摘要 |
A composition and method for acidizing a subterranean formation to minimize sludge formation upon contact of the acid with the crude and any iron present. In accordance with the present invention, an additive comprising a first constituent comprising at least one member selected from the group of thiourea, monomethylthiourea, monoethylthiourea, monoisopropylthiourea, dimethylthiourea, diethylthiourea, diisopropylthiourea, imidazolidine-2-thione and hexahydropyrimidine-2-thione and a second constituent comprising an acid soluble compound capable of providing cuprous ions in solution is admixed with the acid in an amount effective to reduce the formation of sludge resulting from contact with the acid and any iron present in the formation.
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