Hole-Cleaning Capabilities of an Ester-Based Drilling Fluid System

Abstract

Summary Well 33/9-C02, located in the Statfjord field in the Norwegian sector of the North Sea, held the world record in extended-reach drilling from 1993-95. To successfully drill a well of this type, an efficient drilling fluid is required to suspend the weighting material and provide good carrying capacity. The ester-based mud system used in the 12¼ and 8½-in. hole sections of this well exhibited excellent holecleaning capabilities. This paper describes the fluid's performance in the field and in the laboratory where the fluid was tested under downhole conditions. Fluid rheological behavior is described with the more accurate yield-power law (YPL) (Herschel-Bulkley) model.