Adaptive Conditioning Circuit Of Electrode Electrical Spectrum Logging Tool

Electrical Spectrum Logging is mainly based on the complex resistivity dispersion law of rock,the complex resistivity dispersion and dielectric of the formation are obtained by 1k-500 kHz sweep measurement and analysis information,and then through the Cole-Cole model is used to synthetically invert the parameters of fluid saturation,it can also be more effectively in identifying low-resistivity reservoirs and water-flooded layer,and improve the reliability of the evaluation of oil and gas saturation.Electrical Spectrum Logging probe prototype “Twelfth Five-Year” period in Long-dong base wells,access to the preliminary test data,good repeatability,to achieve the desired goal.But the detector still exists some shortcomings,The design of filter circuit bloated problem needs to be optimized,the problem of the range of the input signal which is received by the electrode remains to be improved,in order to acquire the signal.In this paper,through the study of the adaptive conditioning circuit of the pre-stage signal of the Electrical spectrum logging tool,the circuit of the gain control is composed by the PGA(Programmable Gain Amplifier)and the band-pass filter circuit of the integrated center frequency variable filter are adopted.This thesis designs and simulates the pre-conditioning circuit,and then the circuit board of the adaptive pre-conditioning circuit of Electrode Electrical Frequency Spectrum Logging Tool is designed and manufactured.After the pre-conditioning circuit of Electrical Spectrum Logging Tool is debugged and verified,the gain control circuit can realize the active adjustment of the amplitude of the input signal under the under the condition of laboratory,and makes the signal within the appropriate range,and can improve the sampling precision of the signal.In the premise of guaranteeing the signal amplitude ratio and phase difference,the band-pass filter circuit has also been optimized to improve the circuit performance.