Acidization—IV

Abstract

The experimental variables that atfect the acidixation 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 detined as the breakthrough time. The breakthrough time is directly proportional to the core length but inversely proportional to the HP acid concentration and the rate of injection, 0 dimensionless time, t/T p fluid viscosity, centipoise 4 porosity v stoichiometric coefficient 7 space time (time to fill one pore volume of core), min RFJEIWNCES

The Influence of Chelating Agents on the Kinetics of Calcite Dissolution

“…The dominance of the chelation reactions at moderate to reported for the dissolution of calcite by HCl (19).…”

“…When the dissolution is limited by the kinetics of the surface reaction, the rate of dissolution is independent of the rotating speed. Additional details of the theory for mass transfer in the vicinity of a rotating disk are given elsewhere in the literature (19,(21)(22)(23)(24)(25).…”

“…At low pH (values less than about 4 at ambient chelating agent. Aminopolycarboxylic acids are one of a few temperatures), the rate of dissolution has been shown to be classes of chelating agents that are capable of forming stable mass transfer limited in a variety of acidic media ranging complexes with alkaline-earth metals, such as calcium and from HCl to pseudo-sea water (15)(16)(17)(18)(19). At high pH (neutral magnesium (12).…”

“…The rate law for hydrofor the HY 30 and Y 40 species. The dissolution can then be gen ion attack has been given previously (19). In the presdescribed by Eq.…”

Limestone Dissolution in Flue Gas Scrubbing: Effect of Sulfite

“…Lund et al 6 studied limestone dissolution in HC1 solutions at temperatures of -15.6°C to 25°C using the rotating disk apparatus. Only at very low temperatures did they find dissolution to be controlled by combined mass transfer and surface kinetics.…”