Effect of Confinement on the Dynamic Contact Angle of Hydrocarbons

Unconventional hydrocarbon reservoirs and their characteristics have promoted an area of research exploring the effect of small pore size on the reservoir fluid and its associated properties. There is a general agreement that (i) the confined fluid flow and associated properties in shale are substantially different from its corresponding bulk properties and (ii) these differences have a significant impact on the prediction of well performance and ultimate recovery in shale reservoirs. However, experimental measurements of fluid flow and properties in shale rocks are currently very limited, which has led to a significant amount of uncertainty in reservoir modeling. In this study, a nonfluidic device is designed, fabricated, packaged, and tested, and an experimental investigation of the gas liquid contact angle of hydrocarbons confined in nanosized channels within a nanofluidic platform is conducted. Reservoirs in the nanofluidic chip are filled with a hydrocarbon liquid and epi-fluorescence imaging is simultaneously performed to investigate the contact angle. Pure hydrocarbon liquids, hexane, heptane, and octane are confined in nanosized channels, gas liquid contact angle measurements are recorded, and images are captured by high-resolution confocal microscopy.