Paper: Stimulation Production Is Improved Through Improvements In Gelled Acid Technology

Stimulation results from acid treatments of carbonate reservoirs are generally Limited by the extent of live acid penetration, which is determined by the rate of acid spending and fluid-loss. In recently ears, the effort to control acid leakoff and reduce the rate of spending has caused the industry to focus on developing gelled acid systems. Numerous gelling agents have been used, including natural gum, biopolymers, synthetic polymers and surfactants. Many of these materials have been used with only limit & success, due to their inherent instability in live or spent acid, or incompatibility with common additives and contaminants. In 1983, a polymer was introduced, which provides the desired characteristics of stable viscosity, acid retardation and compatibility with most of the common acid additives. It has since been successfully applied in more than 300 matrix and fracture acidizing treatments. This paper provides a description of this gelling agent and details of several case histories.