NGL Recovery in Carbon Dioxide Oil-Field Flood Operations

105 NGL Recovery in Carbon Dioxide Oil-Field Flood Operations--Membrane Technology and Research, Inc., 1360 Willow Road, Suite 103, Menlo Park, CA 94025-1516; (415) 328-2228 Dr. Ingo Pinnau, Principal Investigator Ms. E. G. Weiss, Business Official DOE Grant No. DE-FG03-97ER82429 Amount: $75,000 Carbon dioxide flooding is one of the most promising enhanced oil recovery technologies. To make this process economically viable, however, the gas that accompanies the recovered oil must be treated to recover the associated natural gas liguids and pipeline gas from the carbon dioxide for the latter's reinjection. Current gas separation systems based on a combination of conventional refrigeration and absorption technology are not readily adaptable to the significant changes in composition and flow rate of the gas that occur as a flood operation proceeds. However, membrane systems are modular in design and can be economically scaled up and changed as the stream changes. In fact, membranes are already being used to partially or completely replace absorption processes for carbon dioxide separation. This project will develop a new membrane type to remove and recover the natural gas liquids portion of the gas, thus eliminating the currently-required refrigeration plant. A process based on such membranes is expected to cost less and to be more flexible. In Phase I, the properties of candidate membrane materials will be determined using model gas mixtures representative of associated gas from carbon dioxide flood operations. Based on the experimental data, the economic and operational benefits of the technology will be assessed. In Phase II, the best membrane identified in Phase I will be further developed and the process scaled up for field demonstration. Commercial Applications and Other Benefits as described by the awardee: If successfully developed, this process will solve a number of the operational problems involved in the use of carbon dioxide flood operations for enhanced oil recovery. Treatment costs are expected to be significantly lower than that using existing refrigeration processes.