Application of X-ray imaging techniques to oil sands experiments

Well controlled laboratory experiments are the key to understanding bitumen recovery from oil sands deposits and measurement of basic parameters required to predict field performance. The inability to see what is happening inside test cores is a serious limitation to experimental interpretation. This paper describes the application of three unique X-ray based techniques developed at the Alberta Research Council for visualizing process behaviour and for measuring fluid saturations. This capability has evolved from one-dimensional single beam attenuation to two-dimensional xeroradiography and finally to full three-dimensional computed tomography. The first system uses a single beam approach to directly measure bitumen and water saturations for relative permeability determinations on oils and cores at in situ steam conditions. The second system, X-ray xeroradiography, is a qualitative technique developed to visualize encased field cores and core-flood experiments. The xeroradiography concept has a number of subtle features which lead to high-contrast easily-read two-dimensional images of internal core structure and fluid distributions. The third system, X-ray computed tomography, provides a full three-dimensional imaging capability. The image data are used to provide high resolution quantitative analysis of core structure and fluid saturations. The three complementary techniques provide a unique capability for the study of oil recovery processes. This paper discusses some results of petrophysical studies and the measurement of saturations during core flood experiments. (18 refs., 11 figs.)