Underground in-situ testing system and in-situ static sounding method based on slurry driving

Abstract

The invention discloses an underground in-situ test system and an in-situ static sounding method based on slurry driving, the system comprises a bottom drilling tool assembly and a penetration tool, the penetration tool comprises a penetration barrel, a wireless communication module, a measurement and control cabin, a driving mechanism, a movable plugging component, a flow control module, a switching module, a flow monitoring module and a driving module, the bottom drilling tool assembly comprises an outer barrel, a slurry flow channel is formed between the injection barrel and the outer barrel, the driving mechanism is in transmission connection with the movable plugging component, the driving module comprises a piston, a probe rod connected with the piston and a self-contained probe connected with the probe rod, and the flow control module is used for controlling the amount of slurry entering the switching module. The switching module is used for controlling switching of flow paths of slurry flowing into the piston rodless cavity or the piston rod cavity, and the flow monitoring module is arranged on a flow path leading to the piston rodless cavity. The device has the advantages that the operation efficiency is improved, the tool recovery frequency is reduced, and the system complexity is reduced by using the existing slurry as a driving source.

Description

Technical Field

[0001] This invention relates to the field of geological exploration technology, and in particular to a downhole in-situ testing system and a mud-driven in-situ static cone penetration test method. Background Technology

[0002] In marine geological exploration, traditional methods rely on shipborne drilling rigs to drill and extract formation samples, which are then sent to laboratories for analysis to obtain data on geological composition and mechanical properties. This process has significant drawbacks: drilling operations subject samples to mechanical disturbance, and samples are prone to physicochemical changes after being removed from their original formation environment, leading to data distortion. Furthermore, the laboratory analysis process is time-consuming, severely hindering exploration efficiency. To improve data accuracy, the industry has attempted to combine static cone penetration testing (PCP) technology with downhole drilling, developing downhole PCP tools. These tools need to be lowered from inside the drill string to the bottom of the borehole, secured to the bottom drill string assembly, and then used for penetration testing. However, existing tools require power and data transmission via cables or hybrid hydraulic-electric cables extending from the deck, resulting in a complex system structure. More importantly, due to the limited travel of the probe rod, the entire tool must be retrieved to the deck after each penetration, allowing the drilling rig to clear the probed formation before lowering the tool again. This cyclical process involves multiple tool retrieval and lowering operations, consuming significant drilling time and significantly reducing operational continuity. Meanwhile, drilling mud serves as a necessary lubricating medium continuously flowing through the drill string during drilling. However, existing tools cannot effectively utilize this fluid energy, requiring an additional power source, which increases system cost and operational complexity. Therefore, existing technologies urgently need improvement to address these issues. Summary of the Invention

[0003] To address the shortcomings of the existing technologies, this invention provides a downhole in-situ testing system and a mud-driven in-situ static cone penetration test method, which has the advantages of improving operational efficiency, reducing tool retrieval frequency, and utilizing existing mud as a driving source to reduce system complexity.

[0004] This invention is achieved using the following technical solution: A downhole in-situ testing system includes a bottom drill string assembly and a penetration tool. The penetration tool includes a penetration cylinder and a wireless communication module. The bottom drill string assembly includes an outer cylinder for housing and positioning the penetration cylinder. A mud flow channel is formed between the penetration cylinder and the outer cylinder. A sealing cavity and a drive cavity are formed within the penetration cylinder. A monitoring and control chamber and a drive mechanism are provided within the sealing cavity. The drive cavity contains, from top to bottom, a movable plugging component, a flow control module, a switching module, a flow monitoring module, and a drive module. The drive mechanism is driven by the movable plugging component to drive the movable plugging component to move between a first position and a second position. When the movable plugging component moves to the first position, it embeds itself into and seals the mud flow channel, allowing mud to be introduced into the drive cavity through the movable plugging component for static penetration testing. When the movable plugging component moves to the second position, it withdraws from the mud flow channel, restoring the mud flow channel to its open state. The drive module includes a piston, a probe connected to the piston, and a self-contained probe connected to the probe. The flow control module is used to control the amount of mud entering the switching module. The switching module is used to control the flow path switching of mud into the piston rodless chamber or the piston rod chamber. The flow monitoring module is set on the flow path leading to the piston rodless chamber to monitor the mud flow rate entering the piston rodless chamber in real time. The measurement and control cabin is electrically connected to the wireless communication module, the drive mechanism, the flow control module, the flow monitoring module, and the switching module via cables.

[0005] Furthermore, the penetrating cylinder and the outer cylinder are circumferentially limited by a positioning mechanism. The positioning mechanism includes an annular protrusion structure formed on the inner wall of the outer cylinder and an interlocking portion formed on the outer wall of the penetrating cylinder. The annular protrusion structure has multiple guide protrusions spaced apart in its circumferential direction. An axially extending mud flow channel is formed between adjacent guide protrusions. The interlocking portion is configured to interlock with at least one of the mud flow channels so that the interlocked mud flow channel is blocked, while the remaining mud flow channels are in a continuous state.

[0006] Furthermore, each of the guide protrusions has at least two guide surfaces at its top, and the at least two guide surfaces meet at the center to form a pointed cone-shaped apex. The bottom of the fitting part has a guide mating structure that seals and fits with the guide surfaces. The guide surfaces are configured such that, regardless of the circumferential angle at which the penetrating tool is inserted into the outer cylinder, the fitting part can be guided to a unique predetermined fitting position, so that the penetrating cylinder and the outer cylinder are automatically aligned and circumferentially limited.

[0007] Furthermore, the penetration cylinder and the outer cylinder are axially fixed by a locking mechanism. The locking mechanism includes a locking part disposed in the penetration cylinder and a locking engagement part disposed in the outer cylinder. A positioning module electrically connected to the measurement and control cabin is provided in the sealed cavity. The positioning module is used to drive the locking part to perform telescopic movement. When the penetration tool is inserted into the outer cylinder and reaches a set depth, the locking part extends and engages with the locking engagement part, thereby axially fixing the penetration tool inside the outer cylinder.

[0008] Furthermore, the locking engagement part is an annular locking ring formed on the inner wall of the outer cylinder. The cross-sectional shape of the annular locking ring is triangular. Two locking parts are symmetrically provided in the penetrating cylinder. The penetrating cylinder is provided with a positioning opening for the locking parts to extend or retract. The positioning module is used to drive the two locking parts to perform synchronous telescopic movements. The shape of the locking part is adapted to the annular locking ring with a triangular cross-sectional shape.

[0009] Furthermore, the penetration cylinder is provided with a sealing member that divides its interior into the sealing cavity and the driving cavity. The driving mechanism includes a drive motor and a drive rod connected to the output end of the drive motor. A transmission element is provided at one end of the drive rod that passes through the sealing member. The movable sealing member includes at least one inlet flap. The inlet flap has a mud flow inlet on its upper end face, an internal flow channel communicating with the mud flow inlet, and a mud flow outlet communicating with the internal flow channel. The penetration cylinder is provided with at least one inlet flap that communicates with the inlet flap. The inlet flap has a side opening that is compatible with the plate. The lower part of the inlet flap is pivotally connected to the inside of the penetrating cylinder. The upper part of the inlet flap is connected to the transmission component via a connecting rod. When the drive rod extends downward, it drives the inlet flap to move from the side opening toward the mud flow channel, so that the inlet flap is embedded in the mud flow channel, causing the mud to flow from the mud inlet into the drive cavity. When the drive rod retracts upward, it drives the inlet flap to move into the drive cavity, so that the inlet flap exits from the mud flow channel, and the mud flow channel is reopened.

