New base oil used in low-toxicity oil muds

Abstract

The use of a new and different low-toxicity, low-pollutant oil-mud base fluid is presented. This low-polynuclear-aromatic (LPNA) oil differs from most other white mineral oils in that it is composed of 99 plus % cyclic and branched paraffins with an average carbon number of C//1//3. It contains less than 0. 1% aromatics and less than 1% n-paraffins. This base oil composition provides for some interesting oil mud properties, which are discussed. Toxicity studies by an independent laboratory show the LPNA oil and the oil-mud cuttings to be substantially less toxic than diesel oil and the diesel-mud cuttings, respectively. Oil retention on the cuttings was shown to be less than for a comparable diesel mud. Laboratory formulation data, toxicity testing, and field test results are presented and discussed.