A client operating in the deep water of the Arafura Sea faced a problem with drilling interbedded formations in a 17½-in. section. Previously, the section was drilled with a two-bit trip strategy because of various formation types and hardness; a tungsten carbide insert (TCI) bit for Tertiary limestone and interbedded sand, and a polycrystalline diamond compact (PDC) for Wangarlu shale and Puffin sand. Deepwater drilling is a high-cost operation. The new hybrid bit design is a solution to drill the section with one bit run and to save approximately 28 hours of tripping time. In addition, this run improves rate of penetration (ROP), especially in the Љhard limestoneЉ above Wangarlu.The revolutionary PDC and roller-cone hybrid drill bit combines roller cone and fixed-cutter elements. The bit is designed to combine the best attributes of both bit types; the fast aggressive drilling action of the PDC and the smooth, low-torque action of the TCI. Hybrid bits are now being employed in difficult and challenging applications worldwide and are delivering a step change in performance and significantly lowering overall costs. This paper presents the results of a field test in a deepwater application, and compares the performance of hybrid bits with conventional PDC and roller-cone bits used on offset wells. The interval was drilled in one run, saving USD 1M. Furthermore, the client saved an additional 23 hours, which is equivalent to USD 900,000, by achieving an ROP that is 45% faster than the best offset well.