[0010] Furthermore, the switching module includes a switching valve body with a switchable flow path. The switching valve body is provided with a one-way inlet connected to the output end of the flow control module, a drive port connected to the rodless chamber of the piston, a return port connected to the rod chamber of the piston, and a discharge port leading to the mud flow channel. The penetration cylinder is provided with a return pipe connected to the return port, and the output end of the return pipe is connected to the rod chamber of the piston.

[0011] Furthermore, the flow control module includes an aperture structure and a ring motor. The aperture structure includes multiple relatively movable blades, which are circumferentially enclosed to form a mud outlet. The relative position of the blades can continuously adjust the cross-sectional area of ​​the mud outlet. The ring motor is coaxially arranged with the aperture structure and is used to drive the multiple blades to open and close synchronously.

[0012] Furthermore, the top of the penetration tool is provided with a connecting structure, which is configured to form a releasable mechanical connection with the gripper of the deck recovery device. The wireless communication module is built into or fixed to the connecting structure. The telemetry and control cabin integrates at least a telemetry and control module, a data acquisition module, an acoustic receiving module, and a battery module. The battery module is used to power the wireless communication module, the telemetry and control module, the data acquisition module, and the execution module on the penetration tool.

[0013] A mud-driven in-situ static cone penetration test method, comprising the aforementioned downhole in-situ testing system, wherein the in-situ static cone penetration test method includes the following steps: The penetration tool is pre-installed and fixed in the bottom drill assembly, and is connected together with the drill pipe. It is then lowered into the formation to start the drilling operation and drill into the formation. After the drill pipe is drilled to the designated depth, the movable sealing component is remotely activated to move to the first position, the mud flow channel is closed, and mud is continuously injected into the drill pipe. Using the mud in the mud channel as the driving medium, the mud is delivered to the piston rodless chamber through the switching module, pushing the piston and the probe rod connected to it to extend, so as to perform static penetration test through the probe. The flow rate of mud entering the piston rodless chamber is monitored in real time. The real-time position and speed of the probe are calculated based on the mud flow rate. The calculated data is compared with a preset constant value. By adjusting the input flow rate of mud, the probe is made to penetrate at the constant speed. When the probe displacement calculated based on the flow rate reaches the preset penetration stroke value, the flow path of the switching module is automatically switched, allowing the mud to enter the piston rod chamber, driving the piston and probe to retract, while simultaneously discharging the mud from the piston rodless chamber. After the probe is retrieved, the movable sealing component retracts automatically, and the mud flow channel is reopened. Repeat the process until the in-situ testing is completed.

[0014] Compared with the prior art, the beneficial effects of the present invention include at least the following: This invention's downhole in-situ testing system effectively solves the problems of low efficiency and additional power requirements in traditional downhole in-situ testing by integrating the penetration tool with the bottom drill string assembly and using drilling mud as the driving medium. Compared with existing technologies that require power and data transmission via cables or hybrid hydraulic cables, this system transmits data through a wireless communication module and relies on drilling mud to drive the probe, eliminating the need for additional power lines extending from the drilling deck, thus reducing system complexity and operating costs. The design of the movable plugging component ensures that the mud flow channel remains open when not in testing mode, allowing drilling mud to flow freely, enabling the penetration tool to advance with the drill string without the need for retrieval and re-lowering during hole clearing. This ability to advance while drilling significantly improves operational efficiency and avoids the time-consuming and repetitive tool retrieval and lowering processes of traditional methods. Furthermore, precise control and real-time monitoring of mud flow through the flow control module and flow monitoring module, combined with the flow path switching function of the switching module, achieves constant-speed penetration and precise retrieval of the probe, ensuring the quality of static cone penetration testing and the reliability of data. The electrical connections between the control and measurement cabin and each execution module ensure a high degree of automation and intelligent control of the entire system. Utilizing existing drilling system conditions, this system eliminates the need for an additional power system, reducing overall system costs. It achieves efficient and accurate in-situ downhole testing, and the mud channel design allows downhole tools to be advanced along with the drilling process without retrieval, effectively improving overall operational efficiency. Attached Figure Description

[0015] Figure 1 This is an exploded view of the downhole in-situ testing system according to an embodiment of the present invention; Figure 2 This is an assembly diagram of the downhole in-situ testing system according to an embodiment of the present invention; Figure 3 This is one of the cross-sectional views of the downhole in-situ testing system according to an embodiment of the present invention; Figure 4 This is a second cross-sectional view of the downhole in-situ testing system according to an embodiment of the present invention, in which the movable plugging component is in the second position; Figure 5 This is the third cross-sectional view of the downhole in-situ testing system according to an embodiment of the present invention, in which the movable plugging component is in the first position; Figure 6 This is a top view of the downhole in-situ testing system according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the penetration tool according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the internal structure of the penetration tool according to an embodiment of the present invention; Figure 9 This is an assembly diagram of the drive mechanism and the movable sealing component according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the flow control module according to an embodiment of the present invention; Figure 11 This is a cross-sectional view of the outer cylinder of an embodiment of the present invention; Figure 12 This is a cross-sectional view of the positioning and assembly of the outer cylinder and the penetrating cylinder according to an embodiment of the present invention; Figure 13 This is a top view of the outer cylinder and the penetrating cylinder after positioning and assembly according to an embodiment of the present invention; Figure 14 This is a schematic diagram of the hydraulic control principle according to an embodiment of the present invention; In the diagram: 1. Bottom drill string assembly; 101. Outer cylinder; 102. Guide protrusion; 103. Guide surface; 104. Locking mating part; 2. Penetration tool; 201. Penetration cylinder; 202. Wireless communication module; 203. Measurement and control cabin; 204. Positioning module; 205. Drive mechanism; 2051. Drive motor; 2052. Drive rod; 2053. Transmission component; 206. Sealing component; 207. Movable sealing component; 2071. Inlet flap; 2072. Mud inlet; 2073. Mud outlet; 2074. Connecting rod; 208. Flow rate Control module; 2081, blade; 2082, ring motor; 2083, mud outlet; 209, switching valve body; 2091, one-way inlet; 2092, drive port; 2093, return port; 2094, drain port; 210, flow monitoring module; 211, piston; 212, probe rod; 213, probe; 214, fitting part; 2141, guide fit structure; 215, locking part; 216, cable; 217, return pipe; 218, connection structure; 219, cable conduit; 220, side opening; 221, positioning opening; 3, mud flow channel. Detailed Implementation

[0016] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore repeated descriptions of them will be omitted.

[0017] The terms used to express position and direction in this invention are illustrated with reference to the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of this invention.

