Electro-hydraulic combined type underground power coring system

Abstract

The invention discloses an electro-hydraulic combined type underground power coring system which comprises a coring mechanism, a connecting mechanism and a control mechanism. The coring mechanism comprises a drill column, a hydraulic driving device, a rotary driving device and a coring device. The coring device, the rotary driving device and the hydraulic driving device are stacked in the drill string. The hydraulic driving device is fixedly connected with the rotary driving device, and the rotary driving device is rotationally connected with the coring device. And the control mechanism is connected with the coring mechanism through the connecting mechanism. According to the electro-hydraulic combined type underground coring system, the working modes can be switched according to stratum conditions, and when a soft stratum is drilled, the coring device is pushed into the hydraulic driving device in a piston mode to operate; when a hard rock and other complex stratums are drilled, on the basis of hydraulic propulsion, the rotary driving device drives the coring device to rapidly rotate to cut the stratums, meanwhile, the control mechanism can adjust the rotating speed, the torque, the propulsion speed and other drilling parameters of the coring device in real time, and efficient, low-disturbance and high-quality coring is achieved.

Description

Technical Field

[0001] This application relates to the technical field of offshore drilling, and particularly to an electro-hydraulic compound downhole dynamic coring system. Background Art

[0002] In projects such as deep-sea geological core drilling and ocean science drilling, problems such as low drilling efficiency and poor core recovery rate often occur when encountering hard formations. Existing downhole motor drills mainly rely on drilling fluid for driving, converting hydraulic energy into rock-breaking power, such as turbine drills, positive displacement motor drills, and hydraulic hammer drills, etc. Their high rotational speed can improve drilling efficiency and core collection rate in complex formations. According to the combination method of downhole motor drills and wireline coring technology, they are divided into two types: hollow-type downhole motor drills and wireline coring type downhole motor drills. The hollow-type downhole motor drill integrates the downhole motor drill into the bottom hole assembly, and the wireline coring type downhole motor drill integrates the downhole motor drill into the conventional wireline coring drill. However, these drills generally lack functions such as sensor monitoring, umbilical cable communication, and precise motor speed regulation, making it difficult to achieve closed-loop control, with low automation and intelligence levels, and are prone to deviating from the optimal working conditions, resulting in increased vibration, wear, and even failures; and once the hollow-type drill fails or encounters a soft formation and needs to be switched to conventional wireline coring, it is necessary to trip out of the hole to replace the tool, which is time-consuming and laborious, reducing the operation efficiency. Summary of the Invention

[0003] This application aims to solve at least one of the technical problems existing in the prior art. This application provides an electro-hydraulic compound downhole dynamic coring system, which can change the working mode according to the actual formation conditions, and achieve efficient, low-disturbance, and high-quality coring.

[0004] The electro-hydraulic compound downhole dynamic coring system according to an embodiment of this application includes: A coring mechanism, which includes a drill string, a hydraulic driving device, a rotary driving device, and a coring device; A connecting mechanism, which is connected to the coring mechanism; A control mechanism, which is used to control the coring mechanism and the connecting mechanism; Among them, the coring device, the rotary driving device, and the hydraulic driving device are sequentially stacked along the axial direction of the drill string inside the drill string. The hydraulic driving device is used to drive the rotary driving device and the coring device to move, and the rotary driving device is used to drive the coring device to perform rotary cutting.

[0005] The electro-hydraulic compound downhole dynamic coring system according to an embodiment of this application has at least the following beneficial effects: The electro-hydraulic compound downhole coring system of the present application includes a coring mechanism, a connection mechanism, and a control mechanism. The coring mechanism includes a drill string, a hydraulic driving device, a rotary driving device, and a coring device. The drill string is a hollow cylinder, and the coring device, the rotary driving device, and the hydraulic driving device are stacked in sequence along the axial direction of the drill string from top to bottom inside the drill string. The output end of the hydraulic driving device is fixedly connected to the rotary driving device, and the hydraulic driving device pushes the rotary driving device and the coring device at the lower end of the rotary driving device to move integrally along the axial direction of the drill string through longitudinal expansion and contraction, so as to realize downhole piston-type coring. The rotary driving device is arranged at the lower end of the hydraulic driving device, and the output end of the rotary driving device is rotatably connected to the coring device. The rotary driving device provides rotational power for the coring device so that the coring device rotates to cut the formation and collect the core. The connection mechanism is connected to the upper end of the coring mechanism, and is used to lift and suspend the coring mechanism and provide functions such as hydraulic, electrical, and communication transmission. The control mechanism is connected to the coring mechanism through the connection mechanism, and the control mechanism is used to control the operating states of the hydraulic driving device and the rotary driving device.

[0006] The electro-hydraulic compound downhole coring system of the present application can switch the working mode according to the formation conditions. When drilling through soft formations, the coring mechanism only provides hydraulic power, and the control mechanism keeps the rotary driving device stationary. Only the hydraulic driving device is used to drive the coring device to longitudinally advance, and the hydraulic driving device piston-pushes the coring device to operate. When drilling through complex formations such as hard rocks, the coring mechanism provides both hydraulic power and electric rotary driving at the same time. On the basis of hydraulic propulsion, the rotary driving device drives the coring device to quickly rotate and cut the formation, and at the same time, the control mechanism can adjust drilling parameters such as the rotation speed, torque, and propulsion speed of the coring device in real time to achieve efficient and high-quality coring.

