A rotary blowout preventer and method for oil well construction

Abstract

The present invention relates to the technical field of oilfield drilling equipment, and discloses a rotary blowout preventer for oil well construction operations, including a lower shell; an upper shell, which is detachably arranged on the top of the lower shell, and the upper shell and the lower shell form a cavity; a rotating assembly, which is axially rotatably arranged in the cavity, and the rotating assembly includes an outer shell, a support sleeve is arranged on the upper part of the inner wall of the outer shell, a sealing rubber core is sleeved on the upper part of the support sleeve, and an end cover is detachably arranged on the top of the outer shell. The outer shell, the lower shell and the upper shell of the present invention are sealed, and during the rotation of the drill pipe, the drill pipe drives the outer shell to rotate through the sealing rubber core or the annular rubber core, thereby avoiding the friction between the drill pipe and the sealing rubber core and the annular rubber core during rotation, reducing the wear of the sealing rubber core and the annular rubber core, and improving the service life. The present invention can adapt to drill pipes of different specifications by setting a multi-stage annular rubber core, thereby avoiding frequent shutdowns to replace different rotary blowout preventers and improving work efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield drilling equipment, in particular to a rotary blowout preventer and a method for oil well construction. Background Art

[0002] During oil drilling, a blowout preventer is installed on the casing head at the wellhead to control the blowout of high-pressure oil, gas, and water. When the oil and gas pressure in the well is very high, the blowout preventer can seal the wellhead (shut it off). When heavy mud is pressed into the drill pipe, there is a four-way under the gate to replace the mud invaded by gas, increase the pressure of the liquid column in the well, and suppress the blowout of high-pressure oil and gas. There are ordinary blowout preventers, universal blowout preventers, and rotary blowout preventers. The universal blowout preventer can be activated in an emergency to cope with drilling tools of any size and empty wells; the rotary blowout preventer can achieve drilling and spraying operations.

[0003] Chinese patent CN113309484B discloses a rotary blowout preventer for oil well construction, including a lower shell and a drill pipe. An upper shell is arranged on the top of the lower shell, a rotatable intermediate ring sleeve is arranged on the inner side of the lower shell, an expansion rubber sleeve filled with gas is arranged on the inner side of the intermediate ring sleeve, the inner side of the expansion rubber sleeve is fitted with the inner wall of the drill pipe, and an upper sliding ring that can move longitudinally is arranged on the top of the inner cavity of the intermediate ring sleeve. Through the structural design of the expansion rubber sleeve inside the intermediate ring sleeve, in conjunction with the linked sliding ring plate and the linked compensation device, the high pressure state of the expansion rubber sleeve filled with gas is used to fit and seal the drill pipe, so that when drill pipes of different sizes need to be replaced, the existing rotary blowout preventer is effectively avoided. When in use, due to the fixed size of the rubber core, it can only seal a single-sized drill tool, cannot achieve full-section pressure-controlled drilling operations, and cannot meet the technical problem of composite drilling tool sealing requirements.

[0004] The technical solution provided by the above patent realizes the sealing between the middle ring and the upper end of the upper shell through the contact between the lower sealing rubber ring and the upper sealing rubber ring during use, and the two are always in sliding friction when the drill pipe rotates, which increases unnecessary wear and maintenance costs. Therefore, an adjustable sealing structure is needed to adapt to the use requirements of different drill pipes, and a rotary blowout preventer that can independently play a good sealing role is needed. Summary of the invention

[0005] To solve the above problems, the present invention adopts the following technical solutions.

[0006] A rotary blowout preventer for oil well construction, comprising:

[0007] Lower housing;

[0008] The upper shell is detachably arranged on the top of the lower shell, and the upper shell and the lower shell form a cavity;

[0009] The rotating assembly is axially rotatably arranged in the cavity 1, and the rotating assembly includes an outer shell, a support sleeve is arranged on the upper part of the inner wall of the outer shell, a sealing rubber core is sleeved on the upper part of the support sleeve, and an end cover is detachably arranged on the top of the outer shell, and a plug hole is arranged in the middle of the end cover for inserting a drill rod.

