Visual Methods of Monitoring the Effect of Wettability on Fines Migration in Sandstones

Abstract

Global energy demands are changing, with focus on replacement of hydrocarbons with renewables. However, the reliance on hydrocarbons cannot be removed in the short term, so any methods to improve the efficiency and environmental profile of hydrocarbon extraction are needed. Hydrocarbon extraction rate may be reduced if the formation becomes damaged during the extraction process. This damage may be particularly problematic during low salinity enhanced oil recovery (EOR) and although there are many mechanisms by which this may happen, the mechanism which is of particular interest in this work is that of fines migration, especially in combination with variation of wettability.
This work considers a variety of different methods to investigate the ways in which fine mineral particles move when encountering surfaces with variable wettability, and new test methods to rapidly assess the fines migration potential of a sandstone. Throughout this work, 3D printing is used to assist in these investigations, and hence firstly a comprehensive study of the wettability of commonly used 3D printing materials was undertaken which showed good agreement with the literature. Contributions to the wettability of aspects of the printing process resulting in variation of roughness was also evaluated but did not correlate at the length scales studied. Secondly, a study of the likelihood of removal of fines from sandstones by ultrasonic treatment in various salinity brines was performed, finding increased removal in low salinity brines and giving general agreement to those previously reported in the literature. Finally, several conceptual experiments looking at methods to monitor the movement of fine particles over surfaces of variable wettability, including drop spread and flow through 3D printed flow cells with individual particle tracking, were carried out. The results were compared to flow simulations and showed good agreement between particle tracking and simulated flow.