Assessing Acid Fracturing for Low-Permeability Carbonate Formation to Improve Oil Production

This study investigates the application of hydraulic acid fracturing to enhance oil production in the Mishrif Formation of the Al-Fakkah oilfield due to declining flow rates and wellhead pressures resulting from asphaltene deposition and inadequate permeability. Implementing acid fracturing, an established technique for low-permeability carbonate reserves, was essential due to the inadequacy of prior solvent cleaning and acidizing efforts. The document outlines the protocols established prior to and following the treatment, emphasizing the importance of careful oversight to guarantee safety and efficacy. In the MiniFrac treatment, 150 barrels of #30 cross-linked gel were injected at 25 barrels per minute, followed by an overflush with 30# linear gel. Laboratory tests confirmed the fluid's stability. The simulation results suggest that the average fracture conductivity is 285 millidarcy feet, with an effective etched fracture length of 109 m, an acid height of 41 m, and a mean etched width of 0.195 inches. The peak injection rate was maintained at 25 barrels per minute, and the peak surface treating pressure reached 9,190 psi. Post-fracturing thermal responses were monitored using High Precision Temperature logs, which confirmed significant enhancements in the productivity of the Mishrif Formation. This comprehensive approach addresses the challenges posed by low permeability and optimizes the hydraulic fracturing process, thereby enhancing hydrocarbon recovery in the region.