[0018] like Figures 1 to 13As shown, the present invention provides a downhole in-situ testing system, including a bottom drill string assembly 1 and a penetration tool 2. The penetration tool 2 includes a penetration cylinder 201 and a wireless communication module 202. The bottom drill string assembly 1 includes an outer cylinder 101 for housing and positioning the penetration cylinder 201. A mud flow channel 3 is formed between the penetration cylinder 201 and the outer cylinder 101. A sealing cavity and a driving cavity are formed inside the penetration cylinder 201. A measurement and control chamber 203 and a driving mechanism 205 are provided in the sealing cavity. A movable sealing component 207 and a flow control mechanism 205 are arranged sequentially from top to bottom in the driving cavity. The system includes a control module 208, a switching module, a flow monitoring module 210, and a drive module. The drive mechanism 205 is connected to the movable blocking member 207 to drive the movable blocking member 207 to move between a first position and a second position. When the movable blocking member 207 moves to the first position, it embeds itself in and blocks the mud flow channel 3, and the mud is introduced into the drive cavity through the movable blocking member 207 for static penetration testing. When the movable blocking member 207 moves to the second position, it withdraws from the mud flow channel 3, restoring the mud flow channel 3 to conduction. The drive module includes a piston 211, a probe 212 connected to the piston 211, and a self-contained probe 213 connected to the probe 212. The flow control module 208 is used to control the amount of mud entering the switching module. The switching module is used to control the flow path switching of mud into the piston rodless chamber or the piston rod chamber. The flow monitoring module 210 is set on the flow path leading to the piston rodless chamber to monitor the mud flow rate entering the piston rodless chamber in real time. The measurement and control cabin 203 is electrically connected to the wireless communication module 202, the drive mechanism 205, the flow control module 208, the flow monitoring module 210, and the switching module through a cable 216.

[0019] In this embodiment, the penetration tube 201 is the main structure of the penetration tool 2, integrating various components required for testing and control. The wireless communication module 202 can be located on the top or side of the penetration tube 201, enabling communication with surface equipment via electromagnetic waves. For example, the wireless communication module 202 can employ acoustic or electromagnetic communication technology to transmit downhole data to the surface and receive control commands from the surface. The monitoring and control cabin 203 is responsible for data acquisition, processing, and system control. The drive mechanism 205 is responsible for controlling the movement of the movable plugging member 207. For example, the monitoring and control cabin 203 can be a circuit board assembly integrating a microprocessor, memory, and various sensor interfaces. The drive mechanism 205 can be a small motor or hydraulic cylinder, connected to the movable plugging member 207 via a mechanical linkage 2074 or a gear system.

[0020] The drive chamber is arranged from top to bottom as follows: a movable sealing component 207, a flow control module 208, a switching module, a flow monitoring module 210, and a drive module. This sequential arrangement facilitates the sequential control and functional integration of the mud flow path. The movable sealing component 207 is located at the top and directly controls whether mud enters the drive chamber. The flow control module 208 follows immediately and is used to regulate the amount of mud entering. The switching module, following the flow control, is responsible for switching the mud flow direction. The flow monitoring module 210 is used to monitor the flow rate in real time, while the drive module is located at the bottom and directly drives the probe 212. Specifically, the flow control module 208 is used to control the amount of mud entering the switching module. For example, the flow control module 208 can consist of a needle valve driven by a stepper motor, which adjusts the mud flow rate by precisely controlling the opening of the needle valve. The switching module is used to control the flow path switching of mud into the piston rodless chamber or the piston rod chamber. This module can be a multi-way valve that switches the mud flow direction by changing the position of the valve core. For example, the switching module can be a three-way or four-way spool valve that changes the position of the valve core through electromagnetic drive, thereby guiding the mud to the piston rodless chamber or the piston rod chamber.

[0021] The flow monitoring module 210 is positioned in the flow path leading to the piston rodless chamber to monitor the flow rate of mud entering the piston rodless chamber in real time. This module can be a turbine flow meter or a differential pressure flow meter to measure the instantaneous flow rate of the mud. For example, the flow monitoring module 210 can be a sensor with an impeller. When the mud flows through, the impeller rotates, and its rotational speed is proportional to the mud flow rate. The flow rate data can be obtained by measuring the rotational speed.

[0022] Piston 211 is the core component of the drive module. Under the pressure of the drilling mud, it displaces, thereby driving the probe 212. Probe 212 is a rod-shaped structure connecting piston 211 and probe 213, transmitting the movement of piston 211 to probe 213. The self-contained probe 213 is a probe 213 that integrates sensor and data acquisition functions, capable of independently measuring formation parameters. The rodless chamber of piston 211 is a chamber on one side. When drilling mud enters this chamber, piston 211 is pushed out, driving probe 212 to penetrate. The rod chamber of piston 211 is a chamber on the other side. When drilling mud enters this chamber, piston 211 is pushed back, driving probe 212 to retract. Cable 216 is used for electrical signal transmission and power supply between the various functional modules inside the penetration tool 2. The center of piston 211 is mechanically connected to probe 212, and the tip of probe 212 is connected to probe 213. If the inner diameter of the foremost end of the penetration tool 2 is consistent with that of the probe 213 and the probe rod 212, then it is basically sealed, forming the rod cavity structure of the piston 211.

[0023] The downhole in-situ testing system of this embodiment effectively solves the problems of low efficiency and additional power requirements in traditional downhole in-situ testing by integrating the penetration tool 2 with the bottom drill string assembly 1 and using drilling mud as the driving medium. Compared with the existing technology that requires power and data transmission through cables or oil-electric composite cables, this system transmits data through the wireless communication module 202 and relies on drilling mud to drive the probe 212, eliminating the need for additional power lines extending from the deck, thus reducing system complexity and operating costs.

[0024] Specifically, the design of the movable plugging component 207 ensures that the mud flow channel 3 remains open in non-testing conditions, allowing drilling mud to flow freely. This enables the penetration tool 2 to advance along with the drill pipe, eliminating the need for retrieval and re-lowering during hole sweeping. This ability to advance while drilling significantly improves operational efficiency and avoids the time-consuming and repetitive tool retrieval and lowering process of traditional methods. Furthermore, precise control and real-time monitoring of the mud flow rate through the flow control module 208 and flow monitoring module 210, combined with the flow path switching function of the switching module, achieves constant-speed penetration and precise retrieval of the probe 212, ensuring the quality of static penetration testing and the reliability of data. The electrical connection between the control and measurement cabin 203 and each execution module ensures a high degree of automation and intelligent control of the entire system. Overall, this system, utilizing existing drilling system conditions, achieves efficient and accurate downhole in-situ testing, demonstrating significant technological advancements.

[0025] It should be noted that the upper end of the cable 216 inside the penetration tool 2 is connected to the wireless communication module 202, and the lower end is sequentially connected to the control cabin 203, the positioning module 204, the drive mechanism 205, the flow control module 208, and the switching module. Two cable conduits 219 extend symmetrically from both sides of the drive mechanism 205. The cable conduits 219 extend downward from the drive mechanism 205, connect to the flow control module 208, and continue downward from the flow control module 208 to the switching module. The cable conduits 219 and the drive rod 2052 pass through the sealing member 206, dividing the space of the penetration tool 2 into dry and wet parts. The upper part of the sealing member 206 remains dry, while the lower part allows mud to pass through.

[0026] In a preferred embodiment, the penetrating cylinder 201 and the outer cylinder 101 are circumferentially limited by a positioning mechanism. The positioning mechanism includes an annular protrusion structure formed on the inner wall of the outer cylinder 101 and an engaging portion 214 formed on the outer wall of the penetrating cylinder 201. The annular protrusion structure has a plurality of guide protrusions 102 spaced apart in its circumferential direction. An axially extending mud channel 3 is formed between adjacent guide protrusions 102. The engaging portion 214 is configured to engage with at least one of the mud channels 3 so that the engaged mud channel 3 is blocked, while the remaining mud channels 3 are in a continuous state.

