Data communication control system of variable prediction room formation tester

Abstract

The utility model discloses a data communication control system of a variable prediction room formation tester, which relates to the field of oil exploration, and solves the problem that interference is easy to generate when a direct current brushless motor is used in high-speed operation, a motor driver is connected with the direct current brushless motor, and grounding ends of a motor direct current power supply and the motor driver are suspended. The grounding end of the main control unit is physically grounded; the motor driver is connected with the first CAN isolation transceiver through a CAN bus, the main control unit is connected with the second CAN isolation transceiver through a CAN bus, and the first CAN isolation transceiver is connected with the second CAN isolation transceiver; the motor direct current power supply and the grounding end of the motor driver are suspended, the ground of the main control unit is not connected with the motor driver, the main control unit and the motor driver realize isolated communication through the CAN isolation transceiver, ground wires of equipment at the two ends are completely isolated, the equipment at the two ends can normally communicate, the anti-interference capability is improved, and the advantages of the direct current brushless motor in the logging instrument are fully played.

Description

Technical Field

[0001] The utility model relates to the field of petroleum exploration, in particular to a data communication control system of a variable prediction chamber formation tester. Background Art

[0002] In oil exploration and well testing, the use of formation testers can directly detect the formation pressure, permeability and formation fluid composition at any depth, which is of great significance for oil and gas development.

[0003] During formation testing, a motor drives a hydraulic pump to generate oil pressure, expanding the probe's support arm and pushing it toward the wellbore wall, further penetrating the probe into the formation. Formation fluid flows through the probe into the prediction chamber for measurement, thereby determining formation pressure and permeability. For low-permeability formations with poor permeability, a longer wait (waiting for the pressure to return to formation pressure) is required before measuring formation pressure and permeability. This prolonged wait can easily cause the logging cable and test instrument to become attached to the wellbore wall, potentially causing construction accidents.

[0004] Existing formation testers are mostly powered by brushless DC motors. These motors are gradually replacing AC motors due to their compact size, high output power, and high efficiency. However, brushless DC motors are prone to interference when operating at high speeds, which can reduce the reliability of data communication and control systems. In particular, errors in the control of motors and solenoid valves can cause instrument failures at best, and even construction accidents at worst.

[0005] Therefore, how to solve the problem that the brushless DC motor easily interferes with the control system when running at high speed is a technical problem that needs to be solved urgently by people in this field. Utility Model Content

[0006] The utility model aims to provide a data communication control system for a variable prediction chamber formation tester, which solves the problem that a brushless DC motor easily interferes with the control system when running at high speed.

[0007] In order to solve the above technical problems, the utility model provides a data communication control system for a variable prediction chamber formation tester, comprising:

[0008] Motor driver, main control unit, communication bus interface, first CAN isolation transceiver, second CAN isolation transceiver, motor DC power supply;

[0009] The motor DC power supply supplies power to the motor driver; the motor driver is connected to the brushless DC motor, the grounding terminals of the motor DC power supply and the motor driver are suspended grounds, and the grounding terminal of the main control unit is physically grounded;

[0010] The motor driver is connected to the first CAN isolation transceiver via a CAN bus, the main control unit is connected to the second CAN isolation transceiver via a CAN bus, and the first CAN isolation transceiver is connected to the second CAN isolation transceiver; the main control unit is connected to the communication bus interface, and the communication bus interface is connected to the ground operating system.

[0011] In another optional solution, the data communication control system of the variable prediction chamber formation tester further includes: a slave control unit, a solenoid valve driving module, and a data processing module;

[0012] The solenoid valve driving module is connected to the solenoid valve; the data processing module is connected to the sensor; the slave control unit is connected to the solenoid valve driving module and the data processing module respectively;

[0013] The slave control unit is connected to the master control unit, and a ground terminal of the slave control unit is a physical ground.

[0014] In another optional solution, in the data communication control system of the variable prediction chamber formation tester, the main control unit is connected to the quartz pressure gauge via an I2C bus;

[0015] Also included: a data processing sequential logic module;

[0016] The data processing sequential logic module is connected to the strain gauge, and the data processing sequential logic module is connected to the communication bus interface.

