Down-hole while-drilling CPT tool used on sea

Abstract

The invention relates to the technical field of oceanographic engineering geological exploration equipment, in particular to an offshore down-the-hole while-drilling CPT tool which comprises a multi-channel drill rod assembly which comprises a multi-channel drill rod, a cable pipeline, a slurry pipeline, an air pipeline and a standby channel are integrated in the multi-channel drill rod, and the multi-channel drill rod assembly is used for synchronously transmitting electric signals, slurry media and compressed air. The static sounding penetration mechanism and the underground rock breaking and hole sweeping mechanism are integrated, synchronous transmission of power and media is achieved through the multi-channel drill rod, a continuous operation mode of seamless connection of sounding while drilling is constructed, and after a section of stratum penetration test is completed by the tool, the tool does not need to be lifted out of a hole, and the construction efficiency is improved. The pneumatic motor can be immediately started to drive the drill bit to conduct next-section hole sweeping, the traditional intermittent circulation technology of testing, drill lifting, hole sweeping, recycling and descending is changed, and offshore CPT operation is converted into a continuous process from frequent starting and stopping.

Description

Technical Field

[0001] This invention relates to the field of marine engineering geological exploration equipment technology, specifically a down-the-hole drilling CPT tool for offshore use. Background Technology

[0002] Static cone penetration testing (CPT) is a key in-situ testing technique for obtaining engineering geological parameters of seabed soil. Currently, domestic offshore CPT operations generally adopt an alternating "drilling-penetration" process: after drilling a hole to a certain depth using a drilling rig, a specialized CPT tool is lowered from inside the drill pipe to the bottom of the hole to conduct a penetration test.

[0003] However, with conventional CPT tools, after each penetration test (e.g., 3 meters), the entire tool must be completely removed from the drill pipe and lowered to the deck. Then, the drilling rig performs approximately 3 meters of "hole sweeping" to remove residual drill cuttings. Simultaneously, operators must manually retrieve the used push rod from the CPT tool on deck and prepare for the next test. Only after these steps can the tool be lowered back to the bottom of the hole to continue operations. This cyclical operation of "testing-pulling-hole sweeping-retrieval-lowering" is cumbersome, frequently interrupted, resulting in a low percentage of effective testing time per hole, low overall work efficiency, extended offshore operating windows, and increased exploration costs. Therefore, we propose a down-the-hole drilling CPT tool for offshore use. Summary of the Invention

[0004] The purpose of this invention is to provide a down-the-hole drilling CPT tool for offshore use, which has the advantages of reducing costs, improving efficiency and accuracy, as well as safety and stability. It solves the problems of the existing "test-drilling-sweeping-retrieval-re-deployment" cyclical operation mode, which is cumbersome, frequently interrupted, resulting in a low proportion of effective testing time for single-hole operations, low overall work efficiency, extended offshore operation window, and increased exploration costs.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a down-the-hole drilling CPT tool for offshore use, comprising: A multi-channel drill pipe assembly includes a multi-channel drill pipe, which integrates cable conduits, mud conduits, air conduits, and a spare channel for synchronously transmitting electrical signals, mud media, and compressed air. The downhole power actuator includes a waterproof motor, a ball screw assembly, and a pneumatic motor. The output end of the waterproof motor is equipped with a reducer, and the output end of the reducer is connected to a coupling. The output end of the reducer drives the ball screw assembly through the coupling. The ball screw assembly is bolted to a push rod. The pneumatic motor includes a stator and a rotor, and one end of the rotor is connected to an opening and closing PDC drill bit. The static cone penetrometer assembly includes a four-bridge probe, wherein the four-bridge probe has a built-in sensor; The ground support system includes a data display system, a data acquisition system, an air compressor, and a mud pump. The data display system and the data acquisition system are connected to the four-bridge probe via the cable pipeline. The air compressor supplies air to the pneumatic motor through the air pipeline. The mud output by the mud pump is transported to the opening and closing PDC drill bit through the mud pipeline of the multi-channel drill rod.

