Clarifications on Oil/Heavy Oil Recovery Under Ultrasonic Radiation Through Core and 2D Visualization Experiments

摘要

Our previous research on the effects of ultrasonic waves on oil recovery conducted at the University of Alberta had showed that capillarity and interfacial tension (IFT) might be responsible for the observed improvements in incremental oil recovery.To investigate this further,Hele-Shaw type experiments had been performed with the same fluid pairs,and significant alterations in the morphology of the fingers with ultrasonic waves were observed.Although the results seem encouraging,questions about the mechanism and effective parameters causing additional recovery still remain.To analyze the influence of parameters other than IFT and capillary forces,we conducted capillary imbibition experiments on cylindrical Berea sandstone core samples under ultrasonic radiation in this paper.Through this experimental scheme,we focused on (a) the effect of initial water saturation for different wettability rocks,(b) oil viscosity,and (c) matrix wettability.The cores were placed into imbibition cells where they contacted with aqueous phase.Every experiment was conducted with and without ultrasonic radiation for comparison.Different intensities of ultrasonic waves were tested as well.To profoundly investigate the acoustic interaction between rock and fluid,we further performed some visualization experiments.We used 2-D glass bead models to clarify the effects of ultrasonic waves on oil displacement process for different oil viscosities and matrix wettability through comparative analysis.The qualitative and quantitative observations and analyses are expected to shed light on the further investigations in the use of in-situ recovery of oil/heavy-oil as well as surface extraction.