Kelly bar plug valve for offshore oil field drilling and production

Abstract

The invention discloses a kelly cock valve for offshore oil field drilling, and relates to the technical field of oil field drilling valves, the kelly cock valve comprises a double-cavity valve body, the double-cavity valve body is provided with an upper cavity and a lower cavity which are distributed at an interval along the axial direction, and two ends of the double-cavity valve body are respectively bolted with an I-shaped upper end cover and an I-shaped lower end cover; the I-shaped upper end cover and the upper end opening of the double-cavity valve body are enclosed to form a closed upper mounting cavity; and the I-shaped lower end cover and the lower end opening of the double-cavity valve body are enclosed to form a closed lower mounting cavity. When the two cock liquid control structures are controlled, the electric double-position synchronous driving structure controls the two cock liquid control structures to act at the same time in the low-pressure blowout state so that an inner channel of a drill column can be closed, and the hydraulic rotary driving structure controls the cock liquid control structures to act in the high-pressure blowout state under the supply of an external hydraulic pump station. The problems that a traditional single-valve-ball plug valve is limited in high-pressure blocking effect in the ocean high-pressure drilling environment and is difficult to open and close under the high pressure difference are solved.

Description

Technical Field

[0001] This invention relates to the field of oilfield drilling valve technology, and in particular to a square drill pipe plug valve for offshore oilfield drilling. Background Technology

[0002] As a well control safety component within the drill string system during offshore oilfield drilling operations, the angular drill pipe plug valve is a high-strength manual ball valve that opens and closes rapidly by rotation. Typically installed in pairs at the top and bottom of the angular drill pipe, it can immediately close the plug valve when abnormally high-pressure formation fluid rushes into the drill string, forcibly cutting off the upward flow of fluid through the drill pipe's center borehole. This prevents a blowout from occurring in its initial stage, thus avoiding a direct ejection of high-pressure oil and gas from the wellhead angular drill pipe and the resulting accident. In daily operations, the lower plug valve can also be closed during tripping or connecting single sections to safely release pressure within the angular drill pipe, preventing mud splashing and platform contamination, and ensuring personnel safety. This type of valve has a relatively simple structure, mainly consisting of a valve body, valve stem, plug, and sealing ring. In practical applications, when the plug is aligned with the valve body channel, fluid flow is unobstructed; when the plug is perpendicular to the channel, fluid flow is blocked, and the valve closes.

[0003] As disclosed in CN113503142B, a angular drill pipe plug valve for offshore oilfield drilling includes a pipe body. The pipe body has a transverse groove that connects to the middle inner cavity. An outer sealing sleeve is movably fitted inside the transverse groove. An inner sealing rotating column is fitted inside the bearing of the outer sealing sleeve. The inner sealing rotating column has a central through hole located in the middle inner cavity of the pipe body. A linkage rotating rod is provided on one side of the transverse groove, and the linkage rotating rod can drive the inner sealing rotating column to rotate. Through the structural design of the transverse groove that connects to the middle inner groove in the pipe body and the outer sealing sleeve and inner sealing rotating column set in the transverse groove, the bearing is always used to bear pressure when controlling the opening or closing of the angular drill pipe plug valve, which makes it convenient for the operator to open or close the plug valve.

[0004] It can be seen that the structure and usage of the square drill pipe plug valve in the above technical solution are roughly similar to the existing technology. That is, the valve is opened and closed by rotating the valve stem. It relies solely on the sealing pair formed by a ball and two valve seats (inlet and outlet) to block the fluid. When a blowout occurs in the drill string, the high-pressure fluid rushes upward from the bottom of the drill string and directly impacts the downstream side of the valve ball. At this time, the pressure-assisted sealing effect exists, but all the sealing load is concentrated on the contact surface between the outlet valve seat and the ball. Once the sealing surface fails due to long-term wear, corrosion or slight deformation under high pressure impact, the entire valve will leak internally. There is a lack of redundant plug barrier. Furthermore, when performing the closing operation under high pressure conditions in the well, the operator will feel that the wrench is unusually heavy and it is difficult to quickly complete the opening and closing control. In particular, for drilling fluid containing solid particles, some particles will be squeezed into the tiny gap between the ball and the valve seat at the moment the valve ball rotates, forming a wedging effect, which further increases the rotation resistance, making it impossible to complete the valve control switching in a short time. Summary of the Invention

[0005] The purpose of this invention is to provide a plug valve for angular drill pipe used in offshore oilfield drilling. A plug fluid control structure is installed in each chamber between the dual-chamber valve body and the upper and lower end caps of the H-beam. An encoder detects the angle of the plug fluid control structure in real time, forming an axial dual-valve structure. When controlling the two plug fluid control structures, an electric dual-position synchronous drive structure controls the simultaneous operation of both structures under low-pressure blowout, thereby closing the internal channel of the drill string. Meanwhile, a hydraulic rotary drive structure, supplied by an external hydraulic pump station, controls the operation of the plug fluid control structure under high-pressure blowout, thus solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a square drill pipe plug valve for offshore oilfield drilling, comprising:

[0007] The dual-chamber valve body has an upper chamber and a lower chamber that are spaced apart along the axial direction. The two ends of the dual-chamber valve body are respectively bolted with an upper I-shaped end cap and a lower I-shaped end cap. The upper I-shaped end cap and the upper opening of the dual-chamber valve body form a closed upper mounting cavity, and the lower I-shaped end cap and the lower opening of the dual-chamber valve body form a closed lower mounting cavity.