[0007] According to some embodiments of the present application, the hydraulic driving device includes a piston rod, a double-headed hydraulic cylinder, and a hydraulic cylinder sleeve. The double-headed hydraulic cylinder is telescopically arranged in the hydraulic cylinder sleeve. The hydraulic cylinder sleeve is fixedly connected to the rotary driving device, and the piston rod drives the rotary driving device and the coring device to move longitudinally along the borehole through the cooperation of the double-headed hydraulic cylinder and the hydraulic cylinder sleeve.

[0008] According to some embodiments of the present application, the coring mechanism further includes a locking device. The locking device is arranged in the drill string, and the locking device is used to fix the double-headed hydraulic cylinder in the drill string.

[0009] According to some embodiments of the present application, the double-headed hydraulic cylinder is provided with a first positioning member, and the hydraulic cylinder sleeve is provided with a second positioning member that cooperates with the first positioning member.

[0010] According to some embodiments of the present application, the coring device includes a core barrel and a core bit. The core barrel is fixedly connected to the core bit, and the core barrel is in transmission connection with the rotary drive device.

[0011] According to some embodiments of the present application, the coring mechanism further includes a cable head and an electro-hydraulic control module. The coring mechanism is connected to the connection mechanism through the cable head. The electro-hydraulic control module is used to control the rotary drive device and perform data communication with the control mechanism.

[0012] According to some embodiments of the present application, the connection mechanism includes a pulley assembly, an electro-hydraulic composite cable, and a winch. One end of the electro-hydraulic composite cable is wound and connected to the winch. The electro-hydraulic composite cable is suspended through the pulley assembly and the other end is connected to the cable head.

[0013] According to some embodiments of the present application, the electro-hydraulic composite cable includes a hydraulic pipeline, a power cable, and a communication cable. The electro-hydraulic composite cable is provided with a protective sleeve and a steel wire sleeve outside.

[0014] According to some embodiments of the present application, the piston rod is hollow, and an accommodation cavity is provided inside the piston rod. The hydraulic pipeline, the power cable, and the communication cable are accommodated in the accommodation cavity.

[0015] According to some embodiments of the present application, the control mechanism includes an operation console, an electric control box, a hydraulic station, a wireless receiver, and a wireless remote control box. The operation console is connected to the electric control box. The wireless remote control box communicates with the electric control box through the wireless receiver. The electric control box is respectively electrically connected to the hydraulic station and the connection mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following further describes the present application in conjunction with the drawings and embodiments, where: Figure 1 is a schematic structural diagram of an electro-hydraulic composite downhole power coring system according to an embodiment of the present application; Figure 2 is a schematic structural diagram of a coring mechanism according to an embodiment of the present application; Figure 3 is a schematic structural diagram of a state of an electro-hydraulic composite downhole power coring system according to an embodiment of the present application; Figure 4 is Figure 3 an enlarged schematic diagram of part I in Figure 5 is Figure 3 a schematic structural diagram of another state of Figure 6 is Figure 5 an enlarged schematic diagram of part II in Figure 7For Figure 3 Structural schematic diagram of another state of Figure 8 For Figure 7 Enlarged schematic diagram of part III in

[0017] Reference numerals: Core-taking mechanism 1; core-taking device 11; core-taking bit 111; core barrel 112; rotary drive device 12; hydraulic drive device 13; piston rod 131; double-headed hydraulic cylinder 132; hydraulic cylinder liner 133; locking device 14; cable head 15; electro-hydraulic control module 16; drill string 17; Connecting mechanism 2; pulley assembly 21; electro-hydraulic composite cable 22; winch 23; derrick 24; top drive 25; Control mechanism 3; control console 31; electric control box 32; hydraulic station 33; wireless receiver 34; wireless remote control box 35; Drilling ship 4; Seabed 5; Large drill stop drilling position 6; Core-taking bit stop drilling position 7. Detailed implementation manners

[0018] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application and should not be construed as a limitation to the present application.

[0019] In the description of the present application, it should be understood that if terms such as "center", "middle part", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it should not be construed as a limitation to the present application. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "plurality" is two or more.

[0020] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0021] The following will refer to Figures 1 to 8 Describe the electro-hydraulic compound downhole power coring system in the embodiments of the present application.