[0027] In this embodiment, by introducing a positioning mechanism between the penetration barrel 201 and the outer barrel 101, the problem of inaccurate circumferential positioning of the penetration tool 2 when it is inserted into the bottom drill assembly 1 is effectively solved. Specifically, the positioning mechanism consists of an annular protrusion structure disposed on the inner wall of the outer barrel 101 and an engaging portion 214 on the outer wall of the penetration barrel 201. The annular protrusion structure forms multiple guide protrusions 102 spaced apart in the circumferential direction, and these guide protrusions 102 naturally form axially extending mud channels 3. When the penetration tool 2 is inserted into the outer barrel 101, the engaging portion 214 on the penetration barrel 201 interacts with the annular protrusion structure inside the outer barrel 101. Since the engaging portion 214 is configured to engage with at least one mud channel 3, this means that during the lowering of the penetration barrel 201, the engaging portion 214 will be guided along the guide protrusions 102 until it accurately falls into the predetermined mud channel 3. Once the fitting part 214 engages with the mud channel 3, it seals the engaged mud channel 3. Simultaneously, due to the design of the fitting part 214, the remaining unengaged mud channels 3 remain open. This design ensures the unique and precise circumferential positioning of the penetration cylinder 201, thereby guaranteeing the correct formation of the mud channels 3 and the smooth flow of mud. This provides a structural basis for the accurate operation of the subsequent movable sealing component 207 and the effective implementation of static penetration testing. In this way, the system avoids mud leakage or channel blockage caused by circumferential misalignment, significantly improving the reliability and efficiency of downhole operations.

[0028] In a preferred embodiment, each of the guide protrusions 102 has at least two guide surfaces 103 formed on its top, and the at least two guide surfaces 103 intersect at the center to form a pointed cone-shaped apex. The bottom of the fitting part 214 has a guide mating structure 2141 that seals and fits with the guide surfaces 103. The guide surfaces 103 are configured such that, regardless of the circumferential angle at which the insertion tool 2 is inserted into the outer cylinder 101, the fitting part 214 can be guided to a unique predetermined fitting position, so that the insertion cylinder 201 and the outer cylinder 101 are automatically aligned and circumferentially limited.

[0029] In this embodiment, each guide protrusion 102 has at least two guide surfaces 103 formed on its top. These guide surfaces 103 converge at the center to form a pointed cone-shaped apex. This structure aims to provide a guiding geometry. The guide surfaces 103 can be inclined planes, curved surfaces, or parabolic surfaces, allowing the mating portion 214 to slide along these surfaces when it contacts the guide protrusion 102. The pointed cone-shaped apex is the convergence point of the guide surfaces 103, serving as the final positioning point to ensure the mating portion 214 can be precisely guided to a preset position. The bottom of the mating portion 214 has a guide mating structure 2141 that seals against the guide surfaces 103. This guide mating structure 2141 is a curved surface that matches the guide surfaces 103. Its design allows for close contact with the guide surfaces 103 during guidance, aiding not only in guidance but also providing a sealing effect after positioning. The guide surface 103 is configured to guide the fitting part 214 to a unique predetermined fitting position regardless of the circumferential angle at which the penetration tool 2 is inserted into the outer cylinder 101. This ensures automatic alignment and circumferential limiting between the penetration cylinder 201 and the outer cylinder 101. This demonstrates that the guide surface 103 has omnidirectional guiding capabilities, ensuring that the fitting part 214 ultimately falls into the correct positioning groove regardless of the initial insertion angle, achieving automatic alignment and circumferential limiting. Through this design, automatic and precise circumferential alignment and limiting between the penetration cylinder 201 and the outer cylinder 101 can be achieved without manual adjustment or multiple attempts during the insertion of the penetration tool 2 into the outer cylinder 101. This significantly improves installation efficiency, reduces operational difficulty, and ensures the sealing and functionality of the mud channel 3 after positioning, thus providing a stable and reliable foundation for subsequent static cone penetration testing.

[0030] Specifically, the annular protrusion structure is a concentric circular cylindrical structure extending from the inner wall of the outer cylinder 101, with cross channels cut out in the orthogonal four-axis direction. The inner diameter of the concentric circular cylindrical structure is the same as the diameter of the penetrating cylinder 201, and the outer diameter is the same as the inner diameter of the outer cylinder 101. A specific arc surface is cut out at the top of the concentric circular cylindrical structure. Each specific arc surface forms an upward-opening parabolic structure space at the channel position, which can perfectly fit with the fitting part 214 on the penetrating tool 2. At the same time, the center of each specific arc surface converges to form a pointed cone, ensuring that the top of the concentric circular cylindrical structure has no flat structure. Combined with the guide fitting structure 2141 at the bottom of the fitting part 214, it can be ensured that no matter what posture the penetrating tool 2 is placed into the outer cylinder 101, it can slide into the arc surface designed by the annular protrusion structure and complete the fitting, ensuring proper placement. Furthermore, the inner diameter of the annular protrusion structure fits and seals with the outer diameter of the penetrating cylinder 201, and the outer diameter of the annular protrusion structure fits and seals with the fitting part 214. More specifically, the asymmetrical fitting design consists of two parts, which can seal two channels, while the remaining two channels are mud flow channels 3.

[0031] In a preferred embodiment, the penetration cylinder 201 and the outer cylinder 101 are axially fixed by a locking mechanism. The locking mechanism includes a locking part 215 disposed in the penetration cylinder 201 and a locking engagement part 104 disposed in the outer cylinder 101. A positioning module 204 electrically connected to the measurement and control chamber 203 is provided in the sealed cavity. The positioning module 204 is used to drive the locking part 215 to perform telescopic movement. When the penetration tool 2 is inserted into the outer cylinder 101 and reaches a set depth, the locking part 215 extends and engages with the locking engagement part 104, thereby axially fixing the penetration tool 2 inside the outer cylinder 101.

[0032] In this embodiment, to address the axial stability issue of the penetration tool 2, a locking mechanism is cleverly introduced between the penetration cylinder 201 and the outer cylinder 101. This locking mechanism consists of a locking part 215 on the penetration cylinder 201 and a locking engagement part 104 on the outer cylinder 101. A positioning module 204 is also integrated into the sealed cavity inside the penetration cylinder 201. This positioning module 204 is electrically connected to the control chamber 203 and is responsible for receiving control commands. When the penetration tool 2 is lowered into the outer cylinder 101 and precisely reaches the preset working depth, the control chamber 203 sends an activation signal to the positioning module 204. Upon receiving the signal, the positioning module 204 drives the locking part 215 to extend out of the penetration cylinder 201. The extended locking part 215 then precisely engages with the corresponding locking engagement part 104 on the outer cylinder 101. This locking mechanism forms a robust mechanical connection, effectively securing the penetration tool 2 axially within the outer cylinder 101 and preventing any unnecessary axial displacement during subsequent static penetration tests or mud circulation. In this way, the working position of the penetration tool 2 is precisely maintained, ensuring the accuracy of test data and the operational stability of the system.

[0033] In a preferred embodiment, the locking engagement part 104 is an annular locking ring formed on the inner wall of the outer cylinder 101. The cross-sectional shape of the annular locking ring is triangular. The penetrating cylinder 201 is symmetrically provided with two locking parts 215. The penetrating cylinder 201 is provided with a positioning opening 221 for the locking parts 215 to extend or retract. The positioning module 204 is used to drive the two locking parts 215 to perform synchronous telescopic movements. The shape of the locking part 215 is adapted to the annular locking ring with a triangular cross-sectional shape.

