Target Reliability Levels for Design and Assessment of Onshore Natural Gas Pipelines

Abstract

This paper proposes a set of reliability targets that can be used in the design and assessment of onshore natural gas pipelines. The targets were developed as part of a PRCI-sponsored project that aims to establish reliability-based methods as a viable alternative for pipeline design and assessment. The proposed targets are calibrated to meet risk levels that are considered widely acceptable. The proposed criteria are based on a detailed consideration of both societal and individual risk criteria. Two societal risk criteria were considered; the first based on a fixed expectation of the number of fatalities and the second based on a risk aversion function as characterized by an F/N relationship. Societal risk criteria were calibrated to match or exceed the average safety levels implied by current codes. Individual risk criteria were based on published tolerable levels. The target reliability levels corresponding to the three criteria are presented and a recommended set of targets is presented.

Statistical Analysis of Pitting Corrosion Field Data and Their Use for Realistic Reliability Estimations in Non-Piggable Pipeline Systems

“…As usual, once the time evolution of the failure rate is determined, the pipeline operator can implement reliability-based inspection and maintenance programs based on the comparison of the estimated failure rate with target reliability levels. [22][23] CONCLUSIONS O The analysis of the data gathered from the fi eld sampling inspection of an upstream pipeline system in Southern Mexico helped determine realistic values for the number of corrosion defects per kilometer (defect density) and to obtain a better description of the defect sizes in this system. Also, it has been possible to obtain knowledge about the pipeline variables in the region.…”

Seismic risk assessment for oil and gas pipelines

“…At this time, there are no code requirements on the level of reliability that is required for the design of oil and gas pipelines. Work sponsored by the Pipeline Research Council International (PRCI) has led to a set of guidelines for implementing a reliability-based design framework with a recommendation with respect to performance goals (Nessim and Zhou, 2005). This work has been largely incorporated into the non-mandatory Annex O of CSA Z662.…”

Fitness for Service Assessment of Ageing Pressure Vessel Experiencing External Corrosion: A Case Study

“…Pressurized pressure vessel equipment in the upstream of oil and gas industry usually experience in-service damage due to corrosion induced and process related issues [2]. One of the main leading causes of pressure vessels failure is localized corrosion [3] which has become a major threat in the oil and gas industry [4]. Consequences of pressure vessel failure due to corrosion and ageing sometimes lead to production loss, unintentional release, damage to adjacent structures, catastrophic effect of explosion and fire leading to fatalities and injuries to the public and workers [5].…”