After a successful pilot test, a 92-acre surfactant-flood expansion project was conducted in the William Berryhill lease of the Glenn Pool field, Creek County, OK. The field had been waterflooded and had an average residual oil saturation (ROS) of 30% PV. Al the end of Oct. 1992, approximate to 1.14 million bbl of incremental oil was produced, which accounted for about one-third of the residual oil. This is the largest amount of oil produced by a surfactant flood.