This project is aimed at the development of a new generation of rotary blowout preventers capable of safe, reliable, and cost effective handling of the high pressures expected in underbalanced horizontal and directional drilling applications. Pressures of up to 5,000 psi (or even higher) can be expected when drilling with air, foam, or nitrified mud in the low permeability formations in the U.S. (e.g., Greater Green River Basin) that have large amounts of recoverable natural gas. Attaining the goal of safely and economically recovering gas from these vast reservoirs by underbalanced drilling has been hampered by the lack of a suitable high pressure rotary shaft seal. Recent technological developments relating to a novel hydro-dynamically lubricated rotary shaft seal and a floating seal carrier have increased the pressure goal limits of rotary blowout preventers from 700 psi to 2,000 psi. To meet the high pressure goal of 5,000 psi, Phase I outlines a systematic technical development effort that includes a combination of innovative improvements, rigorous analysis, and testing of the high pressure rotary seal concept. Successful completion of Phases I and II will result in the development of an advanced technology 5,000 psi rotary preventer which has the potential of significantly reducing the cost of recovering natural gas in an environmentally acceptable, safe, and reliable manner. Anticipated Results /Potential Commercial Applications as described by the awardee:Successful completion of this project will result in an advanced technology high pressure and rotary blowout preventer. The new design will be capable of providing reliable, safe, and cost effective operation at pressures of up to 5,000 psi.