Surtek, Inc.

West Kiehl Field- Alkaline-Surfactant-Polymer

The West Kiehl field is located in Campbell Co. Wyoming. The 2,021 m (6,630 ft) deep reservoir produces from the Minnelusa formation and has an average porosity of 23% and average permeability of 350 mD. The crude oil has a viscosity of 17 centipoise at the 56^oC (134^oF) reservoir temperature. The project consists of 1 injection well and 5 production wells. The flood pore volume is 275.7 Mm³ (1,734 Mbbls) with an initial oil in place of 194.1 Mm³ (1,221 Mbbls). Primary production began in September 1985 and was estimated to produce 4.4% of the original oil in place. Waterflooding was estimated to produce an additional 51% of the original oil in place in the flooded pore volume for a total primary plus waterflood recovery of 107.6 Mm³ (677 Mbbls) of oil. An Alkaline-Surfactant-Polymer project was initiated in September of 1987 using a solution of 0.8% sodium carbonate (alkali) plus 0.1% Petrostep B-100 (surfactant) plus 0.1% Pusher 700 (polymer) injected for 28% pore volume until July 1990. This was followed by a polymer buffer for 7% pore volume until May 1991. The total oil production through December 1996 is 147.3 Mm³ (926.57 Mbbls) for a current minimum incremental production of 40.8 Mm³ (256.57 Mbbls) of oil or 21.2% of the original oil in place. This results in a current total cost of applying the Alkaline-Surfactant-Polymer process of less than $11.0 per incremental m³ of oil ($1.75 per incremental barrel). The estimated ultimate recovery is 950,000 barrels of oil for an incremental production of 43.4 Mm³ (273.0 Mbbls) or 22.4% of the original oil in place. ^1,2,3

The West Kiehl project was the first full field application of the Alkaline-Surfactant-Polymer process. A significant amount of literature has been published on this project^.1 SURTEK's design strategy and technology have evolved significantly in the 20 years since the West Kiehl work was performed.