[0017] In another optional solution, in the data communication control system of the variable prediction chamber formation tester, the motor driver includes a hydraulic pump motor driver and a prediction chamber motor driver;

[0018] The hydraulic pump motor driver is connected to the hydraulic pump DC brushless motor, and the prediction chamber motor driver is connected to the prediction chamber DC brushless motor;

[0019] The prediction chamber brushless DC motor is a rotary brushless DC motor;

[0020] The hydraulic pump brushless DC motor is an inductive brushless DC motor.

[0021] In another optional solution, in the data communication control system of the above-mentioned variable prediction chamber formation tester, the sensors include: an oil pressure sensor, a motor high-pressure sampling sensor, a solenoid valve voltage sensor, a displacement sensor for detecting the change in the volume of the prediction chamber, and a low oil sensor for detecting the amount of hydraulic oil in the probe.

[0022] In another optional solution, in the data communication control system of the variable prediction chamber formation tester, the oil pressure sensor is connected to the analog-to-digital converter via an instrument amplifier;

[0023] The motor high-voltage sampling sensor is connected to the analog-to-digital converter via an isolation amplifier;

[0024] The solenoid valve voltage sensor is connected to the analog-to-digital converter via a filter amplifier;

[0025] The displacement sensor is connected to the analog-to-digital converter via a filter amplifier;

[0026] The low oil sensor is connected to the analog-to-digital converter via a filter amplifier;

[0027] Wherein, the analog-to-digital converter is connected to the slave control unit.

[0028] In another optional solution, in the data communication control system of the above-mentioned variable prediction chamber formation tester, the communication bus interface is connected to the main control unit via an SPI bus.

[0029] In another optional solution, in the data communication control system of the variable prediction chamber formation tester, the communication bus interface is a DTB transmission unit, the communication bus interface is communicatively connected to a telemetry transmission instrument via a DTB bus, and the telemetry transmission instrument is connected to the surface operation system via the logging cable;

[0030] The DTB transmission unit includes a downlink signal line, an uplink clock line, an uplink data line, and a loading signal line.

[0031] In another optional solution, in the data communication control system of the variable prediction chamber formation tester, the solenoid valve driving module is a latch driving circuit for controlling the opening, closing and status reading of the solenoid valve;

[0032] The slave control unit is connected to the solenoid valve via a latch drive circuit.

[0033] In another optional solution, in the data communication control system of the above-mentioned variable prediction chamber formation tester, the master control unit and the slave control unit are ARM microcontrollers, and the communication bus interface is a field programmable gate array chip.

[0034] The data communication control system for a variable prediction chamber formation tester provided by the utility model comprises a motor driver, a main control unit, a communication bus interface, a first CAN isolation transceiver, a second CAN isolation transceiver, and a motor DC power supply. The motor DC power supply supplies power to the motor driver. The motor driver is connected to a brushless DC motor. The ground terminals of the motor DC power supply and the motor driver are suspended, and the ground terminal of the main control unit is physically grounded. The motor driver is connected to the first CAN isolation transceiver via a CAN bus. The main control unit is connected to the second CAN isolation transceiver via a CAN bus. The first CAN isolation transceiver is connected to the second CAN isolation transceiver. The main control unit is connected to the communication bus interface, and the communication bus interface is connected to a ground operating system. The main control unit receives instructions from the ground operating system via the communication bus interface and controls the operation of the motor driver. The ground terminals of the motor DC power supply and the motor driver are suspended, and the ground of the main control unit is not connected to them. The main control unit and the motor driver communicate via the CAN isolation transceiver to achieve isolated communication, completely isolating the ground wires of the two devices while enabling normal communication between the two devices. This improves anti-interference capability and fully utilizes the application advantages of brushless DC motors in well logging instruments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A schematic diagram of a data communication control system for a variable prediction chamber formation tester provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of a sensor connection provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of a solenoid valve drive module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0039] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0040] The core of the utility model is to provide a data communication control system for a variable prediction chamber formation tester.

[0041] In order to enable those skilled in the art to better understand the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific implementation methods.

[0042] In oil exploration and well testing, the use of formation testers can directly detect the formation pressure, permeability and formation fluid composition at any depth, which is of great significance for oil and gas development.

