Testing and History Matching ES-SAGD (Using Hexane)

Abstract

Abstract For the first time, we present in public domain, experimental and history-matched results of 2D scaled laboratory testing of ES-SAGD with hexane as the co-injected solvent. Experimental results of ES-SAGD (with hexane) were also compared with the equivalent SAGD. The 2 experiments, which were conducted at the Alberta Research Council's Thermal Gravity laboratory, are 2-D high pressure/high temperature experiments and were conducted at 2100 kPag +/− 50 kPag. The comparison of ES-SAGD and SAGD experiments shows that ES-SAGD using hexane performed better than an equivalent SAGD experiment. The energy consumption per unit oil recovered for ES-SAGD was lower than that of SAGD (11.5% less). The average oil recovery within the first 500 minutes (i.e. 11.3 years at field-scale) for the ES-SAGD process was also much higher (~10.93% higher). The ES-SAGD result was history-matched with a commercial reservoir simulator (CMG STARS). The history-matched ES-SAGD experiment gave satisfactory results in terms of oil production rates, cumulative oil production, and temperature distributions. The results presented in the paper provide data that can be scaled to field and assist in the design, optimization and parameter selection when ES-SAGD (with hexane or a pseudo-hexane solvents mixture) is considered as a recovery technology. Multi-pattern simulations based on history-matched data of a single well pair (pattern) show that multi-well pair (pattern) simulations can provide a suitable approximate analog for multi-pattern experiments, which can be scaled and used for planning and optimizing a pilot or a small-scale commercial project.