An analysis is presented of the benefits and problems experienced with the use of inverted oil emulsion mud in drilling Statfjord 'A' Platform wells. Problems encountered and their solution include both fluids handling (surface equipment) and fluid chemistry (hole stability). The Statfjord 'A' application is unique in that oil emulsion mud is used from surface to total depth, and a solvent immersion system is used to clean the cuttings prior to disposal. The reasons for selecting this system are discussed. A cost/benefit analysis is included.