Cased Hole Formation Resistivity Logging Data Processing And Noise Reduction Technology

Cased Hole Formation Resistivity Logging is by measuring the flow through the casing on the weak among the three electrodes to calculate the voltage drop of the leakage current leakage into the ground。thus further rectifiable the formation of apparent resistivity, the signal of the System is weak in the pay level satisfaction。this research work is done mainly through the casing of the well logging system in data processing and noise reduction work carried out further research。The casing and the weak signal is satisfied that payment of the signal, the second-order differential voltage is a very weak signal nV level, which requires to accurately detect and weak signal processing system. Therefore, in data acquisition and processing before amplification, this paper using a low noise preamplifier, the amplifier is a preamplifier, band-pass filter, level after amplification and isolation output of four parts。In this paper, data acquisition and processing, the design of a module based on24-bit ADS1271and ADS2189converter chip as the main core components of the data acquisition system。After a low-noise preamplifier signal by the ADS1271analog-digital conversion into the ADS1271after processing. ADS2189is responsible for completion of the A/D operating mode, the serial port work input, A/D Conversion of data to read, buffer, process control, and finally through the RS-232serial port and PC communication。In the noise, the noise interference from hardware and software for noise reduction of two aspects, in particular, have MATLAB simulation software, the digital filter function。The experimental results show that:In this system, strong noise, the wavelet noise reduction and phase sensitive detection can be very good noise suppression, improved signal to noise ratio,Also set up filtering method through software, visual programming to achieve noise reduction。...