Impact oscillation excitation self-adaptive control method and system in high-temperature and high-pressure environment

Abstract

The invention relates to the technical field of mechanical control, and discloses an impact oscillation excitation self-adaptive control method and system in a high-temperature and high-pressure environment, and the method comprises the steps: enabling an impact oscillator to enter a shaft, and controlling high-temperature and high-pressure drilling fluid in the shaft to make contact with a pressure sensing diaphragm and a heat conduction fin on the outer wall of the impact oscillator; when the pressure value of the high-temperature and high-pressure drilling fluid exceeds a preset pressure threshold value and the temperature value of the high-temperature and high-pressure drilling fluid exceeds a preset temperature threshold value, the low-boiling-point working medium filled in the phase change cavity is subjected to liquid-gas phase change expansion through the pressure sensing diaphragm and the heat conduction fins; the angle-volume increasing relation between the valve element and the phase change state working medium is kept through the driving piston and the cam mechanism, so that the drift diameter area of the flow channel is adjusted; and the impact frequency and the impact force of the impact oscillator are adaptively controlled through the adjusted drift diameter area. According to the invention, the reliability of adaptive control can be improved.

Description

Technical Field

[0001] This invention relates to an adaptive control method and system for impact oscillation excitation under high temperature and high pressure environment, belonging to the field of mechanical control technology. Background Technology

[0002] In high-temperature and high-pressure downhole environments, drilling and production tools for oil and gas need to be adapted to these conditions. Commonly used drilling and production tools adapted to high-temperature and high-pressure downhole environments include impact oscillators. Impact oscillators are important downhole power tools that can assist in rock breaking downhole by generating high-frequency impact loads. They can also effectively improve the rate of drilling and mitigate stick-slip vibrations. The core performance indicators of impact oscillators include impact frequency and impact force, which need to be matched with the real-time changes in downhole temperature and pressure conditions. In addition, adaptive control methods refer to methods that enable impact oscillators to autonomously adjust their working parameters to cope with changes in the downhole environment without relying too much on surface intervention. Adaptive control methods can maintain a suitable working state in different environments, which is of great significance for the development of deep and ultra-deep oil and gas resources.

[0003] Currently, most methods for achieving adaptive control of downhole tools rely on electronic sensors, microprocessors, and electrically controlled valves. These methods collect downhole data through electronic sensors, process the data using algorithms in the microprocessor, issue commands, and execute adaptive operations using electrically controlled valves. However, electronic sensors and microprocessors are at risk of failure in continuous high-temperature environments, and their lifespan and stability decrease with increasing temperature. Secondly, systems relying on electronic sensors, microprocessors, and electrically controlled valves are highly dependent on a continuous power supply for normal operation, but it is difficult to guarantee a long-term, stable power supply in the harsh downhole environment. Finally, systems relying on electronic sensors, microprocessors, and electrically controlled valves require more interfaces and wiring. Because the entire adaptive control device is relatively complex, a problem with any interface or wiring will affect the execution of the entire control process.

[0004] Therefore, the reliability of existing technologies is insufficient. Summary of the Invention

[0005] This invention provides an adaptive control method and system for impact oscillation excitation under high temperature and high pressure environment, the main purpose of which is to improve the reliability of adaptive control.

[0006] To achieve the above objectives, the present invention provides an adaptive control method for impact oscillation excitation under high temperature and high pressure environment, comprising: An adaptive excitation structure for an impact oscillator is determined, wherein the adaptive excitation structure includes a phase change cavity, a drive piston, a cam mechanism, a valve core, and a flow channel; After the impact oscillator is lowered into the wellbore, the high-temperature and high-pressure drilling fluid in the wellbore is controlled to contact the pressure-sensitive diaphragm and heat-conducting fins on the outer wall of the impact oscillator. When the pressure value of the high-temperature and high-pressure drilling fluid exceeds the preset pressure threshold and the temperature value exceeds the preset temperature threshold, the pressure-sensitive diaphragm and the heat-conducting fins are used to expand the low-boiling-point working fluid filled in the phase change cavity into a liquid-gas phase change to obtain a phase change state working fluid. The angle-volume increasing relationship between the valve core and the phase-change working fluid is maintained by the drive piston and the cam mechanism to adjust the flow channel area and obtain the adjusted flow channel area. The impact frequency and impact force of the impact oscillator are adaptively controlled by the adjusted bore area to obtain an adaptive control result.

[0007] Optionally, determining the adaptive excitation structure of the impact oscillator includes: Pentane and Freon are mixed to form a low-boiling-point working fluid; The phase change cavity is determined to be filled with the low-boiling-point working fluid; Connect the outlet end of the phase change cavity to a drive piston; Connect the output end of the drive piston to the input end of the cam mechanism; Connect the output end of the cam mechanism to the valve core; The valve core is deployed within the flow channel to determine the adaptive excitation structure of the impact oscillator.

[0008] Optionally, the mixing of pentane and Freon to form a low-boiling-point working fluid includes: The highest temperature and pressure in the wellbore were simulated separately to obtain the simulated highest temperature and pressure. The simulated maximum temperature and simulated maximum pressure are converted into the final maximum temperature and final maximum pressure using preset error values, respectively. The mixing ratio between pentane and Freon is back-analyzed using the final maximum temperature and the final maximum pressure to ensure that the mixture of pentane and Freon undergoes volume expansion when it is at the final maximum temperature and the final maximum pressure. The actual maximum temperature and actual maximum pressure of the mixture under the specified mixing ratio conditions when volume expansion occurs were measured. When the first error value between the actual maximum temperature and the final maximum temperature and the second error value between the actual maximum pressure and the final maximum pressure are both not greater than the preset error value, the mixture under the mixing ratio conditions is used as a low-boiling-point working fluid. When the first error value and the second error value are greater than the preset error value, the final maximum temperature and the final maximum pressure are updated with the actual maximum temperature and the actual maximum pressure, respectively, and then the process of back-analyzing the mixing ratio between pentane and Freon is returned to the above steps.