[0010] The rotating assembly also includes an expansion adjustment mechanism, which includes a plurality of slide rails that are evenly distributed on the inner wall of the outer shell and vertically arranged, the slide rails are located below the support sleeve, and a plurality of support plates are arranged on the slide rails from top to bottom, and the lengths of the plurality of support plates increase successively from top to bottom, and a sliding block is arranged at one end of each support plate facing outward, and a plug plate is telescopically arranged at the other end, and an arc-shaped rubber block is designed on the plug plate, and a plurality of arc-shaped rubber blocks at the same height are assembled into a complete annular rubber core, and the outer diameter and inner diameter of the annular rubber core at each height decrease successively from top to bottom, and a telescopic rod 1 is arranged at the bottom of the slide rail, and the top of the telescopic rod 1 contacts the lowest support plate, and a limiting mechanism is arranged at the position of the highest point of each slider on the outer side of the outer shell,

[0011] The slider is arranged on the upper part of the outward end of the support plate, a slot is arranged on the outward side of the slider, a through hole 1 is arranged on the outer shell body opposite to the slot, an oil cylinder 1 is arranged on the outer side of the through hole 1, the extended end of the oil cylinder 1 passes through the through hole and is engaged with the slot, the extended end of the oil cylinder 1 is located on both sides of the through hole 1 and sealing rings are arranged, a limit plate is arranged on the upper part of the support plate, a through hole 2 is arranged on the limit plate, an oil cylinder 2 is arranged on the support plate on the outward side of the limit plate, the extended end of the oil cylinder 2 passes through the through hole 2 and is connected with the plug plate, and a spring is arranged on the extended end of the oil cylinder 2 between the limit plate and the plug plate.

[0012] Preferably, a first step surface is arranged on the outer side of the top end of the lower shell, the bottom of the upper shell is arranged on the first step surface, and an oil seal is arranged on the side wall of the first step surface.

[0013] Preferably, a second step surface is provided in the middle of the inner side of the lower shell body, the top of the outer shell body is provided on the second step surface, a limit ring is provided on the upper part of the outer shell body, and bearing 1 and bearing 2 are provided at the upper and lower ends of the limit ring respectively, and the outer sides of bearing 1 and bearing 2 are in contact with the inner wall of the upper shell body.

[0014] Preferably, a third step surface and a fourth step surface are successively arranged from bottom to top on the upper part of the second step surface, a support ring is arranged on the third step surface, oil seals are arranged on the inner side wall of the third table surface and the inner side wall of the support ring, and bearing three is arranged on the top of the support ring and the fourth step surface.

[0015] Preferably, a refueling hole is provided at a position corresponding to the limiting ring on the outer side of the upper shell.

[0016] Preferably, the inner bottom surface of the sealing rubber core is provided with a first inclined surface, the outer top surface and the inner bottom surface of the annular rubber core are respectively provided with a second inclined surface and a third inclined surface, and the first inclined surface, the second inclined surface and the third inclined surface are provided with mutually embedded protrusions.

[0017] Preferably, a leak-proof device is also provided on the top of the upper shell body, and the leak-proof device includes a protective shell, the lower end of the protective shell is detachably connected to the upper shell body, an opening is provided on the top of the protective shell, a leak-proof rubber sleeve is provided at the bottom of the opening, the leak-proof rubber sleeve includes a funnel portion, and a cylindrical section is connected to the bottom of the funnel portion.

[0018] Preferably, a connecting pull ring is provided on the outside of the cylindrical section, and an oil cylinder three is provided at a position on the inner wall of the protective shell corresponding to the connecting pull ring. The oil inlet end of the oil cylinder three is connected with the interior of the lower shell through a pipeline, and the protruding end of the oil cylinder three is inserted into the connecting pull ring. In this state, the leak-proof rubber sleeve is in an outwardly expanded state.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The outer shell of the present invention is sealed with the lower shell and the upper shell. During the rotation of the drill rod, the drill rod drives the outer shell to rotate through the sealing rubber core or the annular rubber core, thereby avoiding the friction between the drill rod and the sealing rubber core and the annular rubber core during rotation, reducing the wear of the sealing rubber core and the annular rubber core, and increasing the service life.

[0021] Second, the present invention can adapt to drill pipes of different specifications by providing a multi-stage annular rubber core, thereby avoiding frequent shutdowns to replace different rotary blowout preventers and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 for Figure 1 Schematic diagram of the local structure at A in the middle;

[0024] Figure 3 for Figure 1 Schematic diagram of the local structure at B in the middle;

[0025] Figure 4 It is a schematic diagram of the overall structure of the second embodiment of the present invention.