[0008] Two stopcock liquid control structures are installed in the upper and lower mounting cavities respectively. Two encoders are installed on one outer wall of the dual-cavity valve body. The encoders are used to detect the rotation angle of the stopcock liquid control structure in real time and output the angle signal.

[0009] A straight-mouth side shell is installed on the outer wall of the other side of the dual-chamber valve body. A support plate is fixed on the outer wall of the straight-mouth side shell away from the dual-chamber valve body. Two hydraulic rotary drive structures are installed on the outer wall of one side of the support plate in the axial direction. The power output end of the hydraulic rotary drive structure is connected to one of the rotary valve control structures for transmission. It is used to output torque under high pressure differential conditions to drive the corresponding rotary valve control structure to rotate against the friction generated by the high pressure differential.

[0010] The electric dual-position synchronous drive structure is located on one side of the outer wall of the support plate and installed between two hydraulic rotary drive structures. The power output end of the electric dual-position synchronous drive structure is simultaneously connected to the two rotary valve control structures for driving the two rotary valve control structures to rotate synchronously under low pressure differential conditions.

[0011] Preferably, an outer shield is bolted to the outer edge of the straight-mouth side shell away from the dual-chamber valve body. The outer shield is used to wrap and protect the hydraulic rotary drive structure and the electric dual-position synchronous drive structure. Two openings are provided on one side of the outer wall of the outer shield. Liquid injection cleaning structures are provided at both the upper and lower positions of the dual-chamber valve body.

[0012] Preferably, the rotary valve liquid control structure in the upper mounting cavity includes a first plug, a second plug, a valve ball body, and a long shaft. The first plug and the second plug are respectively installed at the lower end of the upper end cap of the H-shaped valve and the upper end of the double-chamber valve body. The valve ball body is rotatably installed between the first plug and the second plug, and a guide hole is provided inside the valve ball body. The long shaft is rotatably installed on one side inside the double-chamber valve body, and one end of the long shaft extends through to the outside of the straight-mouth side shell and is connected to the hydraulic rotary drive structure and the electric dual-position synchronous drive structure. The other end of the long shaft is engaged with one side outer wall of the valve ball body. A short shaft is fixed on the other side outer wall of the valve ball body, and one end of the short shaft is connected to the encoder.

[0013] Preferably, at least one sealing ring is embedded on the inner wall of the first and second plugs, the sealing ring abuts against the outer wall of the valve ball body, and the top and bottom ends of the valve ball body are provided with recesses that gradually extend towards the center.

[0014] Preferably, the electric dual-position synchronous drive structure includes an end plate fixed between two hydraulic rotary drive structures, a motor mounted on the outer wall of the end plate near the support plate, and a pair of driven gear shafts rotatably mounted on the outer wall of the other side of the end plate via bearings. A sprocket reduction transmission structure for power transmission is provided between the ends of the driven gear shafts and the long shaft. A drive gear column is fixed on the output shaft of the motor, and the drive gear column meshes with one of the driven gear shafts.

[0015] Preferably, the sprocket reduction transmission structure includes a driving sprocket fixed on the end of the driven gear shaft and a reduction sprocket fixed on the end of the long shaft. A transmission chain connects the reduction sprocket and the driving sprocket. At least one convex key extending in the axial direction is integrally formed on the outer wall of the long shaft.

[0016] Preferably, the hydraulic rotary drive structure includes an annular end seat fixed to one side of the outer wall of the support plate, a hollow sealing cover bolted to the outer wall of the open end of the annular end seat, and a hollow rotating shaft with an inner groove rotatably mounted at the central axis position inside the annular end seat and the hollow sealing cover via ball bearings. The hollow rotating shaft with an inner groove and the long shaft are fitted by a convex key. An annular oil cavity is provided between the annular end seat and the hollow sealing cover. A connecting ring is fixed on the outer wall of the hollow rotating shaft with an inner groove at the annular oil cavity, and an ear plate is fixed on one side of the outer wall of the connecting ring. The ear plate and the annular oil cavity are slidably fitted. A dynamic seal is installed at one end inside the hollow sealing cover, which is coaxial with the hollow rotating shaft with the inner groove.

