With natural gas deposits now being extracted from previously unattainable shale formations, natural gas transmission networks throughout North America are required to be more dynamic in terms of transportation receipt/delivery points than anytime in the past 50 years. New production sources must access interstate transmission and storage lines to deliver natural gas to market. System modifications and constraints require that a regulated service business built on excess capacity must now demonstrate a high degree of system reliability.
NiSource Gas Transmission & Storage (NGT&S) has commissioned an initiative to review the current state of their natural gas transmission system, identify the future desired state, quantify the tangible gap between the two, and execute in the pursuit of best in class system reliability. It is important to note that the representative information contained in this article is applicable to "non-pipe" assets, i.e. compression, regulation and metering within the transmission network and not the underground pipeline. NGT&S Integrity Management department governs such activity and is in quick pursuit of world-class status as a targeted effort.
As with any competitive industry, natural gas transmission and storage service providers must continue to evolve in terms of balancing market demands with the economic challenges of reliable service. Historical dynamic customer requirements based on ambient temperature fluctuations across North America drive the daily service requirements. This fact alone creates a difficult environment for establishing a holistic system reliability plan with both effective and efficient execution.
For the first time in the past 50 years, the production sources of natural gas requiring transmission to market are growing on an expanding large scale. Many areas of past non-strategic importance are now becoming critical receipt points. This source expansion and diversity is causing flow direction of many pipeline systems to either reverse or become subject to bidirectional flow based on daily market demands.
Production of natural gas trapped in shale formations is now economically attractive to gather by engineered fracturing, directional drilling and other moderately recent technology advancements. Historically, the dynamic nature of the industry was managed by latent compression horsepower and pipeline operating capacity. That is to say that system design included an "overriding" capacity to handle the market fluctuations based on somewhat static producer locations. This capacity was not contractually required and in turn, allowed for mitigation of most system delivery issues as unplanned events occurred - or unreliability.
With new production sources and directional flow modifications affecting the marketplace, capacity constraints are now forcing transmission providers to achieve measured system reliability with tactical actions where and when maximum operational capacity is required.
With foundations in classical reliability program techniques, NGT&S has adopted two simultaneous and complimentary strategies to deliver mass flow rates to market under contract specifications and flexible options. The first initiative focuses on engagement of the enterprise in an autonomous manner, and the second initiative relies on classical engineered solutions for effective risk management.
Pipeline connections at an NiSource compressor facility.
Strategy 1: Defect Elimination by Empowered Workers
In an effort to achieve long-term reliability growth, the first foundational strategy of defect elimination is adopted. Nothing is more critical to success in any endeavor than the tasks of engaging and empowering the stakeholders that are most affected by the daily processes and procedures to ensure positive results. Establishing a foundation and protocol to address "defects" in the system at all levels is fundamental to achieving a reliability culture in any service business. By definition, as related to the NGT&S process, a defect is a condition that inhibits or impedes the designed operation of a system, asset or component in a manner that an individual or small group (fewer than five individuals) can work independently to rectify with in-house, local activity and minimal outside resources.
The intent of such activity is to empower employee stakeholders in an autonomous manner with the least amount of restrictions possible to maintain the physical assets in a "like new" manner. Considerations for regulation and safety oversight are paramount. Engaging outside services to educate the enterprise on defect elimination through game-type instruction has proven to be effective as a culture modification catalyst. Oftentimes, especially in large complex organizations, management truly is the obstacle to tangible improvement.
Defect Elimination Process/NGT&S Protocol:
A. Hold a workshop to establish foundation principles of defect elimination benefits through a common language and vocabulary via an interactive game environment.
B. Form defect elimination teams to identify real defects and potential solutions and resources.
C. Empower teams to execute projects.
D. Report out of project for tracking and compliance with minimal constraints on all involved parties.
E. Improve and repeat process.
Typical NGT&S pipeline right-of-way.
Operations personnel collecting compressor data.
Maintenance personnel removing a panel for an internal inspection.
Typical NiSource prepackaged reciprocating compressor units.
As of November 2010, NGT&S has conducted simulation workshops to engage over 150 employees representing 30 locations. Additional workshops have been scheduled to continue the defect elimination program throughout the enterprise.
The following are just a few examples of teams eliminating defects within NGT&S:
- In Mississippi, a section of rigid conduit was changed to eliminate shorted wiring that was caused by vibration.
- Adding capacity to a compressed air system in Pennsylvania improved system reliability and eliminated call-outs to the station;
- A defect elimination project in Virginia eliminated a path for coolant to migrate to other units that were not running, and another team improved the reliability of a station valve operation by relocating magnetic switches.
Station operator Johnny Gochenour said: ". . . no one in management knows what needs to be addressed at the stations like we do. . . . It (the defect elimination program) has given us the opportunity to correct the small problems. It is one of the best things we have ever done."
As defects are eliminated prior to evolving into sustained functional degradation or catastrophic failure, system reliability growth is experienced over time from these efforts alone. The fewer negative issues there are to contend with in the future, the less planned and unplanned work there is to address.
Strategy 2: Structured Reliability Growth
The second strategy adopted is strategic reliability growth through daily procedures and protocols. Fitting to the nature of natural gas transmission networks, four collaborative focus areas are identified and developed.
