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  • Weak acid stimulates San Andres

    Clint Brian, and Steve Metcalf

    Carbonate formations predominant in the Permian Basin are repeatedly stimulated with acids to maintain productivity over the life of a well. Acid reacts on carbonates to create wormholes when pumped at matrix injection rates. These wormholes facilitate production improvement by virtue of the increased surface area provided. Strong acids, such as hydrochloric, are very efficient at performing this task; however, they react very quickly and therefore when they encounter the beneficial surface area created by a previous acid treatment, they are often spent before achieving any increase in penetration. The success of an acid stimulation is dependent on the penetration into the reservoir. This can be hampered by accelerated reactivity with increased temperature, inefficient distribution of treating fluids over an interval, mineral solubility, rock hardness and changes in the exposed surface area on which the acid can react.

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2013 Fracturing Technology

2013 Fracturing Technology