[0017] Preferably, a main stop and a secondary stop are fixed on one inner wall of the annular end seat at intervals. A first chamber is provided between the main stop and the ear plate, and a second chamber is provided between the secondary stop and the ear plate. A liquid inlet connector one and a liquid inlet connector two are installed on one outer wall of the hollow sealing cover. The liquid inlet connector one and the liquid inlet connector two are used to send hydraulic oil into the first chamber and the second chamber, respectively.

[0018] Preferably, the hollow sealing cover has a stepped portion on the outer wall of the side away from the annular end seat, and the end plate is fixedly installed between the stepped portions of the two hollow sealing covers.

[0019] Preferably, the liquid injection cleaning structure includes at least one internally threaded liquid inlet oblique hole extending into the interior of the dual-chamber valve body and an externally threaded plug threaded in the internally threaded liquid inlet oblique hole. The externally threaded plug is removed from the internally threaded liquid inlet oblique hole and the cleaning medium is injected into the dual-chamber valve body through the internally threaded liquid inlet oblique hole.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: The offshore oilfield drilling rig adopts a square drill pipe plug valve with a structure that is equipped with a dual-chamber valve body, a plug fluid control structure, an encoder, a hydraulic rotary drive structure, and an electric dual-position synchronous drive structure. A plug fluid control structure is set in each chamber between the dual-chamber valve body and the upper and lower end caps of the H-beam. The encoder detects the angle of the plug fluid control structure in real time, forming an axial dual-valve structure. When controlling the two plug fluid control structures, the electric dual-position synchronous drive structure controls the two plug fluid control structures to operate simultaneously under low-pressure blowout conditions, thereby closing the internal channel of the drill string. The hydraulic rotary drive structure, supplied by an external hydraulic pump station, controls the operation of the plug fluid control structure under high-pressure blowout conditions. This solves the problems of limited high-pressure blocking effect and difficulty in switching under high pressure differentials in the traditional single-valve ball plug valve in the offshore high-pressure drilling environment.

[0021] By setting two independent plug control structures in the axial direction of the dual-chamber valve body, two redundant sealing barriers are formed in series. Even if the lower plug control structure fails to seal due to high pressure impact or media erosion during the closing process, the upper plug control structure can still act as a backup sealing barrier to close quickly, achieving secondary cutoff of the well blowout fluid. This reduces the risk of single-point failure of traditional single valve ball. At the same time, the design of two independent chambers also allows each plug control structure to have a relatively independent operating environment, reducing the impact of pressure fluctuations on the double sealing surfaces in a single chamber. This achieves load sharing and risk isolation under high pressure differential conditions. In addition, since the two plugs are physically separated, the wear of the sealing pair between the valve ball and the valve seat can also be dispersed, extending the service life of the entire plug valve.

[0022] Secondly, under conventional drilling or low-pressure blowout conditions, an electric dual-position synchronous drive structure is adopted. In this state, the electric dual-position synchronous drive structure simultaneously drives the upper and lower plug fluid control structures to rotate 90°. Since the pressure difference inside and outside the drill string is small at this time, the lateral thrust on the valve ball is limited, and the required switching torque is within the capacity range of the electric dual-position synchronous drive structure. It can close the two valves at the fastest speed, realize the instantaneous cutoff of the internal channel of the drill string, and effectively prevent the further deterioration of the low-pressure blowout situation. However, when encountering a high-pressure blowout, a huge pressure difference is formed inside and outside the drill string, causing the plug fluid control structure to be difficult to rotate due to the huge unidirectional thrust. The hydraulic rotary drive structure relies on an external independent hydraulic pump station to output a huge rotary torque through hydraulic cylinders or hydraulic motors. This overcomes the huge static and dynamic friction forces generated between the valve ball and valve seat under high pressure difference, ensuring that the valve can be forcibly closed or opened, thereby avoiding well control failure due to insufficient operating force. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0024] Figure 1 This is a schematic diagram of the main structure of the present invention;

[0025] Figure 2 This is a side view of the structure of the present invention;

[0026] Figure 3 yes Figure 2 Sectional view at point AA;

[0027] Figure 4 yes Figure 2 A three-dimensional structural cross-sectional view of point AA;

[0028] Figure 5 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 1 ;

[0029] Figure 6 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 2 ;

[0030] Figure 7 This is a three-dimensional structural diagram of the outer shield and the straight-mouth side shell of the present invention in a separated state;

[0031] Figure 8 This is a schematic diagram of the three-dimensional cross-sectional structure of the dual-chamber valve body of the present invention. Figure 1 ;

[0032] Figure 9 This is a three-dimensional cross-sectional view of the valve liquid control structure of the present invention;

[0033] Figure 10 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 3 ;

[0034] Figure 11 This is a schematic diagram of the three-dimensional cross-sectional structure of the dual-chamber valve body of the present invention. Figure 2 ;

[0035] Figure 12 This is a three-dimensional exploded structure diagram of the present invention;

[0036] Figure 13 This is a three-dimensional structural diagram of the hydraulic rotary drive structure of the present invention. Figure 1 ;

[0037] Figure 14 This is a three-dimensional structural diagram of the hydraulic rotary drive structure of the present invention. Figure 2 ;

[0038] Figure 15This is a three-dimensional structural diagram of the electric dual-position synchronous drive structure of the present invention. Figure 1 ;

[0039] Figure 16 This is a three-dimensional structural diagram of the electric dual-position synchronous drive structure of the present invention. Figure 2 .