[0034] In this embodiment, the locking engagement part 104 is specifically designed as an annular locking ring with a triangular cross-section, and is matched with two symmetrically arranged locking parts 215 of the same shape on the penetration cylinder 201. The positioning module 204 drives them to extend and retract synchronously, thereby achieving axial fixation of the penetration tool 2 inside the outer cylinder 101. When the penetration tool 2 is inserted into the outer cylinder 101 and reaches a set depth, the positioning module 204 issues a command to drive the two locking parts 215 to extend outward synchronously from the opening of the penetration cylinder 201. Because the shape of the locking parts 215 matches the triangular cross-section of the annular locking ring, when the locking parts 215 extend, they will precisely wedge into or engage with the corresponding structure of the annular locking ring. This triangular cross-section design creates a tight contact surface between the locking parts 215 and the locking ring, providing not only strong axial fixing force but also eliminating gaps to a certain extent and enhancing the stability of the lock. Meanwhile, the symmetrical arrangement and synchronous extension / retraction of the two locking parts 215 ensure a uniform distribution of locking force, avoiding tilting or jamming problems that may be caused by unilateral force, thereby improving the reliability and durability of axial fixation. When it is necessary to release the fixation, the positioning module 204 drives the locking parts 215 to retract synchronously in the opposite direction, and the locking parts 215 exit from the annular locking ring, allowing the penetration cylinder 201 to move freely within the outer cylinder 101. This structural design effectively solves the problems of insecure locking, easy wear, or awkward operation that may exist in traditional locking mechanisms, ensuring the stable operation of the downhole in-situ testing system under complex working conditions.

[0035] It can be understood that the annular locking ring can be an annular groove machined on the inner wall of the outer cylinder 101. The locking part 215 fits perfectly into the annular groove, and the annular design ensures that the insertion tool 2 can be fitted regardless of its rotation angle. The cross-section of the annular groove is designed as a triangle, with a natural slope. When the locking part 215 extends, it can drive the entire insertion tool 2 to move, ultimately making the locking part 215 completely fit into the annular groove. At the same time, it can also ensure that the lower fitting part 214 can fit into place even with some obstruction, thereby maximizing the sealing effect. The two locking parts 215 symmetrically arranged on the insertion cylinder 201 can be specifically two wedge-shaped sliders driven by the positioning module 204. The end shape of each wedge-shaped slider matches the triangular groove of the annular locking ring. For example, its end has a slope corresponding to the inclined side of the groove. The insertion cylinder 201 is provided with positioning openings 221 for these wedge-shaped sliders to extend or retract. The positioning module 204 can employ a pair of miniature hydraulic cylinders, each connected to one of the two wedge-shaped sliders, thereby driving the two wedge-shaped sliders to extend outward or retract inward synchronously. When the hydraulic cylinder pushes the wedge-shaped slider to extend, the inclined surface of the wedge-shaped slider will tightly wed into the triangular groove of the annular locking ring, forming a stable axial engagement. When the hydraulic cylinder drives in the opposite direction, the wedge-shaped slider retracts, releasing the engagement.

[0036] In a preferred embodiment, the penetration cylinder 201 is provided with a sealing member 206 that divides its interior into a sealing cavity and a driving cavity. The driving mechanism 205 includes a driving motor 2051 and a driving rod 2052 connected to the output end of the driving motor 2051. One end of the driving rod 2052 that passes through the sealing member 206 is provided with a transmission member 2053. The movable sealing member 207 includes at least one inlet flap 2071. The inlet flap 2071 has a mud flow inlet 2072 disposed on its upper end face, an internal flow channel communicating with the mud flow inlet 2072, and a mud flow outlet 2073 communicating with the internal flow channel. The penetration cylinder 201 is provided with at least one inlet flap 2072 connected to the inlet flap 2071. A side opening 220 is adapted to the flap 2071. The lower part of the inlet flap 2071 is pivotally connected to the interior of the penetrating cylinder 201. The upper part of the inlet flap 2071 is connected to the transmission component 2053 via a connecting rod 2074. When the drive rod 2052 extends downward, it drives the inlet flap 2071 to move from the side opening 220 toward the mud flow channel 3, so that the inlet flap 2071 is embedded in the mud flow channel 3, causing mud to flow from the mud inlet 2072 into the drive cavity. When the drive rod 2052 retracts upward, it drives the inlet flap 2071 to move into the drive cavity, so that the inlet flap 2071 exits from the mud flow channel 3, and the mud flow channel 3 is reopened.

[0037] In this embodiment, the space inside the penetration cylinder 201 is divided into a sealed cavity and a drive cavity by a sealing member 206, ensuring the safe operation of precision electronic equipment such as the control and measurement cabin 203 within the sealed cavity. The drive motor 2051 in the drive mechanism 205 is powered by a drive rod 2052. The linear motion of the drive rod 2052 is cleverly converted into the swinging or rotating motion of the inlet flap 2071 via a transmission member 2053 and a connecting rod 2074. When static penetration testing is required, the control and measurement cabin 203 controls the motor to extend the drive rod 2052 downwards. The downward movement of the drive rod 2052, via the transmission member 2053 and the connecting rod 2074, pushes the inlet flap 2071 through the side opening 220 into the mud channel 3 between the penetration cylinder 201 and the outer cylinder 101. After the inlet flap 2071 is embedded in the mud channel 3, its structural design allows the mud inlet 2072 on its upper end to receive the mud in the mud channel 3, and to guide the mud into the drive chamber through the built-in flow channel and mud outlet 2073, thereby realizing the switching of the mud flow path and the initiation of the static cone penetration test. This design utilizes the pressure of the mud as the driving medium, avoiding additional hydraulic or pneumatic systems and simplifying the system structure. After the static cone penetration test is completed, the control cabin 203 controls the motor again to drive the drive rod 2052 to retract upward. The upward movement of the drive rod 2052, through the transmission component 2053 and the connecting rod 2074, pulls the inlet flap 2071 back from the mud channel 3 into the drive chamber, so that the mud channel 3 is reopened and normal mud circulation is restored.

[0038] The design of the inlet flap 2071 in this embodiment enables the sealing of the mud flow channel 3 and the introduction of mud into the drive chamber to be achieved in one integrated manner, simplifying the system structure. The cooperation between the transmission component 2053 and the connecting rod 2074 allows the linear motion of the drive mechanism 205 to be efficiently converted into the oscillation of the inlet flap 2071, ensuring precise flow path switching in the narrow downhole space. This design effectively solves the problems that may exist in traditional solutions, such as poor sealing, insensitive operation, or complex structure, improving the reliability and efficiency of the downhole in-situ testing system during static penetration testing, while ensuring the unobstructed flow of mud flow channel 3 in the non-operational state.

[0039] It is understood that the inlet flap 2071 is directly controlled to open and close by the drive rod 2052. The lower hinge of the inlet flap 2071 is a fixed hinge, which can only rotate at a fixed point, while the upper hinge is a movable hinge, which can move with the inlet flap 2071. When the drive rod 2052 extends, it drives the inlet flap 2071 to open; when the drive rod 2052 retracts, it drives the inlet flap 2071 to close. Preferably, there are two inlet flaps 2071. When both inlet flaps 2071 are open, they fit precisely into the two mud channels 3 of the cross-shaped channel. At this time, the other two channels are already closed by the cross-shaped fitting part 214, and the mud enters the penetration tool 2 through the mud inlet 2072 at the upper part of the inlet flap 2071. When the inlet flap 2071 is retracted, the mud channel 3 is reopened, and the mud can flow freely again.

[0040] In a preferred embodiment, the switching module includes a switching valve body 209 with a switchable flow path. The switching valve body 209 is provided with a one-way inlet 2091 that communicates with the output end of the flow control module 208, a drive port 2092 that communicates with the rodless chamber of the piston, a return port 2093 that communicates with the rod chamber of the piston, and a discharge port 2094 that leads to the mud flow channel 3. The penetration cylinder 201 is provided with a return pipe 217 that communicates with the return port 2093. The output end of the return pipe 217 communicates with the rod chamber of the piston.

