Protecting oil and gas infrastructure with fiber-optic cable sensing
Distributed acoustic sensing (DAS) can help prevent asset damage by continuously monitoring activity across thousands of miles of oil and gas infrastructure.
Process sensor insights
- Distributed acoustic sensing (DAS) is a fiber-optic sensing method that can protect large swaths of oil and gas pipeline while leaving a small footprint.
- DAS can help against critical oil and gas infrastructure threats such as unplanned activities, user errors and environmental issues.
Protecting critical oil and gas infrastructure from damage due to unplanned construction work, third- party intrusion (TPI), and other unpredictable events has always been a challenge. How can oil and gas companies achieve around-the-clock visibility into conditions across hundreds or even thousands of miles of assets? It is impossible to deploy enough personnel to provide the necessary monitoring and protection through human resources alone.
Fiber-optic sensing methods such as distributed acoustic sensing (DAS) can scale to protect thousands of miles of pipeline with a small footprint. This technology is critical for high-consequence area (HCA), moderate consequence areas (MCA) and utility substations, as it prevents or reduces asset damage, exceeds regulations and compliance requirements, and ensures the safety of technicians, the public and the infrastructure itself.
Five threats to oil and gas infrastructure
Oil and gas infrastructure can be damaged by a range of events that are nearly impossible to plan for.
Unplanned activities. When excavation or construction work is performed with no dig ticket filed, asset owners have no awareness of the situation and accidents are likely to go unreported.
Communication issues around planned work. Even when a dig ticket is filed, there may be locating or marking errors, faded or washed away markers, or lack of notification to asset owners, all of which make accidental damage more likely.
Operator errors during planned work. Operators may dig outside of markings or outside of allotted time windows or fail to maintain clearance.
Unauthorized access. Pipelines and substations face threats from hot tapping, fence climbing, fence cutting and trespassing.
Environmental conditions. O&G assets may be at risk from environmental conditions such fires, falling trees, falling rocks, landslides and earthquakes. Asset owners may have little awareness of these conditions over long stretches of pipeline.
To improve safety and prevent or minimize damage in these situations, early detection is key. Reliable, full-coverage asset monitoring can alert owners to threats as they emerge, while there may still be time to intervene.
Distributed acoustic sensing for infrastructure monitoring
DAS is designed to detect events and activity—from the softest footsteps to the heaviest machinery—based on the vibrations they produce and transfer to a fiber-optic cable via a coupling medium such as the ground. These vibrations cause tiny distortions in the fiber that can be detected with laser light.
DAS-based monitoring systems use fiber-optic cable, optoelectronic devices called interrogators, and intelligent monitoring software to detect, analyze, classify, and respond to a wide variety of events that could pose a threat to critical infrastructure.
In an oil and gas setting, fiber-optic cable buried near a pipeline or other asset acts as a continuous sensor listening for activity in the surrounding area. An interrogator sends pulses of coherent laser light down the fiber and uses Rayleigh scatter to locate and measure distortions in the fiber caused by vibrations transferred into the ground from nearby activity.
Machine learning (ML) is used to analyze and classify the everyday vibrations near the asset, establishing a pattern of life as a baseline to understand when an anomaly occurs—such as walking/trespassing, vehicle movement, digging, excavation and other events a pipeline owner or utility would want to know about in real time.
When an anomaly is detected, the system generates an alert with the event type and exact location so companies can immediately dispatch individuals to investigate and stop the activity, thereby preventing or limiting asset damage. This data can be seamlessly integrated into enterprise business systems via applied programming interface (API).
Protecting infrastructure at scale
DAS is a key component when building monitoring systems that can scale across thousands of miles of pipeline. By transforming fiber-optic cable into a sensor, DAS systems can provide around-the-clock visibility over the entire length of an asset or perimeter. Fiber-optic cable is long lasting, durable, and cost-effective over large distances. And since power is only required at the interrogator unit, it is possible to monitor many miles of assets from a single point of power. The result is a resilient, scalable system that stands up to harsh conditions with little to no ongoing physical maintenance or sensor replacement cost, as no electronic components are exposed to the elements.