[0009] Optionally, after determining the adaptive excitation structure of the shock oscillator, the method further includes: The phase change cavity is fixed to the outer wall of the impact oscillator via a pressure-sensitive diaphragm and heat-conducting fins.

[0010] Optionally, controlling the high-temperature, high-pressure drilling fluid inside the wellbore to contact the pressure-sensitive diaphragm and heat-conducting fins on the outer wall of the impact oscillator includes: The pressure-sensitive diaphragm and the heat-conducting fins are directly exposed to the high-temperature and high-pressure drilling fluid to control the high-temperature and high-pressure drilling fluid in the wellbore to contact the pressure-sensitive diaphragm and the heat-conducting fins on the outer wall of the impact oscillator.

[0011] Optionally, the step of using the pressure-sensitive diaphragm and the thermally conductive fins to perform liquid-gas phase change expansion of the low-boiling-point working fluid filled in the phase change cavity to obtain a working fluid in a phase change state includes: When the pressure-sensitive diaphragm deforms under pressure and the heat-conducting fins heat up, the pressure of the high-temperature and high-pressure drilling fluid is transferred to the phase change cavity through the pressure-sensitive diaphragm, and the heat of the high-temperature and high-pressure drilling fluid is transferred to the phase change cavity through the heat-conducting fins, so as to cause the low-boiling-point working fluid to undergo liquid-gas phase change expansion and obtain a working fluid in a phase change state.

[0012] Optionally, maintaining the angle-volume increasing relationship between the valve core and the phase-change working fluid using the drive piston and the cam mechanism includes: The working fluid in the phase change state is used to drive the driving piston to move in a straight line. The rotation angle of the valve core is calculated based on the displacement of the driving piston when it moves in a straight line. Based on the rotation angle, the valve core is rotated using the cam mechanism to maintain the angle-volume increasing relationship between the valve core and the phase-change working fluid.

[0013] Optionally, adjusting the flow channel's diameter area to obtain the adjusted diameter area includes: When the valve core rotates, the flow channel diameter area is adjusted to obtain the adjusted flow channel area.

[0014] Optionally, the adaptive control of the impact frequency and impact force of the impact oscillator through the adjusted bore area to obtain the adaptive control result includes: By using the stepless adjustment of the adjusted bore area to drive the piston to impact the oscillating hammer in the impact oscillator, the impact frequency and impact force are adjusted to obtain an adaptive control result.

[0015] To address the above problems, the present invention also provides an adaptive control system for impact oscillation excitation under high temperature and high pressure conditions, the system comprising: The structure determination module is used to determine the adaptive excitation structure of the impact oscillator, wherein the adaptive excitation structure includes a phase change cavity, a drive piston, a cam mechanism, a valve core, and a flow channel; The drilling fluid contact module is used to control the high-temperature and high-pressure drilling fluid in the wellbore to contact the pressure-sensitive diaphragm and heat-conducting fins on the outer wall of the impact oscillator after the impact oscillator is lowered into the wellbore. The working fluid phase change module is used to expand the low-boiling-point working fluid filled in the phase change cavity by liquid-gas phase change using the pressure-sensing diaphragm and the heat-conducting fins when the pressure value of the high-temperature and high-pressure drilling fluid exceeds the preset pressure threshold and the temperature value exceeds the preset temperature threshold, so as to obtain the working fluid in a phase change state. An area adjustment module is used to maintain the angle-volume increasing relationship between the valve core and the phase-change working fluid by utilizing the drive piston and the cam mechanism, so as to adjust the flow channel diameter area and obtain the adjusted flow channel area. An adaptive control module is used to adaptively control the impact frequency and impact force of the impact oscillator through the adjusted bore area to obtain an adaptive control result.

[0016] Compared to the problems described in the background art, the embodiments of the present invention, by constructing an excitation structure composed of mechanical components, fundamentally eliminate electronic sensing and control units that are prone to failure under high temperature and high pressure environments. This provides the material prerequisite for subsequent realization of fully mechanical adaptive control that does not rely on electrical energy, ultimately achieving the goal of enhancing reliability. The embodiments of the present invention establish an environmental energy harvesting device through a pressure-sensitive diaphragm and heat-conducting fins, and allow the pressure-sensitive diaphragm and heat-conducting fins to be directly exposed to the drilling fluid. This ensures that changes in downhole environmental temperature and pressure can be efficiently and without delay sensed and transmitted to the low-boiling-point working fluid via the pressure-sensitive diaphragm and heat-conducting fins, providing an accurate and direct power source for subsequent phase change triggering. This avoids signal attenuation or distortion that may result from indirect measurement. The embodiments of the present invention utilize the high-temperature and high-pressure phase change characteristics of the low-boiling-point working fluid to utilize environmental energy that is difficult to directly access. Thermal and pressure energy are converted into workable mechanical energy, and this process is only triggered when the environment exceeds the design conditions, achieving adaptive mechanical control. In this embodiment, a cam mechanism converts the linear displacement of the piston into the rotation angle of the valve core. A continuous, stepless mechanical displacement is converted into the valve core's rotation angle and subsequent flow area according to a pre-designed, fixed correspondence. This mechanical fixed mapping reduces the involvement of microcontroller algorithms and enhances the anti-interference capability of the control process through direct mechanical control, ensuring the reliability of the control results. This embodiment directly adjusts the flow rate and pressure of the high-temperature, high-pressure drilling fluid as it passes through the flow channel by changing the flow channel area, thereby steplessly changing the impact frequency and impact force of the impact oscillator, allowing the impact oscillator's output power to adaptively match the current downhole environment. Therefore, this invention improves the reliability of adaptive control. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating an adaptive control method for impact oscillation excitation under high temperature and high pressure conditions according to an embodiment of the present invention. Figure 2 This is a flowchart illustrating the adjustment area of ​​an adaptive control method for impact oscillation excitation under high temperature and high pressure conditions, provided in an embodiment of the present invention. Figure 3 This is a schematic diagram of a module for implementing the adaptive control system for impact oscillation excitation under high temperature and high pressure environment, according to an embodiment of the present invention.

