fax 01-972-952-9435. AbstractThe benefits of continuous rotary drilling in directional wells through application of 3-Dimensional Rotary Steering Systems (3D RSS) are well documented in the industry. ExxonMobil Development Company (ExxonMobil) continues to expand application of these systems where economic incentive exists. ExxonMobil's targeted strategy to influence the development of low-cost 3D RSS has been published 1 and has generated further discussions with 3D RSS providers. This strategy is intended to accelerate the development of lowcost 3D RSS in order to capture benefits of this technology to improve drilling performance and economics, particularly in lower-margin projects.This paper describes the results to date of the application of our stated strategy. Systematic usage of the tools in various modes (maintaining verticality, building/dropping angle, holding angle and azimuth, etc.) have given the provider valuable real-world testing to validate and improve tool design and to improve reliability of components. The role of field testing in support of the development plan, results of applying this technology at its current level of development and an assessment of its value will be discussed.