PREDICTING RESULTS OF SANDSTONE ACIDIZING

Abstract

Reaction studies of HF-HCl mixtures on sand and clay have been conducted. From these data reaction rate constants were obtained for the reaction on silica and clay. This has been extended by use of radial flow equations to develop a method of calculating the effect of acid penetration on productivity in undamaged formations, mud-damaged formations, and formations naturally damaged by clay. The productivity increases were dependent on severity of damage and ability of the acid to penetrate the damage. The effect of retarding the reaction rate also was investigated.