[0006] Preferably, each section of the multi-channel drill pipe is equipped with independent cable conduits, mud conduits, air conduits, and spare conduits, with each channel extending along the drill pipe axis.

[0007] Preferably, the downhole power actuation component further includes a water-proof connector, which is disposed at the connection end between the multi-channel drill pipe and the downhole component, and is used to isolate downhole mud and water from the internal transmission channel.

[0008] Preferably, the ball screw device is provided with an outer tube, which is fixed relative to the multi-channel drill rod and the stator. The ball screw device includes a screw, a ball nut and an anti-rotation guide sleeve. The screw is connected to the output end of the reducer through the coupling. The ball nut is rigidly connected to the push rod. The anti-rotation guide sleeve restricts the rotation of the ball nut and is used to drive the push rod to perform axial reciprocating motion when the screw rotates.

[0009] Preferably, the waterproof motor has a fixed connector on its exterior, which is fixedly connected to the outer tube, and the waterproof motor receives power from the ground through a cable conduit.

[0010] Preferably, the pneumatic motor uses compressed air as its power source.

[0011] Preferably, the four-bridge probe is provided with a probe protection tube on its exterior, and the probe protection tube is connected to the end of the push rod.

[0012] Preferably, the mud channel of the mud pipeline is an annular pore between the multi-channel drill rod and the outer pipe.

[0013] Preferably, the connection structure between the rotor and the opening / closing PDC drill bit is a detachable design.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention integrates the static cone penetration test (CPPT) mechanism with the downhole rock breaking and hole sweeping mechanism, and uses a multi-channel drill pipe to achieve synchronous transmission of power and media, thus constructing a continuous operation mode that seamlessly connects drilling and penetration testing. After the tool completes a section of formation penetration test, it can immediately start the pneumatic motor to drive the drill bit to perform the next section of hole sweeping without having to be pulled out of the hole. This changes the intermittent cyclic process of traditional testing, drill lifting, hole sweeping, retrieval, and re-deployment, transforming offshore CPT operations from frequent start-stop to a continuous process.

[0015] 2. This invention achieves autonomous, precise, and controllable penetration and retrieval of static cone penetration tests by directly driving the push rod with an integrated downhole motor and ball screw device. This mechanism eliminates the dependence on auxiliary equipment such as deck surface pumps and pulley blocks. The push rod movement is completely driven by electricity within the borehole, which not only provides rapid response and high control precision, but also ensures unlimited reliable reciprocating motion in the underwater environment, providing a fundamental guarantee for obtaining high-density, high-quality in-situ test data.

[0016] 3. This invention achieves high efficiency and low consumption in hole sweeping and rock breaking, and synchronous hole protection through a pneumatic motor with a non-rotating shell and an independent mud cooling and slag discharge circuit. Compressed air drives the rotor and drill bit to rotate efficiently to break rocks, while the stationary shell greatly reduces torque loss. The independent mud flow channel simultaneously cools the drill bit and carries the rock cuttings out of the hole, ensuring hole wall cleanliness and operational safety. This design significantly reduces power consumption and failure risk while improving rock breaking efficiency.

[0017] 4. This invention, through highly integrated modular design and the replacement of expensive peripheral equipment such as imported umbilical cables and large derrick pulleys, forms a set of efficient, reliable and economical domestic marine exploration solutions. This tool significantly reduces single-hole operation time and ship-machine window period, lowers overall exploration costs, and its robust and stable structure is also adapted to complex marine engineering environments. It is of strategic significance for improving the level of equipment self-sufficiency and operational competitiveness of my country's marine engineering geological survey. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is an enlarged structural diagram of point A in the present invention; Figure 3 This is an enlarged structural diagram of section B of the present invention; Figure 4 This is an enlarged structural diagram of point C in the present invention; Figure 5 This is an enlarged structural diagram of point D in the present invention.

