Unique characteristics of clay even though make any clay abundant shales a good source of adsorbed gas, make them equally difficult to produce. The clay-water interaction can cause significant swelling, and fines migration in shale formation both of which can significantly impair the overall hydrocarbon recovery from shale. Geomaterial functionalized micromodels, developed by coating traditional glass or PDMS micromodels with geomaterials (e.g. calcite, quartz, clay) can represent the physico-chemical properties of the natural porous media and have been used during the last few years to understand and evaluate the solid-fluid physicochemical interactions. This study focuses on developing a clay-coated geomaterial surface and investigates the effect of base fluid’s salinity on clay adsorption to the glass surface. Glass capillary tubes and straight channel borosilicate glass micromodels are coated with Illite clay to represent the pore-scale clay chemistry of Caney Shale, a Mississippian unconventional play in Southern Oklahoma, USA. 10 wt. % of Illite clay slurries made with brines of four different salinities are used to coat the capillary tubes and micromodels to understand the effect of salinity in clay adsorption on the glass surface and overall coating quality. To achieve a stable coating, coated surfaces are heat-treated at high temperature (120 oC) and the result is compared with a coated surface treated with hot air drying (80 oC) to evaluate the effect of heat treatment on the stability of the coating. The outcome of the experiments indicated a strong relationship between the salinity of the brine and the adsorption of clay particles on the glass surface. Increase in brine concentration resulted in improved adsorption of clay particles on the glass surface. Experiments involving heat treating the glass following the coating demonstrated improvement in the stability of the coating. The interpretation of the results of this study will be useful to reach a consensus over the solution preparation and drying treatment for clay coating.

Functionalizing glass micromodels with illite clay: Effect of salinity and heat treatment

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.