An electro-hydraulic composite downhole power coring system

Abstract

The present application discloses an electro-hydraulic composite downhole power coring system, including a coring mechanism, a connecting mechanism and a control mechanism. The coring mechanism includes a drill string, a hydraulic drive device, a rotary drive device and a coring device. The coring device, the rotary drive device and the hydraulic drive device are stacked and arranged in the drill string. The hydraulic drive device is fixedly connected to the rotary drive device, and the rotary drive device is rotationally connected to the coring device. The control mechanism is connected to the coring mechanism through a connecting mechanism. The electro-hydraulic composite downhole coring system of the present application can switch the working mode according to the formation conditions. When drilling into soft formations, the coring device is only operated by the piston propulsion of the hydraulic drive device; when drilling into complex formations such as hard rock, the coring device is driven by the rotary drive device to quickly rotate and cut the formation on the basis of hydraulic propulsion. At the same time, the control mechanism can adjust the drilling parameters such as the rotation speed, torque, propulsion speed of the coring device in real time to achieve high-efficiency, low-disturbance, and high-quality coring.

Description

Technical Field

[0001] The present application relates to the field of offshore drilling technology, and in particular to an electro-hydraulic composite downhole power coring system. Background Art

[0002] In deep-sea geological core drilling and ocean scientific drilling projects, low drilling efficiency and poor coring rate often occur when encountering hard formations. Existing downhole power drills mainly rely on drilling fluid to drive, converting liquid energy into rock-breaking power, such as turbine drills, screw drills and hydraulic hammer drills. Their high rotation speed can improve drilling efficiency and core collection rate in complex formations. According to the combination of downhole power drills and rope coring technology, they are divided into hollow power drills and rope coring power drills. Hollow power drills are downhole power drills integrated into the bottom hole drill assembly, and rope coring power drills are downhole power drills integrated into conventional rope coring drills. However, these drilling tools generally lack sensor monitoring, umbilical cable communication and motor precise speed regulation functions, making it difficult to achieve closed-loop control. They have low levels of automation and intelligence and are prone to deviating from optimal working conditions, leading to vibration, increased wear and even failure. Moreover, once the hollow drilling tool fails or encounters soft formations and needs to be switched to conventional rope coring, the drill must be pulled out and the tool replaced, which is time-consuming and labor-intensive, reducing operational efficiency. Summary of the Invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. The present application provides an electro-hydraulic composite downhole dynamic coring system that can change the working mode according to the actual bottom conditions to achieve high efficiency, low disturbance, and high quality coring.

[0004] The electro-hydraulic downhole dynamic coring system according to an embodiment of the present application includes:

[0005] A coring mechanism, comprising a drill string, a hydraulic drive device, a rotary drive device, and a coring device;

[0006] a connecting mechanism connected to the coring mechanism;

[0007] a control mechanism, the control mechanism being used to control the coring mechanism and the connecting mechanism;

[0008] Among them, the coring device, the rotary drive device and the hydraulic drive device are stacked in sequence along the axial direction of the drill string in the drill string, the hydraulic drive device is used to drive the rotary drive device and the coring device to move, and the rotary drive device is used to drive the coring device to perform rotary cutting.

[0009] The electro-hydraulic downhole dynamic coring system according to the embodiment of the present application has at least the following beneficial effects:

[0010] The electro-hydraulic downhole power coring system disclosed herein comprises a coring mechanism, a connecting mechanism, and a control mechanism. The coring mechanism includes a drill string, a hydraulic drive unit, a rotary drive unit, and a coring device. The drill string is hollow and cylindrical, and the coring device, rotary drive unit, and hydraulic drive unit are stacked in sequence from top to bottom along the drill string's axial direction. The output end of the hydraulic drive unit is fixedly connected to the rotary drive unit. The hydraulic drive unit longitudinally extends and contracts, pushing the rotary drive unit and the coring device below the rotary drive unit to move axially along the drill string, thereby achieving downhole piston-like propulsion coring. The rotary drive unit is located at the lower end of the hydraulic drive unit, and its output end is rotatably connected to the coring device. The rotary drive unit provides rotational power to the coring device, enabling it to rotate and cut the formation and collect cores. The connecting mechanism is connected to the upper end of the coring mechanism and is used to lift and suspend the coring mechanism, as well as provide hydraulic, electrical, and communication functions. The control mechanism is connected to the coring mechanism via the connecting mechanism and is used to control the operating status of the hydraulic drive unit and the rotary drive unit.

