Patent ID: 6787505
Filing Date: 2004-09-07
Classification: C09K

Abstract:
A wellbore fluid of the water-in-oil emulsion type useful for electrical well-logging comprising a discontinuous aqueous or brine phase, solids, and having a non-aqueous continuous liquid phase that comprises a polar organic liquid POL which exhibits a dielectric constant of at least about 5.0 and a Hildebrand Solubility Parameter of at least about 17 (J cmâˆ’3)1/2 so that the liquid phase exhibits an electrical conductivity of not less than 10 &mgr;S mâˆ’1 at 1 kHz, and wherein it further comprises a dispersion in the wellbore fluid of finely divided particles of an electrically conducting solid insoluble in the organic liquid or water, and wherein the finely divided electrically conducting solid is selected from the group consisting of metals; carbon preferably in the form of graphite or carbon fibre; metal coated carbon fibre or graphite; and conductive polymers and combinations thereof.