Thermal recovery wellhead blowout prevention device

Abstract

The invention discloses a thermal recovery wellhead blowout prevention device, wherein a first sealing sleeve is provided with a first supporting flange; a first groove for embedding the first supporting flange and a second groove for embedding the second sealing sleeve are provided on the inner contour surface of a sealing body, an external thread is provided on the sealing body, so that the sealing body is fixed on the first sealing sleeve and the second sealing sleeve, and a cavity is formed between the sealing body and the bare rod, a first packing is arranged in the cavity at the upper part of the first sealing sleeve, and a second packing is arranged in the cavity between the first sealing sleeve and the second sealing sleeve; a glue injection hole is provided at the position of the second packing on the sealing body, and a plugging device is provided corresponding to the glue injection hole; the invention has a simple structure and reliable sealing performance, the second packing adopts glue injection sealing, which can increase the temperature and pressure load and reduce the pressure load of the first packing, the first packing can be quickly replaced or the wellhead device can be repaired in a controllable state, and there is no need to discharge sewage or empty, so as to realize safe, efficient, environmentally friendly and energy-saving production of oil pumping operations.

Description

Technical Field

[0001] The invention relates to an oilfield wellhead blowout prevention device, in particular to a thermal recovery wellhead blowout prevention device. Background Art

[0002] At present, pumping wells all use wellhead sealing devices to seal the space around the bare rod, and the sealing materials are mostly sealing fillers such as O-type packing or spiral packing. When replacing the wellhead sealing packing of a pumping well, it is generally used to seal the well with a well sealer, and then replace the packing in the packing box. After the well sealer has been used for a certain period of time, the sealing rubber part of the well sealer ages and wears, resulting in a loose seal of the well sealer. As a result, the wellhead cannot be sealed when the packing is replaced, and the packing cannot be replaced, so it needs to be repaired. Every time the well sealer is repaired, the well needs to be shut down and the well needs to be killed, which is not only time-consuming and labor-intensive, but also affects production and material consumption. If it is not done properly, it will cause a blowout, causing great pollution to the environment.

[0003] Patent document CN110107245A discloses a wellhead blowout prevention control tool for a pumping unit, including an eccentric ball seat, a sphere, an offset pressure adjustment cap, and a blowout prevention cover plate hinged at the lower end of the sphere; a lower packing rubber pad is arranged on the inner hole of the sphere, positioning pins are arranged at the upper and lower ends of the sealing body, and a middle packing rubber pad is arranged on the inner hole separation boss of the sealing body; a wave spring B is arranged on the separation boss of the pressing sleeve, and an upper packing rubber pad is arranged on the upper part of the spring seat; an upper pressing sleeve is arranged on the upper packing rubber pad, and a wave spring A is arranged on the upper part of the upper pressing sleeve; an adjustment sleeve is threadedly connected to the upper part of the pressing sleeve, and a spring pressure cap located at the upper end of the wave spring A is threadedly connected to the adjustment sleeve. The invention can perform bidirectional spring compensation on the packing rubber pad, significantly improve the service life of the packing rubber pad, reduce the damage to the polished rod, solve the problem of scaling of the polished rod in the three-element well, and avoid the use of the well sealer circulation well killing operation when replacing the packing sealing filler, saving expenses and improving production capacity.

[0004] The wellhead blowout prevention control tool of the pumping unit has good sealing effect, but its complex structure makes it time-consuming and laborious to disassemble and replace the packing rubber pad. There is a problem that the sealing condition cannot be known from the outside in a timely and accurate manner. In addition, the sealing packing rubber pad cannot adapt to high-temperature and high-pressure steam injection wells due to the bidirectional spring compensation of the sealing packing rubber pad. Summary of the invention