[0011] The electro-hydraulic composite downhole coring system of the present application can switch the working mode according to the formation conditions. When drilling into soft formations, the coring mechanism only provides hydraulic power, and the control mechanism keeps the rotary drive device stationary. The coring device is driven longitudinally only by the hydraulic drive device, and the hydraulic drive device piston-type propulsion of the coring device is in operation; when drilling into complex formations such as hard rock, the coring mechanism provides hydraulic power and electric rotary drive at the same time. On the basis of hydraulic propulsion, the coring device is driven by the rotary drive device to quickly rotate and cut the formation. At the same time, the control mechanism can adjust the 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.

[0012] According to some embodiments of the present application, the hydraulic drive device includes a piston rod, a double-headed hydraulic cylinder and a hydraulic cylinder liner. The double-headed hydraulic cylinder is telescopically arranged in the hydraulic cylinder liner. The hydraulic cylinder liner is fixedly connected to the rotary drive device. The piston rod drives the rotary drive device and the coring device to move longitudinally along the borehole through the cooperation of the double-headed hydraulic cylinder and the hydraulic cylinder liner.

[0013] According to some embodiments of the present application, the coring mechanism further includes a locking device, which is disposed in the drill string and is used to fix the double-head hydraulic cylinder in the drill string.

[0014] According to some embodiments of the present application, the double-head hydraulic cylinder is provided with a first positioning component, and the hydraulic cylinder sleeve is provided with a second positioning component that cooperates with the first positioning component.

[0015] According to some embodiments of the present application, the coring device includes a coring barrel and a coring drill bit, the coring barrel is fixedly connected to the coring drill bit, and the coring barrel is transmission-connected to the rotary drive device.

[0016] 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 connecting mechanism via the cable head. The electro-hydraulic control module is used to control the rotary drive device and perform data communication with the control mechanism.

[0017] According to some embodiments of the present application, 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 by the pulley assembly and the other end is connected to the cable head.

[0018] According to some embodiments of the present application, the electro-hydraulic composite cable includes a hydraulic pipeline, a power cable and a communication cable, and the electro-hydraulic composite cable is provided with a protective sheath and a steel wire sheath.

[0019] According to some embodiments of the present application, the piston rod is hollow, and an accommodating cavity is provided inside the piston rod, and the hydraulic pipeline, the power cable and the communication cable are accommodated in the accommodating cavity.

[0020] According to some embodiments of the present application, the control mechanism includes a control panel, an electrical control box, a hydraulic station, a wireless receiver and a wireless remote control box. The control panel is connected to the electrical control box, and the wireless remote control box communicates with the electrical control box through the wireless receiver. The electrical control box is electrically connected to the hydraulic station and the connecting mechanism respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present application is further described below with reference to the accompanying drawings and embodiments, wherein:

[0022] Figure 1 This is a schematic structural diagram of an electro-hydraulic composite downhole power coring system according to an embodiment of the present application;

[0023] Figure 2 This is a structural diagram of a coring mechanism according to an embodiment of the present application;

[0024] Figure 3 This 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;

[0025] Figure 4 for Figure 3 An enlarged schematic diagram of part I;

[0026] Figure 5 for Figure 3 A structural diagram of another state;

[0027] Figure 6 for Figure 5 An enlarged schematic diagram of part II;

[0028] Figure 7 for Figure 3 A structural diagram of another state;

[0029] Figure 8 for Figure 7 Enlarged schematic diagram of part III.

[0030] Reference numerals:

[0031] Coring mechanism 1; coring device 11; coring drill bit 111; coring barrel 112; rotary drive device 12; hydraulic drive device 13; piston rod 131; double-head hydraulic cylinder 132; hydraulic cylinder sleeve 133; locking device 14; cable head 15; electro-hydraulic control module 16; drill string 17;

[0032] Connecting mechanism 2; pulley assembly 21; electro-hydraulic composite cable 22; winch 23; derrick 24; top drive 25;

[0033] Control mechanism 3; control console 31; electric control box 32; hydraulic station 33; wireless receiver 34; wireless remote control box 35;

[0034] Drilling Ship 4;

[0035] Under the Sea 5;

[0036] The big drill stops drilling at position 6;

[0037] The core drill bit stops drilling at position 7. DETAILED DESCRIPTION

[0038] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0039] In the description of this application, it should be understood that if the terms "center", "middle", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise specified, "multiple" means two or more.

