Matrix Acidizing of Carbonate Reservoirs Using Organic Acids and Mixture of HCl and Organic Acids

摘要

Hydrochloric acid is the most commonly used acid for carbonate acidizing due to its low cost and high dissolving power. However, there are two major drawbacks associated with using concentrated HCl solutions in deep wells. The first is its high reaction rate with carbonate rocks, which limits acid penetration in the formation. The second is its corrosivity to well tubulars. Hence organic acids become viable material for matrix acidizing to alleviate these two problems. Though organic acids provide the benefit of retardation and low corrosivity, their low dissolving capacity may still limit the wormhole penetration leading to insufficient stimulation of the formation. Therefore, opportunity exists to mix HCl with an organic acid to achieve productivity enhancement by optimizing the wormhole penetration and profile.