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Title: Preinjection of polymers to increase reservoir flooding efficiency

Conference ·
OSTI ID:7301361

A polymer flood was injected before the surfactant slug, in heterogeneous laboratory models, for improved oil recovery. The surfactant slug contains Mahogany AA sulfonate, isopropyl alcohol, and 0.23N sodium chloride brine. Two types of laboratory models were used. The first was a Berea sandstone core with a central core of unconsolidated sand. The five-spot model consisted of heterogeneous biporous filtros slabs. All the models were saturated with oil and water, then waterflooded with brine. Dow Pusher 700 in brine was the preinjection polymer flood for the cores. The five-spot models were injected with ICI 2060 polyacrylamide solutions in brine. The preinjected polymer flood in each case was followed by brine, the surfactant slug, a polymer drive (Kelzan MF biopolymer in brine) and a dilute brine chase water. A maximum of 100 percent OIP was recovered from the cores. A water-preflush in place of the polymer flood gave only 84.3 percent OIP. Oil recovery in the five-spot model was 82 percent OIP with the polymer preflush, but only 63 percent OIP without it. Preinjection of the polymer flood reduced the loss of surfactant to the rock by 40 percent or more. The polymer preflush does not decrease oil displacement efficiency, but it does increase the amount of polymer required for the mobility buffer.

OSTI ID:
7301361
Resource Relation:
Conference: Improved oil recovery symposium of the Society of Petroleum Engineers, Tulsa, OK, USA, 22 Mar 1976; Related Information: Preprint No. 5836
Country of Publication:
United States
Language:
English