Publications

In September 1977, at the tenth Energy World Conference in Istanbul, a Delphi-type poll of companies and experts on ultimate petroleum resources led to the conclusive statement that in the year 2000, 55% of oil produced in the world would come from enhanced oil recovery techniques and 45% from new discoveries. In these 55%, oil shales, schists and coal are not included. Enhanced oil recovery (EOR) refers to the technologies needed to unlock oil remaining in the reservoirs after the conventional primary or secondary techniques have withdrawn all they can. Actually, the conventional techniques of primary depletion, waterflooding or gas flooding recover about one third of the original oil in place because of capillary, viscous and gravitational forces. The EOR methods tend to take into account the physical, chemical and hydrodynamic phenomena involved in these trapping mechanisms, to diminish their effects and to achieve as high a degree of recovery as possible by : mobilizing residual oil saturation, sweeping more homogeneously the entire reservoir, keeping the oil production rate as high as possible. The purpose of this paper is to give people not very familiar with these unconventional methods the basic information they need to help them in deciding which technique might be most applicable to recover additional oil from fields wherein primary or secondary production has already taken place.