First: Critical Assessment and System Strategy (CASS)
Second: Core Reliability Protocol
Third: Real-Time Data Systems (RTDS)
Fourth: Modernization and Automation
First Focus Area: Critical Assessment and System Strategy (CASS)
What does NGT&S want the asset to do?
With current contractual market demand and future corporate marketing strategy considerations being complex, it is critical that a single source (group or department) govern the communication of the subsystems that are required to be available to Gas Control (the central monitoring and control office that ensures customer demands are met) with reasonable resolution. In simple terms, determine when a specific compression unit is required to be available to Gas Control, and define when it is needed based on the constraints - current and/or future - for a specific pipeline segment. A subsystem or segment with redundant capacity will not be considered as critical because a negative event will have little or no impact on the systems service capability during a particular season, month or other defined time segment.
A major developmental milestone for the system reliability plan is the acknowledgment that the complexity of our reticulated transmission system configuration relative to a particular day's market demand allows for a seemingly infinite number of operational strategies for any given day. However, we know that if defined asset functions are readily available to Gas Control, when assigned to be available, we will deliver on all firm customer requirements without exception.
Second Focus Area: Core Reliability Protocol
Foundational to these activities are the processes and procedures that govern the Computerized Maintenance Management System (CMMS) including all preventive and predictive activity. Planned and unplanned work types and guidelines for assignment and tracking are to be documented, communicated and offered in training sessions to system users.
No activity is more essential to system reliability than preventing asset decline and maintaining efficient performance of critical assets. By association, detecting functional degradation in a structured manner with sufficient lead time to mitigate negative impact to the overall system is no less important. By definition at NGT&S, functional degradation is the state of a system, asset or component that is degraded from "like new" status in a manner that will require significant resources, both collaborative and/or financial to return to optimal function or mitigate the source of failure. Robust process education and compliance is not only regulatory in many areas but necessary to operate a system with optimum economic and safety considerations.
Third Focus Area: Real-Time Data Systems (RTDS)
From a business management as well as regulatory mandate, reliability of pipeline distribution and receipt points in real time are critical. However, the nature of inclusion of real-time systems as related to system reliability is rooted in an alternate focus. Real-time condition monitoring protocols for both functional degradation detection as well as execution of performance analytics serves the base requirements. Protocols and procedures for identifying critical data elements, standard Graphical User Interfaces (GUIs), data archiving and transmission to central servers, etc. must be defined and documented. Prognostics program evolution is reliant on the compliance of these defined systems as is the real-time reporting of key performance indicators (KPIs) and key performance parameters (KPPs) relative to multiple stakeholders in proper resolution. The complexity of a seasoned control system is daunting in terms of obsolescence, integration platforms and basic communication. If an RCM strategy for a critical asset is to monitor functional degradation and performance parameter creep, it is imperative that the data system work properly to manage the risk of high value asset loss and overall system impact.
Fourth Focus Area: Modernization and Automation
These two actions are addressed in the final subgroup in spirit to support the other three charters. While RTDS is only focused on data, automation encompasses the control of such assets. It is easy to connect the need for automation upgrades and useful life support from OEMs. How automation serves IT-based data systems is the primary consideration from this scope. As for modernization, capital improvement - ROI assessments in coordination with CASS - is the primary collaborative point. However, options for short- and long-term asset upgrades and improvements related to overall system reliability are considered the central focus. Documented processes and procedures where applicable yield the most consistent and unbiased allocation of human and financial resources.
Measures of Effective and Efficient Execution
To this point, the focus has been primarily on the effective structure of a system reliability plan for natural gas transmission networks. For balance and optimal achievement in any form, an assurance of efficient actions and overall program execution is required. Excessive maintenance can have extreme negative effects on the economic health of any enterprise. With a large repertoire of performance indicators to choose from, many will be adopted with proper resolution at key points within the overall system. Consideration of both leading and lagging KPIs where applicable in a real-time environment is the key to leveraging resources with value.
By combining the power of these two strategic initiatives, NGT&S intends to not only remain a top natural gas transmission system in the U.S., but also gain important ground in continuously improving reliability, minimizing operations and maintenance costs, and mitigating issues with service. The overall goal is that of increasing the company's attractiveness in terms of gaining new contracts for production receipts and expanding the delivery markets in the progressively competitive gas transmission arena.
For the sake of evaluation of these strategies, dominant measures of the localized outcomes of the accomplishments will be in system availability. The major system's inherent availability will be economically weighed against the same system's achieved availability. More definitive key performance indicators will include comparisons and trends of quantified work orders and maintenance hours required to maintain the desired levels of achieved availability to ensure that stakeholder expectations are not only met, but continually exceeded.
Matt Parks serves as subject matter expert for system reliability at NGT&S. Matt has performed reliability analysis as well as program improvement activity in multiple industries. He currently works on system reliability processes and procedures for NGT&S. Visit www.ngts.com
John M. Cox is the Team Leader for Optimization and Gas Quality at NTG&S. Mr. Cox has extensive experience in test and evaluation with the U.S. DoD, and currently leads system optimization and gas quality engineering for all NGT&S companies. Visit www.ngts.com
Bill Butterworth is the Director of Technical Services and is leading the system reliability efforts at NGT&S. He is a Registered Professional Engineer and has has been involved in reliability improvements across NGT&S facilities for the past 10 years. www.ngts.com