Russ Davis, Jim Redmon, Nestor S. Makarigakis and Adam Reale, MISTRAS Group, Inc., USA,

Transcription

1 Russ Davis, Jim Redmon, Nestor S. Makarigakis and Adam Reale, MISTRAS Group, Inc., USA, explore the shift towards risk-based integrity: centralising data management to enhance pipeline risk analysis. I n 2016, the United States Pipeline and Hazardous Materials Safety Administration (PHMSA) proposed a new set of rules governing natural gas transmission pipelines. Known within the industry as the Megarule, the new guidelines are massive, expanding existing integrity management (IM) regulations and imposing new rules on lines that had previously been grandfathered under lax protocols. The goal of the Megarule is to move the industry towards

2 incorporating risk-based IM procedures as the new industry standard, in an attempt to adapt to ever-expanding technological knowledge and shifting population sizes and locations. Figure 1. Through a business intelligence module, database software can provide operators with detail ranging from a top level overview of their entire organisation s equipment counts down to granular, individual inspection information. For pipeline operators in the US, this means updating existing IM procedures and creating new ones in order to meet additional requirements for lines that have not undergone extensive integrity assessments in decades. This is a complicated process that may take years to complete, requiring a wide range of engineering expertise. For pipeline operators outside of PHMSA s jurisdiction, though they may not be lawfully bound by the new guidelines, the underlying messaging and purpose of the proposed rules is indicative of the direction towards which pipeline IM is shifting. Riskbased IM programmes (in short: programmes in which operators assess an asset s criticality by analysing the probability and consequence of failure) maximise the safety and integrity of a pipeline, allowing operators to save on emergency repair costs and to make more informed decisions on pipeline management budgeting. The benefits are not constrained to simply adhering to regulatory guidelines; it is just smart business. The foundation of risk-based IM programmes is effective and detailed data management. This is most efficiently accomplished through the use of a robust inspection data management system (IDMS). An effective IDMS serves as the centrepiece of a cohesive pipeline IM programme that encompasses all inspection, engineering and condition-monitoring data throughout a pipeline s lifetime. This can be accomplished through an IDMS like the one offered by MISTRAS Group, Inc.: a multinational, one source provider of asset protection solutions. MISTRAS solutions span inspection, engineering, maintenance, condition-monitoring, products and the company s proprietary data management software, Plant Condition Management Software (PCMS ). Approximately 50% of the US refining capacity, as well as many pipeline operators, utilise PCMS, validating its advanced capabilities. By effectively managing pipeline integrity data through the powerful PCMS software and implementing a risk-based assessment approach, pipeline operators maximise safety while optimising maintenance budgets. Figure 2. Risk-based criticality assessments are tailored to the properties of each individual pipeline. The more detailed and accurate data available for each of the line s components, the more in-depth an assessment will be. Existing challenges to integrity data management Pipeline integrity data management, at least in the US, has typically been a rather disjointed process. In the November 2016 issue of World Pipelines, MISTRAS detailed the challenges of relying on spreadsheetbased documentation of inline inspections (ILIs), in-ditch assessments (IDAs) and repairs. Terminology is often disparate across reports even within a single organisation, and anomaly-level photos that are crucial to devising a maintenance plan may be stored on an entirely different file server from the design and operating data. Pipeline operators have World Pipelines / REPRINTED FROM NORTH AMERICA 2017

3 moved towards a combination of hard copy and digital documentation, but that data is often located all over the organisation. As technology becomes more advanced and integrity data more exact, reliance on spreadsheet documentation creates avoidable inefficiencies at best, and potentially increases the possibility of overlooking data that may predict a pipeline failure. Prior to the proposed PHMSA rules, pipelines that were constructed before 1970 were exempt from keeping detailed integrity data, since they were built before pipeline regulations existed and pipeline operators would have had to dig up tens of thousands of miles of lines to perform integrity assessments. For these lines, integrity data may have been collected decades ago, stored in a file cabinet and lost over the years. Pipeline operators may also utilise several contractors to manage different portions of their IM programme, which spreads integrity data that is most effectively analysed together across company lines. In some cases, detailed pipeline integrity data never existed at all. But risk factors change, and lines that were once built in loosely populated areas may now be surrounded by communities. The Megarule requires that, regardless of the date of construction, pipelines located in areas where a failure would have the greatest impact on public safety (high consequence areas [HCAs] and moderate consequence areas [MCAs]) must undergo integrity assessments to confirm the line s maximum allowable operating pressure (MAOP). If operators are relying on existing data to reconfirm MAOP, according to PHMSA, they must ensure that the records being used are reliable, traceable, verifiable and complete 1 (though not required for non-us pipelines, this is still good practice for all older lines, as the upfront costs will be mitigated by preventing future failures). For many lines, since storing data in an IDMS was not a common practice, locating and verifying this data is simply not possible. The shift towards risk-based integrity The pipeline industry has been moving towards a riskbased integrity approach since the 1990s, after it became clear to regulatory bodies that IM programmes across the industry varied in scope and complexity, and that no minimum standards or requirements existed. The adoption of risk-based assessments is a response to a few factors: Inefficient data processes. Expanding populations that are increasingly settling near existing pipelines, necessitating more stringent regulations. An ageing pipeline network. High profile pipeline failures (most notably, the San Bruno pipeline explosion in California. As it was built before 1970, operators were not required to conduct integrity assessments on the line. An accident report from the National Transportation Safety Board (NTSB) concluded that integrity assessments likely would have exposed the defective pipe that lead to the failure 2 ). Highly prescriptive rules are difficult to enforce on assets as diverse as pipelines. For example, smart pigs are the most effective assessment solution for certain lines, while a technology like long-term guided wave ultrasonic testing is increasingly becoming the tool of choice for others when pigging is not possible. It would be impractical to impose a one size fits all integrity plan throughout the entire industry. At the same time, pipeline regulatory bodies have a duty to ensure that lines are operating safely. Risk-based criticality assessments provide a compromise: pipeline operators are able to design an IM programme that best fits the needs of their particular asset as long as the line meets certain performance standards, while regulators oversee that required safety goals are being met and that the programme framework addresses any potential personal and environmental safety concerns. Figure 3. Through detailed data management, an IDMS can geospatially display HCAs, MCAs and other problem areas on a map. Assessing risk with an IDMS Risk-based IM programmes use a series of questions specific to each individual pipeline segment to assess the probability and consequence of failure once a defect REPRINTED FROM NORTH AMERICA 2017 / World Pipelines