[0040] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0041] Refer to the following Figures 1 to 8 The electro-hydraulic composite downhole power coring system in the embodiment of the present application is described.

[0042] according to Figures 1 to 8As shown, an electro-hydraulic composite downhole power coring system according to an embodiment of the present application includes a coring mechanism 1, a connecting mechanism 2, and a control mechanism 3. The coring mechanism 1 includes a drill string 17, a hydraulic drive device 13, a rotary drive device 12, and a coring device 11. The drill string 17 is hollow and cylindrical and is used to accommodate various devices. The coring device 11, the rotary drive device 12, and the hydraulic drive device 13 are stacked in sequence from top to bottom along the axial direction of the drill string 17 inside the drill string 17. The hydraulic drive device 13 is arranged at the upper portion of the drill string 17 and is used to provide longitudinal linear propulsion. The rotary drive unit 12 is located in the middle of the drill string 17 and is positioned below the hydraulic drive unit 13. The output end of the hydraulic drive unit 13 is fixedly connected to the rotary drive unit 12, which is also rotationally connected to the coring device 11. The hydraulic drive unit 13 and the rotary drive unit 12 are capable of synchronous axial movement. The hydraulic drive unit 13 longitudinally extends and contracts, pushing the rotary drive unit 12 and the coring device 11 below it to move axially along the drill string 17, thereby achieving piston-like coring. The rotary drive unit 12 provides rotational power to the coring device 11, enabling it to rotate and cut the formation and collect cores. A connecting mechanism 2 is connected to the upper end of the coring mechanism 1, providing the coring mechanism 1 with a lift and suspension, supporting its weight. The connecting mechanism 2 also provides hydraulic, electrical, and communication functions for the coring mechanism 1. A control mechanism 3 is connected to the coring mechanism 1 via the connecting mechanism 2 and is used to control the operating status of the hydraulic drive unit 13 and the rotary drive unit 12.

[0043] The electro-hydraulic composite downhole coring system of the present application can switch the working mode according to the formation conditions. When drilling into 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 propel the coring device 11 longitudinally, and the hydraulic drive device 13 piston-type propulsion of the coring device 11 is in operation; when drilling into complex formations such as hard rock, the coring mechanism 1 provides hydraulic power and electric rotary drive at the same time. On the basis of hydraulic propulsion, the rotary drive device 12 drives the coring device 11 to rotate rapidly to cut the formation. At the same time, the control mechanism 3 can adjust the 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.

[0044] The electro-hydraulic composite downhole coring system of the present application modularly arranges the hydraulic drive unit 13, the rotary drive unit 12, and the coring unit 11 within the drill string 17, resulting in a compact structure and improved integration of the coring mechanism 1. The electro-hydraulic composite drive system provides excellent power redundancy and flexibility, enabling flexible switching of operating modes based on actual formation hardness. This significantly enhances the adaptability of the coring mechanism 1 in complex formations at varying depths, enabling efficient, low-disturbance, and high-quality core acquisition.

[0045] In some embodiments, the electro-hydraulic composite downhole power coring system of the present application is disposed on the drilling vessel 4 .

[0046] In some embodiments, the rotation drive device 12 is configured as a permanent magnet motor; the permanent magnet motor can be configured as a brushless DC motor.

