Getting Ahead of the Game:
adopting best practices in
leak detection
May 2013 / White Paper
Make the most of your energySM
Summary
Executive summary ................................................................................... p	 1
Introdu...
Executive summary
Getting Ahead of the Game: adopting best practices in leak detection
Burgeoning energy exploration is dr...
Introduction
White paper | 02
Getting Ahead of the Game: adopting best practices in leak detection
Kalamazoo River, Mayflo...
CPM methods for
pipeline leak detection
White paper | 04
Getting Ahead of the Game: adopting best practices in leak detection
CPM methods for pipeline leak detect...
Getting Ahead of the Game: adopting best practices in leak detection
White paper | 05
How to choose or evaluate
a leak det...
Getting Ahead of the Game: adopting best practices in leak detection
White paper | 06
High consequence areas
When analyzin...
Getting Ahead of the Game: adopting best practices in leak detection
White paper | 07
API 1149
Although an American standa...
Getting Ahead of the Game: adopting best practices in leak detection
White paper | 08
Leak detection challenges
Successful...
Getting Ahead of the Game: adopting best practices in leak detection
White paper | 09
External based leak detection
Extern...
Getting Ahead of the Game: adopting best practices in leak detection
White paper | 10
Real-time transient model
vs. other ...
When you want volume
balance CPM
White paper | 11
Getting Ahead of the Game: adopting best practices in leak detection
Whi...
When you want a real-time
transient model
White paper | 12
Getting Ahead of the Game: adopting best practices in leak dete...
Association of oil pipe lines
rupture monitoring
White paper | 13
Getting Ahead of the Game: adopting best practices in le...
Conclusion
Technological advances and aggressive exploration are opening up more and
more hydrocarbon sources around the w...
©2013SchneiderElectric.Allrightsreserved.
May 2013
Schneider Electric
10333 Southport Rd SW, Ste 200
Calgary, AB T2W3X6
Ph...
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[Oil & Gas White Paper] Getting Ahead of the Game: adopting best practices in leak detection

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Burgeoning energy exploration is driving the construction of pipeline systems for hydrocarbon transportation. For a variety of reasons, including renewed scrutiny on safety by regulators, this is also driving new practices and standards for leak detection.

Computational pipeline monitoring (CPM) systems use real-time information from the field – such as pressure, temperature, viscosity, density, flow rate, product sonic velocity and product interface locations – to estimate the hydraulic behavior of the product being transported and create a computerized simulation. With it, controllers can be alerted to abnormal operating conditions that might signal the existence of a pipeline leak. Different CPM methodologies provide different leak detection capabilities, so different methods, or a combination of methods, might be better applied to different operations.

Selection of the right CPM for a given company or given pipeline relies on the thorough evaluation of several factors, including pipeline characteristics, business objectives, additional risk factors and special safety concerns, such as proximity to environmentally sensitive or urban areas. New standards and industry initiatives provide tools to assist in this evaluation, ensuring the pipeline industry continues to provide efficient, effective and safe hydrocarbon transportation.

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[Oil & Gas White Paper] Getting Ahead of the Game: adopting best practices in leak detection

  1. 1. Getting Ahead of the Game: adopting best practices in leak detection May 2013 / White Paper Make the most of your energySM
  2. 2. Summary Executive summary ................................................................................... p 1 Introduction ............................................................................................... p 2 CPM methods for pipeline leak detection.................................................... p 4 How to choose or evaluate a leak detection system.................................... p 5 High consequence areas ........................................................................... p 6 API 1149 .................................................................................................... p 7 Leak detection challenges ......................................................................... p 8 External based leak detection .................................................................... p 9 Real-time transient model vs. other CPM’s.................................................. p 10 When you want volume balance CPM......................................................... p 11 When you want a real-time transient model................................................. p 12 Association of oil pipe lines rupture monitoring............................................ p 13 Conclusion ................................................................................................ p 14
  3. 3. Executive summary Getting Ahead of the Game: adopting best practices in leak detection Burgeoning energy exploration is driving the construction of pipeline systems for hydrocarbon transportation. For a variety of reasons, including renewed scrutiny on safety by regulators, this is also driving new practices and standards for leak detection. Computational pipeline monitoring (CPM) systems use real-time information from the field – such as pressure, temperature, viscosity, density, flow rate, product sonic velocity and product interface locations – to estimate the hydraulic behavior of the product being transported and create a computerized simulation. With it, controllers can be alerted to abnormal operating conditions that might signal the existence of a pipeline leak. Different CPM methodologies provide different leak detection capabilities, so different methods, or a combination of methods, might be better applied to different operations. Selection of the right CPM for a given company or given pipeline relies on the thorough evaluation of several factors, including pipeline characteristics, business objectives, additional risk factors and special safety concerns, such as proximity to environmentally sensitive or urban areas. New standards and industry initiatives provide tools to assist in this evaluation, ensuring the pipeline industry continues to provide efficient, effective and safe hydrocarbon transportation. White paper | 01
