pipe in complex formations with both leakage and collapse. It can withstand heavy downward and upward loads, torsional loads, and bending moments, enabling safe connection and separation of ordinary drill pipe and large-diameter fly pipe. The mechanism includes a central shaft, a jaw plate, an inner jaw sleeve, an outer jaw sleeve, a recovery rod, a fly pipe connector, elastic jaws, steel balls, a ball seat, a safety pin, and a support plate. The release mechanism has a central shaft at the center, with the inner jaw sleeve, elastic jaw, and outer jaw sleeve arranged radially outwards. The inner jaw sleeve is suspended from the central shaft, and the upper end of the elastic jaw is suspended from the inner jaw sleeve. The lower end of the elastic jaw is supported on the inner side by the support plate, and the fly pipe is suspended on the outer side. The inner edge of the jaw plate has a hexagonal structure, and the outer edge has a jaw-like structure for transmitting torque. In use, the steel ball is inserted to pressurize and shear the safety pin. The ball seat and support plate descend and detach from the inner wall of the elastic jaw. The inner side of the jaw arm loses support, and the jaw fingers are elastically deformed inwards under gravity, separating from the outer jaw sleeve, thus releasing the fly pipe.

Description

TECHNICAL FIELD

[0001] The present application relates to a matched tool for sealing a cave and a broken zone stratum in the field of oil and gas exploration and development drilling engineering, in particular to a hydraulic release for connecting a drill pipe and a large-diameter flying pipe. BACKGROUND

[0002] In the process of establishing a wellbore in oil and gas exploration and development, multi-layer cave lost circulation occurs during shallow layer drilling, especially when strong drilling is encountered in unstable strata with broken zones, the downhole complex situation of simultaneous collapse and loss is prone to occur, and improper treatment of strong drilling tools or measures can easily lead to drill burying, and finally the wellbore is abandoned, and strong drilling with simultaneous collapse and loss seriously restricts the construction process and becomes an engineering problem to be solved. For such strata with coexisting caves and broken zones, large-diameter flying pipe sealing measures can be used to achieve fixed-point and rapid sealing of the collapsed and dropped sections of the wellbore to ensure the safety of subsequent drilling construction and achieve efficient drilling of such complex strata.

[0003] In the process of flying pipe sealing construction, it is necessary to use a common drill pipe to place a large-diameter sealing flying pipe to the designed depth of the wellbore. The diameter of the flying pipe (generally greater than 26 inches) is much larger than that of the drill pipe, and the weight is huge. The release for connecting the drill pipe and the flying pipe is required to transmit large load under pressure and torsional load when encountering resistance, and in special cases, it is also required to withstand a certain bending moment. Therefore, the use conditions of the release for sealing flying pipe are very special.

[0004] In the field of petroleum engineering, there are many types of releases, which can be divided into hydraulic, threaded connection, automatic claw and steel ball types according to their structures. These releases have different structures according to different purposes and use conditions. For the above-mentioned large-diameter flying pipe, each has some shortcomings that cannot meet the use requirements, such as the existing hydraulic ball release that uses lock blocks to connect the upper and lower pipes, which is mainly used in oil production operations. The diameters of the upper and lower pipes of the release are similar, and the bearing capacity is limited, and it cannot transmit torque; the threaded connection release has large bearing capacity, but the axial load must be unloaded before the release; the automatic claw type has small bearing capacity and cannot withstand impact and vibration; and the steel ball type cannot transmit torque.

[0005] Therefore, a new structure is needed for the release of the large-diameter sealing flying pipe to meet the special use conditions of the large-size flying pipe in the complex stratum with simultaneous collapse and loss, so as to achieve the purpose of safe lowering of the flying pipe in place. SUMMARY

[0006] The purpose of the present application is to provide a hydraulic release for connecting a drill pipe and a large-diameter flying pipe for large-diameter sealing flying pipe in a complex stratum with simultaneous collapse and loss. The hydraulic release provided by the present application overcomes the shortcomings of the prior art, can withstand large load under pressure, torsional load and bending moment, and realizes safe connection and separation of the common drill pipe and the large-diameter flying pipe.

[0007] To achieve the above objectives, the technical solution adopted by the present invention to solve its technical problem is as follows:

[0008] A hydraulic release mechanism for connecting drill pipe and large-diameter fly pipe includes a central shaft, on the outer circle of which an outer hexagon and a load-bearing step are provided sequentially from top to bottom;

[0009] A claw inner sleeve is suspended on the load-bearing step, and an elastic claw is attached to the outside of the claw inner sleeve. A claw outer sleeve is fitted over the elastic claw. A support plate is connected to the lower end of the central shaft through a safety pin. The support plate opens the lower end of the elastic claw to limit the axial movement of the claw outer sleeve. A flying tube connector is connected to the lower end of the claw outer sleeve.

