A Semi-Quantitative Risk Assessment to Support Oil Pipeline Risk-Based Design
Notice bibliographique
Résumé
During the regulatory phase of the Enbridge Northern Gateway Project (Northern Gateway), the Joint Review Panel (JRP) requested information on “how the risk factors resulting from the geotechnical and geographic aspects of the pipeline will be taken into account” and to demonstrate “the integration of risk factors with the environmental and socio-economic consequences from potential hydrocarbon releases”. Furthermore, the JRP required Northern Gateway to identify where a risk-based approach to design would be used to address geotechnical and seismic hazards, valve locations for spill consequence reduction and risk reduction in consequence areas”. [1] To meet this requirement a semi-quantitative risk assessment (SQRA) was undertaken. Risk was defined as a function of probability and consequence, where the probability (expressed as a frequency) of loss of pipe integrity was quantitatively determined and the consequence of failure was qualitatively determined. The frequency of failure was a probabilistic combination of the calculated probability of failure from reliability methods, historical frequencies and assessed geo-hazard failure frequency rates. Consequence scoring was based on intersection of theoretical spills with “consequence areas” for environmental or socio-economic effects Frequency and consequence were then combined to provide risk scoring and ranking. Failure frequencies were developed using reliability methods where appropriate. The use of reliability methods addresses the primary challenge associated with quantifying risk for new pipelines as industry failure statistics are not directly applicable to modern pipeline designs, materials, and operating practices. In the pipeline industry, reliability models exist for the most significant threats, including third-party damage, internal corrosion and external corrosion. In addition, geotechnical threats can be characterized in terms of expected magnitude and associated frequency of occurrence, thereby enabling pipeline reliability to be established for each geo-hazard. Consequence scoring was based on modeling full bore rupture spill scenarios and determining whether these spills would potentially intersect identified “consequence areas”. Over the course of the application and hearing process two SQRA’s were undertaken. Following the filing of the first SQRA, additional measures were included in the pipeline design to reduce the frequency of failure and to reduce potential consequences. This resulted in the calculated overall risk being reduced by a factor of 84%, primarily due to increases in wall thickness resulting in a reduction in the likelihood of 3rd party damage and in a reduction of consequence by an increased number of valves.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,007 | 0,016 |
| Méta-épidémiologie (sens strict) | 0,002 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,004 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,003 | 0,002 |
| Science ouverte | 0,002 | 0,002 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,008 | 0,002 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».