[0040] In the diagram: 1. Dual-chamber valve body; 2. Upper end cap of the I-beam; 3. Lower end cap of the I-beam; 4. Plug control structure; 41. Plug 1; 411. Sealing ring; 42. Plug 2; 43. Valve ball body; 431. Recess; 44. Guide hole; 45. Long shaft; 46. Short shaft; 47. Raised key; 5. Straight-mouth side shell; 51. Support plate; 6. Encoder; 7. Hydraulic rotary drive structure; 71. Annular end seat; 72. Hollow sealing cover; 73. Annular oil chamber; 74. Main stop; 75. Secondary stop; 76. Inner groove hollow 77. Rotary shaft; 78. Dynamic seal; 79. Connecting ring; 70. Ear plate; 710. First chamber; 711. Second chamber; 712. Liquid inlet connector one; 713. Liquid inlet connector two; 8. Electric double-position synchronous drive structure; 81. End plate; 82. Motor; 83. Driving gear column; 84. Driven gear shaft; 85. Reduction sprocket; 86. Transmission chain; 87. Driving sprocket; 9. Outer shield; 91. Opening; 10. Liquid injection and cleaning structure; 1001. Internal threaded liquid inlet oblique hole; 1002. External threaded plug. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0042] Example 1, by Figures 1 to 7 The present invention includes a dual-chamber valve body 1, which has an upper chamber and a lower chamber spaced apart along the axial direction. An I-shaped upper end cap 2 and an I-shaped lower end cap 3 are respectively bolted to both ends of the dual-chamber valve body 1. The I-shaped upper end cap 2 and the upper opening of the dual-chamber valve body 1 form a closed upper mounting cavity, and the I-shaped lower end cap 3 and the lower opening of the dual-chamber valve body 1 form a closed lower mounting cavity.

[0043] Two stopcock liquid control structures 4 are installed in the upper and lower mounting cavities respectively. Two encoders 6 are installed on one outer wall of the dual-cavity valve body 1. The encoders 6 are used to detect the rotation angle of the stopcock liquid control structure 4 in real time and output the angle signal.

[0044] A straight-mouth side shell 5 is installed on the outer wall of the other side of the double-chamber valve body 1. A support plate 51 is fixed on the outer wall of the straight-mouth side shell 5 away from the double-chamber valve body 1. Two hydraulic rotary drive structures 7 are installed on the outer wall of the support plate 51 along the axial direction. The power output end of the hydraulic rotary drive structure 7 is connected to one of the rotary valve control structures 4 for transmission. It is used to output torque under high pressure differential conditions to drive the corresponding rotary valve control structure 4 to rotate against the friction generated by the high pressure differential.

[0045] The electric dual-position synchronous drive structure 8 is located on one side of the outer wall of the support plate 51 and installed between two hydraulic rotary drive structures 7. The power output end of the electric dual-position synchronous drive structure 8 is simultaneously connected to two rotary valve liquid control structures 4 for transmission, and is used to drive the two rotary valve liquid control structures 4 to rotate synchronously under low pressure differential conditions.

[0046] The dual-chamber valve body 1 places two independent stopcock liquid control structures 4 in the interconnected chambers, avoiding the failure of a single point of failure on the entire sealing system. That is, when the stopcock liquid control structure 4 in one chamber fails due to high pressure erosion or foreign object jamming, the other chamber remains intact, forming a second line of sealing defense.

[0047] The upper end cap 2 of the I-beam is responsible for connecting the double-chamber valve body 1 to the faucet or top drive, while the lower end cap 3 of the I-beam connects the valve body to the square drill rod below. The upper end cap 2 and the lower end cap 3 of the I-beam can also be connected to the end of the square drill rod through a rotary joint. When the square drill rod rotates and drills, a huge torque is transmitted to the valve body through the end cap.

[0048] When a blowout occurs and the valve is shut off, the enormous thrust generated by the internal pressure acts on the end cap. The I-shaped structure, through its reasonable force distribution, evenly transmits these loads to the entire valve body, avoiding localized failure.