[0043] A formation tester primarily consists of a mechanical probe and electronic circuitry. The mechanical probe includes a motor, hydraulic pump, solenoid valve, strain gauge, quartz pressure gauge, and various sensors. The electronic circuitry comprises a data acquisition unit, control unit, motor driver, and power supply. During formation testing, the motor acts as a power source, driving the hydraulic pump to generate oil pressure, which opens the probe's support arm and pushes the probe toward the wellbore wall, further penetrating the formation. Formation fluid flows through the probe into the prediction chamber for measurement, thereby determining formation pressure and permeability. Low-permeability formations require a longer wait (waiting for pressure to return to formation pressure) before formation pressure and permeability can be measured. This prolonged wait can easily cause the logging cable and test instrument to become attached to the wellbore wall, leading to operational accidents.

[0044] Existing formation testers are mostly powered by brushless DC motors. These motors are gradually replacing AC motors due to their compact size, high output power, and high efficiency. However, brushless DC motors are prone to interference when operating at high speeds, which can reduce the reliability of data communication and control systems. In particular, errors in the control of motors and solenoid valves can cause instrument failures at best, and even construction accidents at worst.

[0045] In order to solve the above problems, the embodiment of the present application provides a data communication control system for a variable prediction chamber formation tester, such as Figure 1 As shown, including:

[0046] Motor driver 11, main control unit 12, communication bus interface 13, first CAN isolation transceiver 14, second CAN isolation transceiver 15, motor DC power supply 16;

[0047] The motor DC power supply 16 supplies power to the motor driver 11; the motor driver 11 is connected to the brushless DC motor, the grounding terminals of the motor DC power supply 16 and the motor driver 11 are suspended grounds, and the grounding terminal of the main control unit 12 is physically grounded;

[0048] The motor driver 11 is connected to the first CAN isolation transceiver 14 via the CAN bus, the main control unit 12 is connected to the second CAN isolation transceiver 15 via the CAN bus, and the first CAN isolation transceiver 14 is connected to the second CAN isolation transceiver 15; the main control unit 12 is connected to the communication bus interface 13, and the communication bus interface 13 is connected to the ground operating system.

[0049] The variable prediction chamber formation tester is a device that uses motor control to make the prediction chamber with a previously fixed volume unchanged, and can adjust its size according to the permeability of the formation, so as to achieve the purpose of measuring the pressure and permeability parameters of the formation within an effective measurement time.

[0050] In this embodiment, the motor driver 11 is used to drive a DC brushless motor. This embodiment does not specifically limit the type, number and type of the motor driver 11, nor does it limit its specific working type. For example, two motors are set in the probe, one of which serves as a power source for controlling the opening and closing of the mechanical probe support arm to make the probe close to the well wall or released; the other serves as a power source for controlling the adjustment of the prediction chamber volume to change its size. During measurement, the volume of the prediction chamber is adjusted according to the permeability of the formation, and the formation parameters are measured within the optimal measurement time.

[0051] The motor driver 11 is powered by the motor DC power supply 16. The utility model solves the interference caused to the system by the operation of the motor by adopting a suspended ground (the interference source is generated by the driver converting the high-voltage DC power supply into the three-phase high-frequency pulse high voltage required for the operation of the motor, and this interference is injected into the entire system through the driver's ground line). That is, the motor DC power supply 16 required by the motor driver 11 and the ground of the motor driver 11 are suspended and not connected to the ground of the entire control system (insulated state), so that the motor DC power supply 16, the motor driver 11, and the motor form their own ground loop; the main control unit 12 communicates with it through the controller area network (CAN) bus through the isolated transceiver, thereby preventing the generated interference from being injected into the control system through the ground line.

[0052] It should be noted that the power supply is also included to provide corresponding power to each component. You can choose the corresponding power supply type according to your needs, such as digital power supply and analog power supply.

[0053] The data communication control system of the variable prediction chamber formation tester provided by this embodiment includes a motor driver 11, a main control unit 12, a communication bus interface 13, a first CAN isolation transceiver 14, a second CAN isolation transceiver 15, and a motor DC power supply 16; the motor DC power supply 16 supplies power to the motor driver 11; the motor driver 11 is connected to the DC brushless motor, the grounding ends of the motor DC power supply 16 and the motor driver 11 are suspended grounds, and the grounding end of the main control unit 12 is physically grounded; the motor driver 11 is connected to the first CAN isolation transceiver 14 via a CAN bus, the main control unit 12 is connected to the second CAN isolation transceiver 15 via a CAN bus, and the first CAN isolation transceiver 14 is connected to the second CAN isolation transceiver 15; the main control unit 12 is connected to the communication bus interface 13, and the communication bus interface 13 is connected to the ground operating system. The main control unit 12 receives instructions from the ground operating system through the communication bus interface 13 and controls the operation of the motor driver 11. The ground terminals of the motor DC power supply 16 and the motor driver 11 are suspended, and the ground of the main control unit 12 is not connected to them. In addition, the communication between the main control unit 12 and the motor driver 11 is isolated through the CAN isolation transceiver to achieve isolated communication, completely isolating the ground wires of the devices at both ends, while the devices at both ends can communicate normally, thereby improving the anti-interference ability and giving full play to the application advantages of DC brushless motors in logging instruments.

