Innovative Acidizing Technique in Carbonate Reservoir: An Experimental Study

Carbonate reservoirs, which account for a substantial portion of global hydrocarbon resources, often require acid stimulation to enhance permeability and improve well productivity. Conventional acidizing treatments typically involve the use of hydrochloric acid (HCl) to dissolve carbonate minerals such as calcite and dolomite. However, these treatments frequently encounter challenges including rapid acid-rock reactions in high-temperature reservoirs, inefficient acid utilization, and non-uniform penetration, which reduce the overall effectiveness of the stimulation process. Our study aims to develop an acidizing treatment composed of HCl and thermochemical additives for improved acid placement and acid-rock reaction control. The use of reactive additives leads to improved acid distribution in the formation and reduces early acid spending near the wellbore by reducing the local temperature. To assess the effectiveness of this new approach, laboratory core flood tests were done on carbonate rock samples. The tests showed that permeability improvement was much better than conventional acid systems, thus proving the effectiveness of the treatment enhanced with thermochemical additives. The new treatment gives us a feasible and scalable option to enhance the stimulation treatment in the carbonate reservoirs. The results provide a basis for improving the technique's design for implementing on the field in difficult reservoir conditions.