[0041] In this embodiment, a highly efficient and controllable mud-driven flow path switching system is constructed by introducing a switching valve body 209 with a switchable flow path and clarifying its connection relationship with the flow control module 208, the piston rodless chamber, the piston rod chamber, and the mud flow channel 3. Specifically, when static penetration testing is required, the mud output by the flow control module 208 enters through the one-way inlet 2091 of the switching valve body 209. At this time, the switching valve body 209 is configured to guide the mud to the drive port 2092, allowing the mud to flow into the piston rodless chamber, thereby pushing the piston 211 and probe 212 to extend. When it is necessary to retract the probe 212, the switching valve body 209 switches the flow path, guiding the mud to the piston rod chamber, while simultaneously discharging the mud in the piston rodless chamber through the drain port 2094, driving the piston 211 and probe 212 to retract. This design allows for more precise control of mud flow direction and more stable and reliable extension and retraction of piston 211, effectively solving the problems of precise mud flow path switching and mud discharge management in the piston rod chamber, thus ensuring the accuracy and efficiency of static cone penetration testing. Through this refined flow path control, the system can flexibly switch the extension and retraction states of probe rod 212 according to operational requirements, providing a solid driving foundation for in-situ downhole testing. As a specific implementation, the switching module can use a two-position four-way valve as the switching valve body 209, referencing... Figure 14The switching valve body 209 features a one-way inlet 2091 at the top, allowing slurry to flow in unidirectionally. Drainage outlets 2094 on both sides of the middle section allow slurry to flow out unidirectionally to the outside of the penetration tool 2, specifically into the gap between the outer cylinder 101 and the penetration cylinder 201, discharging the slurry to the external environment. The switching valve body 209 also has an outlet at its lower center, where a flow meter is installed. Slurry flows through this outlet to the rodless chamber of the bottom piston 211. The slurry flow rate is recorded during the flow, allowing for the calculation of the piston 211's extension and retraction, and obtaining the penetration information of the probe rod 212. Two additional openings on either side of the bottom of the switching valve body 209 connect to the return pipe 217 and to the end of the piston's rod chamber.

[0042] In a preferred embodiment, the flow control module 208 includes an aperture structure and a ring motor 2082. The aperture structure includes multiple relatively movable blades 2081, which are circumferentially enclosed to form a mud outlet 2083. The relative position of the blades 2081 can continuously adjust the cross-sectional area of ​​the mud outlet 2083. The ring motor 2082 is coaxially arranged with the aperture structure and is used to drive the multiple blades 2081 to open and close synchronously.

[0043] In this embodiment, by designing the flow control module 208 as consisting of an aperture structure and a ring motor 2082, precise and continuous adjustment of the mud flow rate is achieved. Specifically, the ring motor 2082 is coaxially arranged with the aperture structure, and its rotational motion directly drives multiple relatively movable blades 2081. These blades 2081 circumferentially enclose to form a mud outlet 2083, and are synchronously opened and closed by the drive of the ring motor 2082. When the ring motor 2082 rotates forward, the blades 2081 can retract towards the center, reducing the cross-sectional area of ​​the mud outlet 2083 and thus limiting the mud flow rate; when the ring motor 2082 rotates in the reverse direction, the blades 2081 can open outward, increasing the cross-sectional area of ​​the mud outlet 2083 and thus increasing the mud flow rate. Since the relative position change of the blades 2081 is continuous, the cross-sectional area of ​​the mud outlet 2083 can also be continuously adjusted. This precise flow control capability allows the system to dynamically adjust the amount of mud entering the piston rodless chamber based on real-time feedback from the flow monitoring module 210, thereby precisely controlling the extension speed of the probe 212 and enabling it to penetrate at a preset constant speed. This design overcomes the limitations of traditional flow control methods in achieving high-precision, wide-range dynamic adjustment under complex geological conditions, ensuring the accuracy and reliability of static cone penetration testing.

[0044] It is understandable that the ring motor 2082 can drive the opening and closing of the aperture structure like the aperture of a camera, thereby controlling the flow rate of the mud.

[0045] In a preferred embodiment, the top of the penetration tool 2 is provided with a connecting structure 218, which is configured to form a releasable mechanical connection with the gripper of the deck recovery device. The wireless communication module 202 is built into or fixed to the connecting structure 218. The measurement and control cabin 203 integrates at least a measurement and control module, a data acquisition module, an acoustic receiving module, and a battery module. The battery module is used to power the wireless communication module 202, the measurement and control module, the data acquisition module, and the execution module on the penetration tool 2.

[0046] In this embodiment, a connecting structure 218 is provided on the top of the penetration tool 2. This connecting structure 218 forms a releasable mechanical connection with the gripper of the deck recovery device, providing a standardized and reliable recovery interface for the penetration tool 2. This ensures that the penetration tool 2 can be safely and efficiently retrieved from the well after downhole operations are completed, thereby reducing operational risks and costs. Specifically, the connecting structure 218 is preferably a retrieval head structure, which can be combined with a retrieval device pulled by a composite cable. If necessary, the retrieval device can be lowered from the deck and combined with the penetration tool 2 to pull the penetration tool 2 back to the deck. A wireless communication device protrudes from the center of the retrieval head, which can lower the retrieval device during operations and achieve wired communication control in poor environmental conditions. At the same time, the wireless communication module 202 is built into or fixed to the connecting structure 218, optimizing the wireless signal transmission path. Since the connection structure 218 is typically located at the top of the penetration tool 2, close to the wellhead or surface, this layout effectively reduces signal attenuation in the downhole environment, thereby improving the reliability and efficiency of data communication between the downhole and the surface. This makes real-time monitoring and remote control more stable, avoiding data loss or control failure due to communication interruptions. During operations, it allows for the deployment of retrieval equipment and enables tethered communication control even in adverse environmental conditions. Furthermore, the control and measurement cabin 203 is designed as a highly integrated unit, incorporating at least a control and measurement module, a data acquisition module, an acoustic receiving module, and a battery module. It enables data acquisition, storage, transmission, and autonomous tool control, meaning the system possesses self-storage and autonomous adjustment capabilities. On the other hand, the acoustic receiving module can receive acoustic signals transmitted through the metal tube wall. Since the penetration tool 2 is in direct contact with the outer cylinder 101, and metal has excellent acoustic vibration transmission capabilities, acoustic signals can be emitted from the deck through the drill string, enabling the propagation of control signals and achieving wireless remote start / stop control. In addition, the battery module, as the core power source, provides stable and sufficient power to the wireless communication module 202, the measurement and control module, the data acquisition module, and all execution modules on the penetration tool 2. This integrated power management solution enables the penetration tool 2 to achieve a high degree of autonomy during downhole operations, eliminating the need for external power supply and ensuring the continuity of static penetration testing, the integrity of data acquisition, and the overall reliability of system operation. Through the above technical solutions, the downhole in-situ testing system has been significantly enhanced in terms of deployment, retrieval, communication, and energy supply, enabling it to operate more stably and efficiently in complex downhole environments.

