Since May of 1989, the Prudhoe Bay oil field has been on decline. No longer limited by the capacity of the TransAlaska Pipeline- or state offtake restrictions, daily oil production is now restricted primarily by the amount of gas reinjection capability that currently exists at the North Slope.
This paper describes the results of several Prudhoe Bay field trials performed in 1991 in the Eastern Operating Area (EOA) by ARCO Alaska, Inc. The objective of these field trials was to assess the effectiveness of foamable EOR surfactants in preferentially reducing the gas production through direct treatment of high gas/oil ratio (GOR) producing wells. Three different methods of delivering the surfactant into the producing interval were tried. One method, the injection of foam, preformed at the surface using nitrogen, caused a significant GOR reduction which translated into an increase in oil production in the target well for a period of several weeks.
Work is ongoing in this area to determine the effectiveness and economic potential of these foam treatments.