[0018] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0020] This application provides an adaptive control method for shock oscillation excitation under high temperature and high pressure conditions. The executing entity of this adaptive control method for shock oscillation excitation under high temperature and high pressure conditions includes, but is not limited to, at least one of the following electronic devices that can be configured to execute the method provided in this application: a server, a terminal, etc. In other words, the adaptive control method for shock oscillation excitation under high temperature and high pressure conditions can be executed by software or hardware installed on a terminal device or a server device. The server includes, but is not limited to, a single server, a server cluster, a cloud server, or a cloud server cluster.

[0021] Reference Figure 1 The diagram shown is a flowchart illustrating an adaptive control method for impact oscillation excitation under high temperature and high pressure conditions according to an embodiment of the present invention. In this embodiment, the adaptive control method for impact oscillation excitation under high temperature and high pressure conditions includes: S1. Determine the adaptive excitation structure of the impact oscillator, wherein the adaptive excitation structure includes a phase change cavity, a drive piston, a cam mechanism, a valve core, and a flow channel.

[0022] This invention, by constructing an excitation structure composed of mechanical components, fundamentally eliminates electronic sensing and control units that are prone to failure under high temperature and high pressure environments. This provides the material basis for the subsequent realization of fully mechanical adaptive control that does not rely on electrical energy, and ultimately enhances reliability.

[0023] In one embodiment of the present invention, determining the adaptive excitation structure of the impact oscillator includes: mixing pentane and Freon to form a low-boiling-point working fluid; determining a phase change cavity filled with the low-boiling-point working fluid; connecting the outlet end of the phase change cavity to a drive piston; connecting the output end of the drive piston to the input end of a cam mechanism; connecting the output end of the cam mechanism to a valve core; and deploying the valve core within a flow channel to determine the adaptive excitation structure of the impact oscillator.

[0024] The low-boiling-point working fluid refers to a homogeneous liquid mixture of n-pentane and Freon R123. During subsequent preparation, the low-boiling-point working fluid undergoes a liquid-gas phase change expansion under predetermined temperature and pressure conditions. This expansion causes an instantaneous increase in the volume of the low-boiling-point working fluid, pushing the piston to move linearly. Furthermore, the low-boiling-point working fluid is injected into the phase change chamber in a single, liquid state. The phase change chamber is a thick-walled cylindrical shape, with both ends welded and sealed, leaving only tiny through-holes as outlets. Pressure-sensitive diaphragms and heat-conducting fins are welded to the outer surface of the sidewalls of the phase change chamber. It should be noted that the outer surface of the sidewalls of the phase change chamber forms part of the outer wall of the impact oscillator and is in direct contact with the high-temperature, high-pressure drilling fluid inside the wellbore. In other words, a portion of the outer wall of the impact oscillator is selected to embed a pressure-sensitive diaphragm and heat-conducting fins. This outer wall also serves as the sidewall of the phase change cavity. This design ensures that when the pressure-sensitive diaphragm and heat-conducting fins come into contact with the high-temperature, high-pressure drilling fluid, they can transfer the received pressure and temperature to the sidewall of the phase change cavity, and ultimately to the low-boiling-point working fluid filled within the phase change cavity. When the received heat and pressure energy reach certain temperature and pressure levels, the low-boiling-point working fluid will spontaneously expand in volume. Furthermore, it should be noted that the phase change cavity is coaxially positioned within the impact oscillator housing, with its centerline parallel to the impact oscillator axis and its outlet end facing the piston. The driving piston is a solid cylindrical piston, and the front end of the driving piston... The piston is a planar pressure-bearing end with a push rod at the rear. The driving piston is pushed forward by the increased volume of the expanding working fluid, converting the volume change into linear displacement. The front end of the driving piston fits into the outlet hole of the phase change chamber. The push rod passes through the sealing guide sleeve and extends out of the chamber, maintaining constant contact with the rollers of the cam mechanism. The cam mechanism is a cylindrical cam with a helical inclined surface, including the inclined surface lift and the cam outer diameter. The inner hole of the cam mechanism has a spline, which coaxially engages with the corresponding spline on the outer surface of the valve core to transmit the cam torque to the valve core. The cam mechanism converts the linear displacement of the piston into the rotation angle of the valve core in a fixed proportion. The cam center hole is fitted onto the valve core shaft, and the inclined surface forms a rolling contact with the rollers at the end of the piston push rod. The entire cam is encapsulated within a limiting ring in the inner cavity of the impact oscillator, allowing only rotation and no axial movement. The cam mechanism includes a ground-adjustable initial angle assembly, comprising an internal hexagonal sleeve that engages with the splined end of the camshaft and a locking nut. This nut is used to preset the valve core zero position according to well conditions before running it into the well, and to lock it after adjustment, enabling ground pre-adjustment of the impact frequency-impact force curve for different well sections. The internal hexagonal sleeve is located at the upper end of the tool, allowing adjustment and locking at the wellhead using a socket wrench. The lower end of the locking nut has a nylon insert anti-loosening ring, preventing loosening after applying torque. The valve core is cylindrical, with an involute throttling window milled into its sidewall. The valve core is used to infinitely adjust the drilling fluid flow rate by changing the overlap area between the window and the flow channel through rotation.The valve core is coaxially mounted at the center of a flow channel, positioned at both ends by bearings. Its rotation axis is perpendicular to the axis of the impact oscillator, and the window faces the axis of the flow channel. This flow channel, also known as a straight hole, penetrates the body of the impact oscillator, connecting upstream to the mud inlet and downstream to the oscillating hammer. It provides a passage for drilling fluid and transfers the throttled drilling fluid with flow rate and pressure from the valve core downstream. The flow channel and valve core are coaxially mounted, with the valve core completely located inside the flow channel. The window of the valve core is a variable cross-section section of the flow channel.