[0026] In the figure: 1, lower shell; 2, upper shell; 3, cavity 1; 4, outer shell; 5, support sleeve; 6, sealing rubber core; 7, end cover; 8, plug hole; 9, drill rod; 10, first step surface; 11, second step surface; 12, limit ring; 13, bearing 1; 14, bearing 2; 15, third step surface; 16, fourth step surface; 17, support ring; 18, bearing 3; 19, oil filling hole; 20, slide rail; 21, support plate; 22, slider; 23, plug plate; 24, arc rubber block; 25, telescopic rod 1; 26, oil cylinder 3; 27, slot; 28, through hole 1; 29, sealing ring; 30, oil cylinder 1; 31, limit plate; 32, through hole 2; 33, oil cylinder 2; 34, spring 2; 35, protrusion; 36, protective shell; 37, leak-proof rubber sleeve; 38, connecting pull ring. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0028] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the 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 element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example

[0030] like Figure 1-3 As shown, in this embodiment, a rotary blowout preventer for oil well construction operation includes:

[0031] Lower housing 1;

[0032] The upper shell 2 is detachably mounted on the top of the lower shell 1 by bolts, and a cavity 3 is formed inside the upper shell 2 and the lower shell 1;

[0033] The rotating assembly is axially rotatably arranged in the cavity 3, and the rotating assembly includes an outer shell 4, a support sleeve 5 is arranged on the upper part of the inner wall of the outer shell 4, a sealing rubber core 6 is sleeved on the upper part of the support sleeve 5, and an end cover 7 is detachably arranged on the top of the outer shell 4, and a socket 8 is arranged in the middle part of the end cover 7 for inserting a drill rod 9.

[0034] In this embodiment, in order to improve the sealing between the upper shell 2 and the lower shell 1, a first step surface 10 is provided on the outer side of the top end of the lower shell 1, the bottom of the upper shell 2 is provided on the first step surface 10, and an oil seal is provided on the side wall of the first step surface 10.

[0035] In this embodiment, a second step surface 11 is provided in the middle of the inner side of the lower shell 1, and the top of the outer shell 4 is provided on the second step surface 11. A limit ring 12 is provided on the upper part of the outer shell 4, and a bearing 13 and a bearing 2 14 are provided at the upper and lower ends of the limit ring 12 respectively. The outer sides of the bearing 13 and the bearing 2 14 are in contact with the inner wall of the upper shell 2.

[0036] In this embodiment, a third step surface 15 and a fourth step surface 16 are successively arranged on the upper part of the second step surface 11 from bottom to top, a support ring 17 is arranged on the third step surface 15, and oil seals are arranged on the inner side walls of the third step surface 15 and the inner side walls of the support ring 17, and a bearing three 18 is arranged on the top of the support ring 17 and the fourth step surface 16.

[0037] In this embodiment, a refueling hole 19 is provided at a position on the outer side of the upper shell 2 corresponding to the limiting ring 12 , and the refueling hole 19 is used to connect a grease nipple.

[0038] In this embodiment, in order to be applicable to drill rods 9 of different diameters, the rotating assembly also includes an expansion adjustment mechanism, which includes four slide rails 20 evenly distributed on the inner wall of the outer shell 4 and vertically arranged, the slide rails 20 are located below the support sleeve 5, and three horizontally arranged support plates 21 are arranged on the slide rails 20 from top to bottom. The lengths of the three support plates 21 increase from top to bottom in sequence, and each support plate 21 is provided with a slider 22 at one end facing outward, and a plug plate 23 is telescopically arranged at the other end, and an arc-shaped rubber block 24 is designed on the plug plate 23. Four arc-shaped rubber blocks 24 of the same height are assembled into a complete annular rubber core, and the outer diameter and inner diameter of the annular rubber core of each height decrease from top to bottom in sequence, and a telescopic rod 25 is arranged at the bottom of the slide rail 20, and the top of the telescopic rod 25 contacts the lowest support plate 21, and a limit mechanism is arranged at the position corresponding to the highest point of each slider 22 on the outer side of the outer shell 4. In this embodiment, the telescopic rod 25 is an elastic telescopic rod.

[0039] In this embodiment, the slider 22 is arranged at the upper part of the outward end of the support plate 21, and a slot 27 is provided on the outward side of the slider 22. A through hole 28 is provided on the outer shell 4 opposite to the slot 27, and a sealing ring 29 is provided in the through hole 28. A cylinder 30 is provided on the outside of the through hole 28, and the protruding end of the cylinder 30 passes through the through hole 28 and is engaged with the slot 27. A limiting plate 31 is provided on the upper part of the support plate 21, and a through hole 23 is provided on the limiting plate 31. A cylinder 233 is provided on the support plate 21 on the outward side of the limiting plate 31, and the protruding end of the cylinder 23 passes through the through hole 232 and is connected with the plug plate 23. A spring 34 is provided on the protruding end of the cylinder 23 between the limiting plate 31 and the plug plate 23.

