Implementing and Benchmarking of Reliability Methods in Well Design 11-7/8 71.80 (0.582' wall) Q125 T1 S BTC-L Tin Drilling Casing

摘要

Reliability-based design has been in extensive use since thernearly 1960’s, and has been applied by operators for wellrndesign during the last ten years. Reliability-based casingrndesign quantifies drilling and production loads and tubularrnperformance to define reliability. Different reliabilities arernuseful based on the consequence of failure: connector leak-rn99.9684% reliability (10-3.5 probability of failure), pipe yield-rn99.9990% reliability (10-.5 probability of failure), pipe rupture-rn99.99997% reliability (10-6.5 probability of failure). The intentrnof setting rupture reliability requirements very high is to makernthe likelihood of rupture statistically insignificant. Forrnreference, current offshore structure (jackups) reliability isrn99.9684%. Reliability is the quantification of the overlaprnbetween stochastic load and stochastic strength distributionsrnfor a particular failure mode and load combination. Therndetermination of these stochastic distributions requires loadrnand strength data. Load data comes from actual measurementsrnfrom wells, while strength data is derived from mechanicalrnand dimensional variations within the material.