The influence of salinity and mineral components on spontaneous imbibition in tight sandstone

Spontaneous imbibition is one of the fundamental mechanisms to understand the complicated liquid-formation interaction during hydraulic fracturing operations in tight sandstone formation. Salinity and mineral components play important roles for imbibition process, but how these factors affect the imbibition process is not fully resolved. The objective of this paper is to investigate the influence of salinity and mineral components on spontaneous imbibition. We systematically vary salinity to investigate its effect on imbibition capacity, denaturation and permeability by performing a series of spontaneous imbibition and post imbibition experiments on four tight sandstones containing different amount of minerals. Results show that high salinity can restrain the expansion of typical minerals and decrease maximum imbibed liquid volume. Additionally, in post imbibition experiments, samples with high clay minerals will gain a slight permeability increase due to the salinity effect. These observations can improve our understanding for the complicated interactions between fracturing liquid and formation in tight sandstone.