Microfluidic devices containing thin rock sections for oil recovery studies

Abstract

While there has been a shift towards renewable energy sources, oil remains an important source of not only energy but also raw materials. Oil recovery is currently an inefficient process with as much as 50% of the original oil remaining in a field. Improvement of oil recovery techniques requires a model system that is both chemically and physically representative to achieve accurate results. Current large laboratory scale systems use large cores drilled from target rock and large, high-pressure systems to recreate oil recovery systems. The cores and associated equipment required to accurately model oil recovery are expensive and time consuming to obtain and operate. As a result, there has been a continual quest to develop alternative solutions that are faster, less complicated, and less expensive while still providing accurate representation of reservoirs. An alternative to large-scale models are optically transparent two or three-dimensional microfluidic devices. Several examples of microfluidic devices used to study oil recovery processes have been published. Unfortunately, most microfluidic devices require complicated fabrication techniques, inaccurately replicate the reservoir rock surface chemistry and geometry, and are made from materials not representative of surfaces found in oil reservoirs. Herein, the Flow On Rock Device is described as an easy to fabricate microfluidic device that acts as a bridge between fully synthetic microfluidics and large laboratory models due to incorporation of reservoir rock samples directly into the microfluidic device. Results of flooding studies are presented on shale and sandstone models as an example of the potential for this system in studying oil recovery.