[0047] according to Figure 2 、 4 As shown in Figures 6 and 8, in one 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 sleeve 133. The double-headed hydraulic cylinder 132 is the main power output unit. The cylinder body of the double-headed hydraulic cylinder 132 is a cylindrical structure and can be hydraulically controlled in both directions. The hydraulic cylinder sleeve 133 is arranged in the drill string 17. The hydraulic cylinder sleeve 133 only moves axially along the drill string 17. The hydraulic cylinder sleeve 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 sleeve 133. The hydraulic cylinder sleeve 133 realizes linear expansion and contraction along the axial direction through the reciprocating motion of the internal piston. The lower end of the hydraulic cylinder sleeve 133 is fixedly connected to the rotary drive device 12, thereby driving the coring device 11 to move synchronously. The piston rod 131 is arranged on the central axis position of the double-headed hydraulic cylinder 132.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] according to Figures 1 to 8 As shown, in one embodiment of the present application, a double-headed hydraulic cylinder 132 is provided with a first positioning component, and a hydraulic cylinder sleeve 133 is provided with a second positioning component. The first and second positioning components cooperate to restrict the hydraulic drive device 13 to axial movement within the drill string 17. During operation, the double-headed hydraulic cylinder 132 and the hydraulic cylinder sleeve 133 move relative to each other, and the first or second positioning component automatically snaps into place, achieving centering and guiding constraints. The double-headed hydraulic cylinder 132 is restricted to axial movement within the hydraulic cylinder sleeve 133, while simultaneously limiting its radial or rotational freedom, ensuring that the entire hydraulic drive device 13 operates smoothly along a predetermined trajectory. The provision of the first and second positioning components enables the axial guidance function of the double-headed hydraulic cylinder 132, preventing tilting and rotational errors during operation. This improves the structural stability and operational precision of the hydraulic drive device 13, reduces the risk of interference between devices within the drill string 17, and extends the service life of the coring mechanism 1, thereby enhancing system reliability and service life.

[0053] In some embodiments, the first positioning component of the double-headed hydraulic cylinder 132 is configured as a positioning pin, and the second positioning component of the hydraulic cylinder sleeve 133 is configured as a positioning pin slot. In other embodiments, the first positioning component of the double-headed hydraulic cylinder 132 is configured as a positioning pin slot, and the second positioning component of the hydraulic cylinder sleeve 133 is configured as a positioning pin. In still other embodiments, the first positioning component of the double-headed hydraulic cylinder 132 is configured as a guide boss, and the second positioning component of the hydraulic cylinder sleeve 133 is configured as a guide rail.

[0054] In some embodiments, according to Figure 2 、 4 As shown in Figures 6 and 8, the coring device 11 includes a coring barrel 112 and a coring drill bit 111, and the coring drill bit 111 is fixedly connected to the coring barrel 112. The coring drill bit 111 is arranged at the lower end of the coring mechanism 1, and the coring drill bit 111 is used for cutting the formation and coring. The coring barrel 112 is arranged at the upper end of the coring drill bit 111, and the coring barrel 112 is used to collect and accommodate core samples formed by cutting during the operation. The coring barrel 112 is rigidly fixed to the coring drill bit 111 to form an integrated coring device 11. The upper end of the coring 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.

[0055] During operation, the control mechanism 3 starts the rotary drive device 12. When the output shaft rotates, the core barrel 112 rotates accordingly, thereby driving the core drill bit 111 fixed at the lower end of the core barrel 112 to rotate together. The core drill bit 111 cuts the formation to form a columnar core. The core enters the core barrel 112 through the core drill bit 111 and gradually accumulates to complete the coring.

[0056] In some embodiments, the coring drill bit 111 is configured as a polycrystalline diamond compact drill bit, which facilitates cutting the formation.

[0057] according to Figure 1 、 2 , 4, 6, and 8, in one embodiment of the present application, the coring mechanism 1 further comprises a cable head 15 and an electro-hydraulic control module 16. The cable head 15 is disposed at the top of the coring mechanism 1, and the coring mechanism 1 is connected to the connecting mechanism 2 via the cable head 15. The electro-hydraulic control module 16 is disposed within the coring mechanism 1 and is used to perform rotation control and data processing tasks for the coring mechanism 1.

[0058] 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 2800VAC three-phase high-voltage AC power into 500V DC and 24V DC power, with the 500V DC power used to drive the rotary drive device 12 and the 24V DC power used to control the rotary drive device 12. The motor drive module is used to receive instructions from the control mechanism 3 and regulate the rotary drive device 12 according to the speed and torque output set by the control mechanism 3, thereby achieving precise control of the coring device 11. The communication module is used to facilitate communication between the coring mechanism 1 and the control mechanism 3, feeding back real-time data collected downhole (speed, torque, current) to the control mechanism 3, enabling uphole and downhole data exchange and closed-loop control. By setting 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 achieved, the cutting control capability of the complex bottom layer can be improved, the fluctuation during coring can be reduced, and at the same time, real-time two-way communication and closed-loop control between the wellbore and the underground can be achieved, thereby enhancing the intelligence level of the system and enabling better and higher-quality coring.