  4. 4. Introduction White paper | 02 Getting Ahead of the Game: adopting best practices in leak detection Kalamazoo River, Mayflower, Grand Marsh, Bonga Field, Little Buffalo – all places that represent the sites of pipeline spills in the last several years. The rash of significant incidents has many countries spending more and more time investigating the pipeline industry’s safety practices. This comes at a time when the opening of new oil and natural gas plays around the world is putting growing pressure on new pipeline development. Changing attitudes around the world necessitate that pipeline companies vigorously take on the goal of increased safety and reassess their abilities to detect and mitigate product leaks. The consequences of not doing so endanger not only the business of individual companies but the reputation of the industry as a whole. The positive side of this discussion is that significant investments have been made in recent years to develop a new array of industry standards and best practices, as well as continual advancements in the technology that supports leak detection. Of all the different methods for detecting pipeline leaks, what’s observed on the control room operator’s console is almost always the best warning system. Computer-based leak detection is a common industry application that supports the safety of the general population and environment and helps sustain efficient operations and facility management. This paper provides an overview of liquids pipeline leak detection best practices based on Computational Pipeline Monitoring (CPM) software applications. These best practices follow dictates of governmental regulations in place or proposed worldwide, as well as recommendations from leading industry agencies. More importantly, this paper discusses the process for selecting the best leak detection system and reviews the best practice criteria operators need to consider. The goal is to help companies find the right intersection between risk, cost and above all else, safety.
  5. 5. CPM methods for pipeline leak detection
  6. 6. White paper | 04 Getting Ahead of the Game: adopting best practices in leak detection CPM methods for pipeline leak detection The most common technology for detecting pipeline leaks is the CPM system, which uses real- time information from the field to estimate volume, mass or the hydraulic behavior of the product being transported. An example of a hydraulic profile display is shown in Figure 1. Calculated results are then compared to field references to identify an unexpected anomaly that might signal a leak – whether an accidental rupture or an unlawful tap. An example of leak detection is shown in Figure 2. The American Petroleum Institute (API) publication 1130 defines CPM systems as systems that are internally based, utilizing field sensor outputs that monitor internal pipeline parameters such as pressure, temperature, viscosity, density, flow rate, product sonic velocity and product interface locations. Which parameters are considered and how they are interpreted depends on the CPM method being applied. The following is a brief description of the common CPM methods in use on pipelines today: • Line balance – measures the imbalance between the receipt and delivery meters. This is your basic “meters in, meters out” comparison and is the least sensitive to anomaly capture as volume in the pipe is not part of the balance • Volume balance – similar to the line balance but also includes a limited pipe volume adjustment. An overall pipeline density is calculated based on pipeline boundary pressure and temperature • Modified volume balance – similar to volume balance except a different volume adjustment is used for each product in the pipeline. This takes into consideration where the density changes are in the pipeline • Pressure/flow rate modeling – essentially what a controller does by nature, looking for unexplained large drops in pressure or flow, but there are applications that monitor for these anomalies to ensure these large changes are not missed • Acoustic/negative pressure wave – detects a leak by quickly sensing a pressure wave and using those detections to triangulate the location of the event/leaks • Statistical leak detection – pressure and flow inputs that define the perimeter of the pipeline are statistically evaluated in real time for the presence of patterns associated with a leak • Real-time transient model – all the fluid dynamic characteristics are modeled, including line pack, slack, shut-in and transients, under all pipeline flow conditions. A very detailed configuration with very fast calculations and the ability to model hydrocarbons in any phase Important differentiators between real-time transient model detection systems and volume balance systems include increased leak detection sensitivity, fewer false alarms and better leak location estimation. These differentiators allow real-time transient models to perform leak detection across a wide range of pipelines, from simple to complex, transporting many different products under a broad range of operating conditions. They are key to help improve and facilitate effective response times, especially in environmentally sensitive and urban areas. Figure 1 Figure 2
  7. 7. Getting Ahead of the Game: adopting best practices in leak detection White paper | 05 How to choose or evaluate a leak detection system The multitude of choices for leak detection systems is necessitated by the vast variety of pipelines they will be employed on. Therefore, a comprehensive analysis is necessary to identify which CPM technologies and methods are best suited for the pipeline assets in question. A simple A-to-B pipeline route might have simpler operations than a pipeline with many active route connections and elevation changes, multiple receipt and delivery points, and reversible flow. As the complexity increases, the CPM to be applied needs to be flexible enough to handle all operational scenarios possible in the operation of the pipeline. The following is a listing of key factors to be considered when evaluating a new CPM or re-evaluating a legacy CPM for its leak detection capability. Factors should be weighted according to their importance to any particular operation: • Rate of false alarms and misses • Sensitivity to pipeline flow conditions such as transients, shut-ins, starts, and stops • The impact of instrument accuracy and configuration accuracy • Personnel training and qualification requirements • Required response time • Leak location estimation and release volume estimation accuracy and precision • Ability to detect pre-existing leaks • Robustness/high availability • Initial cost/tuning costs/maintenance costs The most important objective in selecting a leak detection system is that the chosen solution must be able to assist the controller in identifying a leak event within a sufficient period of time that mitigates the safety and environmental risk to a level that is acceptable for the stakeholders in a particular pipeline, while also meeting the operating company’s overall business objective and threshold for risk. This includes the potential value of product lost, the cost of clean-up and potential regulatory fines, potential detriment to surrounding environments and the cost to reputation and potential impact on future projects. The most important objective in selecting a leak detection system is that the chosen solution must be able to assist the controller in identifying a leak event within a sufficient period of time that mitigates the safety and environmental risk to a level that is acceptable for the stakeholders in a particular pipeline, while also meeting the operating company’s overall business objective and threshold for risk.