[0022] According to Figures 1 to 8 As shown, an electro-hydraulic compound downhole power coring system of an embodiment of the present application includes a coring mechanism 1, a connection mechanism 2, and a control mechanism 3. The coring mechanism 1 includes a drill string 17, a hydraulic driving device 13, a rotary driving device 12, and a coring device 11. The drill string 17 is a hollow cylinder, and the drill string 17 is used to accommodate each device. The coring device 11, the rotary driving device 12, and the hydraulic driving device 13 are stacked in sequence along the axial direction of the drill string 17 from top to bottom inside the drill string 17. The hydraulic driving device 13 is arranged at the upper part of the drill string 17, and the hydraulic driving device 13 is used to provide a longitudinal linear propulsion force. The rotary driving device 12 is arranged in the middle of the drill string 17, and the rotary driving device 12 is arranged at the lower end of the hydraulic driving device 13. The output end of the hydraulic driving device 13 is fixedly connected to the rotary driving device 12, and the output end of the rotary driving device 12 is rotatably connected to the coring device 11. The hydraulic driving device 13 and the rotary driving device 12 can move axially synchronously. The hydraulic driving device 13 pushes the rotary driving device 12 and the coring device 11 at the lower end of the rotary driving device 12 to move axially along the drill string 17 as a whole through longitudinal telescoping, so as to realize piston-type propulsion coring. The rotary driving device 12 provides rotational power for the coring device 11, so that the coring device 11 rotates to cut the formation and collect the core. The connection mechanism 2 is connected to the upper end of the coring mechanism 1, and is used to lift and suspend the coring mechanism 1 and support the suspended weight of the coring mechanism 1. The connection mechanism 2 also provides functions such as hydraulic, electrical, and communication transmission for the coring mechanism 1. The control mechanism 3 is connected to the coring mechanism 1 through the connection mechanism 2, and the control mechanism 3 is used to control the operating states of the hydraulic driving device 13 and the rotary driving device 12.

[0023] The electro-hydraulic compound downhole coring system of the present application can switch working modes according to formation conditions. When encountering soft formations, the coring mechanism 1 only provides hydraulic power, and the control mechanism 3 keeps the rotary drive device 12 stationary, and only the hydraulic drive device 13 is used to push the coring device 11 longitudinally. The piston of the hydraulic drive device 13 pushes the coring device 11 to operate; when encountering complex formations such as hard rocks, the coring mechanism 1 provides both hydraulic power and electric rotary drive. On the basis of hydraulic propulsion, the rotary drive device 12 drives the coring device 11 to rotate rapidly to cut the formation, and at the same time, the control mechanism 3 can adjust drilling parameters such as the rotation speed, torque, and propulsion speed of the coring device 11 in real time to achieve efficient and high-quality coring.

[0024] The electro-hydraulic compound downhole coring system of the present application modularly arranges the hydraulic drive device 13, the rotary drive device 12 and the coring device 11 in the drill string 17, with a compact structure and improved integration of the coring mechanism 1. Adopting the electro-hydraulic compound drive mode, it has good power redundancy and flexibility, can flexibly switch working modes according to the actual formation hardness, greatly improves the adaptability of the coring mechanism 1 under complex formation conditions at different depths, and realizes efficient, low-disturbance and high-quality core acquisition.

[0025] In some embodiments, the electro-hydraulic compound downhole power coring system of the present application is arranged on the drilling ship 4.

[0026] In some embodiments, the rotary drive device 12 is set as a permanent magnet motor; the permanent magnet motor can be set as a DC brushless motor.

[0027] According to Figure 2 、 4 As shown in 6 and 8, in an embodiment of the present application, the hydraulic drive device 13 includes a piston rod 131, a double-headed hydraulic cylinder 132 and a hydraulic cylinder liner 133. The double-headed hydraulic cylinder 132 is the main power output unit. The cylinder body of the double-headed hydraulic cylinder 132 is in a cylindrical structure and can be hydraulically controlled bidirectionally. The hydraulic cylinder liner 133 is arranged in the drill string 17, and the hydraulic cylinder liner 133 only moves axially along the drill string 17. The hydraulic cylinder liner 133 is used to push the rotary drive device 12 to move longitudinally. The double-headed hydraulic cylinder 132 is telescopically arranged inside the hydraulic cylinder liner 133. The hydraulic cylinder liner 133 realizes linear telescopic movement along the axis through the reciprocating movement of the internal piston. The lower end of the hydraulic cylinder liner 133 is fixedly connected to the rotary drive device 12, thereby driving the coring device 11 to move synchronously. The piston rod 131 passes through the central axis position of the double-headed hydraulic cylinder 132.

[0028] During operation, control mechanism 3 directs hydraulic oil into the interior of double-headed hydraulic cylinder 132 via connecting mechanism 2. The hydraulic oil then displaces the internal piston, causing piston rod 131 and double-headed hydraulic cylinder 132 to extend or retract axially as a whole. The displacement of hydraulic cylinder sleeve 133 relative to double-headed hydraulic cylinder 132 drives rotary drive unit 12 and coring device 11 to advance or retract as a whole, thereby moving coring device 11. The arrangement of piston rod 131, double-headed hydraulic cylinder 132, and hydraulic cylinder sleeve 133 provides hydraulic drive unit 13 with excellent stability and load-bearing capacity, making it suitable for deep well and high-thrust operations.

[0029] according to Figure 1 、 2 As shown in Figures , 4, 6 and 8, in one embodiment of the present application, the coring mechanism 1 also includes a locking device 14, which is fixedly connected to the double-headed hydraulic cylinder 132 and is fixedly arranged on the outer wall of the double-headed hydraulic cylinder 132. The locking device 14 is used to lock the double-headed hydraulic cylinder 132 during operation.

[0030] During operation, the coring mechanism 1 descends to the target depth, locking device 14 enters the locked state, and the double-headed hydraulic cylinder 132 is fixedly connected to the drill string 17, thereby securing the double-headed hydraulic cylinder 132 relative to the drill string 17. Once locked, the locking device 14 acts as a fulcrum, providing a supporting reaction force. The piston rod 131 moves within the double-headed hydraulic cylinder 132, driving the hydraulic cylinder sleeve 133 downward, thereby driving the rotating device and coring device 11. When the piston rod 131 reaches the end of its travel, the locking device 14 is unlocked, and the coring device 11 completes the collection of coring samples.