[0049] Example 2, based on Example 1, is... Figure 8 , Figure 9 and Figure 10The upper mounting cavity includes a stopcock control structure 4 comprising a first plug 41, a second plug 42, a valve ball body 43, and a long shaft 45. The first plug 41 and the second plug 42 are respectively installed at the lower end of the upper end cap 2 and the upper end of the double-chamber valve body 1. The valve ball body 43 is rotatably mounted between the first plug 41 and the second plug 42, and a guide hole 44 is provided inside the valve ball body 43. The long shaft 45 is rotatably mounted on one side inside the double-chamber valve body 1, with one end of the long shaft 45 penetrating to the outside of the straight-mouth side shell 5 and connected to the hydraulic rotary drive structure 7 and the electric dual-position synchronous drive structure 8. The other end of the long shaft 45 is engaged with one side outer wall of the valve ball body 43, and a short shaft 46 is fixed on the other side outer wall of the valve ball body 43. One end of the short shaft 46 is connected to the encoder 6. Whether it is the rotational power generated by the electric dual-position synchronous drive structure 8 or the rotational power generated by the hydraulic rotary drive structure 7, it will ultimately act on the long shaft 45 of the plug control structure 4. The long shaft 45 drives the valve ball body 43 to rotate 90 degrees, realizing the connection or blockage with the dual-chamber valve body 1 and the drill string center channel. During this process, the short shaft 46 follows the long shaft 45 in the same state, and the encoder 6 can identify the rotational position of the valve ball body 43. Thus, when executing the switching command, the drilling instrument control console can accurately control the start and stop of the hydraulic rotary drive structure 7 and the electric dual-position synchronous drive structure 8 according to the real-time feedback value of the encoder 6, ensuring that the valve action is in place without overshoot.

[0050] At least one sealing ring 411 is embedded on the inner wall of plug 1 41 and plug 2 42. The sealing ring 411 abuts against the outer wall of valve ball body 43. Since there are several sealing rings 411 between the inner wall of plug 1 41 and the outer wall of valve ball body 43, a reliable seal can be formed, reducing the risk of fluid leakage.

[0051] The top and bottom of the valve ball body 43 are provided with recesses 431 that gradually extend towards the center. The upper and lower ends of the valve ball body 43 are both recessed with recesses 431. At this time, the recesses 431 are in contact with the fluid medium. When the valve ball body 43 rotates 90 degrees, the axis of the guide hole 44 coincides with the double-chamber valve body 1. The recesses 431 can also form a clearance area with the inner wall of the double-chamber valve body 1, forming more medium flow channels.

[0052] An outer shield 9 is bolted to the outer wall edge of the straight-mouth side shell 5 away from the double-chamber valve body 1. The outer shield 9 is used to wrap and protect the hydraulic rotary drive structure 7 and the electric dual-position synchronous drive structure 8. Two openings 91 are provided on one side of the outer wall of the outer shield 9.

[0053] The dual-chamber valve body 1 is provided with a liquid injection cleaning structure 10 at both the upper and lower positions. The liquid injection cleaning structure 10 includes at least one internal threaded liquid inlet oblique hole 1001 that penetrates into the interior of the dual-chamber valve body 1 and an external threaded plug 1002 that is threaded in the internal threaded liquid inlet oblique hole 1001. The external threaded plug 1002 is removed from the internal threaded liquid inlet oblique hole 1001 and a cleaning medium is injected into the dual-chamber valve body 1 through the internal threaded liquid inlet oblique hole 1001.

[0054] During routine maintenance of the valve body, the operator can unscrew the external threaded plug 1002 from the internal threaded inlet oblique hole 1001. At this time, the extended axes of two adjacent internal threaded inlet oblique holes 1001 on the same circumferential trajectory line intersect. The operator can then use a spray gun to clean the inside of the dual-chamber valve body 1 and the plug control structure 4 from the internal threaded inlet oblique hole 1001. This allows for directional flushing and lubrication of the valve cavity without disassembling the valve, reducing the risk of jamming caused by dirt accumulation and extending the service life of the valve.

[0055] Example 3, based on Example 2, by Figure 15 and Figure 16 The electric dual-position synchronous drive structure 8 includes an end plate 81 fixed between two hydraulic rotary drive structures 7, a motor 82 mounted on the outer wall of the end plate 81 near the support plate 51, and a pair of driven gear shafts 84 rotatably mounted on the outer wall of the other side of the end plate 81 via bearings. A sprocket reduction transmission structure for power transmission is provided between the end of the driven gear shaft 84 and the end of the long shaft 45. A drive gear 83 is fixed on the output shaft of the motor 82, and the drive gear 83 meshes with one of the driven gear shafts 84.

