Environmentally friendly water based drilling fluids

An oil-in-water emulsion composition, comprising a mixture of a brine and

• (A) at least one natural oil wherein the natural oil is a genetically modified vegetable oil triglyceride of the formula ##STR22## wherein R.sup.1, R.sup.2 and R.sup.3 are aliphatic groups that contain from about 7 to about 23 carbon atoms and are at least 60 percent monounsaturated wherein the monounsaturated character is due to an oleic acid residue and further wherein an oleic acid moiety:
• linoleic acid moiety ratio is from 2 up to about 90 and further wherein the genetically modified vegetable oil is selected from the group onsisting of high oleic sunflower oil, high oleic safflower oil, high oleic corn oil, high oleic soybean oil, high oleic rapeseed oil, high oleic cottonseed oil, high oleic canola oil and high oleic peanut oil;
• (B) at least one alcohol, R.sup.4 OH wherein R.sup.4 is an aliphatic group containing from 1 up to about 18 carbon atoms;
• (C) at least one emulsifier wherein the emulsifier is a polyolefin amine ester/salt represented by a formula selected from the group of formulae (I) and (II) ##STR23## wherein n is zero or one, X is oxygen or NH;
• R.sup.5 is a hydrocarbyl group containing from 20 to about 500 carbon atoms;
• R.sup.6 is an alkylene moiety containing from 1 up to 4 carbon atoms;
• R.sup.7 and R.sup.8 are independently hydrogen, alkyl or hydroxy alkyl moieties containing 1 up to 4 carbon atoms,
• a polyolefin ester formed by the reaction of ##STR24## where R.sup.5 is a hydrocarbyl group containing from 20 to about 500 carbon atoms, R.sup.9 is a hydrocarbyl group containing from about 2 to about 40 carbon atoms and m is an integer of from 2 to about 10, or
• a polyolefin salt formed by the coupling of a high molecular weight acylating agent a of the formula ##STR25## and a low molecular weight acylating agent (d) of the formula ##STR26## wherein R.sup.21 is a hydrocarbyl group that contains from 1 up to 18 carbon atoms, wherein the coupling of a and d is accomplished with a coupling component (e) comprising (i) two or more primary amino groups, (ii) two or more secondary amino groups, (iii) at least one primary amino group and at least one secondary amino group, (iv) at least two hydroxyl groups, or (v) at least one primary or secondary amino group and at least one hydroxyl group to form an intermediate and reacting said intermediate with
• an amine (f) comprising ammonia, primary amines, secondary amines, hydroxyamines, primary and secondary monoamines and tertiary mono- and polyamines;
• and
• (D) a sulfurized composition wherein (B), (C) and (D) are soluble and reside within (A).