oa Study on Simulation Algorithm of Borehole Radar for Well Logging and its Application to Measuring Volumetric Water Content of Formation

Borehole radar becomes useful tool for high resolution probing of both deep oil reservoir and shallow subsurface. In order to improve understanding of the electromagnetic wave propagation in single hole, a pseudo-spectral time domain (PSTD) algorithm that allows us to model the full EM wavefield for rotational symmetric structure was developed. This technique is based on Finite Difference Time Domain (FDTD) method and uses fast Fourier transform (FFT) algorithm for spatial derivatives. The PSTD algorithm can reduce grid number and save computer memory for large-scale forward calculation and inversion. The simulation provides a method for processing of field data. The measured volumetric water content from borehole radar data gave good agreement with other logging curves, such as resistivity logging curve.