[0059] In some embodiments, the electro-hydraulic control module 16 is specifically disposed at the lower end of the cable head 15 .

[0060] according to Figure 1 、 3 As shown in Figures 5 and 7, in one 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. The winch 23 is wound with the electro-hydraulic composite cable 22. The winch 23 is used to release and reel in 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 is turned and guided by 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 suspend the coring mechanism 1.

[0061] During operation, the winch 23 slowly releases the electro-hydraulic composite cable 22, and the coring mechanism 1 is stably lowered to the target position through the pulley assembly 21. After arriving at the target position, the connecting mechanism 2 remains in a tensioned state and continues to provide 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 rewind, and the electro-hydraulic composite cable 22 is gradually recovered and guided to the upper coring mechanism 1 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 safe and stable operation of the system. The connecting mechanism 2 realizes 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, while also taking into account the power and signal transmission functions.

[0062] In some embodiments, the winch 23 is specifically arranged on the deck of the drilling ship 4, and the connecting mechanism 2 also 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 on 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.

[0063] according to Figures 1 to 8 As shown, in one embodiment of the present application, the electro-hydraulic composite cable 22 includes a hydraulic pipeline, an electric 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 deliver hydraulic oil to the coring mechanism 1, the electric power cable is used to deliver 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 the three functions of hydraulic transmission, power supply and data communication. A first protective sheath is provided on the outside of the hydraulic pipeline, the electric power cable and the communication cable, and a second protective sheath and a steel wire sheath are provided on the outside of the electro-hydraulic composite cable 22. The steel wire sheath is provided on the outer layer of the electro-hydraulic composite cable 22 to bear the hanging weight of the coring mechanism 1 and ensure the tensile strength and mechanical strength of the overall structure. The second protective sheath is provided on the outermost layer of the electro-hydraulic composite cable 22 and has the characteristics of wear resistance, corrosion resistance and seawater resistance. The inner protection of the first protective sheath and the outer protection of the second protective sheath provide maximum protection for the electro-hydraulic composite cable 22, enabling it to withstand high pressure, high temperature, and seawater corrosion for extended periods, thereby extending its service life. The electro-hydraulic composite cable 22 boasts a compact structure and a high level of functional integration, effectively integrating hydraulic, electrical, and communication functions. This simplifies wiring and reduces the space occupied by the drill string 17, making it particularly suitable for complex deep-sea drilling environments.

[0064] During operation, the hydraulic oil is transported to the hydraulic drive device 13 through the hydraulic pipeline in the electro-hydraulic composite cable 22 to realize the longitudinal propulsion of the coring device 11; the 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 drill bit 111; the communication cable transmits the sensor information (rotation speed, torque, displacement, etc.) to the control mechanism 3, and receives the control instructions of the control mechanism 3 to realize closed-loop control.

[0065] 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, realizing 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 transmits high voltage electricity and control signals simultaneously to the cable head 15 through the electro-hydraulic composite cable 22. The cable head 15 decouples the various signals and transmits them separately to the electro-hydraulic control module 16, which delivers the hydraulic oil to the hydraulic drive device 13.

[0066] In some embodiments, the communication cable is configured as a fiber optic cable.

[0067] according to Figure 2 、 4 , 6 and 8 , in one embodiment of the present application, the piston rod 131 is hollow and has a receiving cavity therein. The receiving cavity extends 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 received in the receiving cavity of the piston rod 131 .

[0068] During operation, the hydraulic oil delivers high-pressure hydraulic oil to the double-headed hydraulic cylinder 132 through the hydraulic pipeline provided in the accommodating chamber of the piston rod 131, thereby driving the rotary drive device 12 and the coring device 11 to perform longitudinal propulsion or recovery. During the propulsion or recovery process, all power and communication signals are transmitted in real time through the power cable and communication cable in the accommodating chamber of the piston rod 131, without the need for additional external wiring, ensuring signal continuity and minimal interference. By setting the piston rod 131 hollow, mechanical propulsion, hydraulic transmission, power supply and data communication can be combined 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 operation efficiency and data accuracy. At the same time, the accommodating chamber of the piston rod 131 provides a fully enclosed sheath for each cable to prevent the underlying sediment and mud from corroding and pulling damage to the power cable and communication cable.

