Seismic EOR—The Optimization of Aging Waterflood Reservoirs

Abstract The majority of enhanced oil recovery projects currently underway are based on Water floods which are known to provide lesser recovery compared to other recovery mechanisms. Many such reservoirs exist where the recovery has been less than 30% altogether due to various drawbacks of the conventional Water floods. The paper would like to discuss a new EOR technique using Acoustic and Seismic energy to reduce interfacial tension and promote coalescence of oil ganglia using the resonant frequency principle. The technique uses pressure and sound waves at pre-determined frequencies to set the oil molecules in motion to promote coalescence and thus reducing the fingering effects. The flood pattern can be optimized by recovering oil from previously unswept areas. It thus enhances the life of the primary flood providing valuable economic savings. The process can also be applied to various reservoirs in their tertiary recovery phase to extend the life of the project. Experiments conducted in the lab show that the frequency of oil and water may differ from reservoir to reservoir and compositional analysis of samples is required to determine the resonating frequency. The design of the downhole tools for injector wells to implement this technique are also discussed briefly.