Session: 03-03-03 Dent Modeling and API 1183 I

Paper Number: 133869

133869 - Development and Implementation of a Dent Engineering Critical Assessment
(ECA) in Accordance with PHMSA’s Gas Mega Rule 

Abstract: 

In the 2019 US Gas Transmission Rule referred to as the “Mega Rule”, PHMSA introduced a new section within  CFR 192.712, allowing operators the opportunity to develop procedures and perform Engineering Critical Assessment (ECA) leveraging industry standards such as API 1183, ASME B31.8S, or other current research findings to determine if dents and mechanical damage anomalies could be responded or monitored beyond the prescriptive requirements referenced in CFR 192.714 and CFR 192.933. In addition, PHMSA provided guidelines to operators on what an acceptable ECA procedure should consider. If an operator chooses to perform an ECA process, submission of advanced notification with the relevant procedures in accordance with CFR 192.18 would be required.

For operators to assess a prevalent pipe integrity threat such as dents, industry standards refer to multiple levels of assessment methods (i.e. Level 1, 2, etc.), with increasing orders of complexity and decreasing levels of conservatism. The purpose of this paper is to provide technical guidance on the development and implementation of a Level 1 “Screening”  methodology as part of a proposed ECA process to determine a dent’s fitness for service from a curvature-based strain analysis and fatigue life prediction. This paper will provide details on how to address different challenges including quantifying quality of dent profiles reported from the in-line inspection (ILI) vendor, recommendations on how to perform dent curvature calculations utilizing a polynomial curve from data points nearest to the dent’s apex,  detail on how to assess the maximum indentation strain determined in alignment with the recommendations in ASME B31.8 and fatigue life in alignment with API 1183, how to account for interaction with secondary features by comparing the caliper data with all other available ILI data, and then comparing to associated limit criteria to clearly identify non-injurious dents. The paper will then establish how the proposed Level 1 “Screening” methodology process performs when applied to a real population of dents on a North American gas pipeline network.

Presenting Author: Derek Kohlenberg Enbridge

Presenting Author Biography: Derek Kohlenberg has 10 years of experience in oil and gas industry and joined Enbridge in 2021 as an Integrity Risk Assessment Sr Engineer. Before joining Enbridge, he was with Dynamic Risk and Baker Hughes and has over 6 years of cumulative experience with both companies. At Dynamic Risk, he worked mainly on engineering assessment projects using reliability or quantitative risk-based approaches to support clients’ decision-making processes. At Baker Hughes, he led in-line inspection field operations for clients across North America. Derek received his bachelor’s degree in mechanical engineering from the University of Texas at San Antonio in 2014 and his Professional Engineering license from the Texas Board of Professional Engineers and Land Surveyors in 2020.

Authors:

Huang Tang Enbridge
Derek Kohlenberg Enbridge
Jialin Sun Enbridge
Guanbo Zheng Enbridge
Fernando Oviedo Enbridge
Martin Di Blasi Enbridge