Green Acid Technology for Carbonate Reservoirs in Kuwait: A Sustainable Approach to Reservoir Stimulation and Management

Abstract This study evaluates the performance of a synthetic Green Acid (Oil Safe AR®) system as an environmentally friendly alternative to hydrochloric acid (HCl) for matrix acidizing in carbonate formations. A comprehensive experimental program was performed, including single-core and dual-core coreflooding tests conducted under low-temperature (40°C) and high-temperature (82°C) conditions, followed by analysis of multi-well field treatments. In laboratory tests, Green Acid (Oil Safe AR®) consistently demonstrated moderated reaction kinetics that promoted deeper acid penetration and more uniform wormhole development compared with conventional 15 wt% HCl. Dual-core experiments showed that Green Acid (Oil Safe AR®) achieved stable and sustained diversion at both low and high temperatures when injected above a critical flow rate, whereas HCl produced only transient diversion dominated by rapid face dissolution. Core-scale results were in strong agreement with field treatments, where Green Acid (Oil Safe AR®) system delivered significant and persistent improvements in production and injectivity. Overall, the findings demonstrate that Green Acid (Oil Safe AR®) provides a safer and more controlled stimulation option, especially in carbonate reservoirs where conventional HCl tends to react too aggressively and unpredictably.