[0047] The present invention also provides a mud-driven in-situ static cone penetration test method, including the above-mentioned downhole in-situ testing system, the mud-driven in-situ static cone penetration test method comprising the following steps: The penetration tool 2 is pre-installed and fixed in the bottom drill assembly 1, and is connected together with the drill pipe. It is then lowered into the formation to start the drilling operation and drill into the formation. After the drill pipe is drilled to the designated depth, the movable sealing component 207 is remotely activated to move to the first position, the mud flow channel 3 is closed, and then mud is continuously injected into the drill pipe. Using the mud in the mud channel 3 as the driving medium, the mud is transported to the piston rodless chamber through the switching module, pushing the piston 211 and the probe rod 212 connected to it to extend, so as to perform static penetration test through the probe 213. The flow rate of mud entering the piston rodless chamber is monitored in real time. The real-time position and speed of probe 212 are calculated based on the mud flow rate. The calculated data is compared with a preset constant value. By adjusting the input flow rate of mud, probe 212 is made to penetrate at the constant speed. When the displacement of probe 212 calculated based on the flow rate reaches the preset penetration stroke value, the flow path of the switching module is automatically switched, allowing the mud to enter the piston rod chamber, driving piston 211 and probe 212 to retract, while simultaneously discharging the mud from the piston rodless chamber. After the probe rod 212 is retrieved, the movable sealing component 207 automatically retracts, and the mud flow channel 3 is reopened; Repeat the process until the in-situ testing is completed.

[0048] In this embodiment, reference Figure 14 In the hydraulic control schematic diagram, the two-position two-way valve is equivalent to the movable sealing component 207, the flow control valve is equivalent to the flow control module 208, and the two-position four-way valve is equivalent to the switching valve body 209. The specific process of the in-situ static cone penetration test method using the downhole in-situ testing system is as follows: First, the penetration tool 2 is pre-installed and fixed in the bottom drill string assembly 1. A mud flow channel 3 is formed between the penetration barrel 201 of the penetration tool 2 and the outer barrel 101 of the bottom drill string assembly 1, ensuring that drilling mud can flow normally during the lowering process. Subsequently, the bottom drill string assembly 1 is assembled with the drill pipe and lowered downhole along with the drill pipe string. Drilling operations are suspended once the drill pipe has reached the designated depth.

[0049] At this time, the control and monitoring room 203 receives a remote start command from the well equipment via the wireless communication module 202. The control and monitoring room 203 then controls the drive mechanism 205 to start, which in turn moves the movable sealing member 207 from the second position to the first position. In the first position, the movable sealing member 207 precisely embeds and seals the mud flow channel 3 between the penetration tube 201 and the outer tube 101, thereby blocking the normal flow path of the mud. Simultaneously, the flow guiding structure inside the movable sealing member 207 guides the continuously injected mud into the drill pipe into the drive cavity inside the penetration tube 201.

[0050] After entering the drive chamber, the drilling mud first passes through the flow control module 208. The control chamber 203 precisely adjusts the opening of the flow control module 208 according to the preset penetration velocity target value to control the amount of drilling mud entering the switching module. Subsequently, the drilling mud enters the switching module. At the beginning of the static cone penetration test, the switching module is controlled by the control chamber 203, guiding the drilling mud to the rodless chamber of the piston 211 in the drive module. Under pressure, the drilling mud pushes the piston 211 downwards, causing the connected probe rod 212 to extend, ultimately allowing the self-contained probe 213 to penetrate the formation at a controlled speed.

[0051] During the penetration of probe 212, a flow monitoring module 210, located on the flow path to the piston rodless chamber, monitors the flow rate of mud entering the piston rodless chamber in real time. This flow data is transmitted to the measurement and control chamber 203. Based on the real-time mud flow rate and the geometric parameters of piston 211 and probe 212, the measurement and control chamber 203 accurately calculates the real-time position and velocity of probe 212. The measurement and control chamber 203 compares this real-time velocity with a preset constant penetration velocity value. If the real-time velocity deviates from the target value, the measurement and control chamber 203 immediately sends a command to the flow control module 208 to fine-tune the mud input flow rate, thereby ensuring that probe 212 can penetrate stably at a constant velocity and guaranteeing the accuracy of the test data.

[0052] When the displacement of the probe 212, calculated by the control and measurement cabin 203 based on the flow data, reaches the preset penetration stroke value, it indicates that a static cone penetration test is completed. The control and measurement cabin 203 automatically controls the flow path of the switching module to guide the mud to the rod chamber of the piston 211. At this time, the mud pressure pushes the piston 211 to move backward, causing the probe 212 to retract, while simultaneously discharging the mud in the rodless chamber of the piston into the mud flow channel 3. After the probe 212 is completely retracted, the control and measurement cabin 203 again controls the drive mechanism 205 to move the movable sealing component 207 from the first position to the second position, exiting the mud flow channel 3, and restoring the mud flow channel 3 to conduction.

[0053] This completes one cycle of static cone penetration testing. Since the deck mud injection pressure has significantly decreased, it indicates that the first penetration operation is finished, and drilling and cleaning operations can be performed again without retrieving the penetration tool 2 to the deck. When the next test is needed, the system can repeat the above steps to achieve continuous operation until the entire downhole in-situ testing operation is completed. At this point, the retrieval device can be lowered first to retrieve the downhole penetration tool 2 to the deck, and the in-situ test data from probe 213 can be read to directly analyze the formation conditions. The drill pipe can then be retrieved to further improve operational efficiency.

[0054] In summary, this invention enables in-situ downhole testing operations through this system. When drilling mud is injected from the deck into the well, the downhole penetration tool 2 can be activated via remote acoustic control, opening the inlet flap 2071, sealing the mud flow channel 3, and initiating the penetration operation. The mud enters the piston rodless chamber through a hydraulic circuit, beginning the ejection of the probe rod 212. At this time, the flow meter can monitor the mud flow rate entering the rodless chamber, thereby calculating the position and penetration speed of the probe rod 212, and transmitting the real-time data back to the control and measurement cabin 203. Using a PID control algorithm, the mud flow rate entering the switching valve body 209 is controlled by opening and closing the aperture structure, ensuring a constant speed for the in-situ penetration operation, meeting the international in-situ static cone penetration test standard. After the penetration operation is completed, the switching valve body 209 automatically switches, allowing mud to enter the piston rod chamber, the piston 211 is retracted, and the mud in the rodless chamber is discharged to the outside through a circuit, thus achieving the retrieval of the probe rod 212.

[0055] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the invention without departing from the principles and spirit of the invention, and all such changes should fall within the protection scope of the claims of the present invention.

Claims

1. A downhole in-situ testing system, characterized in that, The system includes a bottom drill assembly (1) and a penetration tool (2). The penetration tool (2) includes a penetration cylinder (201) and a wireless communication module (202). The bottom drill assembly (1) includes an outer cylinder (101) for housing and positioning the penetration cylinder (201). A mud flow channel (3) is formed between the penetration cylinder (201) and the outer cylinder (101). A sealing cavity and a drive cavity are formed inside the penetration cylinder (201). A control chamber (203) and a drive mechanism (205) are provided inside the sealing cavity. The drive cavity contains a top-to-bottom section... The following components are arranged in sequence: a movable sealing component (207), a flow control module (208), a switching module, a flow monitoring module (210), and a drive module. The drive mechanism (205) is connected to the movable sealing component (207) to drive the movable sealing component (207) to move between a first position and a second position. When the movable sealing component (207) moves to the first position, it is embedded in and blocks the mud flow channel (3), and the mud is introduced into the drive cavity through the movable sealing component (207) for static penetration testing. When the movable sealing member (207) moves to the second position, it withdraws from the mud flow channel (3), thereby restoring the mud flow channel (3) to conduction. The drive module includes a piston (211), a probe rod (212) connected to the piston (211), and a self-contained probe (213) connected to the probe rod (212). The flow control module (208) is used to control the amount of mud entering the switching module. The switching module is used to control the flow path switching of mud into the piston rodless chamber or the piston rod chamber. The flow monitoring module (210) is set on the flow path leading to the piston rodless chamber to monitor the mud flow rate entering the piston rodless chamber in real time. The measurement and control cabin (203) is electrically connected to the wireless communication module (202), the drive mechanism (205), the flow control module (208), the flow monitoring module (210), and the switching module through a cable (216).

