Life-Cycle Reliability Characteristics of Minimum Structures

Abstract

Minimum structures are used primarily because of their low initial investment and fast-track schedule characteristics. These structures generally cost less and take less time to commission than more traditional structures such as four-pile (leg) platforms. A wide variety of configurations of these structures have been proposed and installed in offshore locations around the world (Craig, 1995). This paper details a reliability and risk-based approach that has been used to characterize the life-cycle risk characteristics of three minimum structures and one traditional four-pile structure. The structures were all designed according to current American Petroleum Institute guidelines (1993). Results from the life-cycle (design, construction, operation) analyses of the quality and risk characteristics of the alternative structures are summarized. The occurrences and influences of human errors throughout the life-cycle are included.