Where chemical EOR stands today

Two major factors that stand in the way of chemical recovery of residual oil left in a reservoir after waterflooding are the high cost of efficient processes and reservoir heterogeneity. Under present economic conditions, it appears that chemical enhanced oil recovery (EOR) processes are only marginally profitable when applied under true tertiary conditions. These same processes can be more profitable - and more efficient - if initiated earlier in the life of a reservoir when oil saturations are higher. Experience shows EOR processes to be more sensitive to reservoir heterogeneities than conventional waterflooding. Field tests of various chemical processes demonstrate their ability to recover substantial amounts of oil from reservoirs that had been previously waterflooded to their economic limit.