CN-121976796-A - Direct excitation system for multi-pole acoustic logging while drilling

CN121976796ACN 121976796 ACN121976796 ACN 121976796ACN-121976796-A

Abstract

The invention provides a direct excitation system of multi-pole acoustic logging while drilling, which relates to the technical field of acoustic logging while drilling, and comprises: the circuit on the excitation board card is provided with a low-voltage power supply, a booster circuit, an FPGA, an energy storage capacitor, 4 high-voltage driving circuits and 4 transmitting circuits. The FPGA is used for regulating and controlling the boost voltage according to the boost control value in the control command of receiving the acoustic logging while drilling, logically converting the excitation parameter information of the control command into a low-voltage logic signal, and converting the low-voltage logic signal into a driving logic signal through 4 high-voltage driving, so that the 4-path transmitting circuit is driven to directly excite the transmitting transducer of the acoustic logging while drilling instrument by using the boost voltage stored in the energy storage capacitor. The invention is used for solving the problem that the existing while-drilling acoustic wave instrument is difficult to realize multipole excitation by using consistent sound source emission frequency in a high-voltage environment.

Inventors

LUO MINGZHANG
XU CONG
ZHANG YIHANG
HEI CHUANG
WANG QIUYUE
WANG JIAQI

Assignees

长江大学

Dates

Publication Date: 20260505
Application Date: 20260112

Claims (10)

1. The direct excitation system for the multi-pole sub-acoustic logging while drilling is characterized by comprising a first excitation board card and a second excitation board card, wherein a low-voltage power supply, a booster circuit, an FPGA (field programmable gate array), an energy storage capacitor, 4 high-voltage driving circuits and 4 transmitting circuits are arranged on circuits on the first excitation board card and the second excitation board card; the boost circuit is used for boosting the low-voltage power provided by the low-voltage power supply to obtain a boosted voltage; the FPGA is used for receiving a control command of acoustic logging while drilling, regulating and controlling the boost voltage according to a boost control value included in the control command, and logically converting excitation parameter information included in the control command into a low-voltage logic signal; The energy storage capacitor is used for storing the regulated boost voltage; The 4-path high-voltage drive is used for converting a low-voltage logic signal output by the FPGA into a drive logic signal, and the drive logic signal is used for driving the 4-path transmitting circuit to directly excite a transmitting transducer of the acoustic wave while drilling instrument by utilizing the boost voltage stored in the energy storage capacitor.
2. The direct excitation system of multi-pole while drilling subsonic logging of claim 1, wherein the low voltage power supply, the boost circuit and the storage capacitor are disposed on the second excitation plate, the FPGA is disposed on the first excitation plate, the 4-way high voltage drive is disposed on the first excitation plate and the second excitation plate on average, and the 4-way transmit circuit is disposed on the first excitation plate and the second excitation plate on average.
3. The direct excitation system of multi-pole while drilling sonic logging of claim 1, wherein the boost circuit comprises a single-path driver, a field effect transistor, a high frequency transformer, and a voltage doubler rectifier circuit; the primary coil of the high-frequency transformer is electrically connected with the low-voltage power supply and the field effect transistor respectively, the secondary coil of the high-frequency transformer is electrically connected with the voltage doubling rectifying circuit, the single-path driver is electrically connected with the field effect transistor and the FPGA respectively, and the voltage doubling rectifying circuit is electrically connected with the energy storage capacitor.
4. A direct excitation system for multi-pole while drilling sonic logging according to claim 3, wherein the FPGA is configured to transmit a boost control value included in a control command as logic information to the one-way driver; the single-path driver is used for driving the field effect transistor according to the logic information; the field effect transistor is used for disconnecting the electric connection of the primary coil when the current generated by the primary coil of the high-frequency transformer exceeds a current threshold value, and the current is generated when the low-voltage power supply supplies the voltage of the voltage boosting circuit to form induced electromotive force; the voltage doubling rectifying circuit is used for stabilizing the boosted voltage generated by the high-frequency transformer and storing the stabilized boosted voltage into the energy storage capacitor.
5. The direct excitation system of multi-pole acoustic logging while drilling according to claim 4, wherein the voltage doubling rectifying circuit is provided with a plurality of diodes and a plurality of capacitors, and the boosting voltage generated by the high-frequency transformer does not exceed the withstand voltage value of the diodes; The diode is used for rectifying the boosted voltage generated by the high-frequency transformer from alternating current to direct current; The capacitor is used for raising the boost voltage of the direct current by N times in a charging mode, and N is an integer larger than 1.
6. The direct excitation system of multi-pole while drilling sonic logging of claim 1, wherein the control commands include excitation parameter information including excitation frequency, number of excitation pulses, and excitation pattern; the FPGA is also used for logically converting the excitation frequency and the number of excitation pulses into low-voltage logic signals under various excitation modes and respectively transmitting the low-voltage logic signals to the 4-path high-voltage drive.
7. The direct excitation system of claim 6, wherein the excitation modes comprise monopole excitation, dipole excitation, or quadrupole excitation.
8. The direct excitation system of multi-pole while drilling sonic logging according to claim 1, wherein the 4-way high-voltage drive is electrically connected with the energy storage capacitor through a switch tube respectively, and the boost voltage stored by the energy storage capacitor does not exceed the withstand voltage value of the switch tube.
9. The direct excitation system of multi-pole while drilling sub-acoustic logging according to claim 8, wherein the 4 high voltage drives and the 4 transmitting circuits are in one-to-one correspondence, each high voltage drive is connected with a corresponding transmitting circuit through a switch tube, and each transmitting circuit in the 4 transmitting circuits is connected with a transmitting transducer of an acoustic while drilling instrument.
10. The direct excitation system of multi-pole while drilling sonic logging of claim 9, wherein each high voltage drive is further configured to control a drive direction of a corresponding transmit circuit, the drive direction comprising a forward direction and a reverse direction; If the driving direction of the high-voltage driving control is positive, the corresponding transmitting circuit is used for carrying out positive excitation on the transmitting transducer of the acoustic wave while drilling instrument; If the driving direction of the high-voltage driving control is reverse, the corresponding transmitting circuit is used for reversely exciting the transmitting transducer of the acoustic wave while drilling instrument.