[0019] In the diagram: 1. Outer tube; 2. Ball screw assembly; 3. Coupling; 4. Fixed joint; 5. Reducer; 6. Waterproof motor; 7. Waterproof joint; 8. Mud pipeline; 9. Air pipeline; 10. Cable pipeline; 11. Multi-channel drill pipe; 12. Stator; 13. Pneumatic motor; 14. Push rod; 15. Rotor; 16. Probe protection tube; 17. Opening / closing PDC drill bit; 18. Four-bridge probe; 19. Mud pump; 20. Data display system; 21. Data acquisition system; 22. Air compressor. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The components of this application, including the outer tube 1, ball screw device 2, coupling 3, fixed joint 4, reducer 5, waterproof motor 6, water-proof joint 7, mud pipeline 8, air pipeline 9, cable pipeline 10, multi-channel drill pipe 11, stator 12, pneumatic motor 13, push rod 14, rotor 15, probe protection tube 16, opening and closing PDC drill bit 17, four-bridge probe 18, mud pump 19, data display system 20, data acquisition system 21, and air compressor 22, are all general standard parts or parts known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0022] Please see Figures 1-5 As shown, the present invention provides a technical solution: a down-the-hole drilling CPT tool for offshore use, comprising: The multi-channel drill pipe assembly includes a multi-channel drill pipe 11, which integrates a cable conduit 10, a mud conduit 8, an air conduit 9, and a spare channel for synchronous transmission of electrical signals, mud media, and compressed air. The downhole power actuator includes a waterproof motor 6, a ball screw assembly 2, and a pneumatic motor 13. The output end of the waterproof motor 6 is equipped with a reducer 5, and the output end of the reducer 5 is connected to a coupling 3. The output end of the reducer 5 drives the ball screw assembly 2 through the coupling 3. The ball screw assembly 2 is bolted to a push rod 14. The pneumatic motor 13 includes a stator 12 and a rotor 15. One end of the rotor 15 is connected to an opening and closing PDC drill bit 17. The static cone penetrometer assembly includes a four-bridge probe 18, which has a built-in sensor. The ground support system includes a data display system 20, a data acquisition system 21, an air compressor 22, and a mud pump 19. The data display system 20 and the data acquisition system 21 are connected to the four-bridge probe 18 via a cable conduit 10. The air compressor 22 supplies air to the pneumatic motor 13 through an air conduit 9. The mud output from the mud pump 19 is transported to the opening and closing PDC drill bit 17 via the mud conduit 8 of the multi-channel drill rod 11.

[0023] Each section of the multi-channel drill pipe 11 is equipped with independent cable conduits 10, mud conduits 8, air conduits 9, and spare conduits, with each channel extending along the drill pipe axis.

[0024] The downhole power actuator also includes a water-proof connector 7, which is located at the connection end between the multi-channel drill pipe 11 and the downhole assembly, and is used to isolate downhole mud and water from the internal transmission channel.

[0025] The mud channel of the mud pipeline 8 is an annular pore between the multi-channel drill rod 11 and the outer tube 1.