2. The downhole in-situ testing system according to claim 1, characterized in that, The penetration cylinder (201) and the outer cylinder (101) are circumferentially limited by a positioning mechanism. The positioning mechanism includes an annular protrusion structure formed on the inner wall of the outer cylinder (101) and an interlocking portion (214) formed on the outer wall of the penetration cylinder (201). The annular protrusion structure has a plurality of guide protrusions (102) spaced apart in its circumferential direction. An axially extending mud channel (3) is formed between adjacent guide protrusions (102). The interlocking portion (214) is configured to be able to interlock with at least one of the mud channels (3) so that the interlocked mud channel (3) is blocked and the remaining mud channels (3) are in a continuous state.

3. The downhole in-situ testing system according to claim 2, characterized in that, Each of the guide protrusions (102) has at least two guide surfaces (103) formed at its top, and the at least two guide surfaces (103) meet at the center to form a pointed cone apex. The bottom of the fitting part (214) has a guide mating structure (2141) that is sealed and fitted with the guide surface (103). The guide surface (103) is configured such that, regardless of the circumferential angle at which the insertion tool (2) is inserted into the outer cylinder (101), the fitting part (214) can be guided to a unique predetermined fitting position, so that the insertion cylinder (201) and the outer cylinder (101) are automatically aligned and form a circumferential limit.

4. The downhole in-situ testing system according to claim 1, characterized in that, The penetration cylinder (201) and the outer cylinder (101) are axially fixed by a locking mechanism. The locking mechanism includes a locking part (215) disposed in the penetration cylinder (201) and a locking engagement part (104) disposed in the outer cylinder (101). A positioning module (204) electrically connected to the measurement and control cabin (203) is provided in the sealed cavity. The positioning module (204) is used to drive the locking part (215) to perform telescopic movement. When the penetration tool (2) is inserted into the outer cylinder (101) and reaches a set depth, the locking part (215) extends and engages with the locking engagement part (104), thereby realizing the axial fixation of the penetration tool (2) inside the outer cylinder (101).

5. The downhole in-situ testing system according to claim 4, characterized in that, The locking engagement part (104) is an annular locking ring formed on the inner wall of the outer cylinder (101). The cross-sectional shape of the annular locking ring is triangular. The penetrating cylinder (201) is symmetrically provided with two locking parts (215). The penetrating cylinder (201) is provided with a positioning opening (221) for the locking parts (215) to extend or retract. The positioning module (204) is used to drive the two locking parts (215) to perform synchronous telescopic movements. The shape of the locking part (215) is adapted to the annular locking ring with a triangular cross-sectional shape.

6. The downhole in-situ testing system according to claim 1, characterized in that, The penetration cylinder (201) is provided with a sealing member (206) that divides its interior into a sealing cavity and a driving cavity. The driving mechanism (205) includes a driving motor (2051) and a driving rod (2052) connected to the output end of the driving motor (2051). One end of the driving rod (2052) passing through the sealing member (206) is provided with a transmission member (2053). The movable sealing member (207) includes at least one inlet flap (2071). The inlet flap (2071) has a mud flow inlet (2072) disposed on its upper end face, an internal flow channel communicating with the mud flow inlet (2072), and a mud flow outlet (2073) communicating with the internal flow channel. The penetration cylinder (201) is provided with at least one inlet flap (2071). The lower part of the inlet flap (2071) is pivotally connected to the interior of the penetrating cylinder (201) through a matching side opening (220). The upper part of the inlet flap (2071) is connected to the transmission component (2053) through a connecting rod (2074). When the drive rod (2052) extends downward, it drives the inlet flap (2071) to move from the side opening (220) toward the mud flow channel (3), so that the inlet flap (2071) is embedded in the mud flow channel (3), causing the mud to flow from the mud inlet (2072) into the drive cavity. When the drive rod (2052) retracts upward, it drives the inlet flap (2071) to move into the drive cavity, so that the inlet flap (2071) exits from the mud flow channel (3), and the mud flow channel (3) is reopened.

7. The downhole in-situ testing system according to claim 1, characterized in that, The switching module includes a switching valve body (209) with a switchable flow path. The switching valve body (209) is provided with a one-way inlet (2091) connected to the output end of the flow control module (208), a drive port (2092) connected to the rodless chamber of the piston, a return port (2093) connected to the rod chamber of the piston, and a discharge port (2094) leading to the mud flow channel (3). The penetration cylinder (201) is provided with a return pipe (217) connected to the return port (2093). The output end of the return pipe (217) is connected to the rod chamber of the piston.

8. The downhole in-situ testing system according to claim 1, characterized in that, The flow control module (208) includes an aperture structure and a ring motor (2082). The aperture structure includes multiple relatively movable blades (2081). The multiple blades (2081) are circumferentially enclosed to form a mud outlet (2083). The relative position change of the blades (2081) can continuously adjust the cross-sectional area of ​​the mud outlet (2083). The ring motor (2082) is coaxially arranged with the aperture structure and is used to drive the multiple blades (2081) to open and close synchronously.

9. The downhole in-situ testing system according to claim 1, characterized in that, The top of the penetration tool (2) is provided with a connection structure (218), which is configured to form a releasable mechanical connection with the grabber of the deck recovery device. The wireless communication module (202) is built into or fixed to the connection structure (218). The telemetry and control cabin (203) integrates at least a telemetry and control module, a data acquisition module, an acoustic receiving module, and a battery module. The battery module is used to power the wireless communication module (202), the telemetry and control module, the data acquisition module, and the execution module on the penetration tool (2).

10. A mud-driven in-situ static cone penetration test method, characterized in that, The in-situ static cone penetration test method, comprising the downhole in-situ testing system according to any one of claims 1-9, includes the following steps: The penetration tool (2) is pre-installed and fixed in the bottom drill assembly (1), and is connected together with the drill pipe. It is lowered into the formation to start the drilling operation and drill into the formation. After the drill pipe is drilled to the specified depth, the movable sealing component (207) is remotely activated to drive the movable sealing component (207) to move to the first position, the mud flow channel (3) is closed, and then mud is continuously injected into the drill pipe; Using the mud in the mud channel (3) as the driving medium, the mud is transported to the piston rodless chamber through the switching module, pushing the piston (211) and the probe rod (212) connected thereto to extend out, so as to carry out static penetration operation through the probe (213); The flow rate of mud entering the piston rodless chamber is monitored in real time. The real-time position and speed of the probe (212) are calculated based on the mud flow rate. The calculated data is compared with the preset constant value. By adjusting the input flow rate of mud, the probe (212) is made to penetrate at the constant speed. When the displacement of the probe (212) calculated according to the flow rate reaches the preset penetration stroke value, the flow path of the switching module is automatically switched so that the mud enters the piston rod chamber, drives the piston (211) and probe (212) to retract, and at the same time discharges the mud in the piston rodless chamber. After the probe (212) is retrieved, the movable sealing component (207) is automatically retracted, and the mud flow channel (3) is reopened; Repeat the process until the in-situ testing is completed.

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