Calibration of casing/tubing design criteria by use of structural reliability techniques

This paper reviews the state-of-the-art in casing/tubing structural reliabi lity analysis, and the knowledge gained from it to date. Results are presen ted to show that, as previously suspected, burst design based on casing ful l of gas is over-conservative for noncritical wells. However, the risk-cali brated design criteria are strongly dependent on the design philosophy for underground blowout loads. It is demonstrated that well control is the larg est single factor in reducing risk; gaps in current knowledge are identifie d, and recommendations made for future work.