[0069] In some embodiments, after the electro-hydraulic composite cable 22 is disassembled at the cable head 15, the communication cable and the power cable start from the electro-hydraulic control module 16, enter the accommodating cavity of the piston rod 131 and extend downward to the rotary drive device 12 and the coring device 11 for connecting to drive the rotary drive device 12 and transmit operating data back.

[0070] In some embodiments, a plurality of slots are provided on the inner wall of the accommodating cavity of the piston rod 131 to fix and protect the cable and avoid damage caused by vibration or friction.

[0071] according to Figure 1 、 3As shown in Figures 5 and 7, in one embodiment of the present application, the control mechanism 3 includes a control console 31, an electrical control box 32, a hydraulic station 33, a wireless receiver 34, and a wireless remote control box 35. The control console 31 serves as the interface for the operator to interact with the entire electro-hydraulic composite downhole coring system. The control console 31 can display the downhole coring status and other system parameters in real time, facilitating the operator's operational control. The control console 31 is connected to the electrical control box 32 via a data cable, sending control commands and receiving feedback data. The electrical control box 32 is the core control unit of the control mechanism 3, responsible for processing control commands from the control console 31 and executing corresponding actions. The electrical control box 32 is electrically connected to the control console 31, the electro-hydraulic control module 16, the electro-hydraulic composite cable 22, and the hydraulic station 33, ensuring that parameters such as the oil pump pressure and oil flow in the hydraulic station 33 can be controlled to precisely control the propulsion and cutting force of the coring mechanism 1. The hydraulic station 33 is regulated by the electrical control box 32 to ensure accurate output of hydraulic oil pressure and flow. A wireless receiver 34 is mounted on and connected to the electrical control box 32 to receive signals from the wireless remote control box 35, ensuring accurate signal reception. The wireless remote control box 35 communicates with the electrical control box 32 via the wireless receiver 34, providing convenience for the operator during operation and enabling remote control. This is particularly useful when the control console 31 is unavailable, under maintenance, or requires remote adjustment.

[0072] During operation, the control console 31 receives operator-defined parameters, such as drilling depth, rotational speed, and hydraulic thrust. These commands are transmitted and processed by the electronic control box 32. The electronic control box 32 then sends commands to the hydraulic station 33 via an electrical connection, controlling the pressure and flow of the hydraulic oil, thereby adjusting the propulsion speed and thrust of the hydraulic drive unit 13. The electronic control box 32 is also connected to a wireless receiver 34, allowing the operator to remotely control the system via a wireless remote control box 35, providing a backup control method. Upon receiving signals from the electronic control box 32, the hydraulic station 33 adjusts the hydraulic output, and the hydraulic drive unit 13 adjusts the propulsion speed based on the control signals, driving the rotary drive unit 12 and coring device 11 to complete the drilling operation. Communication between the control console 31 and the electronic control box 32 enables operators to monitor and adjust operating parameters in real time, improving operational accuracy and reducing human error. The wireless receiver 34 and wireless remote control box 35 provide remote operation capabilities, allowing operators to conveniently start, stop, and adjust parameters of the system even from a distance from the control console 31. This is particularly suitable for downhole operations in complex formations. The electrical control box 32 integrates an automatic control module, enabling automated and intelligent downhole operation adjustments based on the parameters of the coring device 11. This reduces manual intervention and improves system stability and safety. By precisely controlling the hydraulic drive 13 and rotary drive 12, the electro-hydraulic downhole dynamic coring system automatically adjusts operating parameters to varying formation conditions, adapting to diverse operating conditions and improving coring efficiency and core quality.

[0073] In some embodiments, the electrical control box 32 includes a transformer, a PLC controller, an optoelectronic conversion module, relays, and contactors. The transformer is used to convert three-phase 380V AC power into three-phase 2800V AC power. The PLC controller is used to perform logical control and signal processing for the entire system, receiving operating instructions, monitoring sensor signals, controlling the start and stop of the rotary drive device 12 and speed regulation, and adjusting the hydraulic drive device 13, thereby achieving automated control. The optoelectronic conversion module is used to convert control signals transmitted by optical fiber into electrical signals and transmit them to the PLC controller, thereby achieving efficient and interference-resistant communication. The relay serves to protect the circuit. The contactor is used to control the on and off of high-voltage and high-current equipment.

