摘要 |
This invention relates to lignosulfonate derivatives and alkali metal salts thereof derived from sulfite waste liquor that has been subjected to alkaline oxidation, hydrolysis and partial desulfonation with subsequent resulfonation; and followed by one or more addition and double decomposition and reactions thereof; as well as the method of cementing subterranean geological formations penetrated by well bores utilizing these additives in well cementing compositions. |