Enhanced Oil Recovery Using CO2 in Alaska

Alaska holds more than 68 billion barrels of proved oil reserves and more than 36.7 trillion cubic feet of proved natural gas reserves with some special conditions such as proximity to permafrost, making Alaskan petroleum reserves unique. The low temperature in shallow reservoirs prohibited hydrocarbons' ideal maturation, thereby generating several heavy and viscous oil accumulations in this state. This also limits the enhanced oil recovery (EOR) options, leaving the thermal methods off the table to avoid permafrost thawing, which can cause wellbore collapse. Several solutions have been attempted for improving oil production from heavy and viscous oil in Alaska; however, they have not yielded the desired recovery, and ultimate recovery factors are still less than the global average. One solution identified as a better alternative is using CO2 as an injecting fluid, alternated by water or mixed with other injectants. This paper provides a comprehensive overview of all studies on using CO2 for enhanced oil recovery purposes in Alaska and highlights common and unique challenges this approach may face. The suitability of CO2-EOR methods in the Alaskan oil pools is examined, and a ranking of the oil pools with publicly available data is provided.