Spectral Induced Polarization Measurements of Hydrocarbon-bearing Rocks and Fluids

As part of our research into spectral induced polarization (IP) methods, we have measured the complex resistivity (CR) spectra of hydrocarbon-bearing rock and fluid samples from 0.1 Hz to 1 MHz using laboratory CR and dielectric spectroscopy equipment. Our rock-fluid samples included artificial and sandstone reservoir rocks saturated with synthetic oil, tap water, and distilled water. Our fluid samples included oil-based mud, tap water, and distilled water. Statistical analysis of our measurements conclude that hydrocarbon-bearing rock and fluid samples contain significant SIP responses; the mechanisms of which are only partially understood at present. Additional research is needed to clarify the different IP mechanisms in different frequency regimes, but we can conclude that it will be necessary to account for SIP effects when interpreting electromagnetic (EM) data for hydrocarbon exploration and formation evaluation.