Abstract: A fluid loss additive for oil-based well-working fluids, the fluid loss additive comprisingthe product of mixing in an oil or oil based liquid,(i) lignite or humic acid(ii) (a) an oil soluble or oil dispersible amine or amine salt;(b) an aliphatic amide or hydroxyamide, or a cyclic derivative thereof, containing no primary or secondary amine or amine salt groups; and/or(c) an oil soluble or oil dispersible amine salt containing at least one C.sub.1-22 alkyl, C.sub.2-22 alkenyl or C.sub.1-22 acyl group partially or fully salted with phosphoric acid; and(iii) a dimer and/or trimer fatty acid.

Abstract: A fluid loss reducing additive for an oil-based well working fluid is the product of mixing together, in an oil or oil-based fluid, lignite or humic acid with an aliphatic amide or hydroxyamide, or a cyclic derivative thereof, containing no primary or secondary amine or amine salt groups.

Abstract: A thickened aqueous bleach composition comprising(a) an alkali metal hypochloriteand (b) one or more carboxylated surfactants of formula IRO-- CH.sub.2 CH.sub.2 O ].sub.n R.sub.1 --COO.crclbar.A.sym.Iin whichR is a straight chain C.sub.6-20 alkyl, phenyl, a straight or branched chain C.sub.7-30 alkaryl or a straight or branched chain C.sub.7-30 aralkyl, unsubstituted or substituted with substituents unreactive to hypochlorite,R.sub.1 is C.sub.1-4 alkylene,A.sym. is hydrogen ion, an alkali metal cation, or an equivalently charged amount of an alkaline earth metal cation and n is 0.5 to 45. Additionally free ethoxylate can be present in the mixture together with further bleach additives including perfumes.