HEAVY OIL-SAND MODELING DURING THERMAL PRODUCTION AND ITS SEISMIC RESPONSE

This dissertation focuses on the study of the change of heavy oil-sand properties during thermal production. It characterizes the heavy oil-sand properties on micro-scale and macro-scale. The key contributions of this dissertation include the measurements and comparison of pre-steam and post-steam oil-sand samples, analysis of the compaction effect, establishment of a new model to simulate heavy oil-sand velocities, and extension of the heavy oil-sand property prediction to field-production temperature range. I also developed a Modified-Cauchy prior-constraint based on a time-lapse seismic-inversion method, applied the method on real field data, and finally inverted the temperature distributions on the 2D profile. To characterize the oil-sand properties on micro-scale, I measured eight oil-sand samples. Both the P-wave and S-wave velocities under different pressure and temperature conditions were measured, compared, and analyzed. Based on the measured data, a new model was developed, which integrates the oil moduli change, sand frame change, and solid-oil percentage change during heating. The model was tested on the measured data, and showed a good match between the prediction and data. To characterize the heavy-oil reservoir on macro-scale, I developed a Modified-Cauchy prior-constraint based time-lapse inversion method. The Modified-Cauchy distribution fit well with the statistics of reflectivity. The inversion method effectively detected the steam chamber by the impedance change from baseline survey to monitorline survey. Seismic attributes were also utilized to distinguish the steam chamber through attribute change. Combining the rock-physics model and the impedance, the temperature distributions were obtained which clearly showed a steam chamber.