[0054] According to the above embodiment, in a specific implementation scheme, the data communication control system of the variable prediction chamber formation tester further includes: a slave control unit 17, a solenoid valve driving module 18, and a data processing module 19;

[0055] The solenoid valve driving module 18 is connected to the solenoid valve; the data processing module 19 is connected to the sensor; the slave control unit 17 is connected to the solenoid valve driving module 18 and the data processing module 19 respectively;

[0056] The slave control unit 17 is connected to the master control unit 12 , and a ground terminal of the slave control unit 17 is a physical ground.

[0057] In this embodiment, in order to minimize the interference of the brushless DC motor on the control system during operation, the control system is differentiated and explained, such as Figure 1 As shown in the figure, the control system is divided into an upper electronic circuit and a lower electronic circuit, and the power supply, grounding and communication systems of the two are isolated. Since the motor and solenoid valve are installed on the upper part of the mechanical probe, and the quartz pressure gauge and strain gauge are installed on the lower end of the probe, the upper electronic circuit is mainly used for control functions, and the lower electronic circuit is mainly used to process the measurement signals of the formation and upload the data to the ground operating system.

[0058] The slave control unit 17 in this embodiment is mainly used to parse the control information from the main control unit 12, control the solenoid valve drive module 18 to control the solenoid valve to achieve the pushing and recovery of the probe, read the status of the solenoid valve, and receive the data of various sensors collected by the data processing module 19 and send it to the main control unit 12.

[0059] In this embodiment, the solenoid valve is used in the probe to control the opening and closing of the hydraulic oil in the pushing oil pipeline and the recovery oil pipeline, thereby realizing the pushing and recovery functions of the probe.

[0060] The data processing module 19 is used to pre-process the signals from various sensors, the motor high-voltage sampling signal, and the solenoid valve voltage signal, converting them into data signals and transmitting them to the slave control unit 17. This embodiment does not limit the specific type of sensor. Typically, these sensors include a pressure gauge in the probe to detect oil pressure in the oil pipeline, a low-oil switch to detect a low-oil condition, and a displacement sensor to measure and predict chamber volume changes. Specifically, the data processing module 19 is isolated from ground via an isolation amplifier. Preferably, the HCPL-7800 is used as the isolation amplifier.

[0061] According to the above embodiment, in a specific implementation scheme, the main control unit 12 is connected to the quartz pressure gauge via the I2C bus;

[0062] Also included: a data processing sequential logic module 20;

[0063] The data processing sequential logic module 20 is connected to the strain gauge, and the data processing sequential logic module 20 is connected to the communication bus interface 13 .

[0064] The main control unit 12 directly reads the measurement data of the quartz pressure gauge on the formation through the I2C bus and sends it to the communication bus interface unit 13 for uploading to the ground operating system.

[0065] Both quartz pressure gauge and strain gauge are used to measure the pressure parameters of the formation. Two pressure gauges are used to achieve better measurement results.

[0066] The formation pressure is measured by a quartz pressure gauge and a strain gauge. The quartz pressure gauge transmits the measured pressure count (XP) and temperature count (XT) related to the formation pressure to the main control unit 12 through the I2C bus, and the combined data is uploaded to the ground operating system.

[0067] The data processing timing logic module 20 is used to process and collect the measurement signals of the strain gauge on the formation to form measurement data, and send it to the communication bus interface 13 to be uploaded to the ground operating system.

[0068] The data processing timing logic of the strain gauge pressure gauge first generates a power supply square wave unit to supply power to the strain gauge in the form of a square wave (different from the DC +5V power supply for the quartz pressure gauge). The formation pressure signal measured by the strain gauge pressure gauge is also output in the form of a square wave, including pressure signal and temperature signal. The functional unit also has its own second scale signal. Under logical control, each signal selects a different channel to be converted to data through the instrument amplifier, converting the analog signal into a pulse signal and counting it, and then sending it to the communication bus interface 13 for upload.