Description

Direct excitation system for multi-pole acoustic logging while drilling Technical Field The invention relates to the technical field of acoustic logging while drilling, in particular to a direct excitation system of multi-pole acoustic logging while drilling. Background The multi-pole acoustic logging while drilling technology is one of the requisite technologies for deep ground and deep water detection at present. The multi-pole sub-acoustic wave while drilling needs to excite multiple transducers simultaneously, which requires consistency in acoustic source excitation while drilling. The direct acoustic wave excitation technology can realize the consistency of excitation of a plurality of acoustic wave logging transducers, and has the advantages that the consistency of excitation energy of the acoustic wave transducers in the environment while drilling can be improved, and meanwhile, the volume occupied by an excitation circuit can be reduced. The existing while-drilling acoustic wave instrument only has two working modes of a monopole and a quadrupole. The acoustic logging while drilling instrument device mainly utilizes a monopole to measure the longitudinal wave sound velocity of the stratum and a quadrupole to measure the transverse wave sound velocity of the stratum. While research on far detection imaging in the range of tens of meters around a well by using four-pole acoustic logging while drilling has been carried out, it is difficult to distinguish the azimuth of a reflector around the well by using four-pole while drilling. The dipole sound source has good azimuth identification performance, and the azimuth identification of the well periphery reflector can be realized by utilizing the combination of the dipole sound source and the quadrupole sound source. Adding a dipole sound source to the current acoustic while drilling instrument requires designing monopole, dipole and quadrupole transmitting circuits, respectively. Because the emission frequencies of different sound sources are different, the adopted high-voltage transformer needs to be manufactured by matching with corresponding frequencies, and the problem of transformer consistency needs to be considered. The exciting frequency of the monopole is higher than that of the dipole and the quadrupole, and the difficulty in developing a broadband high-voltage transformer is high, so that a multi-frequency exciting mode is urgently needed to replace the high-voltage transformer. Disclosure of Invention In view of the foregoing, it is desirable to provide a direct excitation system for multi-pole acoustic logging while drilling, which is used for solving the problem that the conventional acoustic while drilling instrument is difficult to realize multi-pole excitation by using a consistent sound source emission frequency in a high-voltage environment. In order to solve the problems, the invention provides a direct excitation system of multi-pole acoustic logging while drilling, which comprises a first excitation board card and a second excitation board card, wherein low-voltage power supplies, a booster circuit, an FPGA (field programmable gate array), an energy storage capacitor, 4 high-voltage driving circuits and 4 transmitting circuits are arranged on circuits on the first excitation board card and the second excitation board card; the boost circuit is used for boosting the low-voltage power provided by the low-voltage power supply to obtain a boosted voltage; the FPGA is used for receiving a control command of acoustic logging while drilling, regulating and controlling the boost voltage according to a boost control value included in the control command, and logically converting excitation parameter information included in the control command into a low-voltage logic signal; The energy storage capacitor is used for storing the regulated boost voltage; The 4-path high-voltage drive is used for converting a low-voltage logic signal output by the FPGA into a drive logic signal, and the drive logic signal is used for driving the 4-path transmitting circuit to directly excite a transmitting transducer of the acoustic wave while drilling instrument by utilizing the boost voltage stored in the energy storage capacitor. In one possible implementation manner, the low-voltage power supply, the boost circuit and the energy storage capacitor are arranged on the second excitation plate, the FPGA is arranged on the first excitation plate, the 4-way high-voltage driving circuit is arranged on the first excitation plate and the second excitation plate on average, and the 4-way transmitting circuit is arranged on the first excitation plate and the second excitation plate on average. In one possible implementation, the boost circuit includes a single-path driver, a field effect transistor, a high frequency transformer, and a voltage doubler rectifier circuit; the primary coil of the high-frequency transformer is electrically connected with the low-voltage powe