Forced Imbibition of Oil into Water-Filled Nanopores

Ejaz Ahmed, Mechanical Engineering

Authors: E. Ahmed, M.A. Rahman, H. Zhang, A. Aboubakri, R. Qiao

Abstract: Predicting hydrocarbon imbibition into nanoporous media is critical for optimizing oil recovery from unconventional reservoirs and surfactant-based enhanced oil recovery. Here, we use molecular dynamics simulations to study the forced imbibition of decane (C10) into water-filled nanopores. We examine four cases with different surface wettability (strongly hydrophilic vs. less hydrophilic) and surfactant presence. The critical pressure for forced imbibition of oil, the threshold pressure for quasi-static oil imbibition, and the dynamics of oil imbibition are examined in detail. We show that the classical capillary pressure and its modification by surfactants are insufficient to explain the observed imbibition. The molecular mechanisms of the deviations are elucidated, and their implications for surfactant-based enhanced oil recovery in unconventional reservoirs are discussed.