[0056] The sprocket reduction transmission structure includes a driving sprocket 87 fixed on the end of the driven gear shaft 84 and a reduction sprocket 85 fixed on the end of the long shaft 45. A transmission chain 86 connects the reduction sprocket 85 and the driving sprocket 87. At least one convex key 47 extending in the axial direction is integrally formed on the outer wall of the long shaft 45. The long shaft 45 and the hollow rotating shaft 76 with the inner groove are keyed together by the convex key 47 to ensure that the long shaft 45, the valve ball body 43, and the short shaft 46 can rotate together with the hollow rotating shaft 76 with the inner groove.

[0057] When the electric dual-position synchronous drive structure 8 controls the operation of the two rotary valve liquid control structures 4, the output shaft of the motor 82 drives the active gear column 83 to rotate. The active gear column 83 drives the two driven gear shafts 84 in the meshing state to rotate synchronously in opposite directions. Then, the driven gear shafts 84 use the active sprocket 87 and the transmission chain 86 to drive the reduction sprocket 85 and the long shaft 45 to rotate. Thus, in low-pressure overflow or normal operation, the upper and lower valve ball bodies 43 are driven to move synchronously to achieve the cut-off control of the drill string channel.

[0058] Because the electric dual-position synchronous drive structure 8 is mechanically synchronized, the rotation of the two valve ball bodies 43 always remains consistent. The encoder 6 monitors the angle of the two valve balls in real time and feeds it back to the drilling instrument control console to form a closed-loop control, ensuring that the two reach the designated position in precise synchronization.

[0059] Example 4, based on Example 3, by Figure 11 , Figure 12 , Figure 13 and Figure 14 The hydraulic rotary drive structure 7 includes an annular end seat 71 fixed to the outer wall of one side of the support plate 51, a hollow sealing cover 72 bolted to the outer wall of the open end of the annular end seat 71, and a hollow rotating shaft 76 with an inner groove rotatably mounted at the central axis position inside the annular end seat 71 and the hollow sealing cover 72 via ball bearings. The hollow rotating shaft 76 with the inner groove rotatable shaft 45 is engaged with the long shaft 45 by a convex key 47. An annular oil cavity 73 is provided between the annular end seat 71 and the hollow sealing cover 72. A connecting ring 78 is fixed on the outer wall of the hollow rotating shaft 76 in the inner groove of the annular oil cavity 73, and an ear plate 79 is fixed on one side of the outer wall of the connecting ring 78. The ear plate 79 and the annular oil cavity 73 are slidably engaged. A dynamic seal 77 is installed at one end inside the hollow sealing cover 72, which is coaxial with the hollow rotating shaft 76 in the inner groove. A stepped portion is provided on the outer wall of the hollow sealing cover 72 away from the annular end seat 71. An end plate 81 is fixedly installed between the stepped portions of the two hollow sealing covers 72.

[0060] A main stop 74 and a secondary stop 75 are fixed on one inner wall of the annular end seat 71 at intervals. A first chamber 710 is provided between the main stop 74 and the ear plate 79, and a second chamber 711 is provided between the secondary stop 75 and the ear plate 79. A liquid inlet connector 1 712 and a liquid inlet connector 2 713 are installed on one outer wall of the hollow sealing cover 72. The liquid inlet connector 1 712 and the liquid inlet connector 2 713 are used to send hydraulic oil into the first chamber 710 and the second chamber 711, respectively.

[0061] When the hydraulic rotary drive structure 7 controls the corresponding position of the valve control structure 4 to perform the action, taking the inlet connector 712 to supply hydraulic oil as an example, the external hydraulic pump station supplies hydraulic oil through the inlet connector 712 into the first chamber 710 between the main stop 74 and the ear plate 79. The hydraulic energy is converted into mechanical energy, driving the connecting ring 78, the hollow rotating shaft 76 with the inner groove and the long shaft 45 to rotate. During this process, the annular end seat 71, the hollow sealing cover 72 and the dynamic seal 77 form a sealed annular oil chamber 73 to prevent hydraulic oil leakage until the valve ball body 43 is driven to rotate ninety degrees, overcoming the huge static friction force and medium wedging force generated between the valve body under high pressure differential, ensuring that the valve can still be forcibly closed or opened under extreme working conditions.

[0062] When the rotary valve control structure 4 needs to be rotated and reset, hydraulic oil can also be supplied to the inlet connector 713, so that the hydraulic oil flows at the connecting ring 78 between the auxiliary stop 75 and the ear plate 79, thereby changing the direction of action of the rotary valve control structure 4.

