Enhanced Oil Recovery by CO sub 2 Foam Flooding. First Annual Report (Exthoxylated Adducts of C sub 8 -C sub 14 Linear Alcohols; Sulfate Esters of Ethoxylated C sub 9 -C sub 16 Linear Alcohols; Low Molecular Weight CO-Polymers of

摘要

The objective is to identify commercially available additives which are effective in reducing the mobility of carbon dioxide, CO sub 2 , thereby improving its efficiency in the recovery of tertiary oil, and which are low enough in cost to be economically attractive. During the past year significant progress has been made in developing a commercial method of reducing the mobility of carbon dioxide in enhanced oil recovery processes. Interest in the industry is high and several companies have agreed to underwrite a portion of funding necessary to continue the research over the next two years. Experiments on gas mobility control, conducted in linear sand-pack models, show only a general correlation with the static foam test. In general, all surfactants that produce reasonable quantities of foam in the blender test also impart some degree of mobility control to gas during two-phase flow. The best mobility control additives however, are only modest foam volume producers. In addition, the best additives spontaneously produce a viscous foam under flow conditions present in a petroleum reservoir. Three basic chemical structures listed below appear to show most promise for gas mobility control: (1) ethoxylated adducts of C sub 8 -C sub 14 linear alcohols, (2) sulfate esters of ethoxylated C sub 9 -C sub 16 linear alcohols, (3) low molecular weight co-polymers of ethylene oxide and propylene oxide. (ERA citation 08:038444)