Experimental investigation of the role of hexamethylenediamine in controlling fine migration in clay-rich sandstones

This research investigated the effect of hexamethylenediamine (HMDA) on the fine migration phenomenon in sandstones containing kaolinite clay. Fine migration, which refers to the movement of fine particles during oil and gas extraction, can lead to decreased production efficiency and severe problems in hydrocarbon reservoirs. Therefore, understanding and controlling this phenomenon is of great importance. In this study, zeta potential (ζ) values were measured for clay and sand in different fluids with different concentrations of HMDA. The results showed that HMDA effectively reduces the ζ of both materials. This reduction is due to hydrogen bonds and electrostatic interactions between HMDA and the surface of clay and sand particles. Considering that the ζ is a measure of the tendency of particles to accumulate or disperse, its reduction can lead to an increase in the system's stability and a decrease in the possibility of fine migration. Wettability measurement and clay-rich core flooding tests were performed to verify the results. These experiments showed that HMDA at an optimal concentration of 1 wt% alters the wettability of sandstones from oil-wet to neutral and significantly reduces fine migration. Wettability alteration is caused by the neutralization of surface charges of particles and the increase of interactions between particles and fluid. XRD analyses also showed that the concentration of kaolin particles in the studied sandstone is 3.2%, with an original permeability of about 62 md. Conducting five core flooding experiments on these sandstone plugs confirmed that HMDA, due to ζ compensation, prevents fine migration and inhibits pressure from increasing during the core flooding experiment. Under controlled fine migration conditions (HMDA solution), the magnitude of core permeability remained almost constant at the level between 50 and 60 md. However, low salinity water reduced it to below 10, while pressure increased and fluctuated.