[0010] The central shaft and the support plate are provided with shaft holes in the middle, and a steel ball and a ball seat are provided above the shaft hole of the support plate;

[0011] A dental insert is suspended on the outer hexagon, and the dental insert is provided with an inner hexagon that is engaged with the outer hexagon.

[0012] Furthermore, it also includes a recovery rod, the upper end of which is suspended from the inner sleeve of the claw, the middle part of which passes through the support plate, and the lower end which is limited and engaged with the support plate.

[0013] Furthermore, it also includes a threaded sleeve connected to the central shaft, which presses down on the toothed insert and the claw inner sleeve.

[0014] Furthermore, the dental insert is a hollow disc-shaped body with an inner hexagonal structure, forming a torque transmission connection with the central shaft.

[0015] Furthermore, the outer edge of the toothed plate is a toothed tooth, which forms a torque transmission connection with the claw sleeve through the toothed structure.

[0016] Furthermore, the central shaft is a hollow cylinder. From top to bottom, the outer surface of the cylinder has a clamping thread, an external hexagon, and a load-bearing step. The upper inner end has a drill rod buckle, and the lower inner cylindrical surface has a ball seat sealing surface and a support plate hole. The support plate hole has evenly distributed pin holes radially.

[0017] Furthermore, the elastic claw is a sleeve-like body with a claw structure. The inner side of the upper end is a claw support step, the lower end of the sleeve-like body is a finger-like claw arm, and the outer end of the claw arm is a claw finger with a certain angle step.

[0018] Furthermore, the inner sleeve of the claw is a hollow stepped column with claw steps arranged on the outside of the column, multiple recovery rod holes evenly distributed around the axis in the middle of the column, and a shaft step arranged in the middle of the inner side of the column.

[0019] Furthermore, the lower end of the recovery rod is limited by a nut with an increased outer diameter to restrict the support plate.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This invention is applicable to the safe connection and separation of ordinary drill pipes and large-diameter fly pipes. It adopts an independent torsion transmission structure and axial bearing structure, which can apply downward pressure and torsional loads. It has strong bearing capacity and a safe and reliable structure.

[0022] 2. This invention uses an elastic claw to connect the fly tube, and releases the ball by pressing down on it during the throw. It can release the ball under any load conditions, and the action is accurate and reliable. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the hydraulic release mechanism of the present invention for connecting drill rods and large-diameter fly pipes.

[0024] Figure 2 This is a structural diagram of the central shaft of the hydraulic release mechanism for connecting drill pipe and large-diameter fly pipe according to the present invention.

[0025] Figure 3 This is a structural diagram of the hydraulic release mechanism of the present invention for connecting drill pipe and large-diameter fly pipe.

[0026] Figure 4 This is a structural diagram of the inner sleeve of the hydraulic release handle for connecting drill pipe and large-diameter fly pipe according to the present invention.

[0027] Figure 5 This is a structural diagram of the elastic claw of the hydraulic release mechanism of the present invention for connecting drill pipe and large-diameter fly pipe.

[0028] In the image above:

[0029] 1. Central shaft, 2. Screw sleeve, 3. Tooth insert plate, 4. Claw inner sleeve, 5. Claw outer sleeve, 6. Retrieval rod, 7. Flying tube connector, 8. Elastic claw, 9. Steel ball, 10. Ball seat, 11. Safety pin, 12. Support plate, 101. Clamping thread, 102. External hexagon, 103. Load-bearing step, 104. Drill rod buckle, 105. Ball seat sealing surface, 106. Pin hole, 107. Support plate hole, 301. Tooth insert tooth, 302. Internal hexagon, 401. Claw step, 402. Retrieval rod hole, 403. Hanging shaft step, 801. Claw support step, 802. Claw arm, 803. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0031] Example 1:

[0032] A hydraulic release mechanism for connecting drill pipe and large-diameter fly pipe includes a central shaft 1, a jaw insert 3, an inner jaw sleeve 4, an outer jaw sleeve 5, a recovery rod 6, a fly pipe connector 7, an elastic jaw 8, a steel ball 9, a ball seat 10, a safety pin 11, and a support plate 12.