[0069] According to the above embodiment, in a specific embodiment, the motor driver 11 includes a hydraulic pump motor driver 111 and a prediction chamber motor driver 112;

[0070] The hydraulic pump motor driver 111 is connected to the hydraulic pump DC brushless motor, and the prediction chamber motor driver 112 is connected to the prediction chamber DC brushless motor;

[0071] The brushless DC motor in the prediction room is a rotary brushless DC motor;

[0072] The hydraulic pump brushless DC motor is a sensorless DC brushless motor.

[0073] The prediction chamber consists of a cylindrical cavity and a movable piston, powered by a motor, reducer, and lead screw. The motor drives the roller screw's rotational motion, which is converted into linear motion by the lead screw nut. This in turn drives the prediction chamber's piston back and forth, achieving suction and discharge functions. The stroke and movement rate of the prediction chamber's piston are set based on the permeability of the formation, and the length of the stroke determines the volume of the prediction chamber.

[0074] The master control unit 12 can receive instructions from the ground operating system through the communication bus interface 13 unit, parse the instructions in the master control unit 12, and then control the slave control unit 17 and the hydraulic pump motor driver 111 and the prediction chamber motor driver 112 through the CAN bus. The master control unit 12 can also receive data from the slave control unit 17, the hydraulic pump motor driver 111, and the prediction chamber motor driver 112 through the CAN bus, send it to the communication bus interface 13 unit, and upload it to the ground operating system.

[0075] The hydraulic pump motor driver 111 and the prediction chamber motor driver 112 are used to convert the motor DC high voltage into three-phase pulse high voltage to drive the hydraulic pump motor and the prediction chamber motor to rotate respectively;

[0076] The prediction chamber's brushless DC motor that controls the movement of the prediction chamber's piston is a resolver-type brushless DC motor, which can accurately position the prediction chamber when adjusting its volume. The resolver-type brushless DC motor uses a rotating transformer to detect the position of the motor's rotor and control the timing of the pulsed high voltage to achieve the purpose of controlling the motor to rotate a certain number of turns.

[0077] The hydraulic pump brushless DC motor that controls the hydraulic pump is an inductive DC brushless motor, which does not require control of the number of rotations and is simple to control. The inductive DC brushless motor detects the position of the motor rotor by means of back electromotive force and controls the timing of pulse high voltage to rotate the motor.

[0078] The communication mode between the master control unit 12 and the slave control unit 17, the hydraulic pump motor driver 111, and the prediction chamber motor driver 112 all adopts the CAN (Control Area Network) bus communication mode, which effectively ensures the reliable transmission of instructions and data.

[0079] In order to enable those skilled in the art to better understand the present solution, a specific working scenario is now described. The communication bus interface 13 receives the instructions issued by the ground operating system, and the main control unit 12 parses the instructions. After receiving the push instruction, the instruction is sent to the slave control unit 17 of the upper electronic circuit. The slave control unit 17 controls the solenoid valve drive module 18 to open the corresponding solenoid valve, and at the same time sends the status of the solenoid valve to the main control unit 12; after the main control unit 12 detects that the corresponding solenoid valve is in place and the motor DC power supply 16 is ready, it controls the hydraulic pump driver of the upper electronic circuit to operate the motor; the slave control unit 17 continuously receives various data from the data processing module 19 and sends it to the main control unit 12 in real time. When the main control unit 12 detects that the oil pressure of the oil pipeline pressure sensor in the probe reaches a predetermined value, it stops the operation of the motor driven by the hydraulic pump driver. At this time, the support arm of the probe has been opened, the probe push plate is close to the well wall, and the probe is penetrated into the formation;

[0080] After receiving the test instruction from the surface operating system, the main control unit 12 sends an instruction to make the prediction chamber driver control the motor to rotate forward, control the prediction chamber piston to move and start to suck the formation fluid into the prediction chamber to start the pressure test, and obtain the detection data of the strain gauge and quartz pressure gauge. When the pressure values ​​of the strain gauge and quartz pressure gauge slowly recover and stabilize, the test can be ended;

[0081] After receiving the probe recovery instruction from the ground operating system, the main control unit 12 sends a solenoid valve control instruction to the slave control unit 17. After receiving the instruction, the slave control unit 17 closes the corresponding solenoid valve. After the main control unit 12 detects that the solenoid valve is in place through the status returned by the slave control unit 17, it sends an instruction to control the hydraulic pump driver to rotate the motor. At the same time, the slave control unit 17 receives various data from the data processing module 19 and sends it to the main control unit 12 in real time. When the main control unit 12 detects that the oil pressure of the oil pipeline reaches a predetermined value, it stops the rotation of the motor driven by the hydraulic pump driver. At this time, the probe support arm, the push plate and the probe have been completely retracted.

