1.0E+00 1.0E-01 1.0E-02 1.0E-03
Probability of Exceedance
1.0E-04 1.0E-05 1.0E-06 1.0E-07 1.0E-08 1.0E-09 1.0E-10 1.0E-11 0 per year 1 per year 2 per year 3 per year 4 per year 5 per year
1.0E-12 1.0E-13 1.0E-14 1.0E-15 2004
Probability of Exceedance Determining the likelihood of a leak or rupture CC Technologies and DNV (CCT/DNV) are now one company providing you with the expertise to help you prioritize your maintenance plans and dollars What POE Does
Accounting for Tool Tolerances
With Probability of Exceedance (POE) analyses, CCT/DNV’s expert staff can evaluate the likelihood of a leak or rupture occurring on your pipeline now or in the future. Our POE calculations are conducted dynamically along the pipeline. We take into consideration past excavation results and variable corrosion growth rates. We utilize several corrosion growth rate methods for projection purposes:
Rather than adding the tool tolerance to reported depths and lengths, POE uses the actual or reported tool accuracy. We can utilize the ILI vendor’s performance specifications or, when field data from your line is available, we use them to customize the results to your pipeline. If field calculations are not available, CCT/DNV provides a proprietary database of dig/pig comparisons.
• • • •
Uniform A function of each indication’s initial depth A function of vintage and coating type As specified by the pipeline operator
The growth rates can be applied deterministically, as they have been in the past, or probabilistically using distributions that take into account the natural variability in the corrosion process.
What POE Can do for You POE results are most often used by pipeline operators to prioritize their excavation efforts. With POE results, CCT/DNV can provide timeframes for when and where maintenance should be done to reduce the risk of failure. We can even perform cost-benefit analyses to compare different repair strategies. POE has been used for clients to analyze “what-if” scenarios related to scheduled digs. The results can then be used to compare the relative benefit of different repair methods based on the associated costs.
Dublin, Ohio 43017 USA 614.761.1214 Calgary, AB Canada T2E 8M5 403.250.9041 www.cctechnologies.com Email: firstname.lastname@example.org (USA) email@example.com (Canada)