OILFIELD CHEMICALS
Lubricants or crude oil drilling fluids based on lubricating oils contain a thickening agent of 1 - 40% uncontracted gels of amphoteric metal oxides or hydroxides, such as
Al2O3 or Zn[OH]2
in organic acids with a minimum of 10 carbon atoms, such as naphthenic acids and their chlorinated, sulphonated and phosphorylated derivatives.