[0082] After receiving the prediction chamber clearing instruction from the ground operating system, the main control unit 12 sends a control instruction to the prediction chamber motor driver 112, causing the prediction chamber driver to control the motor to rotate in the opposite direction, controlling the prediction chamber piston to move and discharge the formation fluid, thereby ending the test operation process at a depth point.

[0083] One caveat: If the formation pressure takes a long time to recover during the test, and the measured pressure fails to stabilize—for example, after 5 to 10 minutes (generally no more than 20 minutes, as this increases the risk of the instrument adsorbing to the wellbore wall and causing an engineering accident)—this indicates poor formation permeability. The instrument should be raised or lowered 30 cm (less than or equal to 30 cm, but no more than 30 cm) and retested at a different depth. During the retest, the surface operating system sends a command to appropriately reduce the volume of the prediction chamber, which will quickly restore the pressure to a stable value and complete the test. The prediction chamber volume can be adjusted from 0 to 36 ml, depending on the formation permeability (the speed of pressure recovery during the test can provide a rough estimate of the permeability).

[0084] It is foreseeable that changing the prediction chamber volume can effectively solve the testing problem in low-permeability formations. The permeability of the formation can be obtained by using the prediction chamber volume and effective pressure recovery time. For formations with normal permeability, testing can be performed using the conventional prediction chamber volume. Effective pressure recovery time refers to the time from the initial pressure change to the pressure stabilization.

[0085] In a specific embodiment, the above-mentioned sensors include: an oil pressure sensor 21, a motor high-pressure sampling sensor 22, a solenoid valve voltage sensor 23, a displacement sensor 24 for detecting the change in the volume of the prediction chamber, and a low oil sensor 25 for detecting the amount of hydraulic oil in the probe.

[0086] The oil pressure sensor is connected to the analog-to-digital converter through an instrumentation amplifier;

[0087] The motor high-voltage sampling sensor is connected to the analog-to-digital converter through an isolation amplifier;

[0088] The solenoid valve voltage sensor is connected to the analog-to-digital converter through a filter amplifier;

[0089] The displacement sensor is connected to the analog-to-digital converter through a filter amplifier;

[0090] The low oil sensor is connected to the analog-to-digital converter through a filter amplifier;

[0091] The analog-to-digital converter is connected to the slave control unit 17 .

[0092] Figure 2 A schematic diagram of a sensor connection provided in an embodiment of the present application is shown in FIG. Figure 2As shown in the figure, during the pushing, retrieving and testing process, the oil pressure sensor signal that reflects the oil pressure of the oil pipeline in real time is processed by the instrument amplifier circuit and then enters the analog-to-digital converter (ADC);

[0093] The motor's high-voltage sampling signal is isolated and amplified before entering the analog-to-digital converter. The purpose of using isolation amplification is to isolate the motor's DC power ground from the system ground, preventing interference from the brushless DC motor from entering the control system through the ground.

[0094] The solenoid valve voltage collected by the solenoid valve voltage sensor is filtered and amplified before entering the analog-to-digital converter;

[0095] The data (in milliliters) of the predicted chamber volume adjustment sent by the ground operating system can be reflected by the displacement sensor. The signal reflecting the volume size is filtered and amplified before entering the analog-to-digital converter;

[0096] The low oil sensor can reflect the amount of hydraulic oil in the probe. In order to ensure the normal operation of the instrument, the amount of hydraulic oil must be known. The sensor signal is filtered and amplified before entering the analog-to-digital converter.

[0097] After all the above sensor signals enter the analog-to-digital converter, they are converted into data signals. The slave control unit 17 continuously reads the converted data and sends it to the main control unit 12 to grasp the current working status of the instrument in real time, and uploads it to the ground operating system.