[0005] The purpose of the present invention is to provide a thermal recovery wellhead blowout prevention device with a simple structure and reliable sealing performance. The second packing is sealed by glue injection, which can increase the temperature and pressure load and reduce the pressure load of the first packing. The first packing can be quickly replaced or the wellhead device can be repaired under a controllable state without draining sewage, thereby realizing safe, efficient, environmentally friendly and energy-saving production of oil pumping operations.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A thermal recovery wellhead blowout prevention device comprises a sealing body coaxially arranged with a polished rod, a first sealing sleeve, a second sealing sleeve, a first packing, a second packing, a packing pressing sleeve and a pressing cap; the first sealing sleeve is provided with a first supporting flange, the inner contour surface of the sealing body is provided with a first groove for embedding the first supporting flange and a second groove for embedding the second sealing sleeve, the outer contour surface of the sealing body is provided with a thread, so that the sealing body is fixed on the first sealing sleeve and the second sealing sleeve, and a cavity is formed between the sealing body and the polished rod;

[0008] The first packing is arranged in the cavity on the upper part of the first sealing sleeve, and the second packing is arranged in the cavity between the first sealing sleeve and the second sealing sleeve; the sealing body is provided with a glue injection hole at the position of the second packing, and a sealing device is provided corresponding to the glue injection hole;

[0009] The packing sleeve is arranged on the upper part of the first packing, and the packing sleeve has a first through hole axially for the light rod to pass through. A second supporting flange is provided on the outer contour surface of the packing sleeve, and a third groove is provided at the lower part of the second supporting flange; a fourth groove for embedding the second supporting flange and a fifth groove for embedding the sealing body are provided on the inner contour surface of the pressure cap, and an internal thread is provided at the fifth groove on the inner contour surface of the pressure cap, so that the pressure cap can be fixed on the packing sleeve and screwed on the sealing body.

[0010] Furthermore, in the above-mentioned thermal recovery wellhead blowout prevention device, the glue injection hole is provided with an internal thread, one end of the sealing device is provided with an external thread screwed into the glue injection hole, the middle part of the sealing device is provided with a glue injection channel connected to the glue injection hole, and the sealing device is also provided with a shut-off device for controlling the opening and closing of the glue injection channel.

[0011] Furthermore, the above-mentioned thermal recovery wellhead blowout prevention device is provided with a second through hole perpendicular to the glue injection channel on the plugging device, and a bolt or a baffle is provided in the second through hole to control the opening and closing of the glue injection channel.

[0012] Furthermore, the above-mentioned thermal recovery wellhead blowout prevention device also includes a sealing member, which has a top wall, a middle wall and a side wall, wherein the top wall abuts against the second supporting flange, and the middle wall is placed on the upper part of the sealing body, so that an oil storage portion is defined between the top wall, the middle wall and the third groove, and threads are provided on the inner contour surface and the outer contour surface of the side wall, so that the side wall is screwed onto the sealing body, a third packing is provided between the middle wall and the top of the sealing body, an oil drain hole is provided on the middle wall, and an oil drain channel is provided in the sealing body corresponding to the oil drain hole, the side wall is screwed into the fourth groove, and exhaust holes are provided at the pressure cap and the side wall corresponding to the oil storage portion, and a closing device is provided corresponding to the exhaust hole.

[0013] Furthermore, in the above-mentioned thermal recovery wellhead blowout prevention device, the closing device includes a base, one end of the base is provided with an external thread, the exhaust hole is provided with an internal thread, so that the base and the exhaust hole are screwed together, an exhaust flow channel connected to the oil storage part is provided in the middle of the base, the exhaust flow channel forms an expanded diameter blocking flow channel after extending for a period, a vent hole connected to the blocking flow channel is provided on the base, and a wire plug is provided in the exhaust flow channel.

[0014] Furthermore, in the above-mentioned thermal recovery wellhead blowout prevention device, a third through hole is provided at the lower end of the pressure cap, and the pressure cap and the sealing body are fixed by inserting a positioning pin into the third through hole.

[0015] Furthermore, in the above-mentioned thermal recovery wellhead blowout prevention device, the inner contour surface of the sealing body at the upper part of the first sealing sleeve is inclined, so that after the first packing is placed, an expansion cavity is provided between the first packing and the first sealing sleeve.

