Performance of sodium lignosulfonate as thickening additive in compositions for matrix acidizing of bottom hole zone

Abstract

Abstract The work considers one of the promising directions for optimizing matrix acidizing using sodium lignosulfonate as a thickening agent. The mechanism of the interaction of acid solutions containing lignosulfonate with carbonate reservoirs is described. The use of sodium lignosulfonate in acid solutions solves several problems. Slowing the reaction rate allows the acid solution penetrate deeper into the formation, with maintaining the HCl concentration. The increased viscosity of the compositions increases the sweep efficiency of the bottomhole zone in the process of matrix acidizing. These two aspects increase the efficiency of matrix acidizing and the permeability of the bottomhole zone. In the course of this work, the chemical reaction rate of sodium lignosulfonate and hydrochloric acid solutions with carbonate core samples were evaluated. Sodium lignosulfonate in an acid solution reduces the dissolution rate of carbonate samples. It is assumed that slowing down the reaction rate allows the acid solution to form long high permeability channels which increases the efficiency of acidizing.