[0031] Locking device 14 provides the necessary counterforce support during the coring and recovery phases of coring device 11, ensuring stable operation of coring mechanism 1 and preventing the hydraulic drive unit 13 from moving with the lower structure or experiencing axial oscillation. This effectively improves the coring accuracy, stability, and safety of the electro-hydraulic downhole power coring system. Locking device 14 works in conjunction with hydraulic drive unit 13 to achieve automatic locking and arming, facilitating flexible switching between different operation phases and improving operational efficiency.

[0032] according to Figures 1 to 8As shown in the figure, in an embodiment of the present application, the double-headed hydraulic cylinder 132 is provided with a first positioning component, and the hydraulic cylinder liner 133 is provided with a second positioning component. The first positioning component and the second positioning component cooperate with each other to enable the hydraulic driving device 13 to perform only axial movement in the drill string 17. During operation, the double-headed hydraulic cylinder 132 and the hydraulic cylinder liner 133 move relative to each other, and the first positioning component or the second positioning component automatically engages in the corresponding position to achieve mating centering and guiding restriction. The double-headed hydraulic cylinder 132 can only perform axial movement within the hydraulic cylinder liner 133, and at the same time, the degrees of freedom of the double-headed hydraulic cylinder 132 in the radial or rotational direction are restricted, ensuring that the entire hydraulic driving device 13 always runs smoothly along a predetermined trajectory during operation. Through the setting of the first positioning component and the second positioning component, the axial guiding function of the double-headed hydraulic cylinder 132 is realized, preventing situations such as inclination and rotational error during the operation process, improving the structural stability and movement accuracy of the hydraulic driving device 13, reducing the interference risk between the devices in the drill string 17, extending the service life of the coring mechanism 1, and enhancing the system reliability and service life.

[0033] In some embodiments, the first positioning component of the double-headed hydraulic cylinder 132 is set as a positioning pin, and the second positioning component of the hydraulic cylinder liner 133 is set as a positioning pin groove. In some other embodiments, the first positioning component of the double-headed hydraulic cylinder 132 is set as a positioning pin groove, and the second positioning component of the hydraulic cylinder liner 133 is set as a positioning pin. In some other embodiments, the first positioning component of the double-headed hydraulic cylinder 132 is set as a guiding boss, and the second positioning component of the hydraulic cylinder liner 133 is set as a guide rail.

[0034] In some embodiments, according to Figure 2 、 4 As shown in 6 and 8, the coring device 11 includes a core barrel 112 and a core bit 111, and the core bit 111 is fixedly connected to the core barrel 112. The core bit 111 is arranged at the lowermost end of the coring mechanism 1, and the core bit 111 is used for cutting the formation and coring. The core barrel 112 is arranged at the upper end of the core bit 111, and the core barrel 112 is used for collecting and accommodating the core samples formed by cutting during the operation. The core barrel 112 and the core bit 111 are rigidly fixed to form an integrated coring device 11. The upper end of the core barrel 112 is rotatably connected to the drive shaft of the rotary drive device 12 to ensure that the torque generated by the rotary drive device 12 can be efficiently transmitted to the coring device 11 to achieve synchronous rotation.

[0035] During operation, when the control mechanism 3 starts the rotary drive device 12 and the output shaft rotates, the core barrel 112 rotates accordingly, thereby driving the core bit 111 fixed at the lower end of the core barrel 112 to rotate together. The core bit 111 cuts the formation to form a columnar core, and the core enters the inside of the core barrel 112 through the core bit 111 and accumulates gradually to complete coring.

[0036] In some embodiments, the coring bit 111 is set as a polycrystalline diamond compact bit, which helps to cut the formation.

[0037] According to Figure 1 、 2 As shown in FIGS. 4, 6 and 8, in an embodiment of the present application, the coring mechanism 1 further includes a cable head 15 and an electro-hydraulic control module 16. The cable head 15 is arranged at the top of the coring mechanism 1, and the coring mechanism 1 is connected to the connecting mechanism 2 through the cable head 15. The electro-hydraulic control module 16 is arranged inside the coring mechanism 1, and the electro-hydraulic control module 16 is used to perform the rotation control and data processing tasks of the coring mechanism 1.

[0038] In some embodiments, the electro-hydraulic control module 16 integrates a transformer, a motor drive module and a communication module. The transformer is used to convert the three-phase high-voltage alternating current of 2800VAC into direct current of 500V and direct current of 24V. Among them, the 500V direct current is used to drive the rotary drive device 12, and the 24V direct current is used to control the rotary drive device 12. The motor drive module is used to receive the instructions of the control mechanism 3, and adjusts and controls the rotary drive device 12 according to the set speed and torque output of the control mechanism 3, so as to realize the precise control of the coring device 11. The communication module is used to realize the communication between the coring mechanism 1 and the control mechanism 3, and feedback the downhole real-time collected data (speed, torque, current) to the control mechanism 3, so as to realize the data interaction and closed-loop control between the wellhead and the downhole. By arranging the electro-hydraulic control module 16 in the coring mechanism 1, the response time of the system can be shortened, the communication delay can be reduced, the precise speed regulation and stable control of the rotary drive device 12 can be realized, the cutting control ability for complex formations can be improved, the fluctuation during coring can be reduced, and at the same time, the real-time two-way communication and closed-loop control between the wellhead and the downhole are realized, the intelligent level of the system is enhanced, and better and higher-quality coring can be achieved.

