ExxonMobil and its Canadian affiliate Imperial Oil Resources are pursuing an integrated research program targeted at developing the next generation of heavy oil recovery processes which utilize hydrocarbon solvents as a mobilizing agent. The key benefits of solvent-based processes are improved environmental performance, improved economics and recovery of resource that is impractical with thermal processes.
The integrated research program encompasses fundamental laboratory work, analytical modeling, advanced numerical modeling, scaled physical modeling in the laboratory, a solvent-only pilot which is in the design phase, an operating solvent-assisted SAGD pilot and a first commercial scale application of a solvent-assisted cyclic steam stimulation (CSS) process known as Liquid Addition for Steam Enhanced Recovery (LASER). This paper provides a systematic review of the scope, technical challenges, benefits and successes of research efforts in each of the areas cited above. In general, the results of laboratory modeling and simulation studies are strongly supportive of the potential success of solvent-assisted and solvent-based recovery processes. Reliably demonstrating solvent recovery processes at the field scale remains a key challenge that can only be addressed through well designed field pilot programs and enhanced reservoir surveillance programs for commercial scale applications. These challenges are highlighted in the paper utilizing specific examples from the integrated research program.
In conclusion, there are some very significant technical challenges that need to be addressed before solvent-assisted and solvent-based heavy oil recovery processes will be broadly commercialized. Nonetheless, consideration of the results across the full breadth of ExxonMobil's integrated technology program provides strong support that a new generation of solvent recovery processes will emerge as an economically competitive option for heavy oil recovery with significant environmental benefits relative to today's thermal recovery processes.