随钻方位远探测声波测井仪器多模式相控阵发射系统设计OA

Acoustic logging-while-drilling technology is the core means to obtain formation parameters in real time in oil and gas exploration.Due to the solidification of hardware architecture,it is difficult to achieve efficient switching of multi-mode(unipolar,dipole,quadrupole,etc.)in traditional transmission systems.In addition,there are problems such as timing conflict,signal distortion and poor environmental adaptability,resulting in insufficient recognition ability of thin interbeds and low resolution of formation interface,which seriously restricts the accuracy of intelligent guidance while drilling and 3D geological modeling.In this paper,a dynamic reconfigurable logic framework is constructed by using field programmable gate array(FPGA)technology,and a multi-mode phased array transmission system is designed by combining the full-bridge and half-bridge hybrid drive topology.The research results show that:①The system realizes the real-time configuration of multi-mode excitation waveform and the precise control of phase control timing through dynamic reconfigurable logic.②The transmission circuit based on full-bridge excitation and half-bridge excitation is adopted,which takes into account the stability of high-voltage transmission and the fast switching ability of signal output.The circuit can maintain stable and reliable operation under different load conditions.③The system can control the phased array acoustic emission transducer array at the same time,support the directional radiation in the phased array working mode,and can also independently control a single phased array acoustic emission transducer to realize multi-mode excitation such as unipolar,dipole or quadrupole.It is concluded that the multi-mode phased array transmitting system based on FPGA effectively solves the problem of multi-mode excitation and timing control in the acoustic logging tool for azimuth remote detection while drilling,and provides reliable hardware technical support for the development of acoustic logging tool for azimuth remote detection while drilling.