[0063] Working principle: Under normal drilling or circulation operation conditions of the angular drill pipe, the two rotary valve control structures 4 located in the upper and lower independent chambers of the dual-chamber valve body 1 are both in the fully open position. The through hole at the center of the valve ball is completely aligned with the drill string axis, allowing the drilling fluid to pass through with minimal flow resistance. The electric dual-position synchronous drive structure 8 inside the outer shield 9 is in a standby but not engaged state, while the hydraulic rotary drive structure 7 remains connected to the external hydraulic pump station. The hydraulic system is in a low-pressure standby or pressure-holding state. The encoder 6 installed on the rotary valve control structure 4 continuously detects the actual angle of the valve ball, and the position signal it acquires is fed back to the drilling system in real time. The instrument panel allows operators to view the status of the drill string's internal channels. When routine single-strut or column connection operations are required, the operator operates a valve closing command on the drilling instrument control panel. This command is sent to the electric dual-position synchronous drive structure 8, which controls the two rotary valve control structures 4 to rotate 90 degrees together. During the rotation, the encoder 6 transmits angle data in real time. Based on this data, the drilling instrument control panel precisely controls the start and stop of the electric dual-position synchronous drive structure 8 to ensure that the rotary valve control structures 4 accurately reach the closed position without overshoot or undershoot. Once the closed position is confirmed by the encoder 6, the uncoupling operation can be performed without risk. After the new drill string is connected, the electric dual-position synchronous drive structure 8 is used to precisely open the plug valve to the fully open state, restoring the offshore oilfield drilling and production cycle. In the event of a sudden well kick, i.e., formation fluid begins to flow into the drill string, if the drilling instrument control panel determines it is a low-pressure overflow, the electric dual-position synchronous drive structure 8 will simultaneously drive the upper and lower plug fluid control structures 4 to close synchronously at the fastest speed. Both encoders 6 will return a 90-degree closed position signal, indicating that the two redundant seals have taken effect and the internal passage of the drill string has been reliably cut off. If the blowout pressure is extremely high, causing a huge pressure difference between the inside and outside of the drill string, the electric dual-position synchronous drive structure 8 may stall due to insufficient torque, requiring external intervention. High-pressure hydraulic oil supplied by the hydraulic pump station enters the hydraulic rotary drive structure 7, which generates a huge torque several times that of the motor and acts on the plug control structure 4. This overcomes the huge static friction and medium wedging force generated between the valve ball and the dual-chamber valve body 1 under high pressure differential, forcibly driving the valve ball to rotate to the closed position. After successful well shut-in, the valve can be reliably sealed by the precise angle fed back by the encoder 6. When it is necessary to open the plug valve to restore circulation, if there is still a large pressure differential on both sides of the plug control structure 4, the hydraulic rotary drive structure 7 can be used for pressurized opening to avoid damage to the sealing surface caused by forced operation.

[0064] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A rotary valve for angular drill pipe used in offshore oilfield drilling, characterized in that, include: The double-chamber valve body (1) has an upper chamber and a lower chamber that are spaced apart along the axial direction. The two ends of the double-chamber valve body (1) are respectively bolted with an upper end cap (2) and a lower end cap (3). The upper end cap (2) and the upper opening of the double-chamber valve body (1) form a closed upper mounting cavity, and the lower end cap (3) and the lower opening of the double-chamber valve body (1) form a closed lower mounting cavity. Two stopcock liquid control structures (4) are installed in the upper and lower mounting cavities respectively. Two encoders (6) are installed on one side of the outer wall of the dual-cavity valve body (1). The encoders (6) are used to detect the rotation angle of the stopcock liquid control structure (4) in real time and output the angle signal. A straight-mouth side shell (5) is installed on the outer wall of the other side of the double-chamber valve body (1), and a support plate (51) is fixed on the outer wall of the straight-mouth side shell (5) away from the double-chamber valve body (1). Two hydraulic rotary drive structures (7) are installed on the outer wall of the support plate (51) along the axial direction. The power output end of the hydraulic rotary drive structure (7) is connected to one of the rotary valve control structures (4) for transmission. It is used to output torque under high pressure differential conditions to drive the corresponding rotary valve control structure (4) to rotate against the friction generated by the high pressure differential. The electric dual-position synchronous drive structure (8) is located on one side of the outer wall of the support plate (51) and installed between two hydraulic rotary drive structures (7). The power output end of the electric dual-position synchronous drive structure (8) is simultaneously connected to two rotary valve liquid control structures (4) for driving the two rotary valve liquid control structures (4) to rotate synchronously under low pressure differential conditions.

2. The rotary valve for offshore oilfield drilling using square drill pipe according to claim 1, characterized in that, An outer shield (9) is bolted to the outer edge of the straight-mouth side shell (5) away from the double-chamber valve body (1). The outer shield (9) is used to wrap and protect the hydraulic rotary drive structure (7) and the electric dual-position synchronous drive structure (8). Two openings (91) are provided on one side of the outer wall of the outer shield (9). Liquid injection cleaning structures (10) are provided at both the upper and lower positions of the double-chamber valve body (1).

