Abstract An extended-reach [ERD] well was planned and successfully drilled in Block 16/26 of the U.K. Central North Sea with water-based drilling fluid in an area where wells have historically been drilled with mineral oil-based and ester-based drilling fluids. With increasingly stringent environmental regulations, the current utilization of mineral oil-based fluids is dependent upon shipping all cuttings back to shore for processing and subsequent disposal, resulting in high supplemental costs. Additionally, potential adverse weather conditions could temporarily preventing the transfer of cuttings from the platform to a supply vessel, thereby curtailing the drilling operations and further increasing drilling costs. The operator realized that significant savings to the current overall well costs could be realized if a water-based drilling fluid system were successfully used to drill the large-diameter hole interval that produced the highest volumes of cuttings.