Description: 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. Four 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; and (4) synthetic organic sulfonates. With the exception of the sulfonates, the above types are compatible with normal oil field brines, unaffected by the presence of crude oil and stable under conditions common in a petroleum reservoir. The second significant result during the year involves identification of several sulfonate structures that have high potential for mobility control for carbon dioxide. Commercial sulfonate additives are available that appear optimum for reservoirs where freshwater will be used to inject the surfactant solution. They can also be considered for limited brine applications, for as temperature increases the utility of sulfonates for mobility control also increases. This is encouraging since some of the previously identified additives are chemically unstable at temperatures encountered in most petroleum reservoirs. 113 references, 23 figures, 4 tables.
Date: December 22, 1983
Partner: UNT Libraries Government Documents Department