Circuit Design And Performance Study Of Three-dimensional Induction Logging Instrument

Three-dimension induction logging is a new oil and gas detection system.Three-dimension induction logging both theoretically measured the conductivity in thehorizontal direction, and measure the conductivity in the vertical direction and the difference,it is possible to review more accurate petrophysical properties, It is effective methods forpeople to recognize the stratum characteristics and have an oil or gas reservoirs evaluation.This paper studies the characteristics and principles of Three-dimension inductionlogging tool, forward a new kind design scheme of three-dimension induction logging tooldata acquisition system. The design with digital signal processing (DSP) and fieldprogrammable gates array (FPGA) as the core framework, realized overall control and dataprocessing function of the whole system. The Three-dimension induction logging tool dataacquisition system is mainly composed of the preamplifier module, modulus conversionmodule, filter module, acquisition control and data conversion module, CAN bus interfacemodule, data processing module and power supply module.In order to verify the feasibility of the design, this paper firstly has a calculation andsimulation analysis before design on the key modules such as the filter module, preamplifiermodule and differential module. In software design, this paper firstly introduces the digitalsignal processing algorithm principle of the digital phase-sensitive detection (DPSD) and finiteimpulse response (FIR) filter, and then separately designed and implemented the suitabledigital phase-sensitive detection (DPSD) and finite impulse response (FIR) filter algorithmwhich can be in practical use.Experimental results show the system can not only ensure raising sample efficiency,thehigh-speed synchronous sample of wide band signal and data reliability but also well extractthe multi-frequency weak signal about4μV from the strong environmental noise.