[0039] In some embodiments, the electro-hydraulic control module 16 is specifically arranged at the lower end of the cable head 15.

[0040] According to Figure 1 、 3 、5 and 7, in an embodiment of the present application, the connecting mechanism 2 includes a pulley assembly 21, an electro-hydraulic composite cable 22 and a winch 23. The connecting mechanism 2 is used to connect the coring mechanism 1 and the control mechanism 3 and transmit energy and signals. The winch 23 is arranged on the ground, and the electro-hydraulic composite cable 22 is wound on the winch 23. The winch 23 is used to release and wind up the electro-hydraulic composite cable 22. One end of the electro-hydraulic composite cable 22 is wound and connected to the winch 23. After the electro-hydraulic composite cable 22 is led out from the winch 23, it passes through the pulley assembly 21, and the turning and guiding are realized through the pulley assembly 21. The other end of the electro-hydraulic composite cable 22 is connected to the cable head 15 of the coring mechanism 1 to realize the suspension of the coring mechanism 1.

[0041] During operation, the winch 23 slowly releases the electro-hydraulic composite cable 22, and the coring mechanism 1 is steadily lowered to the target position through the pulley assembly 21. After reaching the target position, the connecting mechanism 2 remains in a tensioned state, continuously supplying hydraulic oil, electricity, and communication signals to the coring mechanism 1. After the coring mechanism 1 completes coring, the winch 23 starts to reverse and wind up, and the electro-hydraulic composite cable 22 is gradually recovered, guiding the coring mechanism 1 to be lifted up through the pulley assembly 21. During the operation, the control mechanism 3 controls the speed of the winch 23 and the cable tension in real time to ensure the safe and stable operation of the system. The connecting mechanism 2 realizes the reliable suspension and lifting control of the coring mechanism 1 through the combination of the pulley assembly 21, the electro-hydraulic composite cable 22, and the winch 23, and also takes into account the functions of power and signal transmission.

[0042] In some embodiments, the winch 23 is specifically arranged on the deck of the drilling ship 4. The connecting mechanism 2 further includes a derrick 24 and a top drive 25. The derrick 24 is arranged on the deck of the drilling ship 4, and the pulley assembly 21 is arranged at the top of the derrick 24. The electro-hydraulic composite cable 22 is connected to the coring mechanism 1 through the top drive 25 under the guidance of the pulley assembly 21.

[0043] According to Figures 1 to 8 As shown, in an embodiment of the present application, the electro-hydraulic composite cable 22 includes a hydraulic pipeline, a power cable, and a communication cable. The electro-hydraulic composite cable 22 has multiple functions of mechanical suspension, hydraulic transmission, power supply, and communication data transmission. The hydraulic pipeline is used to transport hydraulic oil to the coring mechanism 1, the power cable is used to transport high-voltage direct current to the electro-hydraulic control module 16, and the communication cable is used to realize high-speed data transmission between the control mechanism 3 and the electro-hydraulic control module 16. The electro-hydraulic composite cable 22 integrates three functions of hydraulic transmission, power supply, and data communication at the same time. The outer sides of the hydraulic pipeline, the power cable, and the communication cable are all provided with a first protective sleeve, and the electro-hydraulic composite cable 22 is provided with a second protective sleeve and a steel wire sleeve on the outside. The steel wire sleeve is arranged on the outer layer of the electro-hydraulic composite cable 22 and is used to bear the suspension weight of the coring mechanism 1, ensuring the tensile strength and mechanical strength of the overall structure. The second protective sleeve is arranged on the outermost layer of the electro-hydraulic composite cable 22 and has the characteristics of wear resistance, corrosion resistance, and seawater resistance. Through the inner layer protection of the first protective sleeve and the outer layer protection of the second protective sleeve, the electro-hydraulic composite cable 22 can be protected to the greatest extent, can withstand high pressure, high temperature, and seawater corrosion for a long time, thereby extending the service life. The electro-hydraulic composite cable 22 has a compact structure and a high degree of functional integration, effectively integrating hydraulic, power, and communication functions, simplifying the number of wirings, reducing the occupied space of the drill string 17, and is particularly suitable for deep-sea complex drilling environments.

[0044] During operation, hydraulic oil is transported to the hydraulic drive device 13 through the hydraulic pipeline in the electro-hydraulic composite cable 22 to achieve the longitudinal advancement of the coring device 11; high-voltage electricity is transported to the electro-hydraulic control module 16 and the rotary drive device 12 through the power cable to provide energy for the rotary cutting and control of the coring bit 111; the communication cable transports sensing information (such as rotational speed, torque, displacement, etc.) to the control mechanism 3 and receives the control instructions from the control mechanism 3 to achieve closed-loop control.

[0045] In some embodiments, one end of the electro-hydraulic composite cable 22 is connected to the winch 23, and the other end of the electro-hydraulic composite cable 22 is connected to the coring mechanism 1 through the cable head 15 to achieve the unified input of hydraulic oil, electricity, and communication signals. The cable head 15 separates the hydraulic pipeline, power cable, and communication cable in the electro-hydraulic composite cable 22. During operation, the control mechanism 3 simultaneously transmits high-voltage electricity and control signals to the cable head 15 through the electro-hydraulic composite cable 22. The cable head 15 decouples various signals and then transmits them to the electro-hydraulic control module 16 respectively, and transports the hydraulic oil to the hydraulic drive device 13.