[0025] In another embodiment of the present invention, the mixing of pentane and Freon as a low-boiling-point working fluid includes: simulating the highest temperature and highest pressure of the wellbore to obtain simulated highest temperature and simulated highest pressure; converting the simulated highest temperature and simulated highest pressure into final highest temperature and final highest pressure using preset error values; using the final highest temperature and final highest pressure to back-analyze the mixing ratio between pentane and Freon to ensure that the mixture between pentane and Freon undergoes volume expansion at the final highest temperature and final highest pressure; and measuring the mixing ratio under the specified mixing conditions. The actual highest temperature and actual highest pressure when the mixture undergoes volume expansion; when the first error value between the actual highest temperature and the final highest temperature and the second error value between the actual highest pressure and the final highest pressure are both not greater than the preset error value, the mixture under the mixing ratio conditions is used as a low-boiling-point working fluid; when the first error value and the second error value are greater than the preset error value, the final highest temperature and the final highest pressure are updated with the actual highest temperature and the actual highest pressure respectively, and then the process of back-analyzing the mixing ratio between pentane and Freon is returned to the above steps.

[0026] For example, the simulated maximum temperature and pressure of the wellbore are obtained by simulating the simulated maximum temperature and pressure, for example: using Landmark WellPlan software, measuring the current well depth (4500m), geothermal gradient (3.5 degrees Celsius per 100m), design mud density (1.85 grams per cubic centimeter), and maximum discharge rate (28 L / s), and inputting the above parameters of the current well into the Landmark WellPlan software. The WellPlan software calculates the equivalent circulating temperature and equivalent circulating pressure at the bottom of the well. These are the simulated maximum temperature and pressure. Further, the simulated maximum temperature and pressure are converted to the final maximum temperature and pressure using preset error values. For example, an acceptable standard and measured error can be set manually, randomly selecting one from 5% to 10% as the preset error value. When 5% is selected, the final maximum temperature = simulated maximum temperature * (1 + 0.05). The calculation of the final maximum pressure is similar. Further, the final maximum temperature and pressure are used to back-analyze the mixing ratio between pentane and Freon. For example, using NIST... REFPROP establishes a binary mixture model between pentane and R123. Under the condition of the final maximum pressure, ensuring that the bubble point temperature of the binary mixture model is the final maximum temperature, the determined mass fraction ratio of the binary mixture model is the mixing ratio. Furthermore, the actual maximum temperature and actual maximum pressure at which the mixture under the mixing ratio conditions undergoes volume expansion can be obtained by, for example, by filling the mixture under the mixing ratio conditions into a visual reactor, using a displacement sensor to determine when the mixture undergoes volume expansion, and recording the reaction temperature and pressure at the moment when volume expansion begins.

[0027] In one embodiment of the present invention, after determining the adaptive excitation structure of the impact oscillator, the method further includes: fixing the phase change cavity to the pressure-sensitive diaphragm and heat-conducting fins of the outer wall of the impact oscillator.

[0028] For example, the pressure-sensitive diaphragm and heat-conducting fins are made of nickel-based high-temperature alloy Inconel 718 with a thickness in the range of [0.25 mm, 0.35 mm]. They are laser-welded to the sidewall of the phase change cavity with a weld penetration depth in the range of [0.20 mm, 0.30 mm]. An erosion test is performed on the Inconel 718 specimens made of the pressure-sensitive diaphragm and heat-conducting fins according to ASTM G76 standard. Specifically, the nozzle angle is set to 90 degrees, the air velocity is in the range of [25 m / s, 35 m / s], the quartz sand particle size is 50-200 μm, the sand flow rate is in the range of [0.2 kg / min, 0.4 kg / min], and the test time is in the range of [60 h, 80 h]. No penetrating pits are observed on the specimen surface before and after the test. The test is conducted at 250 degrees Celsius and 100 MPa, with a oscillation frequency of [20 Hz, ...]. Accelerated fatigue simulation of the weld was performed using fatigue frequencies within the range of 30Hz. No penetrating cracks were observed after the simulation. This result serves as the accelerated evaluation benchmark for 1000-hour working life in downhole applications, meeting the accelerated testing principles of API 7K for fatigue assessment of downhole tools. Furthermore, a layer of nickel foam metal was welded onto the inner wall of the phase change cavity. The porosity was within the range of 80%, 90%, the pore density was within the range of 40%, 50%, and the thickness was within the range of 1.5mm, 2.5mm. This shortens the thermal boundary layer of the working fluid. The one-dimensional liquid-gas phase change expansion-heat transfer model shows that the response time of the traditional cavity is within the range of 2.5s, 3.5s, while that after adding the foam metal is within the range of 0.7s, 1.1s. The one-dimensional liquid-gas phase change expansion-heat transfer model adopts the Peng-Robinson equation of state, and the boundary conditions are determined by NIST REFPROP. Version 10.0 provides that 60wt% n-pentane and 40wt% Freon R123 are filled into a visual vessel, the outer wall is steppedly heated to 250 degrees Celsius, and the piston's initial displacement is recorded by camera. The three averages are within the range of [0.8s, 0.9s]. The liquid-gas phase change expansion is calibrated by the ground-based visual vessel and corresponds linearly to the piston displacement.