[0016] The beneficial effects of the solution provided by the embodiment of the present invention are:

[0017] The present invention has a simple structure, and the sealing body, the sealing sleeve, the packing sleeve and the pressure cap are installed by embedding the flange and the groove. The packing sleeve, the sealing sleeve and the sealing filler are fixed by screwing the pressure cap on the sealing body. When the first packing sealing well control device fails, the glue injection sealing well control device is activated to perform well control sealing on the wellhead. At the same time, the pressure cap and the packing sleeve can be quickly disassembled to replace the first packing, and the glue injection sealing well control device does not need to be emptied during operation. The sealing reliability is high, and it is suitable for the sealing operation of high-temperature and high-pressure pumping wells, realizing safe, efficient, environmentally friendly and energy-saving production of pumping operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the thermal recovery wellhead blowout prevention device of the present invention;

[0019] Figure 2 It is a schematic diagram of Example 4 of the thermal recovery wellhead blowout prevention device of the present invention.

[0020] The figure marks in the drawings of the specification include: sealing body 1, first sealing sleeve 2, second sealing sleeve 3, first supporting flange 4, first groove 5, second groove 6, first through hole 7, first packing 8, second packing 9, glue injection hole 10, plugging device 11, packing sleeve 12, second supporting flange 13, third groove 14, pressure cap 15, fourth groove 16, fifth groove 17, glue injection channel 18, second through hole 19, oil storage part 20, exhaust hole 21, third through hole 22, expansion cavity 23, top wall 25-1, middle wall 25-2, side wall 25-3, third packing 26, oil discharge hole 27, oil discharge channel 28, exhaust hole 29, base 30, exhaust channel 31, plugging channel 32, vent hole 33, wire plug 34. DETAILED DESCRIPTION

[0021] To make the purpose, technical solution and advantages of the present invention clearer, the specific implementation of the present invention will be further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] Example 1: Reference Figure 1

[0023] The present invention provides a thermal recovery wellhead blowout prevention device, comprising a sealing body 1, a first sealing sleeve 2, a second sealing sleeve 3, a first packing 8, a second packing 9, a packing pressing sleeve 12 and a pressing cap 15, which are arranged coaxially with a polished rod; a first supporting flange 4 is provided on the first sealing sleeve 2, a first groove 5 for embedding the first supporting flange 4 and a second groove 6 for embedding the second sealing sleeve 3 are provided on the inner contour surface of the sealing body 1, and a thread is provided on the outer contour surface of the sealing body 1, so that the sealing body 1 is fixed on the first sealing sleeve 2 and the second sealing sleeve 3, and a cavity is formed between the sealing body 1 and the polished rod;

[0024] The first packing 8 is arranged in the cavity at the upper part of the first sealing sleeve 2, and the second packing 9 is arranged in the cavity between the first sealing sleeve 2 and the second sealing sleeve 3; the sealing body 1 is provided with a glue injection hole 10 at the position of the second packing 9, and a plugging device 11 is provided corresponding to the glue injection hole 10. When the wellhead needs to be plugged, glue can be injected into the inside of the sealing body through the glue injection hole 10;

[0025] The packing sleeve 12 is arranged on the upper part of the first packing 8, and the packing sleeve 12 has a first through hole 7 axially for the light rod to pass through. A second supporting flange 13 is provided on the outer contour surface of the packing sleeve 12, and a third groove 14 is provided at the lower part of the second supporting flange 13; a fourth groove 16 for embedding the second supporting flange 13 and a fifth groove 17 for embedding the sealing body 1 are provided on the inner contour surface of the pressure cap 15, and an internal thread is provided at the fifth groove 17 of the inner contour surface of the pressure cap 15, so that the pressure cap 15 can be fixed on the packing sleeve 12 and screwed on the sealing body 1.

[0026] Installation method:

[0027] First, fit the second sealing sleeve 3 on the outer contour surface of the polished rod, and then insert the sealing body 1 into the polished rod. At this time, the second sealing sleeve 3 is embedded in the second groove 6 of the sealing body 1 to fix the sealing body 1 and the second sealing sleeve 3. The second packing 9 is pressed into the cavity on the upper part of the second sealing sleeve 3. After the second packing 9 is pressed in, the first packing 8 is pressed into the cavity on the upper part of the second packing 9, and then the packing sleeve 12 is placed on the upper part of the first packing 8. The polished rod passes through the first through hole 7 of the packing sleeve 12, and then the pressing cap 15 is inserted into the outside of the packing sleeve 12. At this time, the second supporting flange 13 of the packing sleeve 12 is embedded in the fourth groove 16 on the pressing cap 15, and the sealing body 1 is embedded in the fifth groove 17, and the sealing body 1 and the fifth groove 17 are screwed together to form a fixation.

