Nanoparticle-Associated Surfactant Micellar Fluids: An Alternative to Crosslinked Polymer Systems

Abstract

Abstract Hydraulic fracturing has become an increasingly important completion method to allow reservoirs to become economically producible and to improve the rate of hydrocarbon production. Crosslinked polymer fluids have been the most commonly used fracturing fluid. These fluids exhibit exceptional performance to initiate and propagate a fracture and carry proppant into the reservoir during a treatment. However, crosslinked polymer fluids can leave a significant amount of polymer in the fracture once a treatment is completed. Decades of improving oxidative, enzyme and other breakers for the polymer fluids has only marginally improved the amount of polymer residue left within the fracture. The result has been wells with subpar hydrocarbon recovery rates and in many geographic areas the return of large volume waterfracs. Over the past two decades surfactant-based fluids have been developed as a low-damage alternative. However, surfactant-based systems have had major limitations for hydraulic fracturing. This paper will introduce improved fluid technology that uses nanoparticles, internal breakers and low molecular weight surfactants to achieve the performance of crosslinked polymer fluids but leaves little to no gel residue. Nanoparticles have been found that uniquely associate thread-like micelles into 3-deminsional network that imparts wall-building leak-off control and fluid efficiency. The system also utilizes internal breakers that reside within the micelles and go wherever the fluid goes to insure complete viscosity reduction. The nanoparticle enhanced surfactant-based fluid technology may allow a wide range of hydraulically fractured reservoirs to produce at higher sustained rates than presently achievable, particularly for wells highly sensitive to fracture conductivity damage. This paper will present laboratory data that shows how uniquely charged nanoparticles improve surfactant-based fluid rheology and leak-off control properties. The mechanisms for the observed performance enhancements also will be discussed.