[0029] S2. After the impact oscillator is lowered into the wellbore, the high-temperature and high-pressure drilling fluid in the wellbore is controlled to contact the pressure-sensitive diaphragm and heat-conducting fins on the outer wall of the impact oscillator.

[0030] This invention establishes an environmental energy harvesting device using a pressure-sensitive diaphragm and heat-conducting fins, and exposes the pressure-sensitive diaphragm and heat-conducting fins directly to the drilling fluid. This ensures that changes in downhole ambient temperature and pressure can be efficiently and without delay sensed and transmitted to the low-boiling-point working fluid via the pressure-sensitive diaphragm and heat-conducting fins, providing an accurate and direct power source for subsequent phase change triggering and avoiding signal attenuation or distortion that may result from indirect measurement.

[0031] In one embodiment of the present invention, controlling the high-temperature and high-pressure drilling fluid in the wellbore to contact the pressure-sensitive diaphragm and heat-conducting fins on the outer wall of the impact oscillator includes: controlling the pressure-sensitive diaphragm and the heat-conducting fins to be directly exposed to the high-temperature and high-pressure drilling fluid, so as to control the high-temperature and high-pressure drilling fluid in the wellbore to contact the pressure-sensitive diaphragm and heat-conducting fins on the outer wall of the impact oscillator.

[0032] S3. When the pressure value of the high-temperature and high-pressure drilling fluid exceeds the preset pressure threshold and the temperature value exceeds the preset temperature threshold, the low-boiling-point working fluid filled in the phase change cavity is expanded by liquid-gas phase change using the pressure-sensitive diaphragm and the heat-conducting fins to obtain the working fluid in the phase change state.

[0033] This invention utilizes the high-temperature and high-pressure phase change characteristics of a low-boiling-point working fluid to convert environmental thermal and pressure energy, which are difficult to use directly, into mechanical energy that can perform work. Moreover, it is only triggered when the environment exceeds the design conditions, thus achieving adaptive control of the machinery.

[0034] In one embodiment of the present invention, the step of using the pressure-sensitive diaphragm and the heat-conducting fins to perform liquid-gas phase change expansion of the low-boiling-point working fluid filled in the phase change cavity to obtain a phase change working fluid includes: when the pressure-sensitive diaphragm undergoes pressure deformation and the heat-conducting fins undergo heating, the pressure of the high-temperature and high-pressure drilling fluid is transferred to the phase change cavity through the pressure-sensitive diaphragm, and the heat of the high-temperature and high-pressure drilling fluid is transferred to the phase change cavity through the heat-conducting fins, so as to perform liquid-gas phase change expansion of the low-boiling-point working fluid to obtain a phase change working fluid.

[0035] S4. By using the drive piston and the cam mechanism to maintain the angle-volume increasing relationship between the valve core and the phase change working fluid, the flow channel diameter area is adjusted to obtain the adjusted flow channel diameter area.

[0036] In this embodiment of the invention, the linear displacement of the piston is converted into the rotation angle of the valve core through a cam mechanism. A continuous, stepless mechanical displacement is converted into the rotation angle of the valve core and the subsequent flow area according to a pre-designed, fixed correspondence. This mechanical fixed mapping reduces the involvement of microcontroller algorithms and enhances the anti-interference ability in the control process through direct mechanical control, thus ensuring the reliability of the control results.

[0037] In one embodiment of the present invention, maintaining the angle-volume increasing relationship between the valve core and the phase-change working medium using the driving piston and the cam mechanism includes: using the phase-change working medium to drive the driving piston to move in a straight line; calculating the rotation angle of the valve core based on the driving piston displacement of the driving piston during the straight line movement; and using the cam mechanism to rotate the valve core based on the rotation angle, so as to maintain the angle-volume increasing relationship between the valve core and the phase-change working medium.

[0038] As another embodiment, calculating the rotation angle of the valve core based on the displacement of the driving piston during linear motion includes: calculating the rotation angle of the valve core using the following formula based on the displacement of the driving piston during linear motion:

[0039] in, Indicates the rotation angle. This represents the calibration coefficient between the historical rotation angle and the historical expansion volume. This represents the expansion volume of the working fluid in the phase transition state. Indicates the displacement of the driving piston. This represents the effective cross-sectional area of ​​the driving piston.

