The Success of Synthetic-Based Drilling Fluids Offshore Gulf of Mexico: A Field Comparison to Conventional Systems

Abstract

ABSTRACT The first wells have been successfully completed offshore Gulf of Mexico using a new synthetic-based drilling fluid. Potyalphaolefin (PAO), the synthetic base used for these fluids, is unique to the drilling fluids industry at this time. The environmental benefits of PAO-based synthetic systems over conventional oil-based fluids and some water-based fluids has already been presented in prior papers. However, the practical benefits gained from utilizing PAO as an alternative to conventional systems can now be documented after a series of highly successful field tests in the Gulf of Mexico. The non-aqueous PAO system has been used on several wells in the Gulf of Mexico to drill problematic formations previously drilled with either inhibitive water-based or oil-based fluids. Wells with angles up to 86° and formations from 4500 ft to 18300 ft have been successfully drilled. Direct comparisons can be made regarding performance benefits of PAO-based synthetic systems verses water-based and oil-based systems previously used to drill in the same location. Benefits in hole stability, cuttings integrity, lubrication, and gauge wellbores, all leading to increased penetration rates and subsequent reduction in drilling days, can be seen. This paper reviews the results of the first field tests with PAO synthetic systems in the Gulf of Mexico concentrating on the practical aspects of drilling rather than the detailed environmental information which has been covered in prior literature.