A lack of data and models for corrosion and scale at the extreme temperatures and pressures (xHTHP) encountered in ultra deepwater reservoirs increases the economic and safety risks of offshore production. It is therefore very important and urgent to develop the reliable testing methods necessary data models and experimental tools to assess corrosion and scale formation at extremes of temperature and pressure encountered in deepwater development.The present work aimed at developing a protocol for evaluation of the corrosion of deepwater operation tubing materials at realistic ultra deepwater temperature (up to 250 °C) and CO2 partial pressure (up to 900 psi) in a static HTHP reactor under different salinity conditions. Corrosion behavior of carbon steel C1018 and alloy steel L80 was assessed using weight loss (WL) method as well as electrochemical techniques including linear polarization resistance (LPR) electrochemical impedance spectroscopy (EIS) and potentiodynamic sweeps (PDS). Corrosion products formed at various conditions were identified using scanning electron microscopy (SEM) and x-ray diffraction (XRD). A methodology to apply vertical scanning interferometer (VSI) to assess severity of localized corrosion was developed as well.*Funding for the projects is provided through the “Ultra-Deepwater and Unconventional Natural Gas and Other Petroleum Resources Research and Development Program” authorized by the Energy Policy Act of 2005. This program—funded from lease bonuses and royalties paid by industry to produce oil and gas on federal lands—is designed to assess and mitigate risk enhancing the environmental sustainability of oil and gas exploration and production activities. RPSEA is under contract with the U.S. Department of Energy’s National Energy Technology Laboratory to administer three areas of research. RPSEA is a 501(c)(3) nonprofit consortium with more than 180 members including 24 of the nation's premier research universities five national laboratories other major research institutions large and small energy producers and energy consumers. The mission of RPSEA headquartered in Sugar Land Texas is to provide a stewardship role in ensuring the focused research development and deployment of safe and environmentally responsible technology that can effectively deliver hydrocarbons from domestic resources to the citizens of the United States. Additional information can be found atwww.rpsea.org.