[0046] In some embodiments, the communication cable is set as an optical fiber cable.

[0047] According to Figure 2 、 4 As shown in 6 and 8, in an embodiment of the present application, the piston rod 131 is hollowly arranged, and an accommodation cavity is arranged inside the piston rod 131. The accommodation cavity penetrates through the double-headed hydraulic cylinder 132 and the cable head 15. The cable head 15 separates the hydraulic pipeline, power cable, and communication cable in the electro-hydraulic composite cable 22, and the separated hydraulic pipeline, power cable, and communication cable are accommodated in the accommodation cavity of the piston rod 131.

[0048] During operation, hydraulic oil transports high-pressure hydraulic oil to the double-headed hydraulic cylinder 132 through the hydraulic pipeline arranged in the accommodation cavity of the piston rod 131, and then drives the rotary drive device 12 and the coring device 11 to perform longitudinal advancement or recovery. During the advancement or recovery process, all electrical and communication signals are transmitted in real time through the power cable and communication cable in the accommodation cavity of the piston rod 131, without the need for additional external wiring, ensuring continuous signals and less interference. By arranging the piston rod 131 hollowly, it is possible to integrate mechanical propulsion, hydraulic transmission, power supply, and data communication into one, without the need to arrange external pipelines separately, simplifying the structure of the coring mechanism 1, realizing the combination of integrated power propulsion and integrated signal transmission, and improving the operation efficiency and data accuracy. At the same time, the accommodation cavity of the piston rod 131 provides a fully enclosed sheath for each cable, avoiding the erosion and pulling damage of the power cable and communication cable by the underlying sediment and mud.

[0049] In some embodiments, after the cable head 15 is disassembled, the communication cable and the power cable start from the electro-hydraulic control module 16, extend downward through the accommodation cavity of the piston rod 131 to the rotary drive device 12 and the coring device 11 for connection, and are used to drive the rotary drive device 12 and transmit the operation data back.

[0050] In some embodiments, multiple card slots are provided on the inner wall of the accommodation cavity of the piston rod 131 to fix and protect the cable, avoiding damage caused by vibration or friction.

[0051] According to Figure 1 , 3 , 5, and 7 show that in an embodiment of the present application, the control mechanism 3 includes an operation console 31, an electric control box 32, a hydraulic station 33, a wireless receiver 34, and a wireless remote control box 35. The operation console 31 serves as an interface for the operator to interact with the entire electro-hydraulic composite downhole coring system. The operation console 31 can display the downhole coring status and other system parameters in real time, facilitating the operator to perform operation control. The operation console 31 is connected to the electric control box 32 through a data line, sending control instructions and receiving feedback data. The electric control box 32 is the core control unit of the control mechanism 3. The electric control box 32 is used to process the control instructions from the operation console 31 and execute corresponding actions. The electric control box 32 is electrically connected to the operation console 31, the electro-hydraulic control module 16, the electro-hydraulic composite cable 22, and the hydraulic station 33 to ensure that parameters such as the oil pump pressure and oil flow rate in the hydraulic station 33 can be controlled, so as to accurately control the propulsion force and cutting force of the coring mechanism 1. The hydraulic station 33 is adjusted through the electric control box 32 to ensure the accurate output of the hydraulic oil pressure and flow rate. The wireless receiver 34 is provided on the electric control box 32 and is connected to the electric control box 32, and is used to receive the signal instructions from the wireless remote control box 35 to ensure the accurate reception of the signals. The wireless remote control box 35 can communicate with the electric control box 32 through the wireless receiver 34, providing convenience for the operator during operation. It can perform remote control during the operation process. Especially when the operation console 31 cannot be used, is under maintenance, or needs remote adjustment, the operator can complete the work through the wireless remote control box 35.

[0052] During operation, the control console 31 receives preset parameters from the operator, such as parameters for setting the drilling depth, rotation speed, hydraulic thrust, etc. The instructions are transmitted and processed through the electric control box 32. The electric control box 32 issues instructions to the hydraulic station 33 through electrical connection to control the pressure and flow rate of the hydraulic oil, thereby adjusting the propulsion speed and thrust of the hydraulic drive device 13. The electric control box 32 is also connected to the wireless receiver 34, allowing the operator to perform remote control through the wireless remote control box 35, providing an alternative control means. After receiving the signal from the electric control box 32, the hydraulic station 33 adjusts the hydraulic output, and the hydraulic drive device 13 adjusts the propulsion speed according to the control signal, driving the rotary drive device 12 and the coring device 11 to complete the drilling operation. The communication between the control console 31 and the electric control box 32 ensures that the operator can monitor and adjust the operation parameters in real time, improving the operation accuracy and reducing human error. The wireless receiver 34 and the wireless remote control box 35 provide the ability of remote operation. Even when the operator is at a place far from the control console 31, he can conveniently perform operations such as starting, stopping, and parameter adjustment of the system, which is especially suitable for the downhole operation environment of complex formations. The electric control box 32 integrates an automatic control module, which can realize the automatic and intelligent adjustment of downhole operations according to the parameter data of the coring device 11, reducing manual intervention and improving the stability and safety of the system. By precisely controlling the hydraulic drive device 13 and the rotary drive device 12, the electro-hydraulic compound downhole power coring system can automatically adjust the working parameters under different formation conditions, adapt to different operating conditions, and improve the coring efficiency and core quality.