[0028] Working principle: In normal oil pumping operation, the first packing 8 first blocks all or part of the wellhead pressure to achieve sealing. When the first packing 8 cannot achieve good sealing, the first packing 8 can be pressed down in the cavity of the sealing body 1 by pressing down the packing sleeve 12 and rotating the pressure cap 15 synchronously. At this time, the first packing 8 is synchronously pressed down in the cavity of the sealing body 1 and gradually expands laterally, so that the first packing 8 and the polished rod are in close contact, thereby achieving sealing of the oil wellhead.

[0029] When the first packing 8 is not sealed tightly due to wear, the plugging device 11 on the sealing body 1 is opened, and then glue is injected into the second packing 9 through the glue injection hole 10. After the injection, the gap between the second packing 9 and the polished rod is filled, and the overall sealing performance and sealing pressure of the second packing 9 are improved. At this time, the first packing 8 can be replaced, and the glue injection seals the well control device. It does not need to be vented during operation, and the sealing reliability is high. It is suitable for sealing high-temperature and high-pressure oil and gas wells.

[0030] In summary, the thermal recovery wellhead blowout prevention device has a simple structure and reliable sealing performance. The second packing 9 is sealed by glue injection, which improves the temperature and pressure bearing loads and ensures that the first packing 8 can be quickly replaced under a controllable state without the need for sewage discharge and emptying, thereby ensuring safe, efficient, energy-saving and environmentally friendly oil pumping operations.

[0031] Example 2: Reference Figure 1

[0032] Compared with Example 1, the difference is that the injection hole 10 is arranged as an internal threaded hole, one end of the sealing device 11 is arranged as an external thread screwed with the injection hole 10, the middle part of the sealing device 11 is provided with a glue injection channel 18 connected with the glue injection hole 10, and the sealing device 11 is also provided with a cut-off device for controlling the opening and closing of the glue injection channel 18; during normal oil production operations, only one end of the sealing device 11 with the external thread needs to be screwed into the glue injection hole 10. When the first packing 8 is not sealed tightly and needs to be replaced, only the cut-off device needs to be opened and glue is injected into the second packing 9 through the glue injection channel 18, so that the glue injection and the second packing 9 can be quickly sealed, which is convenient for well sealing operations.

[0033] Example 3: Reference Figure 1

[0034] Compared with Example 2, the difference is that the setting form of the cut-off device can be various. For example, a second through hole 19 perpendicular to the glue injection channel 18 is set on the sealing device 11, and a bolt or a baffle is provided in the second through hole 19 to control the opening and closing of the glue injection channel 18. The glue injection channel 18 is closed by tightening the bolt or pressing down the baffle, and the glue injection channel 18 is opened by reverse operation.

[0035] Example 4: Reference Figure 2

[0036] Compared with the above embodiment, the difference is that a seal is further provided, which has a top wall 25-1, a middle wall 25-2 and a side wall 25-3, wherein the top wall 25-1 is abutted against the second support flange 13, and the middle wall 25-2 is placed on the upper part of the sealing body 1, so that an oil storage portion 20 is defined between the top wall 25-1, the middle wall 25-2 and the third groove 14, and threads are provided on the inner contour surface and the outer contour surface of the side wall 25-3, so that the side wall 25-3 is screwed on the sealing body 1, and a third packing 26 is provided between the middle wall 25-2 and the top of the sealing body 1, and an oil drain hole 27 is provided on the middle wall 25-2, and an oil drain channel 28 is provided in the sealing body 1 corresponding to the oil drain hole 27, and the side wall 25-3 is screwed into the fourth groove 16, and an exhaust hole 29 is provided at the pressure cap 15 and the side wall 25-3 corresponding to the oil storage portion 20, and a closing device is provided corresponding to the exhaust hole 29.

