| 摘要 |
<p>Hydrofluoric acid compositions and methods for dissolving siliceous materials in subterranean formations to stimulate the production of fluids therefrom are provided. The compositions have a pH value of no more than 2 and are comprised of at least one mineral acid, at least one fluoride compound which is a source of hydrofluoric acid in the mineral acid, and an aluminum compound which is soluble in the mineral acid, and which upon dissolution in the mineral acid produces aluminum III ions. The fluoride compound is present in the compositions in an amount sufficient to produce a fluoride ion concentration of at least 0.05 gram-moles of fluoride per liter of solution. The aluminum compound is present in the compositions to produce a molar ratio of fluoride ions to aluminum III ions of from about 1 to 1 to about 6 to 1. The presence of aluminum in the compositions retards the reaction rates thereof to thereby enable deeper penetration of formations by the acid compositions.</p> |