[0053] In some embodiments, the electric control box 32 includes a transformer, a PLC controller, an optoelectronic conversion module, a relay, and a contactor. The transformer is used to convert three-phase 380V alternating current into three-phase 2800V alternating current; the PLC controller is used for logical control and signal processing of the entire system, receiving operation instructions, monitoring sensor signals, controlling the start-stop and speed adjustment of the rotary drive device 12, adjusting the hydraulic drive device 13, etc., to achieve automatic control; the optoelectronic conversion module is used to convert the control signal transmitted by the optical fiber into an electrical signal and transmit it to the PLC controller, thereby realizing efficient and anti-interference communication; the relay plays a role in protecting the circuit; the contactor is used to control the on-off of high-voltage and high-current equipment.

[0054] In some embodiments, the hydraulic station 33 includes an oil tank, a constant pressure variable pump, a proportional reversing valve, a filter, a safety valve, and a pressure sensor, and is used to provide high-pressure liquid power for the hydraulic drive device 13.

[0055] In some embodiments, the control console 31 is specifically arranged in the driller's cabin of the drilling ship 4, and the operator operates the control system through the control console 31 in the driller's cabin.

[0056] According to Figures 1 to 8As shown in the figure, in an embodiment of the present application, the following are the specific working steps of the electro-hydraulic composite downhole coring system of the present application: S1. The control console 31 controls the top drive 25 to drive the drill string 17 and the large drill bit to rotate and drill into the seabed 5.

[0057] When the drilling efficiency is low and the coring quality is poor, the large drill bit is located at the large drill stop drilling position 6: S2. The control console 31 controls the coring mechanism 1 to lower, the electric control box 32 drives the winch 23 to release the cable, and the electro-hydraulic composite cable 22 slowly lowers the coring mechanism 1 through the pulley assembly  21; The coring device 11, the rotary drive device 12, and the hydraulic drive device 13 are kept in a modular stacked state in the drill string 17.

[0058] After the coring mechanism 1 is lowered to the large drill stop drilling position 6, the position is confirmed in real time with the electro-hydraulic control module 16 through the communication cable, and the tension of the electro-hydraulic composite cable 22 is adjusted; The locking device 14 triggers the locking action to fix the double-headed hydraulic cylinder 132 in the drill string 17. The positioning pin of the double-headed hydraulic cylinder 132 meshes with the positioning pin groove on the hydraulic cylinder liner 133. After locking, relative movement is possible between the double-headed hydraulic cylinder 132 and the hydraulic cylinder liner 133. The locking device 14 provides a stable reaction force for subsequent operations.

[0059] S4. When drilling through a relatively soft formation, only the hydraulic drive is started. The electric control box 32 sends a start signal to the hydraulic station 33. The hydraulic oil is transported through the hydraulic pipeline in the electro-hydraulic composite cable 22 to the double-headed hydraulic cylinder 132 to push the piston rod 131, thereby driving the hydraulic cylinder liner 133 to move downward; The hydraulic cylinder liner 133, the rotary drive device 12, and the coring device 11 move downward as a whole, and the coring bit 111 piston-pushes and cuts the core; The sensor of the coring device 11 detects the pushing force and position of the coring bit 111 in real time. The communication cable transmits the data back to the electric control box 32, and the PLC controller precisely adjusts the hydraulic pressure according to the feedback to achieve stable propulsion.

[0060] When drilling through complex formations such as hard rock, electro-hydraulic composite drive is used. The electric control box 32 sends start signals to the hydraulic station 33 and the electro-hydraulic control module 16 at the same time. The hydraulic drive device 13 continues to provide axial propulsion power. The electro-hydraulic control module 16 transmits the electric power through the power cable in the electro-hydraulic composite cable 22 and the power cable in the accommodation cavity of the piston rod 131 to the rotary drive device 12, and the rotary drive device 12 drives the coring device 11 to rotate at high speed to cut the hard rock at high speed; The sensors of the coring device 11 detect in real time parameters such as the weight on bit, rotational speed, and torque of the coring bit 111. The communication module feeds back through the communication cable and the PLC controller automatically fine-tunes the thrust and rotational speed to ensure continuous and efficient cutting, achieving efficient, low-disturbance, and high-quality coring in complex formations such as hard rock.

[0061] S5. When the stroke of the piston rod 131 ends, the coring bit 111 is located at the coring bit stop drilling position 7, and the core barrel 112 is filled with core samples. The locking device 14 is unlocked, the double-headed hydraulic cylinder 132 is released, and the coring device 11 can move together with the rotary drive device 12 and the hydraulic drive device 13. The console 31 controls the winch 23 to reverse, the electro-hydraulic composite cable 22 is tightened, the coring mechanism 1 is lifted to the deck, and the core barrel 112 filled with core samples is lifted to the deck of the drilling ship 4, and the coring is completed.