[0026] This technical solution involves the following steps: Before use, the equipment needs to be inspected to ensure it can operate normally and stably without any safety hazards. Next, the equipment is connected to a regulated power source, such as mains power. After power is supplied, the power is transmitted through the cable conduit 10 of the multi-channel drill rod 11 to the waterproof motor 6 inside the fixed connector 4. Once started, the waterproof motor 6 drives the reducer 5 to reduce speed and increase torque. Then, the output end of the reducer 5 transmits power to the ball screw device 2 through the coupling 3, thereby converting the rotational motion into the axial linear motion of the push rod 14. When the waterproof motor 6 rotates forward, the push rod 14 extends downward, pushing the four-bridge probe 18 inside the probe protection tube 16 into the formation. At this time, the sensor built into the four-bridge probe 18 penetrates into the formation. During the penetration process, mechanical parameters such as formation cone tip resistance and sidewall friction resistance can be collected in real time. The collected electrical signals are transmitted in reverse to the ground data acquisition system 21 via cable duct 10. After data processing, the data is finally displayed in real time in the data display system 20, completing the parameter acquisition and monitoring of static penetration. When the waterproof motor 6 reverses, the push rod 14 retracts upward, realizing the lifting and reset of the four-bridge probe 18. Since the retraction and extension of the push rod 14 are directly driven by the downhole integrated waterproof motor 6, reducer 5, coupling 3, and ball screw device 2, there is no need to rely on auxiliary equipment such as ground water pumps and pulley blocks. Therefore, the push rod 14 can complete countless reciprocating actions in the underwater environment, realizing continuous underwater static penetration operation. During borehole clearing operations, compressed air output from the ground air compressor 22 is delivered to the pneumatic motor 13 via the air pipeline 9 of the multi-channel drill rod 11. The stator 12 of the pneumatic motor 13 is relatively fixed to the outer tube 1 and the multi-channel drill rod 11, causing the rotor 15 to rotate at high speed under the action of compressed air. This directly transmits power to the opening and closing PDC drill bit 17, thereby driving the opening and closing PDC drill bit 17 to rotate and achieve borehole clearing and rock breaking. During the borehole clearing process, the multi-channel drill rod 11, the outer tube 1, and the pneumatic motor housing are kept in a safe environment. The drill bit remains stationary, with only the rotor 15 and the opening / closing PDC drill bit 17 rotating, reducing torque loss. While the hole sweeping operation is underway, the mud pump 19 outputs mud through the mud pipeline 8 of the multi-channel drill rod 11 to the annular gap between the multi-channel drill rod 11 and the outer tube 1, and finally flows to the opening / closing PDC drill bit 17. The mud cools the high-speed rotating opening / closing PDC drill bit 17 to prevent it from overheating and being damaged, and carries the slag generated during hole sweeping to the ground to complete the slag removal operation. Because it uses a ground-based supporting system, it eliminates the need for imported umbilical cables, large pulleys on the derrick, recovery push rod pumps, and high-torque power heads on drilling rigs. It can use ordinary cables to transmit signals and supply power, which reduces equipment procurement and maintenance costs. Moreover, this tool can operate continuously underwater without frequent tripping out of the hole, greatly improving work efficiency. Furthermore, the reasonable power transmission structure can reduce power loss, further improving downhole work efficiency.

[0027] Please see Figures 1-5 As shown, the ball screw device 2 is provided with an outer tube 1. The outer tube 1 is fixed relative to the multi-channel drill rod 11 and the stator 12. The ball screw device 2 includes a screw, a ball nut and an anti-rotation guide sleeve. The screw is connected to the output end of the reducer 5 through a coupling 3. The ball nut is rigidly connected to the push rod 14. The anti-rotation guide sleeve restricts the rotation of the ball nut and is used to drive the push rod 14 to perform axial reciprocating motion when the screw rotates.

[0028] It is understandable that: because the anti-rotation guide sleeve restricts the rotation of the ball nut, it is used to drive the push rod 14 to make smooth axial reciprocating motion when the screw rotates, and the ball screw device 2 is used to replace the traditional range cylinder, thereby improving the penetration depth and speed control accuracy of the static penetration test, thus solving the problem of large measurement error of the range cylinder.

[0029] Please see Figures 1-5 As shown, the waterproof motor 6 is provided with a fixed connector 4 on the outside, which is fixedly connected to the outer pipe 1. The waterproof motor 6 receives power from the ground through the cable pipe 10.

[0030] It is understandable that the tool can provide stable power support and enable the waterproof motor 6 to drive the reducer 5, coupling 3 and ball screw device 2 in sequence.

[0031] Please see Figures 1-5As shown, the pneumatic motor 13 uses compressed air as its power source.

[0032] It is understandable that when compressed air is delivered to the pneumatic motor 13 through the air pipeline 9 of the multi-channel drill pipe 11, it will drive the rotor 15 to rotate the opening and closing PDC drill bit 17 to achieve hole sweeping operation. The multi-channel drill pipe 11, the outer pipe 1, and the pneumatic motor housing remain stationary. The pneumatic motor 13 adopts a non-rotating housing design, which improves the torque transmission efficiency and reduces the failure rate of the equipment. The transmission structure of the waterproof motor 6, the reducer 5, and the coupling 3 is reasonably matched, and the power transmission is smooth, which improves the stability of the downhole equipment operation.