[0033] The center of the release mechanism is the central axis 1, and radially outwards are the inner claw sleeve 4, the elastic claw 8, and the outer claw sleeve 5;

[0034] The inner sleeve of the claw 4 is suspended on the central shaft 1. The upper end of the elastic claw 8 is suspended on the inner sleeve of the claw 4. The inner side of the lower end of the elastic claw 8 is radially supported by the support plate 12, and the outer side is suspended by the outer sleeve of the claw 5. The lower end of the outer sleeve of the claw 5 is the flying tube connector 7.

[0035] The inner sleeve of the claw 4 is topped with a toothed plate 3, which is connected to the central shaft 1 by a torque transmission. The outer edge of the toothed plate 3 is connected to the outer sleeve of the claw 5 by a torque transmission. The inner sleeve of the claw 4 and the toothed plate 3 are connected by an axial fastening.

[0036] The lower inner side of the central shaft 1 is successively equipped with a ball seat 10 and a support plate 12. The ball seat 10 sits on the support plate 12, and the support plate 12 is inserted into the central shaft 1. The support plate 12 and the central shaft 1 are fixedly connected by a safety pin 11. The upper end of the recovery rod 6 is suspended on the inner sleeve of the claw 4, and the lower end is limited by the support plate 12. The middle part passes through the support plate 12 to recover the steel ball 9 and the ball seat 10 after being dropped.

[0037] The central shaft 1 is a hollow column. From top to bottom, the outer side of the column has a clamping thread 101, an outer hexagon 102, and a load-bearing step 103. The upper inner end has a drill rod buckle 104. The lower inner cylindrical surface has a ball seat sealing surface 105, a support plate hole 107, and radially evenly distributed pin holes 106.

[0038] The dental insert 3 is a hollow disc-shaped body with an inner hexagonal structure 302 along its inner edge, which forms a torque transmission connection with the central shaft 1.

[0039] The outer edge of the toothed plate 3 is a toothed tooth 301, which is connected to the claw sleeve 5 through the toothed structure to form a torque transmission connection.

[0040] The elastic claw 8 is a sleeve-like body with a claw structure. The inner side of the upper end is a claw support step 801, the lower end of the sleeve-like body is a finger-like claw arm 802, and the outer end of the claw arm is a claw finger 803 with a certain angle step.

[0041] It also includes a screw sleeve 2; the screw sleeve 2 is on the toothed plate 1, and the screw sleeve 2 is screwed on the central shaft 1 to axially fasten the inner sleeve 4 of the claw and the toothed plate 3.

[0042] The inner sleeve 4 of the claw is a hollow stepped column. The outer side of the column is arranged with a claw step 401, and multiple recovery rod holes 402 are evenly distributed around the axis in the middle of the column. The inner side of the column is arranged with a shaft step 403.

[0043] The lower end of the recovery rod 6 is limited by a nut with an increased outer diameter to restrict the support plate 12.

[0044] Example 2:

[0045] A hydraulic release mechanism for connecting drill pipe and large-diameter fly pipe includes a central shaft, threaded sleeve, jaw insert, inner jaw sleeve, outer jaw sleeve, recovery rod, fly pipe connector, elastic jaw, steel ball, ball seat, safety pin, and support plate. The release mechanism consists of a central shaft at the center, with the following radially outward components: an inner claw sleeve, an elastic claw, and an outer claw sleeve. The inner claw sleeve is suspended from the central shaft, and the upper end of the elastic claw is suspended from the inner claw sleeve. The lower inner side of the elastic claw is supported by a support plate, while the outer claw sleeve is suspended from the outside. The lower end of the outer claw sleeve is a flight tube connector for connecting to the flight tube. Above the inner claw sleeve is a jaw plate with a hexagonal inner edge that connects to the central shaft for transmission. Above the jaw plate is a threaded sleeve that is screwed onto the central shaft, axially securing the inner claw sleeve and the jaw plate. The outer edge of the jaw plate has a jaw clamp structure that connects to the outer claw sleeve for transmission of torque. On the lower inner side of the central shaft are a ball seat and a support plate. The ball seat sits on the support plate, which is inserted into the central shaft. The support plate and the central shaft are fixedly connected by a safety pin, which can withstand large bending moments. After the safety pin is sheared, the support plate descends and disengages from the elastic claw. The elastic claw, under the weight of the flight tube, elastically deforms and disengages from the flight tube, thus releasing the device. The upper end of the recovery rod is suspended from the inner claw sleeve, and the lower end is a nut. The support plate passes through the middle to retrieve the moving parts after the device has been released.