[0062] S6. The core barrel 112 unloads the core. The top drive 25 drives the drill string 17 and the large bit to rotate and drill to the coring bit stop drilling position 7 in step S5, and returns to step S3 until drilling to the target formation and the core collection is completed.

[0063] For the electro-hydraulic composite downhole power coring system of the present application, when drilling through soft formations, only the hydraulic drive is enabled, and the coring mechanism 1 is converted into a piston-type propulsion tool to achieve low-disturbance and high-quality core collection with controllable weight on bit and uniform propulsion; when drilling through hard rock or complex formations, both hydraulic propulsion and electric rotary cutting are started, and the weight on bit, rotational speed, and torque are adjusted in real time and closed-loop through the deck electric control box 32 to break rock efficiently and core completely; the modularly stacked hydraulic drive device 13, rotary drive device 12, and coring device 11, together with the cable inside the hollow piston rod 131 and the locking device 14, ensure the compact structure, accurate guidance, and stable operation of the system; the use of fiber optic communication and PLC automatic control supports the switching between soft and hard formation modes and remote wired / wireless dual control, significantly improving the coring efficiency, core integrity, and the continuity and reliability of on-site operations.

[0064] In the description of this specification, if there are descriptions of reference terms such as "one embodiment", "some examples", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", it means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0065] The above has described the embodiments of the present application in detail with reference to the accompanying drawings. However, the present application is not limited to the above embodiments, and various changes can be made without departing from the gist of the present application within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. An electro-hydraulic composite downhole dynamic coring system, characterized in that: including a coring mechanism, which includes a drill string, a hydraulic driving device, a rotary driving device and a coring device; a connecting mechanism, which is connected to the coring mechanism; a control mechanism, which is used to control the coring mechanism and the connecting mechanism; wherein, the coring device, the rotary driving device and the hydraulic driving device are sequentially stacked along the axial direction of the drill string and arranged inside the drill string. The hydraulic driving device is used to drive the rotary driving device and the coring device to move, and the rotary driving device is used to drive the coring device to perform rotary cutting.

2. The electro-hydraulic composite downhole dynamic coring system according to claim 1, wherein: The hydraulic driving device includes a piston rod, a double-headed hydraulic cylinder and a hydraulic cylinder sleeve. The double-headed hydraulic cylinder is telescopically arranged inside the hydraulic cylinder sleeve. The hydraulic cylinder sleeve is fixedly connected to the rotary driving device. The piston rod drives the rotary driving device and the coring device to move longitudinally along the drill string through the cooperation of the double-headed hydraulic cylinder and the hydraulic cylinder sleeve.

3. The electro-hydraulic composite downhole power coring system according to claim 2, wherein: The coring mechanism further includes a locking device, which is fixedly connected to the double-headed hydraulic cylinder. The locking device is used to fix the double-headed hydraulic cylinder inside the drill string.

4. The electro-hydraulic composite downhole dynamic coring system according to claim 2, characterized in that: The double-headed hydraulic cylinder is provided with a first positioning part, and the hydraulic cylinder sleeve is provided with a second positioning part that cooperates with the first positioning part.

5. The electro-hydraulic composite downhole dynamic coring system according to claim 2, characterized in that: The coring mechanism further includes a cable head and an electro-hydraulic control module. The coring mechanism is connected to the connecting mechanism through the cable head. The electro-hydraulic control module is used to control the rotary driving device and perform data communication with the control mechanism.

6. The electro-hydraulic composite downhole power coring system according to claim 5, characterized in that: The connecting mechanism includes a pulley assembly, an electro-hydraulic composite cable and a winch. One end of the electro-hydraulic composite cable is wound and connected to the winch. The electro-hydraulic composite cable is suspended through the pulley assembly and the other end is connected to the cable head.

7. The electro-hydraulic composite downhole dynamic coring system according to claim 6, characterized in that: The electro-hydraulic composite cable includes a hydraulic pipeline, a power cable and a communication cable. First protective sleeves are arranged on the outer sides of the hydraulic pipeline, the power cable and the communication cable. A second protective sleeve and a steel wire sleeve are arranged outside the electro-hydraulic composite cable.

8. The electro-hydraulic composite downhole dynamic coring system according to claim 7, wherein: The piston rod is hollow inside, and an accommodating cavity is arranged inside the piston rod. The hydraulic pipeline, the power cable and the communication cable are accommodated in the accommodating cavity.

9. The electro-hydraulic composite downhole dynamic coring system according to claim 1, characterized in that: The control mechanism includes a control console, an electric control box, a hydraulic station, a wireless receiver and a wireless remote control box. The control console is connected to the electric control box. The wireless remote control box communicates with the electric control box through the wireless receiver. The electric control box is respectively electrically connected to the hydraulic station and the connecting mechanism.

10. The electro-hydraulic composite downhole dynamic coring system according to any one of claims 1 to 9, characterized in that: The control mechanism performs the following steps: Control the drill string to drill into the seabed; When encountering a difficult formation, control the coring mechanism to lower; When encountering a soft formation, start the hydraulic driving device, and the rotary driving device and the coring device move as a whole. The coring device advances in a piston-like manner for coring; When encountering hard rock or complex formations, start the hydraulic driving device and the rotary driving device simultaneously to drive the coring device to perform rotary cutting for coring; After coring is completed, unlock the locking device, recover the coring mechanism, and remove the core.

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