Comparison of Steam and Polymer Injection for the Recovery of Heavy Oil

Abstract

Abstract Steam injection (including cyclic steam and SAGD) has long been recognized as the favored recovery method for heavy oil, with applications in many fields around the world in particular in California and Canada. More recently, polymer flooding has also become a relatively well accepted method to increase production and recovery in heavy oil fields. Numerous successful pilots have been reported these last few years and field expansions are currently ongoing in Canada, Oman, China and Albania for instance but surprisingly enough, there has been to the best of the author's knowledge no such application in the US. Both steam and polymer injection have their advantages and their limitations and simple screening criteria have been developed by several authors, however there has never been a detailed comparison of the two methods and this is what this paper proposes to do. The pros and cons of both steam injection and polymer flood are reviewed in light of fundamentals and field experience: reservoir depth, thickness, oil viscosity, expected recovery, water usage and economics of both processes (in particular capital requirements) are all addressed. Guidelines are then provided for the selection of the right process given the reservoir conditions and the capital constraints. Results show that while steam injection can achieve much higher recovery than polymer flood and is also applicable in much higher oil viscosity, polymer flooding is not limited by depth or reservoir thickness, has lower operating costs and is also less capital intensive. Thus, there is a large opportunity to develop heavy oil reservoirs using polymer where steam injection is not possible. Delamaide and Euzen (Delamaide & Euzen, 2014) estimated that in the US alone, over 5 billion bbl of oil could be targeted by this technique. This paper will provide guidance to engineers who need to select the optimum Enhanced Oil Recovery method to apply in given heavy oil fields, going beyond the standard screening criteria. It will also increase awareness on the possibilities of polymer flooding in some reservoirs, with a significant potential target not only in the US but also worldwide.