  8. 8. Getting Ahead of the Game: adopting best practices in leak detection White paper | 06 High consequence areas When analyzing which leak detection systems to employ, the question of whether the pipelines being monitored are located close to or in high consequence areas (HCAs) must be answered. High risk, or high consequence areas are defined as areas where a pipeline leak will have a significant impact on people, property, the environment, or all three. Whether through regulation, local authority or community requirements and expectations, HCA’s typically demand higher levels of leak detection capability and sensitivity to mitigate the higher risk of significant consequences from a leak. If located in such an area, pipeline operators must take additional measures to meet these requirements. These measures include conducting a more thorough risk analysis and employing additional leak detection measures to enhance public safety and protect property and the environment. • Automating data collection for over-short analysis • Integrating alarm and status information between connected pipelines • Use of, or more frequent, operational shut-in tests • Addition and/or the relocation of instrumentation • Application or tighter parameters on pressure/ flow deviation monitoring • Higher degree of data integration between operations support applications • Deploying a higher fidelity leak detection application If the pipeline network has locations close to or in high consequence areas (HCAs) – or if it is a large and complex network with diverse operating parameters and products – more than one leak detection system might be warranted. A multi-tiered approach might be necessary to satisfy specific requirements.
  9. 9. Getting Ahead of the Game: adopting best practices in leak detection White paper | 07 API 1149 Although an American standard, the API 1149 is a best practice evaluation around the world. This is a theoretical analysis of a given leak detection system’s ability to detect a leak of a given size, based on the specifications of a given pipeline. It weighs the time to detection against the size of the leak. While not always necessary to employ techniques that achieve the lowest theoretical capability as determined by 1149, it provides a measure to weigh against when analyzing the cost of leak detection systems against the risk of undetected leaks. As important, if not more so, the API 1149 calculations can assist pipeline operators in determining the benefit of specific pipeline infrastructure enhancements on their leak detection capability. For example, what increase in leak detection sensitivity can be achieved by adding, replacing, or upgrading instrumentation on all, or sections of a pipeline.
  10. 10. Getting Ahead of the Game: adopting best practices in leak detection White paper | 08 Leak detection challenges Successful pipeline leak detection can present many challenges to the operator. Issues that impact leak detection include: • Batched systems – multiple products; multiple phase products; reversible flow systems • Transient and steady state flow conditions; turbulent and laminar flow transitions • Step change product temperature gradients; elevation induced hydraulic variations, such as over a mountain or under a shipping channel • Varying P/L diameters, telescoping systems, restrictions, block valves, tees, relief systems, control valves and unique physical characteristics • Multiple pump configurations – series, parallel, varying and multiple speed, electric and engine drives • Branch connections and multiple inlets, outlets and partial flow alignments • Slack line and product separation static conditions • HVL versus crude versus condensate versus refined products physical property and hydraulic characteristics operated within a single SCADA console • Communication outages; variable signal scan and refresh rates; errant signal and data filtering versus non-HCA system variances • Human factors – operator sensory overload; fatigue • Varying individual operating procedures • Employee turnover and limited training time for new controllers • External and internal resource availability When evaluating leak detection needs and effectiveness, these should be evaluated to determine their impact. Mitigation of many of those listed above will be directly related to the CPM chosen for the pipeline. Others, such as human factors of operator overload and fatigue, will rely on the implementation of control room management, human machine interface and training best-practices.
