Anti-settling lubricity agent for water/oil dispersion compositions

A method to prevent settling and improve lubricity in water-based drilling fluids comprising the steps of:

• introducing into a well borehole an oil in water dispersion composition comprising a mixture of water, and
• (A) an overbased non-Newtonian colloidal disperse system comprising
• (1) solid metal-containing colloidal particles predispersed in
• (2) a disperse medium of at least one inert organic liquid and
• (3) at least one member selected from the class consisting of organic compounds which are substantially soluble in the disperse medium, where the molecules of said organic compound have polar substituents and hydrophobic portions;
• (B) a water soluble associative thickener comprising a base-neutralized copolymer having copolymerized therein about 90 to about 99 mole percent of a carboxyl-containing, ethylenically unsaturated hydrocarbon and about 1 to about 10 mole percent of a nonionic surfactant acrylate having the formula:
• ##STR32## wherein R.sup.1 is hydrogen or methyl, R.sup.2 is a hydrophobe selected from the group consisting of alkyl and alkyl ##STR33## wherein the alkyl contains 4 to 30 carbon atoms, Z is a divalent radical selected from the group consisting of oxyethylene units or mixed oxyalkylene units having the general formula:
• ##STR34## where n is an integer having values from 2 to 4 and x is an integer having values of about 5 to 40;
• (C) at least one dispersant;
• and
• drilling the well borehole.