[0040] It should be noted that, This indicates the distance the piston is pushed out by the expanding gas. This represents the cross-sectional area of ​​the piston head. This represents the additional volume that the working fluid expands due to the phase transition. This indicates how much expansion volume the valve core needs to absorb for every 1 degree of rotation. (Regarding the formula...) The piston was pushed out. After the length is increased, it is equivalent to giving up a section of cylindrical volume in the plunger cavity. This refers to the extra volume of the working fluid that is filled by the expanding gas. Since the expansion volume is not easy to measure, it is determined by measuring the displacement of the driven piston. Furthermore, a temperature-controlled autoclave was used to simulate the displacement of the driven piston under different temperature and pressure conditions. With corner The least squares method was used to fit the result. The specific value.

[0041] In one embodiment of the present invention, adjusting the flow channel diameter area to obtain the adjusted flow channel diameter area includes: adjusting the flow channel diameter area to obtain the adjusted flow channel diameter area while the valve core is rotating.

[0042] It should be noted that the valve core is a cylinder with a throttling window of varying width along its side wall. Initially, the beginning of the window is completely offset from the flow channel, and the flow area is zero. As the valve core rotates, the window gradually coincides with the flow channel, and the flow area monotonically increases. When the windows completely coincide... When the flow channel is fully open, rotating in the opposite direction will cause the opening to shrink until it closes.

[0043] As another embodiment, adjusting the flow channel's diameter area to obtain the adjusted diameter area includes: adjusting the flow channel's diameter area using the following formula to obtain the adjusted diameter area:

[0044] in, This indicates the adjusted bore area. This indicates the maximum fully open area of ​​the throttling window on the valve core. Indicates the maximum design rotation angle of the valve core. Indicates the rotation angle. This represents the normalization coefficient.

[0045] It should be noted that here It's a 90-degree angle, used to turn corners. Mapped linearly to the 0 to 90 degree range, The function is exactly between 0 degrees and It monotonically increases from 0 to 1 within the range.

[0046] S5. The impact frequency and impact force of the impact oscillator are adaptively controlled by the adjusted bore area to obtain the adaptive control result.

[0047] This invention directly adjusts the flow rate and pressure of high-temperature and high-pressure drilling fluid as it passes through the flow channel by changing the flow channel diameter area, thereby steplessly changing the impact frequency and impact force of the impact oscillator, enabling the output power of the impact oscillator to adaptively match the current downhole environment.

[0048] In one embodiment of the present invention, the adaptive control of the impact frequency and impact force of the impact oscillator by means of the adjusted bore area to obtain an adaptive control result includes: using the adjusted bore area to steplessly adjust the impact frequency and impact force of the driving piston impacting the swing hammer in the impact oscillator to obtain an adaptive control result.

[0049] Optionally, the stepless adjustment of the adjusted pipe diameter area to drive the piston to impact the oscillating hammer in the impact oscillator to obtain an adaptive control result means that: when the pipe diameter area increases, the flow rate through the flow channel increases, the piston return is faster and the cycle is shortened, and the impact frequency automatically increases; when the pipe diameter area decreases, the pressure per stroke increases and the impact force automatically increases, thereby realizing adaptive control of the impact frequency and impact force of the impact oscillator.

[0050] Furthermore, to better understand the adaptive control logic and effect data in the above-mentioned adaptive control method for shock oscillation excitation under high temperature and high pressure environment, please refer to Table 1 below, which is a table of adaptive control logic and effect data in the adaptive control method for shock oscillation excitation under high temperature and high pressure environment provided by an embodiment of the present invention.

[0051] Table 1 Adaptive Control Logic and Effect Data Table

[0052] As can be clearly seen from Table 1 above, in the adaptive control method for shock oscillation excitation under high temperature and high pressure environment, adaptive control can be automatically achieved without the participation of microcontrollers or other algorithms. It should also be noted that all the above calculation formulas are only intended to more clearly describe the implementation logic of the mechanical process. In actual control, it is not necessary to perform the calculations of the formulas.

[0053] See Figure 2 The diagram shown is a flowchart illustrating the adjustment area of ​​an adaptive control method for impact oscillation excitation under high temperature and high pressure conditions, according to an embodiment of the present invention. Figure 2 In the process, the high-temperature and high-pressure drilling fluid first contacts the diaphragm and fins, transferring heat and force into the phase change chamber. The working fluid inside the chamber expands, the piston moves linearly, the cam mechanism switches, the valve core rotates, and the flow channel diameter area is adjusted steplessly, ultimately achieving adaptive excitation of the impact oscillator. It should also be noted that high-temperature and high-pressure drilling fluid does not mean that the drilling fluid is high-temperature and high-pressure, but rather that the downhole environment is high-temperature and high-pressure.

[0054] It should be noted that this invention is not intended to replace electronic control systems, but rather to provide a purely mechanical redundant control path that does not rely on electrical energy, specifically for scenarios where electronic sensors and microprocessors are prone to failure under ultra-high temperature and high pressure environments. Although its response characteristics are fixed, it has irreplaceable reliability advantages under extreme environments.

