Gas Injection Evaluated for EOR in Organic-Rich Shale

摘要

This synopsis contains elements of two papers.In the first,the authors describe their comprehensive experimental evaluation of gas injection for enhanced oil recovery(EOR) in organic-rich shale.Experiments in preserved core demonstrated the potential of CO2 to extract the naturally occurring oil in organic-rich shale reservoirs,whereas tests in resaturated core plugs were used to compute accurate recovery factors,and evaluate the effect of soak time,operating pressure,and the relevance of slimtube minimum miscibility pressure(MMP) on recovery.In the second paper,the authors focus on the effect of fluid transport in organic-rich shale on recovery mechanisms under gas injection,and provide the rationale behind the proposed operational philosophy.Part I-Operational Philosophy Background.The notion that industry experience in the implementation of gas-injection methods in conventional reservoirs can be applied to unconventional reservoirs is a problematic one.A lack of understanding exists regarding the effect of contrast in mechanisms at the pore scale on the implementation of a gas-injection process.Experimental research so far,though encouraging,suffers from serious limitations.Also,there still is a significant lack of understanding of the mechanisms of recovery under gas injection for enhanced recovery in organic-rich shales.