[0098] During the test, if the main control unit 12 detects that the oil pressure value of the oil pressure sensor is lower than the specified value, it will start the hydraulic pump motor to rotate to replenish the pressure to prevent the instrument from sliding down due to the reduction of the thrust against the support arm.

[0099] The analog-to-digital converter (ADC) can use the ADS8688 as the ADC conversion chip. This chip is an 8-channel integrated data acquisition system based on a 16-bit successive approximation (SAR) analog-to-digital converter (ADC), and performs serial data communication with the slave control unit 17. The analog-to-digital converters mentioned in this embodiment can be shared or independent, depending on actual needs.

[0100] The slave control unit 17 can adopt an ARM microcontroller of the STM32L496X series to realize CAN communication with the master control unit 12, control and read the status of the solenoid valve drive module 18, and receive ADC data from the data processing and acquisition unit.

[0101] In a specific embodiment, the communication bus interface 13 is connected to the main control unit 12 via an SPI bus.

[0102] The communication bus interface unit 13 and the main control unit 12 use a serial peripheral interface (SPI) bus to transmit data, the purpose of which is to improve transmission efficiency and reduce interference effects.

[0103] In a specific embodiment, the communication bus interface 13 is a data transfer bus (DTB) transmission unit, and the communication bus interface 13 is connected to the telemetry transmission instrument in a DTB bus manner, and the telemetry transmission instrument is connected to the surface operation system through a logging cable;

[0104] The DTB transmission unit includes a downlink signal line, an uplink clock line, an uplink data line, and a loading signal line.

[0105] The communication bus interface 13 is a DTB transmission unit; the DTB transmission unit includes a downlink signal line, an uplink clock line and an uplink data line, and a loading signal line; the communication bus interface 13 receives instructions from the ground operating system through the DTB bus and sends them to the main control unit 12, and at the same time receives data from the main control unit 12 and sends it to the ground operating system.

[0106] Specifically, the master control unit 12 and the slave control unit 17 are ARM (Advanced RISC Machines) microcontrollers, and the communication bus interface 13 is a field programmable gate array chip.

[0107] The main control unit 12 can adopt an ARM microcontroller of the STM32L496X series to realize the main control unit 12 to perform data calculation, data analysis, command reception and data transmission functions; the communication bus interface 13 can adopt a ProASIC3 series field programmable gate array chip to realize the timing logic of the DTB bus, encoding / decoding of communication data with the ground operating system, SPI data communication with the main control unit 12 and other functions.

[0108] In a specific embodiment, the solenoid valve driving module 18 is a latch driving circuit that controls the opening, closing, and status reading of the solenoid valve;

[0109] The slave control unit 17 is connected to the solenoid valve via a latch drive circuit.

[0110] Figure 3A schematic diagram of a solenoid valve drive module 18 provided in an embodiment of the present application, wherein the latch drive circuit includes: a state latch unit, a latch drive unit, a first resistor R1, a second resistor R2, a field effect transistor Q1, and a first diode D1; the control output end of the slave control unit 17 is connected to the control end of the field effect transistor through the latch drive unit, the first end of the field effect transistor is grounded, the first end of the field effect transistor is connected to the first end of the first resistor through the second resistor, the second end of the first resistor is connected to the second end of the field effect transistor, the anode of the first diode, and the first end of the solenoid valve; the cathode of the first diode is connected to the power supply and to the second end of the solenoid valve; the first end of the first resistor is connected to the state receiving end of the slave control unit 17 through the state latch unit.

[0111] After receiving the push or retract instruction from the ground operating system, the master control unit 12 sends the instruction to the slave control unit 17. After parsing the instruction, the slave control unit 17 controls the solenoid valve drive module 18. Figure 3 As shown, the latch drive unit latches Figure 1 The control level of the slave control unit 17 controls the field effect transistor Q1. When the latch level is high, Q1 is turned on to open the solenoid valve and prepare for pushing. When the latch level is low, Q1 is turned off to close the solenoid valve and prepare for recovery. The open and closed states of the solenoid valve are latched by the state latch unit, and its current state is read by the microcontroller of the slave control unit 17. In a possible implementation scheme, there are 3 solenoid valves in the probe, and their drive circuits are the same.

