Expandable Proppants for In-Situ Well Stimulation

The exploitation and recovery of gas from unconventional formations, such as shale are changing the United States from a net energy importer to potentially an exporter due to the economics of hydraulic stimulation to enhance oil recovery. According to the U.S. Energy Information Administration, Office of Energy Analysis, over 33 million barrels of oil and 1,480 trillion cubic feet of natural gas are technically recoverable from tight and shale formations in the United States. Currently, Oil recovery rates are less than 7% on average, while gas recovery rates remain around 25% of total recoverable reserves. Furthermore, currently, hydraulic stimulation processes utilize large amounts of water, which must be treated and disposed of during flowback. How Problem is Being Addressed This Phase I SBIR will develop engineered stimulation fluid alternatives and modifications to slickwater fluids that provide the controlled application of force independent of flowrate to widen and extend fracture networks. The ability to stimulate with higher degrees of control and expand fracture networks that are not in the primary tensile direction (eg, shear fractures). The addition of materials that expand the fluid volume in-situ during completion is the approach being taken Actions of Phase I The phase I program will characterize the underlying kinetics and effectiveness of the novel stimulation fluids, and will experimentally determine the engineering design basis for their use. Methods of controlling the rate and under what conditions (timing) the expansion force is delivered into crack networks will be experimentally verified, and their function and resultant fracture conductivity after stimulation will be measured using API reference methods in the laboratory to demonstrate feasibility and support transition to scale-up and field trials. Commercial Applications and Other Benefits This program will develop unconventional stimulation fluids that have improved control over crack widening and extension compared to current fluids used in the oil and gas industry. This ability to produce improved fracture network conductivity with lower water use can potentially increase oil recovery by 20-40%, and are also applicable to the development of the 200,000 exojoule enhanced geothermal energy sources available in North America.