[0074] In some embodiments, the hydraulic station 33 includes an oil tank, a constant pressure variable displacement pump, a proportional reversing valve, a filter, a safety valve, and a pressure sensor, and is configured to provide high-pressure liquid power to the hydraulic drive device 13 .

[0075] In some embodiments, the control console 31 is specifically disposed in the driller's room of the drilling vessel 4 , and an operator operates the control system through the control console 31 in the driller's room.

[0076] according to Figures 1 to 8As shown, in one embodiment of the present application, the following are the specific working steps of the electro-hydraulic composite downhole coring system of the present application:

[0077] 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.

[0078] When the drilling efficiency is low and the coring quality is poor, the large drill bit is in the large drill stop drilling position 6:

[0079] S2 console 31 controls the coring mechanism 1 to lower, the electrical control box 32 drives the winch 23 loose cable, the electro-hydraulic composite cable 22 through the pulley assembly 21 to slowly lower the coring mechanism 1;

[0080] 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 .

[0081] S3 coring mechanism 1 is lowered to the drill stop drilling position 6, through the communication cable and the electro-hydraulic control module 16 to confirm the position in real time, and adjust the tension of the electro-hydraulic composite cable 22;

[0082] The locking device 14 triggers the locking action, fixing the double-headed hydraulic cylinder 132 in the drill string 17, and the locating pin of the double-headed hydraulic cylinder 132 engages with the locating pin groove on the hydraulic cylinder sleeve 133. After locking, the double-headed hydraulic cylinder 132 and the hydraulic cylinder sleeve 133 can move relative to each other, and the locking device 14 provides a stable support reaction force for subsequent operations.

[0083] S4. When drilling into softer formations, only the hydraulic drive is activated. The electrical control box 32 sends a start signal to the hydraulic station 33. The hydraulic oil is delivered to the double-headed hydraulic cylinder 132 through the hydraulic pipeline within the electro-hydraulic composite cable 22, pushing the piston rod 131, thereby driving the hydraulic cylinder sleeve 133 downward;

[0084] The hydraulic cylinder sleeve 133, the rotary drive device 12 and the coring device 11 move downward as a whole, and the coring drill bit 111 piston-type advances to cut the core;

[0085] The sensor of the coring device 11 detects the propulsion force and position of the coring drill bit 111 in real time, and the communication cable transmits the data back to the electric control box 32. The PLC controller accurately adjusts the hydraulic pressure according to the feedback to achieve stable propulsion.

[0086] When drilling in complex formations such as hard rock, the electric-hydraulic composite drive is activated, and the electric control box 32 simultaneously sends a start signal to the hydraulic station 33 and the electro-hydraulic control module 16. The hydraulic drive device 13 continues to provide axial propulsion power, and the electro-hydraulic control module 16 transmits electricity to the rotary drive device 12 via the power cable in the electro-hydraulic composite cable 22 and the power cable in the accommodating cavity of the piston rod 131. The rotary drive device 12 drives the coring device 11 to rotate at high speed, thereby cutting the hard rock with high-speed rotation.

[0087] The sensors of the coring device 11 detect the drilling pressure, rotation speed, torque and other parameters of the coring drill bit 111 in real time. The communication module provides feedback through the communication cable and the PLC controller automatically fine-tunes the thrust and rotation speed to ensure continuous and efficient cutting, and achieve efficient, low-disturbance, high-quality coring in complex formations such as hard rock.

[0088] S5. When the piston rod 131 ends its stroke, the coring drill bit 111 is located at the coring drill bit stop drilling position 7, and the coring barrel 112 is filled with core samples;

[0089] The locking device 14 is unlocked, the double-headed hydraulic cylinder 132 is loosened, and the coring device 11, the rotary drive device 12, and the hydraulic drive device 13 can move;

[0090] The control console 31 controls the winch 23 to reverse, the electro-hydraulic composite cable 22 to tighten, the coring mechanism 1 to be lifted to the deck, and the coring barrel 112 filled with core samples to be lifted to the deck of the drilling ship 4, and the coring is completed.

