Patent ID: 6107255
Filing Date: 2000-08-22
Classification: C09K,Y10S

Abstract:
A system for drilling a well comprising:(A) at least one subterranean formation;(B) a borehole penetrating a portion of at least one of the subterranean formations;(C) a drill bit suspended in the borehole; and(D) a drilling fluid located in the borehole and proximate the drill bit,where the drilling fluid is non-toxic and comprises:(I) at least one additive selected from the group consisting of emulsifiers, wetting agents, viscosifiers, weighting agents, and fluid loss control agents; and(II) a base fluid comprising a paraffinic mixture that comprises (a) a total combined concentration of iso-paraffins and n-paraffins of at least about 90 weight percent, (b) greater than 50 weight percent iso-paraffins, (c) 1 or less weight percent naphthenics, (d) 0.1 or less weight percent aromatics, (e) at least 1 weight percent hydrocarbons containing 11 or less carbon atoms, (f) at least 5 weight percent hydrocarbons containing 13 or less carbon atoms, and (g) at least two hydrocarbons containing a consecutive number of carbon atoms.