3. A rotary valve for offshore oilfield drilling using square drill pipe according to claim 1, characterized in that, The plug control structure (4) in the upper mounting cavity includes plug one (41), plug two (42), valve ball body (43) and long shaft (45). Plug one (41) and plug two (42) are respectively installed at the lower end of the upper end cap (2) of the H-shaped valve and the upper end of the double-chamber valve body (1). The valve ball body (43) is rotatably installed between plug one (41) and plug two (42), and a guide hole (44) is provided inside the valve ball body (43). The long shaft (45) is rotatably installed on one side inside the double-chamber valve body (1), and one end of the long shaft (45) extends through to the outside of the straight-mouth side shell (5) and is connected to the hydraulic rotary drive structure (7) and the electric dual-position synchronous drive structure (8). The other end of the long shaft (45) is engaged with the outer wall of one side of the valve ball body (43). A short shaft (46) is fixed on the outer wall of the other side of the valve ball body (43). One end of the short shaft (46) is connected to the encoder (6).

4. A rotary valve for offshore oilfield drilling using square drill pipe according to claim 3, characterized in that, At least one sealing ring (411) is embedded on the inner wall of the first plug (41) and the second plug (42). The sealing ring (411) abuts against the outer wall of the valve ball body (43). The top and bottom of the valve ball body (43) are provided with recesses (431) that gradually extend towards the center.

5. A rotary valve for offshore oilfield drilling using square drill pipe according to claim 3, characterized in that, The electric dual-position synchronous drive structure (8) includes an end plate (81) fixed between two hydraulic rotary drive structures (7), a motor (82) mounted on the outer wall of the end plate (81) near the support plate (51), and a pair of driven gear shafts (84) rotatably mounted on the outer wall of the other side of the end plate (81) via bearings. A sprocket reduction transmission structure for power transmission is provided between the end of the driven gear shaft (84) and the end of the long shaft (45). An active gear column (83) is fixed on the output shaft of the motor (82), and the active gear column (83) meshes with one of the driven gear shafts (84).

6. A rotary valve for offshore oilfield drilling using square drill pipe according to claim 5, characterized in that, The sprocket reduction transmission structure includes a drive sprocket (87) fixed on the end of the driven gear shaft (84) and a reduction sprocket (85) fixed on the end of the long shaft (45). A transmission chain (86) connects the reduction sprocket (85) and the drive sprocket (87). At least one convex key (47) extending in the axial direction is integrally formed on the outer wall of the long shaft (45).

7. A rotary valve for offshore oilfield drilling using square drill pipe according to claim 6, characterized in that, The hydraulic rotary drive structure (7) includes an annular end seat (71) fixed to the outer wall of one side of the support plate (51), a hollow sealing cover (72) installed on the outer wall of the opening end of the annular end seat (71) with a sealing bolt, and an inner groove hollow rotating shaft (76) rotatably installed at the central axis position inside the annular end seat (71) and the hollow sealing cover (72) by ball bearings. The inner groove hollow rotating shaft (76) and the long shaft (45) are connected by a convex key (47). An annular oil cavity (73) is provided between the annular end seat (71) and the hollow sealing cover (72). A connecting ring (78) is fixed on the outer wall of the inner groove hollow rotating shaft (76) at the annular oil cavity (73), and an ear plate (79) is fixed on one side of the outer wall of the connecting ring (78). The ear plate (79) and the annular oil cavity (73) are slidably connected. A dynamic seal (77) is installed at one end inside the hollow sealing cover (72) and is coaxial with the inner groove hollow rotating shaft (76).

8. A rotary valve for offshore oilfield drilling using square drill pipe according to claim 7, characterized in that, The inner wall of one side of the annular end seat (71) is fixed with a main stop (74) and a secondary stop (75) distributed at intervals. A first chamber (710) is provided between the main stop (74) and the ear plate (79), and a second chamber (711) is provided between the secondary stop (75) and the ear plate (79). A liquid inlet connector one (712) and a liquid inlet connector two (713) are installed on the outer wall of one side of the hollow sealing cover (72). The liquid inlet connector one (712) and the liquid inlet connector two (713) are used to send hydraulic oil into the first chamber (710) and the second chamber (711), respectively.

9. A rotary valve for offshore oilfield drilling using square drill pipe according to claim 7, characterized in that, The hollow sealing cover (72) has a stepped portion on the outer wall of the side away from the annular end seat (71), and the end plate (81) is fixedly installed between the stepped portions of the two hollow sealing covers (72).

10. A rotary valve for offshore oilfield drilling using square drill pipe according to claim 2, characterized in that, The liquid injection cleaning structure (10) includes at least one internal threaded liquid inlet oblique hole (1001) penetrating into the interior of the dual-chamber valve body (1) and an external threaded plug (1002) threaded in the internal threaded liquid inlet oblique hole (1001). The external threaded plug (1002) is removed from the internal threaded liquid inlet oblique hole (1001) and the cleaning medium is injected into the dual-chamber valve body (1) through the internal threaded liquid inlet oblique hole (1001).

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