Maintaining the Fitness of our Systems
We undertake the following measures to ensure the long-term fitness of our systems:
Design and Construction
We build safety and reliability into our infrastructure long before we begin to build and operate any project.
We carefully select pipeline routes and line locations, and maintain world-class standards for engineering and design. We incorporate special design considerations for areas such as road, river and creek crossings and high consequence areas where the public may be affected. We adopt the same rigorous approach with our other facilities, such as pump stations, terminals and gas processing plants.
We use precisely manufactured pipe and, during construction, inspect each weld using x-ray or ultrasound technology. As we build our projects, we identify, mitigate and proactively manage potential effects on the environment, while paying close attention to environmentally sensitive areas and wildlife. For more information, please see the Environment & Land Management section of this report.
Monitoring and Prevention
Once our pipelines are running, we continually monitor them for any signs of trouble and operate them in a way that protects their reliability. This work involves recognizing conditions that have been known to cause failures in the past and carefully analyzing failures from our peers, and then working to minimize the risks. We do this through a comprehensive set of programs:
In-line Inspections – We use specialized in-line inspection tools that travel inside our pipelines to collect data and evaluate each millimeter of our pipelines. These tools can measure the size, frequency and location of even small changes in our pipes.
Preventive Maintenance (Integrity) Digs – Sometimes our regular monitoring and in-line inspection program alerts us to pipeline features that require us to conduct preventive maintenance—or, integrity—digs. For each integrity dig, we excavate a section of buried pipe so that we can examine it and make necessary repairs. If we find a defect, we repair it, and then recoat and re-bury the pipe. Even if we don’t find a defect, we use the data we gain from our integrity digs to add to our overall knowledge about our pipelines’ condition, and to compare what we see firsthand with the data we gather using our in-line inspection tools.
Hydrostatic Pressure Testing – Hydrostatic testing involves filling a segment of pipeline with potable water from an approved municipal water source and carefully raising the operating pressure on the segment while continuously monitoring the pipe and observing its performance. We may perform these tests on specific sections of pipe. If the tests result in water leaks, we immediately make any necessary repairs.
Pressure Cycling – We operate our liquid pipelines in a way that protects the quality we build into them at the start. For example, we minimize pressure cycling (the fluctuations that occur during the course of operations as we start and stop pumps and move crude oil products with varying densities and viscosities) on our crude oil pipelines to reduce the stresses that can lead to wear on our pipeline systems.
Managing Cracks – We are at the forefront of technological developments and research related to cracking, and have rigorous programs in place for monitoring and managing it. A key activity in this area is our use of high-resolution ultrasonic in-line inspection technologies on our crude oil pipelines.
Combating Corrosion –We prevent corrosion of the steel in our pipelines and facilities using several methods, including anti-corrosion coatings, cathodic protection (where we apply low electrical currents to the pipeline to protect the steel against corrosion), chemicals that prevent internal corrosion, regular monitoring and inspections, and interior cleaning of pipes using in-line tools.
Maintaining Facility Integrity – We operate and maintain all of our facilities, including our stations and terminals, in a safe, responsible manner. We do this by adhering to standards and specifications, and abiding by commissioning, operating and maintenance procedures, that we regularly review and update to ensure that they incorporate the latest legal requirements and learnings from incidents and safety reviews. We also regularly inspect our tankage, equipment and piping.
Preventing Third-Party and Mechanical Damage – Third-party damage is one of the leading causes of pipeline leaks. Through our Public Awareness Programs, we communicate regularly with our neighbors and customers about our systems, projects and operations to ensure that they know how to stay safe and avoid accidentally damaging our facilities, pipelines and distribution systems. We mark all of our pipelines with signage showing our toll-free number. We also support and promote the Call/Click Before You Dig programs in Canada and the U.S. In Canada, community members can call 8-1-1, and in the U.S., they can visit clickbeforeyoudig.com before excavating so that a locator can visit their location and mark underground utilities. For more information, please see the Emergency Preparedness & Response section of this report.
Our Gas Distribution business segment (GD) also has a natural gas sewer safety inspection program in place to mitigate the risk of an excavator damaging a natural gas line that may have inadvertently intersected with a sewer line outside a home or business.
Replacing and Repairing Pipe – Although we build, maintain and manage all of our pipelines to ensure that they have long operating lifespans, at times, through the data we gather from our inspections and integrity digs, we may determine that a pipeline or a pipeline segment should be replaced. We base our decision to replace or repair a pipeline or pipeline segment on ease and safety of construction, landowner concerns, economic evaluations and operational expectations, all with the requirement that we effectively maintain fitness, reliability and safety.
Leak Detection Programs
Pipeline fitness, safety and reliability also involve taking a comprehensive approach to leak detection. We devote resources—both the people and automated systems—on a continuous, 24/7 basis toward ensuring that we control and mitigate any potential problem, should it arise. We monitor our pipelines for possible leaks using a number of methods, each with a different focus and each using different technology, resources and timing. Together these methods provide overlapping and layered leak detection capabilities.
Control Room Monitoring – Our Liquids Pipelines business segment (LP) manages all of its operations from a remote system control center. In addition to keeping in close contact with local operators via telephone and computer, LP controllers use a supervisory control and data acquisition (SCADA) computer system to monitor what is occurring within our pipeline and terminal systems. Using the SCADA system, computers in the control room and at remote sites continually relay information back and forth, enabling our controllers to constantly monitor pressures, flow rates and other conditions on our pipelines and terminal tankage, and to respond quickly when they see abnormal or emergency conditions.
LP also employs a computational pipeline monitoring (CPM) system that collects data from strategically located flow meters and pressure and temperature sensors along our pipelines, and calculates the amount of inventory in the pipeline. If the inventory amount is less than expected, the system triggers an alarm and our controllers immediately investigate.
Similarly, GD and our Gas Pipelines and Processing business segment (GPP&ES) closely monitor their pipelines from their own control centers, in some cases using SCADA systems.
Patrolling our Pipelines – We regularly fly along all of our crude oil pipelines, watching for potential issues including excavation or activity near our pipelines that might pose a risk to safety. Our ground-based surveys, including foot and vehicle patrols, incorporate GPS and advanced imaging technology that enables us to check the depth and position of our pipelines and to detect ground movement.
Leak Surveys – GD completes regular leak surveys along gas mains and service lines, and GPP&ES carries out regular leak surveys along gas pipelines to detect and report natural gas leaks for repair. GD and GPP&ES complete their leak surveys under a variety of programs that are designed to reduce the risk of a potential leak becoming hazardous. To conduct the surveys, GD and GPP&ES technicians carry out foot patrols or drive vehicles that are equipped with sensitive leak detection equipment. During the surveys, they identify any abnormal operating conditions, including signage and code compliance issues. They immediately repair hazardous leaks, and schedule prompt repairs for non-hazardous leaks.
Natural Gas Odorization – In its natural state, natural gas is odorless. As a result, GD adds odorant to gas entering its distribution systems.
GD also educates its customers on the smell of natural gas and what to do if they detect its smell through public education, including scratch and sniff bill inserts. In this way, customers and the public assist GD when natural gas may be escaping its piping systems. GD responds to natural gas odor calls as emergency calls and engages first responders.
GPP&ES works with landowners and others who have access to its rights-of-way to educate them about natural gas facilities and enable them to report potential concerns.