[0046] The central shaft is a hollow cylinder that bears axial loads, torsion, and bending moments. From top to bottom, the outer surface of the cylinder has a clamping thread, an external hexagon, and a load-bearing step. The upper inner end has a drill rod thread, and the lower inner cylindrical surface has a ball seat sealing surface and a support plate hole. Multiple pin holes are evenly distributed radially at the support plate hole position.

[0047] The dental insert is a hollow disc-shaped body used to transmit torsional loads. The inner edge of the disc has an internal hexagonal structure for input torque, and the outer edge has dental teeth for rapid torque output.

[0048] The inner sleeve of the claw is a hollow stepped column for axial load bearing. The inner side of the column is arranged with a hanging shaft step, and the outer side of the column is arranged with a hanging claw step. Multiple recovery rod holes are evenly distributed around the axis in the middle of the column.

[0049] The elastic claw is a sleeve-shaped body with a claw structure. The inner side of the upper column is a claw support step for axial load bearing. The lower sleeve-shaped body is axially and uniformly cut into finger-shaped claw arms. The protruding steps with a certain angle on the outer side of the claw arms are claw fingers, which are used to bear the load of the flight tube.

[0050] A hydraulic release mechanism for connecting drill pipe and large-diameter fly pipe is used as follows: the upper end of the release mechanism is connected to the drill pipe or drill collar, and the lower end is connected to the large-diameter fly pipe. When the fly pipe is lowered to the designed position, a steel ball is inserted to pressurize and cut the safety pin. The ball seat and support plate descend and detach from the inner wall of the elastic claw. The inner side of the claw arm loses support, and the claw fingers are squeezed inward by gravity and elastically deformed, detaching from the outer claw sleeve, thus releasing the fly pipe. The recovery rod blocks the support plate from descending and simultaneously recovers the movable steel ball and ball seat.

[0051] Example 3:

[0052] Refer to the instruction manual appendix Figures 1 to 5 The present invention provides a hydraulic release mechanism for connecting drill pipe and large-diameter fly pipe, comprising a central shaft 1, a threaded sleeve 2, a toothed insert 3, an inner claw sleeve 4, an outer claw sleeve 5, a recovery rod 6, a fly pipe connector 7, an elastic claw 8, a steel ball 9, a ball seat 10, a safety pin 11, and a support plate 12.

[0053] The center axis 1 is located in the middle of the release mechanism. Radially outward, there are the inner claw sleeve 4, the elastic claw 8, and the outer claw sleeve 5. The inner claw sleeve 4 is suspended on the center axis 1. The upper end of the elastic claw 8 is suspended on the inner claw sleeve 4. The lower inner side of the elastic claw 8 is radially supported by the support plate 12, and the outer claw sleeve 5 is suspended on the outer side.

[0054] The lower end of the claw outer sleeve 5 is the flight tube connector 7, used to connect the flight tube. Above the claw inner sleeve 4 is the jaw insert 3, whose inner edge has a hexagonal structure that is torque-driven connected to the central shaft 1. Above the jaw insert 1 is the threaded sleeve 2, which is screwed onto the central shaft 1, axially securing the claw inner sleeve 4 and the jaw insert 3. The outer edge of the jaw insert 3 has a jaw clamp structure that is torque-driven connected to the claw outer sleeve 5, used to transmit torque.

[0055] The lower inner side of the central shaft 1 is successively a ball seat 10 and a support plate 12. The ball seat 10 sits on the support plate 12, and the support plate 12 is inserted into the central shaft 1. The support plate 12 and the central shaft 1 are fixedly connected by a safety pin 11, which can withstand a large bending moment. After the safety pin 11 is cut, the support plate 12 moves downward and disengages from the elastic claw 8. The elastic claw 8 is elastically deformed by the gravity of the flight tube and disengages from the flight tube to release the grip.

[0056] The upper end of the recovery rod 6 is suspended on the inner sleeve of the claw 4. The middle of the recovery rod 6 passes through the support plate 12 to recover the movable parts after being dropped. The lower end is a nut with an increased outer diameter to limit the support plate 12.

[0057] See attached document Figure 2 The central shaft 1 is a hollow cylinder that bears axial load, torsion and bending moment. From top to bottom, the outer surface of the cylinder has a clamping thread 101, an outer hexagon 102, and a load-bearing step 103. The upper inner end has a drill rod buckle 104, and the lower inner cylindrical surface has a ball seat sealing surface 105 and a support plate hole 107. Multiple pin holes 106 are radially evenly distributed at the position of the support plate hole 107.