[0037] When the first packing 8 is not sealed tightly due to the wear of the bare rod, the leaked crude oil enters the sealed oil storage part 20 through the gap between the first packing 8 and the packing sleeve 12, and then the crude oil is gathered in the oil storage part 20 due to the limitation of the seal and the packing sleeve 12, and then discharged along the oil discharge channel 28. The outside of the oil discharge channel 28 can be connected to the oil discharge pipe and the oil unloading valve, so as to flexibly discharge the crude oil in the oil storage part 20 for emptying, open the sealing device to exhaust and relieve pressure, and when the pressure cap 15 applies force to the packing sleeve 12, the positions of the internal packing sleeve 12 and the first packing 8 can be observed through the oil storage part 20 through the exhaust hole 21, so that the sealing state of the first packing 8 can be timely and accurately known, and the first packing 8 can be replaced in time after it is worn.

[0038] Example 5: Reference Figure 2

[0039] Compared with the above embodiment, the difference is that the specific sealing device includes a base 30, one end of the base 30 is provided with an external thread, and the exhaust hole 29 is provided with an internal thread, so that the base 30 is screwed with the exhaust hole 29, and an exhaust channel 31 connected to the oil storage part 20 is provided in the middle of the base 30, and the exhaust channel 31 forms an expanded plugging channel 32 after extending for a period, and a venting hole 33 connected to the plugging channel 32 is provided on the base 30, and a thread plug 34 is provided in the exhaust channel 31; when exhaust is required, it is only necessary to withdraw the thread plug 34 to the rear of the venting hole 33, at this time, the exhaust hole 29, the exhaust channel 31 and the venting hole 33 are connected, and exhaust pressure relief work can be performed. When it is necessary to observe the sealing state of the first packing 8, the thread plug 34 can be completely removed, so as to observe the position of the packing sleeve 12 and the first packing 8 through the exhaust channel 31, and timely understand the sealing state of the first packing 8. Of course, there are many forms of sealing devices to achieve the plugging of the exhaust hole 29, which are not listed here. A third through hole 22 is provided at the lower end of the pressing cap 15 , and a positioning pin can be inserted into the third through hole 22 to fix the pressing cap 15 and the sealing body 1 .

[0040] Example 6: Reference Figure 1 and Figure 2

[0041] Compared with the above embodiment, the difference is that the inner contour surface of the sealing body 1 on the upper part of the first sealing sleeve 2 is inclined, so that after the first packing 8 is placed, an expansion cavity 23 is provided between the first packing 8 and the first sealing sleeve 2; when the packing pressing sleeve 12 presses down the first packing 8, the first packing 8 moves downward to the above-mentioned inclined position to expand laterally and fill into the expansion cavity 23, and then the first packing 8 is in closer contact with the light rod, thereby improving the sealing effect of the first packing 8. A handle is also provided on the packing pressing sleeve 12, and it is convenient and labor-saving to press down the packing pressing sleeve 12 by operating the handle.

[0042] Although the present invention is susceptible to various modifications and alternative forms, the drawings and the drawings show specific embodiments of the present invention by way of example. However, it should be understood that the detailed description of the specific embodiments of the present invention and the drawings is not intended to limit the present invention to the specific forms disclosed, but on the contrary, the present invention will cover all modifications, equivalents and alternative forms within the spirit and scope of the present invention as defined by the appended claims.

[0043] The above is only a preferred embodiment of the present invention, and any equivalent changes made within the scope of the claims of the present invention shall fall within the scope of the claims of the present invention. The parts not involved in the present invention are the same as the prior art or can be implemented by the prior art.

