Abstract
Using flowback additives in slickwater fracturing fluids is a relatively recent innovation, and regained permeability testing using corefloods is the preferred performance evaluation method. The coreflood rig simulates the hydraulic fracturing process by injecting the fracturing fluid through a core under relevant pressure and temperature conditions, and measures the permeability and relative permeability changes during injection. Permeability measurements indicate whether the fracturing fluid damages the formation during hydraulic fracturing that in turn reduces oil productivity during flowback. While coreflooding is useful for comparing the performance of different flowback aids, it is unable to resolve the mechanisms associated with porescale transport. The goal of this study is to directly visualize and quantify the pore-scale dynamics of fracturing fluid injection and oil flowback using a microfluidic chip device and correlate these observations to the coreflood test results. Microfluidics-based measurements provide pore-scale visual evidence of the flowback dynamics, not achievable using conventional experimental methods such as the coreflood.
