Assessing Fitness for Purpose of Offshore Platforms. I: Analytical Methods and Inspections

Abstract

Existing structures, including offshore platforms, often do not meet the same standards as those mandated for new designs. It is also recognized by the engineering community that acceptance criteria for existing structures: (1) Should not necessarily be the same as those for new designs, and (2) should be dependent on the consequences of structural failure. Because of a large population of aging offshore platforms worldwide, reassessment of platforms to determine their fitness for purpose has gained considerable attention by the oil and gas industry and regulatory agencies in the United States and overseas. The reassessment process could be time‐consuming and costly because it requires many steps such as: gathering information on design and physical condition of the platform, modeling of all important damage found, structural evaluation of the platform, calculation of reliability indices, and determination of mitigation and repair schemes. Therefore, a reassessment process covers a large span of technical topics and could require more effort and expertise compared to a new design.