Potential of Improving Oil Recovery with Surfactant Additives to Completion Fluids for the Bakken

Fracture treatment performance in Bakken liquid-rich shale reservoirs can be improved by altering rock wettability from oil-wet to water-wet. The use of surfactant additives for altering wettability also results in alteration of the interfacial tension (IFT). The Young–Laplace equation relates the capillary pressure to IFT and contact angle. Thus, it follows that capillarity is significant in nanopores associated with unconventional liquid reservoirs (ULRs) and complex as the contact angle (CA) and IFT varies simultaneously. This study carefully evaluates these interactive variables and compares the performance of anionic, nonionic, blended, and complex nanofluid (CnF) surfactants in recovering liquid hydrocarbon from siliceous and carbonate Bakken shale cores through spontaneous imbibition experiments. In addition, we also analyze the effect of wettability, surfactant adsorption, and IFT alteration on the process. CA measurement is used in determining the original wettability of Bakken cores, as well as ...