Interaction mechanism and factors influencing dynamics of rock-heavy oil-chemical agent interface

Abstract

The interactions among the rock, oil, and chemical agent are critical for oil recovery. However, the mechanisms underlying this synergistic effect remain unclear. Therefore, this study used custom-made experimental methods to analyze these interactions and behavior of heavy oil on rock surfaces and elucidate the micro-interaction mechanism of the liquid–solid interface. Oil adhesion, flow, and deformation were studied via experiments on oil spreading, oil film emulsification, oil film shrinkage, and oil droplet peeling and deformation. Moreover, the contributions of oil diffusion on rock surface and flow through porous media to oil spread dynamics were detailed for the first time. The influence of the oil flow in porous media on oil recovery and the influencing factors were also studied. Furthermore, the effects of the rock–oil–water interface on the emulsification, shrinkage, and peeling of oil film were studied via chemical agent–oil film interactions. The main mechanisms underlying the effects of chemical agents on heavy oil flow were elucidated. Finally, the morphologies of the oil droplets under weak buoyancy were studied. The degree of deformation of oil droplets was evaluated to analyze the effect of chemical agents on the oil–water interface and factors influencing this process. Therefore, this study offers insights into the oil recovery process by analyzing heavy oil flow through porous media and the effects of chemical agents on rock surfaces and oil–water interfaces and lays the groundwork for chemical agent optimization to enhance oil recovery.