Cost Effective Minimum Platform Designs Considering Damage Tolerance and Potential Consequences of Failure

With their simplicity and light structural weight, minimum platforms are a popular solution — even though they may not have the same robustness levels as conventional jackets to withstand extreme or accidental events. These competing attributes are investigated by comparing the cost and structural reliability characteristics of five structures designed using API RP2A. The braced monopod and tripod structures have considerably lower ultimate strengths and residual strengths, and damage scenarios play a much greater role in the overall probability of failure, than for the four-legged jacket. In determining the relative economic merits of the different configurations, the magnitude of the potential consequences of failure becomes an important parameter. Bands of conditional costs of failure for which each structure is the most cost-effective option are derived, with the sturdy monopods and tripod shown to be the optimal solutions for moderate consequence levels.