Changes

The acid used in acid fracturing is normally hydrochloric acid (HCl). Occasionally, organic acids such as formic or acetic acid may be used, either alone or in mixtures with hydrochloric acid. Organic acids are used principally in hot wells (>[[temperature::250°F]]) to reduce the corrosiveness of the acid mixture.

The acid used in acid fracturing is normally hydrochloric acid (HCl). Occasionally, organic acids such as formic or acetic acid may be used, either alone or in mixtures with hydrochloric acid. Organic acids are used principally in hot wells (>[[temperature::250°F]]) to reduce the corrosiveness of the acid mixture.

Hydrochloric acid is commonly used in acid fracturing because of its low cost per unit of dissolving power (hydrogen ion concentration) and because it develops soluble salts (principally the chlorides of calcium and magnesium) when reacted with limestone or [[dolomite]].

Hydrochloric acid is commonly used in acid fracturing because of its low cost per unit of dissolving power (hydrogen ion concentration) and because it develops soluble salts (principally the chlorides of calcium and magnesium) when reacted with [[limestone]] or [[dolomite]].

Typically, 15% (by weight) HCl is used, and this is often referred to as “regular” acid. Half strength acid (7.5% HCl) is used in some applications in which dissolving power is not the main consideration. Double strength acid (28% HCl) has found application in certain areas, but the higher strength is more corrosive and requires more effective inhibitors than 15% HCl.

Typically, 15% (by weight) HCl is used, and this is often referred to as “regular” acid. Half strength acid (7.5% HCl) is used in some applications in which dissolving power is not the main consideration. Double strength acid (28% HCl) has found application in certain areas, but the higher strength is more corrosive and requires more effective inhibitors than 15% HCl.