[0055] Compared to the problems described in the background art, the embodiments of the present invention, by constructing an excitation structure composed of mechanical components, fundamentally eliminate electronic sensing and control units that are prone to failure under high temperature and high pressure environments. This provides the material prerequisite for subsequent realization of fully mechanical adaptive control that does not rely on electrical energy, ultimately achieving the goal of enhancing reliability. The embodiments of the present invention establish an environmental energy harvesting device through a pressure-sensitive diaphragm and heat-conducting fins, and allow the pressure-sensitive diaphragm and heat-conducting fins to be directly exposed to the drilling fluid. This ensures that changes in downhole environmental temperature and pressure can be efficiently and without delay sensed and transmitted to the low-boiling-point working fluid via the pressure-sensitive diaphragm and heat-conducting fins, providing an accurate and direct power source for subsequent phase change triggering. This avoids signal attenuation or distortion that may result from indirect measurement. The embodiments of the present invention utilize the high-temperature and high-pressure phase change characteristics of the low-boiling-point working fluid to utilize environmental energy that is difficult to directly access. Thermal and pressure energy are converted into workable mechanical energy, and this process is only triggered when the environment exceeds the design conditions, achieving adaptive mechanical control. In this embodiment, a cam mechanism converts the linear displacement of the piston into the rotation angle of the valve core. A continuous, stepless mechanical displacement is converted into the valve core's rotation angle and subsequent flow area according to a pre-designed, fixed correspondence. This mechanical fixed mapping reduces the involvement of microcontroller algorithms and enhances the anti-interference capability of the control process through direct mechanical control, ensuring the reliability of the control results. This embodiment directly adjusts the flow rate and pressure of the high-temperature, high-pressure drilling fluid as it passes through the flow channel by changing the flow channel area, thereby steplessly changing the impact frequency and impact force of the impact oscillator, allowing the impact oscillator's output power to adaptively match the current downhole environment. Therefore, this invention improves the reliability of adaptive control.

[0056] like Figure 3 The diagram shown is a functional block diagram of an adaptive control system for impact oscillation excitation under high temperature and high pressure environment according to the present invention.

[0057] The adaptive control system 300 for impact oscillation excitation under high temperature and high pressure environment described in this invention can be installed in an electronic device. Depending on the functions implemented, the adaptive control system for impact oscillation excitation under high temperature and high pressure environment may include a structure determination module 301, a drilling fluid contact module 302, a working fluid phase change module 303, an area adjustment module 304, and an adaptive control module 305. The module described in this invention can also be called a unit, which refers to a series of computer program segments that can be executed by the processor of an electronic device and can perform a fixed function, and is stored in the memory of the electronic device.

[0058] In this embodiment of the invention, the functions of each module / unit are as follows: The structure determination module 301 is used to determine the adaptive excitation structure of the impact oscillator, wherein the adaptive excitation structure includes a phase change cavity, a drive piston, a cam mechanism, a valve core, and a flow channel. The drilling fluid contact module 302 is used to control the high-temperature and high-pressure drilling fluid in the well to contact the pressure-sensitive diaphragm and heat-conducting fins on the outer wall of the impact oscillator after the impact oscillator is lowered into the well. The working fluid phase change module 303 is used to expand the low-boiling-point working fluid filled in the phase change cavity by liquid-gas phase change using the pressure-sensing diaphragm and the heat-conducting fins when the pressure value of the high-temperature and high-pressure drilling fluid exceeds the preset pressure threshold and the temperature value exceeds the preset temperature threshold, so as to obtain the working fluid in the phase change state. The area adjustment module 304 is used to maintain the angle-volume increasing relationship between the valve core and the phase change state working fluid by using the drive piston and the cam mechanism, so as to adjust the flow channel diameter area and obtain the adjusted flow channel area. The adaptive control module 305 is used to adaptively control the impact frequency and impact force of the impact oscillator through the adjusted bore area to obtain an adaptive control result.

[0059] In detail, the modules in the high-temperature and high-pressure environment impact oscillation excitation adaptive control system 300 described in this embodiment of the invention adopt the same characteristics as described above during use. Figure 1 The method used is the same as the adaptive control method for impact oscillation excitation under high temperature and high pressure conditions described above, and can produce the same technical effect, so it will not be elaborated here.

[0060] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0061] Finally, it should be noted that in the above embodiments, each embodiment can be combined with each other or independent. Deleting any one of them will not affect the technical implementation of other embodiments. The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. 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 spirit and scope of the technical solutions of the present invention.

Claims

1. An adaptive control method for impact oscillation excitation under high temperature and high pressure environment, characterized in that, The method includes: An adaptive excitation structure for an impact oscillator is determined, wherein the adaptive excitation structure includes a phase change cavity, a drive piston, a cam mechanism, a valve core, and a flow channel; After the impact oscillator is lowered into the wellbore, the high-temperature and high-pressure drilling fluid in the wellbore is controlled to contact the pressure-sensitive diaphragm and heat-conducting fins on the outer wall of the impact oscillator. When the pressure value of the high-temperature and high-pressure drilling fluid exceeds the preset pressure threshold and the temperature value exceeds the preset temperature threshold, the pressure-sensitive diaphragm and the heat-conducting fins are used to expand the low-boiling-point working fluid filled in the phase change cavity into a liquid-gas phase change to obtain a phase change state working fluid. The angle-volume increasing relationship between the valve core and the phase-change working fluid is maintained by the drive piston and the cam mechanism to adjust the flow channel area and obtain the adjusted flow channel area. The impact frequency and impact force of the impact oscillator are adaptively controlled by the adjusted bore area to obtain an adaptive control result.

2. The adaptive control method for impact oscillation excitation under high temperature and high pressure environment as described in claim 1, characterized in that, The determination of the adaptive excitation structure of the impact oscillator includes: Pentane and Freon are mixed to form a low-boiling-point working fluid; The phase change cavity is determined to be filled with the low-boiling-point working fluid; Connect the outlet end of the phase change cavity to a drive piston; Connect the output end of the drive piston to the input end of the cam mechanism; Connect the output end of the cam mechanism to the valve core; The valve core is deployed within the flow channel to determine the adaptive excitation structure of the impact oscillator.