[0040] In this embodiment, the inner bottom surface of the sealing rubber core 6 is provided with a first inclined surface, and the outer top surface and the inner bottom surface of the annular rubber core are respectively provided with a second inclined surface and a third inclined surface, and the first inclined surface, the second inclined surface and the third inclined surface are provided with mutually embedded protrusions 35.

[0041] The working principle of the above technical solution is:

[0042] When in use, the drill rod 9 is inserted from the insertion hole 8, and the outer wall of the drill rod 9 is in close contact with the inner wall of the sealing rubber core 6. When rotating, the sealing rubber core 6 drives the outer shell 4 to rotate in the cavity 3. In this embodiment, the annular rubber core is divided into three sizes from top to bottom, namely, the primary rubber core, the secondary rubber core and the tertiary rubber core. This embodiment takes the matching primary rubber core as an example. The drill rod 9 is inserted from the insertion hole 8, and its lower end is against the top of the secondary rubber core. The secondary rubber core and the oil cylinder 1 30 corresponding to the side of the tertiary rubber core are controlled by the controller to contract, so that the extended end of the oil cylinder 1 30 is separated from the slot 27 and retracted into the through hole 1 28. During the downward pressing process of the drill rod 9, the secondary rubber core is squeezed to drive the support plate 21 of the secondary rubber core and the support plate 21 of the tertiary rubber core to slide downward. When the secondary rubber core is separated from the primary rubber core, the controller controls the oil cylinder 2 33 corresponding to the secondary rubber core to contract, and the oil cylinder 2 33 corresponding to the tertiary rubber core to contract synchronously, so as to break contact with the drill rod 9. After the drill rod 9 breaks contact, under the action of the telescopic rod 1 25, the secondary rubber core and the tertiary rubber core both return upward.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The outer shell 4 of the present invention is sealed with the lower shell 1 and the upper shell 2. During the rotation of the drill rod 9, the drill rod 9 drives the outer shell 4 to rotate through the sealing rubber core 6 or the annular rubber core, thereby avoiding the friction between the drill rod 9 and the sealing rubber core 6 and the annular rubber core during rotation, reducing the wear of the sealing rubber core 6 and the annular rubber core, and improving the service life.

[0045] Second, the present invention can adapt to drill pipes 9 of different specifications by providing a multi-stage annular rubber core, thereby avoiding frequent shutdowns to replace different rotary blowout preventers and improving work efficiency. Example

[0046] like Figure 4 As shown, in this embodiment, a leak-proof device is also provided on the top of the upper shell 2, and the leak-proof device includes a protective shell 36, the lower end of the protective shell 36 is detachably connected to the upper shell 2, an opening is provided on the top of the protective shell 36, and a leak-proof rubber sleeve 37 is provided at the bottom of the opening. The leak-proof rubber sleeve 37 includes a funnel portion, and a cylindrical section is connected to the bottom of the funnel portion.

[0047] A connecting pull ring 38 is provided on the outside of the cylindrical section, and an oil cylinder 3 26 is provided on the inner wall of the protective shell 36 at a position corresponding to the connecting pull ring 38. The oil inlet end of the oil cylinder 3 26 is connected to the inside of the lower shell 1 through a pipeline, and the protruding end of the oil cylinder 3 26 is inserted into the connecting pull ring 38. In this state, the leak-proof rubber sleeve 37 is in an outward expansion state.

[0048] The working principle and beneficial effects of the above technical solution are:

[0049] When in use, under normal working conditions, the extended end of the oil cylinder three 26 is inserted into the connecting pull ring 38 so that the leak-proof rubber sleeve 37 is in an outwardly expanded state and does not contact the drill rod 9. When the sealing rubber core 6 or the annular rubber core in the outer shell 4 leaks, the pressure in the outer shell 4 decreases, causing the extended end of the oil cylinder three 26 to shrink and break away from the contact with the connecting pull ring 38, causing the leak-proof rubber sleeve 37 to shrink and contact the drill rod 9, thereby preventing leakage.

