| 摘要 |
<p>A fluid loss reducing additive for an oil-based, well-working fluid is produced by mixing together lignite or humic acid with an oil-soluble or oil-dispersible amine salt, amide-amine or amide-amine salt containing at least one alkyl, alkenyl or acyl radical having from 12 to 22 carbon atoms in a straight chain, in an oil or oil-based fluid at a temperature not greater than 70 DEG C, preferably not greater than 50 DEG C.</p> |
