Acidization--IV : Experimental correlations and techniques for the acidization of sandstone cores

Abstract

The experimental variables that affect the acidization of sandstone cores in a permeameter are discussed. It was found that as HCl/HF acid mixtures are injected into porous sandstone cores a reaction front between selective minerals and the acid is formed. This reaction front and a corresponding permeability front move through the core with a constant axial velocity. The time for the permeability front to move through the core is defined as the break-through time. The breakthrough time is directly proportional to the core length but inversely proportional to the HF acid concentration and the rate of injection.