There is estimated to be about 250 billion barrels of oil in this country that are currently deemed economically unrecoverable. With conventional recovery techniques it is possible to recover about 47% of the estimated total oil in place, and steady improvement in technology may eventually bring crude oil recovery up to 65% of the oil in place. It is apparent that oil recovery is a relatively inefficient process. Therefore, in light of the increasing costs of finding and drilling for new oil, there is an enormous economic incentive to recover even a fraction of the vast amount of oil left behind in our existing reservoirs. Water injection has been the most successful additional recovery process developed in the last century. It is estimated that by 1975, 41% of the nation's crude output will be recovered by this technique. For years the idea of developing a chemical that could be added to the injected water to increase ultimate oil recovery has intrigued the entire industry. This paper deals with recent attempts by the industry to develop surfactants to recover the oil that remains after conventional recovery operations. The requirements for developing an effective surfactant are discussed in detail and the chemist's role in assisting in this development is highlighted. © 1969 American Oil Chemists' Society.