[0112] The above is a detailed introduction to the data communication control system of the variable prediction chamber formation tester provided by the present invention. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0113] It should also be noted that, in this specification, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

Claims

1. A data communication control system for a variable prediction chamber formation tester, characterized in that: include: Motor driver, main control unit, communication bus interface, first CAN isolation transceiver, second CAN isolation transceiver, motor DC power supply; The motor DC power supply supplies power to the motor driver; the motor driver is connected to the brushless DC motor, the grounding terminals of the motor DC power supply and the motor driver are suspended grounds, and the grounding terminal of the main control unit is physically grounded; The motor driver is connected to the first CAN isolation transceiver via a CAN bus, the main control unit is connected to the second CAN isolation transceiver via a CAN bus, and the first CAN isolation transceiver is connected to the second CAN isolation transceiver; the main control unit is connected to the communication bus interface, and the communication bus interface is connected to the ground operating system.

2. The data communication control system of the variable prediction chamber formation tester according to claim 1, characterized in that: Also includes: Slave control unit, solenoid valve drive module, data processing module; The solenoid valve driving module is connected to the solenoid valve; the data processing module is connected to the sensor; the slave control unit is connected to the solenoid valve driving module and the data processing module respectively; The slave control unit is connected to the master control unit, and a ground terminal of the slave control unit is a physical ground.

3. The data communication control system of the variable prediction chamber formation tester according to claim 2, characterized in that: The solenoid valve drive module is a latch drive circuit that controls the opening, closing and status reading of the solenoid valve; The slave control unit is connected to the solenoid valve via a latch drive circuit; The latch driving circuit includes: a state latch unit, a latch driving unit, a first resistor, a second resistor, a field effect transistor, and a first diode; The control output end of the slave control unit is connected to the control end of the field effect tube through a latch driving unit, the first end of the field effect tube is grounded, the first end of the field effect tube is connected to the first end of the first resistor through a second resistor, the second end of the first resistor is connected to the second end of the field effect tube, the anode of the first diode, and the first end of the solenoid valve; the cathode of the first diode is connected to the power supply and the second end of the solenoid valve; the first end of the first resistor is connected to the state receiving end of the slave control unit through the state latch unit.

4. The data communication control system of the variable prediction chamber formation tester according to claim 1, characterized in that: The main control unit is connected to the quartz pressure gauge via an I2C bus; Also included: a data processing sequential logic module; The data processing sequential logic module is connected to the strain gauge, and the data processing sequential logic module is connected to the communication bus interface.

5. The data communication control system of the variable prediction chamber formation tester according to claim 1, characterized in that: The motor driver includes a hydraulic pump motor driver and a prediction chamber motor driver; The hydraulic pump motor driver is connected to the hydraulic pump DC brushless motor, and the prediction chamber motor driver is connected to the prediction chamber DC brushless motor; The prediction chamber brushless DC motor is a rotary brushless DC motor; The hydraulic pump brushless DC motor is an inductive brushless DC motor.

6. The data communication control system of the variable prediction chamber formation tester according to claim 2, characterized in that: The sensors include: an oil pressure sensor, a motor high-pressure sampling sensor, a solenoid valve voltage sensor, a displacement sensor for detecting changes in the volume of the prediction chamber, and a low oil sensor for detecting the amount of hydraulic oil stored in the probe.

7. The data communication control system of the variable prediction chamber formation tester according to claim 6, characterized in that: The oil pressure sensor is connected to the analog-to-digital converter via an instrument amplifier; The motor high-voltage sampling sensor is connected to the analog-to-digital converter via an isolation amplifier; The solenoid valve voltage sensor is connected to the analog-to-digital converter via a filter amplifier; The displacement sensor is connected to the analog-to-digital converter via a filter amplifier; The low oil sensor is connected to the analog-to-digital converter via a filter amplifier; Wherein, the analog-to-digital converter is connected to the slave control unit.

8. The data communication control system of the variable prediction chamber formation tester according to claim 1, characterized in that: The communication bus interface is connected to the main control unit via an SPI bus.

9. The data communication control system of the variable prediction chamber formation tester according to claim 1, characterized in that: The communication bus interface is a DTB transmission unit, the communication bus interface is connected to the telemetry transmission instrument in a DTB bus manner, and the telemetry transmission instrument is connected to the ground operating system via a logging cable; The DTB transmission unit includes a downlink signal line, an uplink clock line, an uplink data line, and a loading signal line.

10. The data communication control system of the variable prediction chamber formation tester according to claim 2, characterized in that: The master control unit and the slave control unit are ARM microcontrollers, and the communication bus interface is a field programmable gate array chip.

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