4 Figure 4. Engineering SMEs can help operators develop a risk assessment algorithm utilising historical design, operating and integrity data. has been identified. Operators seek to identify factors including, but not limited to: Population near the affected segment. segments with the highest probability of failure, geospatially display areas of concern on a map, and aid operators in prioritising assessment digs. Second, at a more advanced level, a powerful IDMS such as MISTRAS PCMS is able to perform complex engineering calculations that provide greater insight into a defect s potential failure. Risk-based criticality assessments, at present, stop short of the in-depth quantitative analyses of risk-based inspection that has become the industry standard in refineries and other process plants. This is partly due to those industries extremely detailed regulations, in addition to the sheer number of individual assets and components in play at these facilities (high volume, highly structured data creates opportunities for more advanced risk algorithms). But, an organisation that dedicates itself to effectively collecting and storing historical pipeline integrity data into its IDMS can work with engineering and software subject matter experts (SMEs) to eventually create a truly quantitative approach to pipeline risk assessment. An integrated risk-based integrity programme So, what would a risk-based integrity programme that is managed through a single provider look like? Amongst others, PHMSA offers the following components as essential to an IM programme: Identify all HCAs and MCAs. Material of construction. Pipeline age. Type of product. Soil type. Likely damage mechanism(s). Previous repairs. MAOP. Based on the answers, operators are able to determine how critical a repair is for the identified defect, optimising maintenance planning. Criticality assessments are impossible without the effective use of an IDMS like PCMS, for two reasons. First, the baseline application of an IDMS is to serve simply as a data warehouse a central repository of all historical inspection and mechanical integrity data. Rather than having to locate scattered, incomplete data strewn across an organisation, operators can identify all of the line s historical integrity data through a central hub in order to answer each of the programme s questions. Working with as much accurate data as possible, an IDMS can help to identify HCAs and MCAs, inform operators of pipeline Develop a risk-based plan through inspection data and engineering support. Repair any identified defects within a timely manner. Integrate assessment results with all other relevant data to improve understanding of the pipe s condition. Implement additional risk control measures, including the use of long-term monitoring and leak detection systems. It can be difficult for a pipeline operator to implement this programme without the help of a third party, specialised service provider. These requirements span a wide swath of asset protection disciplines requiring inspection, engineering, condition-monitoring, maintenance and software solutions, and many pipeline operators are not equipped with SMEs in each of these fields. In addition, PHMSA encourages the use of outside technical experts to verify risk plans as a form of bias control from internal SMEs, for an added layer of plan integrity. Again, while not all operators are bound by this requirement, efficient business practices would suggest that the longterm safety and cost saving benefits of a third party verification far outweigh whatever initial cost may be incurred. World Pipelines / REPRINTED FROM NORTH AMERICA 2017

5 Finally, each of these activities involve their own sets of data. But IM programmes, whatever the approach, are most effectively served by analysing these datasets in conjunction with each other. If the foundation to a successful risk-based integrity programme is access to complete, accurate and timely data, then the likelihood of failure increases when that data is spread across multiple, often competing contractors. Utilising a single service provider and PCMS circumvents these preventable inefficiencies. In an integrated risk-based integrity programme, a onesource service provider can: Provide engineering support during the pipeline s design and construction. Offer engineering SMEs to develop and verify riskbased integrity plans. Complete new construction inspections and integrity assessments. Perform coating and other light maintenance work to repair defects. Remotely monitor assets in between direct assessments to provide early warning of potential damage areas. Store, manage, and analyse all the data from the previous steps in a central IDMS, utilising a comprehensive risk algorithm consistent with the properties of an individual pipeline. Pipeline operators already perform or contract many of these services. But, they are done in a largely inefficient matter, with the biggest culprit being poor data collection, management and analysis. An effective pipeline integrity programme at the topmost level has two goals: preserve the safety of the public and the environment, and optimise operators maintenance budget planning. Risk-based integrity programmes that are backed by a complete, easily located set of historical data and managed by a single provider are the clearest path to both of these objectives. At present, through qualitative answers and solid foundational data management, criticality assessments are one of the most effective means the industry has to prioritise probabilities and consequences of failure. Over time, through a continued commitment to effective data management and with the help of external SMEs, pipeline operators can continue quantifying this information on the path to improving safety and saving money. References 1. United States Pipeline and Hazardous Materials Safety Administration, Pipeline Safety: Safety of Gas Transmission and Gathering Pipelines, 81 FR 20721, 2016, documents/2016/04/08/ /pipeline-safety-safety-of-gastransmission-and-gathering-pipelines 2. United States Department of Transportation (DOT), Pipeline Accident Report: San Bruno, California Natural Gas Transmission Pipeline Rupture and Fire, 2010, Reports/PAR1101.pdf REPRINTED FROM NORTH AMERICA 2017 / World Pipelines