[0058] See attached document Figure 3 The dental insert 3 is a hollow disc-shaped body used to transmit torsional loads. Its outer edge is a dental insert tooth 301 used to output torque, and its inner edge is an internal hexagonal structure 302 used to input torque.

[0059] See attached document Figure 4 The inner sleeve 4 of the claw is a hollow stepped column for axial bearing. The outer side of the column is arranged with a claw step 401, and multiple recovery rod holes 402 are evenly distributed around the axis in the middle of the column. The inner side of the column is arranged with a shaft step 403.

[0060] See attached document Figure 5 The elastic claw 8 is a sleeve-shaped body with a claw structure. The inner side of the upper column is a claw support step 801 for axial bearing. The lower sleeve-shaped body is axially and uniformly cut into finger-shaped claw arms 802. The protruding steps with a certain angle on the outer side of the claw arms are claw fingers 803, which are used to bear the load of the flight tube.

[0061] Usage: Connect the upper end of the hydraulic release hand of the present invention, which is used to connect the drill rod and the large-diameter fly pipe, to the drill rod or drill collar, and connect the lower end to the large-diameter fly pipe through the fly pipe connector 7.

[0062] The fly pipe is lowered into the wellbore to the designed position. A steel ball 9 is dropped into the drill pipe or drill collar bore at the wellhead. The drilling pump is started to pressurize, shearing the safety pin 11. The ball seat 10 and support plate 12 descend and detach from the inner wall of the elastic claw 8. The inner side of the claw arm 802 loses support, and the claw fingers 803 are elastically deformed inward under gravity, detaching from the claw sleeve 5. The claw sleeve 5 is released from its restraint and falls along with the fly pipe connector 7, thus releasing the fly pipe.

[0063] The nut at the lower end of the recovery rod 6 blocks the support plate 12 from moving downwards, while simultaneously recovering the movable steel ball 9 and the ball seat 10.

[0064] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hydraulic back-off for connecting a drill pipe and a large diameter fly pipe, comprising a central shaft, characterized in that, The outer circle of the central shaft is sequentially provided with an outer hexagon and a load bearing step from top to bottom; The claw inner sleeve is hung on the load bearing step, the elastic claw is hung on the outer part of the claw inner sleeve, the claw outer sleeve is sleeved on the elastic claw, the lower end of the central shaft is connected with the support plate through the safety pin, the support plate supports the lower end of the elastic claw to axially limit the claw outer sleeve, and the lower end of the claw outer sleeve is connected with the flying pipe joint; The central shaft and the support plate are provided with shaft holes in the middle part, and the shaft hole of the support plate is provided with a steel ball and a ball seat above; The toothed plate is hung on the outer hexagon, and the toothed plate is provided with an inner hexagon matched with the outer hexagon Also includes: The recovery rod is hung on the claw inner sleeve, passes through the support plate in the middle part, and is limited and matched with the support plate in the lower end; The screw sleeve is screwed on the central shaft, and the screw sleeve presses the toothed plate and the claw inner sleeve downward; The elastic claw is a sleeve body with a claw structure, the inner side of the upper end is a claw supporting step, the lower end of the sleeve body is a finger claw arm, and the outer side end of the claw arm is a claw finger with a certain angle step; The claw inner sleeve is a hollow stepped column, the outer side of the column is arranged with a claw hanging step, the middle part of the inner side of the column is arranged with a plurality of recovery rod holes around the axis, and the middle part of the inner side of the column is arranged with a hanging shaft step.

2. A hydraulic back-off for connecting drill pipe and oversize flypipe according to claim 1, characterized in that, The toothed plate is a hollow disc body, the inner side is an inner hexagon structure, and the central shaft is connected in torque transmission.

3. A hydraulic back-off for connecting drill pipe and oversize flypipe as defined in claim 1, wherein, The outer side of the toothed plate is a toothed gear, and the toothed gear is connected in torque transmission with the claw outer sleeve.

4. A hydraulic back-off for connecting drill pipe and oversize flypipe as defined in claim 1, wherein, The central shaft is a hollow column, the outer side of the column is sequentially provided with a pressing thread, an outer hexagon and a load bearing step from top to bottom, the inner side of the upper end is a drill rod buckle, the inner side of the lower end is sequentially provided with a ball seat sealing surface and a support plate hole, and the support plate hole is radially uniformly arranged with a pin hole.

5. A hydraulic back-off for connecting drill pipe and oversize flypipe as defined in claim 1, wherein, The lower end of the recovery rod is limited to the support plate through the nut with increased outer diameter.

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