Claims

1. A thermal recovery wellhead blowout prevention device, comprising a sealing body (1) arranged coaxially with a polished rod, a first sealing sleeve (2), a second sealing sleeve (3), a first packing (8), a second packing (9), a packing pressing sleeve (12) and a pressing cap (15); characterized in that: The first sealing sleeve (2) is provided with a first supporting flange (4), and the inner contour surface of the sealing body (1) is provided with a first groove (5) for the first supporting flange (4) to be embedded, and a second groove (6) for the second sealing sleeve (3) to be embedded, so that the sealing body (1) is fixed to the first sealing sleeve (2) and the second sealing sleeve (3), and the outer contour surface of the sealing body (1) is provided with a thread, and a cavity is formed between the sealing body (1) and the polished rod; The first packing (8) is arranged in a cavity at the top of the first sealing sleeve (2), and the second packing (9) is arranged in a cavity between the first sealing sleeve (2) and the second sealing sleeve (3); the sealing body (1) is provided with a glue injection hole (10) at the position of the second packing (9), and a blocking device (11) is provided corresponding to the glue injection hole (10); The packing sleeve (12) is arranged on the upper part of the first packing (8), and the packing sleeve (12) has a first through hole (7) in the axial direction for the light rod to pass through. A second supporting flange (13) is provided on the outer contour surface of the packing sleeve (12), and a third groove (14) is provided at the lower part of the second supporting flange (13); the inner contour surface of the pressing cap (15) is provided with a fourth groove (16) for embedding the second supporting flange (13) and a fifth groove (17) for embedding the sealing body (1), and an internal thread is provided at the fifth groove (17) on the inner contour surface of the pressing cap (15), so that the pressing cap (15) can be fixed on the packing sleeve (12) and screwed on the sealing body (1); The invention also comprises a sealing member, which comprises a top wall (25-1), a middle wall (25-2) and a side wall (25-3), wherein the top wall (25-1) is in contact with the second supporting flange (13), and the middle wall (25-2) is placed on the upper part of the sealing body (1), so that an oil storage portion (20) is defined between the top wall (25-1), the middle wall (25-2) and the third groove (14), and the inner contour surface and the outer contour surface of the side wall (25-3) are both provided with threads, so that the side wall (25-3) is screwed on the sealing body (13). On the main body (1), a third packing (26) is provided between the middle wall (25-2) and the top of the sealing main body (1), an oil drain hole (27) is provided on the middle wall (25-2), an oil drain passage (28) is provided in the sealing main body (1) at a position corresponding to the oil drain hole (27), the side wall (25-3) is screwed into the fourth groove (16), an exhaust hole (29) is provided on the pressure cap (15) and the side wall (25-3) at a position corresponding to the oil storage portion (20), and a sealing device is provided corresponding to the exhaust hole (29); The sealing device comprises a base (30), one end of which is provided with an external thread, and the exhaust hole (29) is provided with an internal thread, so that the base (30) and the exhaust hole (29) are screwed together, an exhaust flow channel (31) connected to the oil storage part (20) is provided in the middle of the base (30), the exhaust flow channel (31) is extended for a period of time to form a plugging flow channel (32) with an expanded diameter, and a venting hole (33) connected to the plugging flow channel (32) is provided on the base (30), and a gas discharge hole (33) connected to the plugging flow channel (32) is provided on the exhaust flow channel (31). ) is provided with a screw plug (34); when exhaust is required, the screw plug (34) is simply withdrawn to the rear of the vent hole (33), and then the exhaust hole (29), the exhaust flow channel (31) and the vent hole (33) are connected, and exhaust pressure relief can be performed. When the sealing state of the first packing (8) needs to be observed, the screw plug (34) can be completely removed, so that the position of the packing sleeve (12) and the first packing (8) can be observed through the exhaust flow channel (31), and the sealing state of the first packing (8) can be timely understood; The inner contour surface of the sealing body (1) at the upper part of the first sealing sleeve (2) is arranged in an inclined manner, so that after the first packing (8) is inserted, an expansion cavity (23) is provided between the first packing (8) and the first sealing sleeve (2).

2. The thermal recovery wellhead blowout prevention device according to claim 1, characterized in that: The glue injection hole (10) is provided with an internal thread, one end of the blocking device (11) is provided with an external thread threadedly engaged with the glue injection hole (10), the middle of the blocking device (11) is provided with a glue injection channel (18) connected to the glue injection hole (10), and the blocking device (11) is also provided with a shutoff device for controlling the opening and closing of the glue injection channel (18).

3. The thermal recovery wellhead blowout prevention device according to claim 2 is characterized in that: A second through hole (19) perpendicular to the glue injection flow channel (18) is provided on the blocking device (11), and a bolt or a baffle is provided in the second through hole (19) to control the opening and closing of the glue injection flow channel (18).

4. The thermal recovery wellhead blowout prevention device according to claim 1, characterized in that: A third through hole (22) is provided at the lower end of the pressing cap (15), and the pressing cap (15) and the sealing body (1) are fixed by a positioning pin penetrating into the third through hole (22).

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