[0033] Please see Figure 5 As shown, the four-bridge probe 18 is provided with a probe protection tube 16 on the outside, and the probe protection tube 16 is connected to the end of the push rod 14.

[0034] It is understandable that the probe protection tube 16 can protect the four-bridge probe 18 and help extend its service life.

[0035] Please see Figure 5 As shown, the connection structure between the rotor 15 and the opening / closing PDC drill bit 17 is a detachable design.

[0036] Understandably, this makes it easier to replace and maintain the PDC drill bit 17 later.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A down-the-hole drilling CPT tool for offshore use, characterized in that, include: The multi-channel drill pipe assembly includes a multi-channel drill pipe (11), which integrates a cable conduit (10), a mud conduit (8), an air conduit (9) and a spare channel for synchronous transmission of electrical signals, mud medium and compressed air. The downhole power actuator includes a waterproof motor (6), a ball screw device (2), and a pneumatic motor (13). The output end of the waterproof motor (6) is equipped with a reducer (5), and the output end of the reducer (5) is connected to a coupling (3). The output end of the reducer (5) drives the ball screw device (2) through the coupling (3). The ball screw device (2) is bolted to a push rod (14). The pneumatic motor (13) includes a stator (12) and a rotor (15). One end of the rotor (15) is connected to an opening and closing PDC drill bit (17). The static penetration assembly includes a four-bridge probe (18) with a built-in sensor. The ground support system includes a data display system (20), a data acquisition system (21), an air compressor (22), and a mud pump (19). The data display system (20) and the data acquisition system (21) are connected to the four-bridge probe (18) via the cable pipeline (10). The air compressor (22) supplies air to the pneumatic motor (13) via the air pipeline (9). The mud output by the mud pump (19) is transported to the opening and closing PDC drill bit (17) via the mud pipeline (8) of the multi-channel drill rod (11).

2. The CPT (Continuous Down-the-Hole Pulsation) tool for offshore use according to claim 1, characterized in that: Each section of the multi-channel drill pipe (11) is equipped with independent cable conduits (10), mud conduits (8), air conduits (9), and spare conduits, with each channel extending along the drill pipe axis.

3. The CPT (Continuous Down-the-Hole Pulsing) tool for offshore use according to claim 1, characterized in that: The downhole power execution assembly also includes a water-proof connector (7), which is located at the connection end between the multi-channel drill pipe (11) and the downhole assembly, and is used to isolate downhole mud and water from the internal transmission channel.

4. The CPT (Continuous Down-the-Hole Pulsing) tool for offshore use according to claim 1, characterized in that: The ball screw device (2) is provided with an outer tube (1), which is fixed relative to the multi-channel drill rod (11) and the stator (12). The ball screw device (2) includes a screw, a ball nut and an anti-rotation guide sleeve. The screw is connected to the output end of the reducer (5) through the coupling (3). The ball nut is rigidly connected to the push rod (14). The anti-rotation guide sleeve restricts the rotation of the ball nut and is used to drive the push rod (14) to make axial reciprocating motion when the screw rotates.

5. A down-the-hole drilling CPT tool for offshore use according to claim 4, characterized in that: The waterproof motor (6) is provided with a fixed connector (4) on its exterior. The fixed connector (4) is fixedly connected to the outer tube (1). The waterproof motor (6) receives power from the ground through the cable pipeline (10).

6. A down-the-hole drilling CPT tool for offshore use according to claim 1, characterized in that: The pneumatic motor (13) uses compressed air as its power source.

7. A down-the-hole drilling CPT tool for offshore use according to claim 1, characterized in that: The four-bridge probe (18) is provided with a probe protection tube (16) on the outside, and the probe protection tube (16) is connected to the end of the push rod (14).

8. A down-the-hole drilling CPT tool for offshore use according to claim 1, characterized in that: The mud channel of the mud pipeline (8) is the annular pore between the multi-channel drill rod (11) and the outer pipe (1).

9. A down-the-hole drilling CPT tool for offshore use according to claim 1, characterized in that: The connection structure between the rotor (15) and the opening / closing PDC drill bit (17) is a detachable design.

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