Abstract

Increased demand to minimize drilling waste created a need for a Chemically Enhanced Centrifuge (CEC) package to process all effluent from two drilling rigs operating for Mobil Oil Indonesia in the Arun Field, in Aceh Province, North Sumatra. This environmental program, which commenced in 1989, has proven effective and will continue through 1992 when primary production drilling is complete. Arun is a giant gas field producing out of four cluster pads from 22 directionally drilled wells per cluster. Prior to 1989, about 25,000 bbls of waste drilling fluid was generated per well and almost a quarter of this volume was contaminated with oil base drilling fluid. This waste was dumped into a drill site sump and then transported to four large cluster pits. After twelve years of development drilling, all four pits were full. The MOI environmental project, not only reclaimed the existing pits by spreading and land farming, but minimized the waste generated at the rig site by improved solids control and eliminated the remaining waste by water clarification and cuttings land farming. The paper describes the process used for waste disposal and documents rig equipment, cost, and other waste handling improvements implemented during a three year period. The project demonstrates that it is most effective to establish a waste handling program at the commencement of a development project and emphasizes the critical importance of cooperation between related functions.