[0050] The above are only preferred specific implementations of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and improved concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A rotary blowout preventer for oil well construction, characterized in that: include, Lower housing (1); An upper shell (2) is detachably arranged on the top of the lower shell (1), and a cavity (3) is formed inside the upper shell (2) and the lower shell (1); A rotating assembly is axially rotatably arranged in the cavity (3), the rotating assembly comprising an outer shell (4), a support sleeve (5) is arranged on the upper part of the inner wall of the outer shell (4), a sealing rubber core (6) is sleeved on the upper part of the support sleeve (5), a top of the outer shell (4) is detachably provided with an end cover (7), a middle part of the end cover (7) is provided with a plug hole (8) for inserting a drill rod (9), The rotating assembly further comprises an expansion adjustment mechanism, which comprises a plurality of slide rails (20) evenly distributed on the inner wall of the outer shell (4) and arranged vertically, the slide rail (20) being located below the support sleeve (5), a plurality of support plates (21) being arranged on the slide rail (20) from top to bottom, the lengths of the plurality of support plates (21) increasing from top to bottom, a slider (22) being arranged at one end facing outwards of each support plate (21), and a plug plate (23) being telescopically arranged at the other end, an arc-shaped rubber block (24) being sleeved on the plug plate (23), a plurality of arc-shaped rubber blocks (24) of the same height being assembled into a complete annular rubber core, the outer diameter and inner diameter of the annular rubber core of each height decreasing from top to bottom, a telescopic rod (25) being arranged at the bottom of the slide rail (20), the top of the telescopic rod (25) being in contact with the lowest support plate (21), a limit mechanism being arranged on the outer side of the outer shell (4) at the position corresponding to the highest point of each slider (22), The slider (22) is arranged at the upper part of the outward end of the support plate (21); a slot (27) is arranged on the outward side of the slider (22); a through hole (28) is arranged on the outer shell (4) opposite to the slot (27); a sealing ring (29) is arranged in the through hole (28); an oil cylinder (30) is arranged outside the through hole (28); the protruding end of the oil cylinder (30) passes through the through hole and is engaged with the slot (27); a limit plate (31) is arranged on the upper part of the support plate (21); a through hole (32) is arranged on the limit plate (31); a second oil cylinder (33) is arranged on the support plate (21) on the outward side of the limit plate (31); the protruding end of the second oil cylinder (33) passes through the second through hole (32) and is connected to the plug plate (23); a spring (34) is sleeved on the protruding end of the second oil cylinder (33) between the limit plate (31) and the plug plate (23).

2. A rotary blowout preventer for oil well construction according to claim 1, characterized in that: A first step surface (10) is provided on the outer side of the top end of the lower shell (1), the bottom of the upper shell (2) is provided on the first step surface (10), and an oil seal is provided on the side wall of the first step surface (10).

3. A rotary blowout preventer for oil well construction according to claim 2, characterized in that: A second step surface (11) is provided at the middle of the inner side of the lower shell (1), the top of the outer shell (4) is provided on the second step surface (11), a limit ring (12) is provided at the upper part of the outer shell (4), a bearing 1 (13) and a bearing 2 (14) are provided at the upper and lower ends of the limit ring (12), and the outer sides of the bearing 1 (13) and the bearing 2 (14) are in contact with the inner wall of the upper shell (2).

4. A rotary blowout preventer for oil well construction according to claim 3, characterized in that: A third step surface (15) and a fourth step surface (16) are arranged in sequence from bottom to top on the upper part of the second step surface (11); a support ring (17) is arranged on the third step surface (15); an inner side wall of the third step surface (15) and an inner side wall of the support ring (17) are both provided with oil seals; and a bearing three (18) is arranged on the top of the support ring (17) and the fourth step surface (16).

5. A rotary blowout preventer for oil well construction according to claim 3, characterized in that: A refueling hole (19) is provided on the outer side of the upper shell (2) at a position corresponding to the limiting ring (12).

6. A rotary blowout preventer for oil well construction according to claim 1, characterized in that: The inner bottom surface of the sealing rubber core (6) is provided with a first inclined surface, and the outer top surface and the inner bottom surface of the annular rubber core are respectively provided with a second inclined surface and a third inclined surface, and the first inclined surface, the second inclined surface and the third inclined surface are provided with mutually embedded protrusions (35).

7. A rotary blowout preventer for oil well construction according to claim 1, characterized in that: The top of the upper shell (2) is also provided with a leak-proof device, the leak-proof device comprising a protective shell (36), the lower end of the protective shell (36) being detachably connected to the upper shell (2), the top of the protective shell (36) being provided with an opening, the bottom of the opening being provided with a leak-proof rubber sleeve (37), the leak-proof rubber sleeve (37) comprising a funnel portion, the bottom of the funnel portion being connected to a cylindrical section.

8. A rotary blowout preventer for oil well construction according to claim 7, characterized in that: A connecting ring (38) is arranged on the outside of the cylindrical section, and a cylinder three (26) is arranged on the inner wall of the protective shell (36) at a position corresponding to the connecting ring (38). The oil inlet end of the cylinder three (26) is connected to the inside of the lower shell (1) through a pipeline, and the protruding end of the cylinder three (26) is inserted into the connecting ring (38). In this state, the leak-proof rubber sleeve (37) is in an outwardly expanded state.

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