ABSTRACT
Beginning in 1968 Pennzoil installed and operated two field tests of the Maraflood™ oil recovery process in the Bradford field of Pennsylvania. The oil reservoir tested was the oil-wet, watered-out Bradford Third sand at a depth of 1850 ft.
The initial 3/4-acre inverted five-spot pilot, operated from 1968 to 1970, proved that residual waterflood oil could be mobilized and produced by micellar-polymer flooding. The outgrowth of the technically successful pilot test was a 46.2-acre expanded project adjacent to the pilot. The expansion, Special Project No. 7, was developed in 1970 and placed on injection in 1971. Through July 1981, the project has recovered 208,000 bbl of oil, equivalent to 4500 bbl per acre or 300 bbl per acre-ft. Ultimate oil recovery is projected at 218,000 bbl or 52% of the oil in-place following waterflood.
Because of the encouraging results of the previous field tests, Pennzoil started work in 1979 on a 220-acre development in the same area. This development, Special Project No. 8, was self-certified under the DOE front-end incentive program in March 1980. A staggered line drive pattern containing 126 production wells and 57 injection wells was developed in 1980 and 1981. Injection of micellar solution will begin in January 1982, and will be followed by three years of polymer injection. Fluid injection will be concluded by 1990. Oil recovery from the 220-acres is estimated at one million bbl. The cost to develop and produce a barrel of oil (1981 $) by the Maraflood process in the current project is estimated at $27 before taxes (local, federal income and excise tax) and royalty.
