Recent advances in chemical flooding technology, including new high-performance chemicals, have the potential to recover significant amounts of oil left behind after primary recovery and waterflooding processes. The Tertiary Oil Recovery Project (TORP) at The University of Kansas is conducting research and design work on applications of chemical flooding in Kansas. A grant from the US Department of Energy has boosted TORP’s efforts.
Generally more than half of the oil is left in the ground at the end of waterflooding operations due to partial sweep of the reservoir by the water and the residual oil that is left where the water has invaded. Chemical flooding has the potential to displace and produce a significant portion of that remaining oil. A slug of a chemical formulation is injected and displaced through the reservoir. The chemical formulation, which includes surfactants, solvents, polymer and/or alkali, is designed for the particular oil/brine/reservoir rock system. Surfactants in the formulation mobilize the residual oil forming an oil bank which is displaced to production wells. Concentration of polymer is selected to minimize the mixing zone between the chemical slug and the oil bank. Solvents and alkali are added to the chemical formulation to improve the performance of the surfactants. The chemical slug is displaced through the reservoir by a solution containing polymer to minimize mixing, followed by a water drive.
Chemical flooding has performed exceedingly well in the laboratory and a few field trials are underway, but the field performance results are confidential and have not been reported in the literature. A successful, well-documented field trial is key to stimulating interest by oil producers and engaging them with chemical flooding technology. It is TORP’s goal to be a partner with a producer in a field project to test the viability of the process in a Kansas reservoir and to provide field performance results to the public.
Successful field applications of chemical flooding rely on a high-quality design. Laboratory evaluation to determine an efficient chemical formulation for an oil/brine/reservoir system, and reservoir simulations to predict performance and economic evaluation of the process are key elements of the design. Kansas oil producers are not equipped for this type of design work. This is where TORP, through the DOE project, can provide a service to the industry.
The principal objective of the work conducted by TORP under the DOE grant is to supply the design work for chemical flooding processes that is necessary for oil producers to make an informed assessment for implementation of a pilot or demonstration project. TORP will (1) develop a database of Kansas oil reservoirs that will be used to screen, rate and select reservoirs for study, (2) conduct laboratory testing to design chemical formulations for specific oils/reservoirs, (3) determine field responses to chemical flooding by reservoir simulations, (4) evaluate economics of pilot/demonstration and field applications, and (5) transfer the laboratory, simulation and economic results to oil producers and the greater scientific community through technical papers and presentations.
Government funding for implementation of a demonstration project based on one or more of the designs will be pursued. This would allow an oil operator to apply chemical flooding at a much reduced risk and would also assure public access to the performance data of a field trial.
TORP is presently classifying Kansas reservoirs for their chemical flooding potential. TORP plans to partner with several lease holders in the targeted reservoirs to provide designs for chemical flooding applications. Efficient waterfloods that are near completion are prime candidates. Oil operators that are interested in evaluation of chemical flooding potential for their Kansas leases should contact Mark Ballard [785-864-4491, markt@ku.edu] or Stan McCool [785-864-2914, mccool@ku.edu] at the Tertiary Oil Recovery Project.
