Visualization and Quantification of Thermally Induced Porosity Alteration of Immature Source Rock Using X-ray Computed Tomography

摘要

This paper summarizes results of a successful laboratory investigation to visualize and quantify pyrolysis-induced porosity evolution of Uinta Basin organic-rich source rock using X-ray computed tomography (CT). Combining CT imaging techniques with a radio-opaque gas as a pore contrast fluid allowed for the description of porosity changes within source rock rather than limiting quantification to a single bulk value, as obtained by conventional porosity measurement techniques. The porosity of the immature and thermally matured rock sample, a Green River oil shale, increased from 9 to 25% as a result of kerogen conversion and delamination. Porosity distributions of immature samples showed unimodal behavior, whereas matured samples displayed multimodal characteristics. These new measurements indicate that porosity evolution during maturation is not well-described by bulk measurements.