Superheated steam distillation for treatment of drill cuttings contaminated with oil based drilling fluids

Abstract

Offshore drilling activities for the oil and gas industry produce massive quantities of waste material including drill cuttings contaminated with oil based drilling fluids/muds. In offshore Norway and other Oslo Paris Commission (OSPAR) signatory countries contaminated drill cuttings are permitted for discharge if they contain less than one percent retained oil on cuttings. There are very few currently available offshore treatment technologies that can meet the stringent retained oil on cuttings requirements. This thesis describes the utilization of the Ideal Gas Law and Dalton's Law of Partial Pressure in an oil distillation process using superheated steam. The overall objective is to develop a technology which can be used for offshore treatment of drill cuttings to remove retained oil on cuttings. In the thesis, the superheated steam distillation process is performed in a laboratory setup, and deviations between the standardized reference results and the results from the superheated steam trials are discussed. The results of the superheated steam distillation experiments clearly show that the base oil distillation rates using superheated steam are significantly increased when compared to conventional distillation at 100 ⁰C. The superheated steam distillation technology shows promise for potential use in the offshore treatment of drill cuttings to remove retained oil on cuttings.