3. The adaptive control method for impact oscillation excitation under high temperature and high pressure environment as described in claim 1, characterized in that, The process of mixing pentane and Freon to form a low-boiling-point working fluid includes: The highest temperature and pressure in the wellbore were simulated separately to obtain the simulated highest temperature and pressure. The simulated maximum temperature and simulated maximum pressure are converted into the final maximum temperature and final maximum pressure using preset error values, respectively. The mixing ratio between pentane and Freon is back-analyzed using the final maximum temperature and the final maximum pressure to ensure that the mixture of pentane and Freon undergoes volume expansion when it is at the final maximum temperature and the final maximum pressure. The actual maximum temperature and actual maximum pressure of the mixture under the specified mixing ratio conditions when volume expansion occurs were measured. When the first error value between the actual maximum temperature and the final maximum temperature and the second error value between the actual maximum pressure and the final maximum pressure are both not greater than the preset error value, the mixture under the mixing ratio conditions is used as a low-boiling-point working fluid. When the first error value and the second error value are greater than the preset error value, the final maximum temperature and the final maximum pressure are updated with the actual maximum temperature and the actual maximum pressure, respectively, and then the process of back-analyzing the mixing ratio between pentane and Freon is returned to the above steps.

4. The adaptive control method for impact oscillation excitation under high temperature and high pressure environment as described in claim 1, characterized in that, After determining the adaptive excitation structure of the impact oscillator, the method further includes: The phase change cavity is fixed to the outer wall of the impact oscillator via a pressure-sensitive diaphragm and heat-conducting fins.

5. The adaptive control method for impact oscillation excitation under high temperature and high pressure environment as described in claim 1, characterized in that, The control of the high-temperature, high-pressure drilling fluid in the wellbore to contact the pressure-sensitive diaphragm and heat-conducting fins on the outer wall of the impact oscillator includes: The pressure-sensitive diaphragm and the heat-conducting fins are directly exposed to the high-temperature and high-pressure drilling fluid to control the high-temperature and high-pressure drilling fluid in the wellbore to contact the pressure-sensitive diaphragm and the heat-conducting fins on the outer wall of the impact oscillator.

6. The adaptive control method for impact oscillation excitation under high temperature and high pressure environment as described in claim 1, characterized in that, The process of using the pressure-sensitive diaphragm and the heat-conducting fins to perform liquid-gas phase change expansion on the low-boiling-point working fluid filled in the phase change cavity to obtain a working fluid in a phase change state includes: When the pressure-sensitive diaphragm deforms under pressure and the heat-conducting fins heat up, the pressure of the high-temperature and high-pressure drilling fluid is transferred to the phase change cavity through the pressure-sensitive diaphragm, and the heat of the high-temperature and high-pressure drilling fluid is transferred to the phase change cavity through the heat-conducting fins, so as to cause the low-boiling-point working fluid to undergo liquid-gas phase change expansion and obtain a working fluid in a phase change state.

7. The adaptive control method for impact oscillation excitation under high temperature and high pressure environment as described in claim 1, characterized in that, The method of maintaining the angle-volume increasing relationship between the valve core and the phase-change working fluid using the drive piston and the cam mechanism includes: The working fluid in the phase change state is used to drive the driving piston to move in a straight line. The rotation angle of the valve core is calculated based on the displacement of the driving piston when it moves in a straight line. Based on the rotation angle, the valve core is rotated using the cam mechanism to maintain the angle-volume increasing relationship between the valve core and the phase-change working fluid.

8. The adaptive control method for impact oscillation excitation under high temperature and high pressure environment as described in claim 1, characterized in that, The process of adjusting the flow channel's diameter area to obtain the adjusted diameter area includes: When the valve core rotates, the flow channel diameter area is adjusted to obtain the adjusted flow channel area.

9. The adaptive control method for impact oscillation excitation under high temperature and high pressure environment as described in claim 1, characterized in that, The adaptive control of the impact frequency and impact force of the impact oscillator through the adjusted bore area to obtain the adaptive control result includes: By using the stepless adjustment of the adjusted bore area to drive the piston to impact the oscillating hammer in the impact oscillator, the impact frequency and impact force are adjusted to obtain an adaptive control result.

10. An adaptive control system for impact oscillation excitation under high temperature and high pressure environment, characterized in that, The system includes: The structure determination module is used to determine the adaptive excitation structure of the impact oscillator, wherein the adaptive excitation structure includes a phase change cavity, a drive piston, a cam mechanism, a valve core, and a flow channel; The drilling fluid contact module is used to control the high-temperature and high-pressure drilling fluid in the wellbore to contact the pressure-sensitive diaphragm and heat-conducting fins on the outer wall of the impact oscillator after the impact oscillator is lowered into the wellbore. The working fluid phase change module is used to expand the low-boiling-point working fluid filled in the phase change cavity by liquid-gas phase change using the pressure-sensing diaphragm and the heat-conducting fins when the pressure value of the high-temperature and high-pressure drilling fluid exceeds the preset pressure threshold and the temperature value exceeds the preset temperature threshold, so as to obtain the working fluid in a phase change state. An area adjustment module is used to maintain the angle-volume increasing relationship between the valve core and the phase-change working fluid by utilizing the drive piston and the cam mechanism, so as to adjust the flow channel diameter area and obtain the adjusted flow channel area. An adaptive control module is used to adaptively control the impact frequency and impact force of the impact oscillator through the adjusted bore area to obtain an adaptive control result.

Images