  11. 11. Getting Ahead of the Game: adopting best practices in leak detection White paper | 09 External based leak detection External based leak detection systems are being increasingly employed due to their abilities to detect very small spills and locate leaks with a high degree of accuracy. Technologies include hydrocarbon sensors, thermal imaging, acoustic/ pressure wave sensors and fiber optics. Unfortunately, while external technologies can be retrofitted to existing pipelines, the fieldwork to do so is still relatively expensive, increasingly so the longer the pipeline. However, new and shorter pipelines are increasingly using external technologies and more and more these technologies are used in conjunction with a CPM based leak detection applications.
  12. 12. Getting Ahead of the Game: adopting best practices in leak detection White paper | 10 Real-time transient model vs. other CPM’s As operators walk through the above checklists, eventually a point is reached where decisions need to be made on selecting a leak detection system. Again, the selection should match the characteristics of the pipeline as closely as possible and fit the company’s business goals and risk threshold.
  13. 13. When you want volume balance CPM White paper | 11 Getting Ahead of the Game: adopting best practices in leak detection While less robust and not well matched to complex pipeline systems, volume balance CPMs can offer effective, and cost-efficient solutions for companies with low risk/low consequence systems, such as: • Pipelines generally operating in steady state conditions and non-HCA areas • Pipelines with shorter segments and steady temperature • Pipeline operators whose risk assessment calls for a lower fidelity leak detection system • Pipeline operators who want to provide some level of interim leak detection coverage while a higher fidelity model is being deployed or upgraded
  14. 14. When you want a real-time transient model White paper | 12 Getting Ahead of the Game: adopting best practices in leak detection For pipelines that operate in HCA’s and for the risk averse pipeline operator, the real-time transient model is unmatched in its ability to support highly effective leak detection for high risk, or complex pipeline systems: • Great for both steady state, transient and shut-in conditions • Leak detection thresholds well under one percent of flow are possible • False alarm rates significantly lower versus other leak detection systems • Leak location and leak volume estimation • Excellent leak detection performance with compressible products • Accounts for use of drag reducing agents in pipeline • Leak detection for pump stations and tank farms • Two phase model maintains leak detection through slack line conditions • For expedited permitting on new pipelines
  15. 15. Association of oil pipe lines rupture monitoring White paper | 13 Getting Ahead of the Game: adopting best practices in leak detection Although leak detection technology has advanced a long way in terms of detection time and detectable leak size, damaging pipeline ruptures and large volume release events have still occurred and, unfortunately, been missed. In addition to individual companies taking initiative to improve their leak detection capabilities using the strategies discussed above, the Association of Oil Pipelines (AOPL) has created a Leak Detection Rupture Monitoring project as part of their “Pipeline Leadership Initiative” to develop additional strategies to continue improvements in leak detection. A key area of improvement the initiative has identified is execution on the “3R’s”: Recognition, Response and Reporting. They have developed performance standards for the industry to follow in this area, with the target goal of 30 minutes for 3R execution: Recognize (5 minutes): Recognize a 50% flow change within five minutes. Response (5 minutes): A response to the rupture must come within five minutes of the recognition. Responses can be tailored to particular situations. Report (20 minutes): A report must come within 20 minutes. While these may seem like basic standards, meeting them is important to the goal of the industry to be “great” in the execution of the 3R’s of rupture detection.
  16. 16. Conclusion Technological advances and aggressive exploration are opening up more and more hydrocarbon sources around the world. This will mean an increasing demand for pipeline development. It will also mean increasing pressure for pipeline operators to demonstrate and maintain effective safety practices, namely in leak detection and prevention, as regulators place more scrutiny on projects. Not only is this important for individual companies to maintain competitiveness in the market but it is important for the reputation and health of the industry as a whole. The upside is with greater focus on leak detection comes more advanced solutions and industry standards for guidance. CPMs provide a wide array of powerful solutions for pipeline companies to identify leaks, and even potential leaks, faster and with greater accuracy. Industry guidelines and assessment tools, such as API 1149 and AOPL rupture monitoring, give companies the tools to evaluate their program and implement the appropriate solution. Whether choosing a volume balance CPM or a real-time transient model, the selection needs to be based on a thorough evaluation of the business objective against the threshold for risk. At the intersection of those points is where companies will find the appropriate leak detection system solution. Getting Ahead of the Game: adopting best practices in leak detection White paper | 14
  17. 17. ©2013SchneiderElectric.Allrightsreserved. May 2013 Schneider Electric 10333 Southport Rd SW, Ste 200 Calgary, AB T2W3X6 Phone: 1-403-212-2407 Fax: 1-403-259-2926 http://www.schneider-electric.com

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