[0091] S6. Unloading the core from the coring barrel 112;

[0092] The top drive 25 drives the drill string 17 and the large drill bit to rotate and drill to the coring drill bit stop drilling position 7 in step S5, and returns to step S3 until the target layer is drilled and the core collection is completed.

[0093] The electro-hydraulic composite downhole power coring system of the present application only activates hydraulic drive when drilling into soft formations, converting the coring mechanism 1 into a piston-type propulsion tool, achieving low-disturbance, high-quality core collection with controllable drilling pressure and uniform propulsion; when drilling into hard rock or complex formations, hydraulic propulsion and electric rotary cutting are started simultaneously, and the drilling pressure, speed and torque are adjusted in a closed loop in real time through the deck electrical control box 32, so as to efficiently break the rock and completely coring; the modular stacked hydraulic drive device 13, rotary drive device 12 and coring device 11, combined with the built-in cable and locking device 14 of the hollow piston rod 131, ensure that the system has a compact structure, precise guidance and stable operation; optical fiber communication and PLC automation control are used, supporting soft and hard formation mode switching and remote wired / wireless dual control, which significantly improves the coring efficiency, core integrity and the continuity and reliability of field operations.

[0094] In the description of this specification, if the reference terms "one embodiment," "some examples," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" appear, it means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations 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 any appropriate manner in any one or more embodiments or examples.

[0095] The above describes the implementation methods of the present application in detail in conjunction with the accompanying drawings, but the present application is not limited to the above implementation methods. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the technical field without departing from the purpose of the present application.

Claims

1. An electro-hydraulic composite downhole dynamic coring system, characterized by: include A coring mechanism, comprising a drill string, a hydraulic drive device, a rotary drive device, and a coring device; a connecting mechanism connected to the coring mechanism; a control mechanism, the control mechanism being used to control the coring mechanism and the connecting mechanism; The coring device, the rotary drive device and the hydraulic drive device are sequentially stacked and arranged in the drill string along the axial direction of the drill string. The hydraulic drive device is used to drive the rotary drive device and the coring device to move, and the rotary drive device is used to drive the coring device to perform rotary cutting. The hydraulic drive 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 drive device. The piston rod drives the rotary drive 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. The coring mechanism further includes a locking device, which is fixedly connected to the double-headed hydraulic cylinder and is used to fix the double-headed hydraulic cylinder in the drill string; The double-head hydraulic cylinder is provided with a first positioning component, and the hydraulic cylinder sleeve is provided with a second positioning component that matches the first positioning component; The coring mechanism further includes a cable head and an electro-hydraulic control module. The coring mechanism is connected to the connecting mechanism via the cable head. The electro-hydraulic control module is used to control the rotary drive device and perform data communication with the control mechanism.

2. The electro-hydraulic composite downhole dynamic coring system according to claim 1, 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 by the pulley assembly and the other end is connected to the cable head.

3. The electro-hydraulic composite downhole dynamic coring system according to claim 2, characterized in that: The electro-hydraulic composite cable includes a hydraulic pipeline, an electric power cable and a communication cable. The outer sides of the hydraulic pipeline, the electric power cable and the communication cable are all provided with a first protective sheath, and the electro-hydraulic composite cable is provided with a second protective sheath and a steel wire sheath.

4. The electro-hydraulic combined downhole dynamic coring system according to claim 3, characterized in that: The piston rod is hollow and has an accommodating cavity inside. The hydraulic pipeline, the power cable and the communication cable are accommodated in the accommodating cavity.

5. 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 electrically connected to the hydraulic station and the connecting mechanism respectively.

6. The method for using the electro-hydraulic composite downhole power coring system according to any one of claims 1 to 5, characterized in that: The control mechanism performs the following steps: Control the drill string to drill into the seabed; When drilling into difficult formations, control the coring mechanism to lower; When encountering soft formations, the hydraulic drive device is started, the rotary drive device and the coring device move as a whole, and the coring device piston-driven coring is carried out; When drilling into hard rock or complex formations, the hydraulic drive unit and the rotary drive unit are activated simultaneously to drive the coring device to rotate and cut the core; After coring is completed, the locking device is unlocked, the coring mechanism is recovered, and the core is removed.

Images