Next-Generation Leak Detection For Safe, Reliable Delivery

By Jian Wei, Principal, Mark Menzie, Director and Jared Racine, Manager, PwC Advisory | October 2013, Vol. 240 No. 10
Buyer's Guide

Leak detection and repair have become increasingly critical to the safe and reliable delivery of natural gas and to protecting the environment. Yet many gas distribution companies are finding that their pipelines are aging at a faster rate than they can be surveyed and repaired. That’s because the traditional flame-ionization leak-detection process is hard-pressed to keep pace with emerging demand for more frequent, accurate and efficient surveys and repairs.

The incumbent leak-survey process is time-consuming and essentially manual. Surveyors walk the length of the territory and use hand-held equipment to check for leaks; often they must get permission from property owners to enter. If surveyors find a hazardous leak, they must place a call to report it and remain onsite until the repair crew arrives. Furthermore, paper-based documentation of leaks must later be manually entered into pipeline information systems, a method that creates delay and invites human error.

These factors all contribute to high leak survey unit costs and long cycle times. As a result, many gas utilities survey pipelines on five-year cycles – despite increasingly vocal demands for more frequent surveys by customers and environmental groups.

What’s more, the accuracy of existing technology is archaic compared with new leak-detection tools which enable surveyors to discover leaks at sensitivities as high as one part per billion – one thousand times more precise than traditional tools.

New Technologies, Opportunities
Next-generation leak-detection technologies can fundamentally change utility leak management processes. Using highly accurate detection equipment, the entire pipeline system – and high consequence areas in particular – can be surveyed more frequently and efficiently. Consider the comparison below between the traditional leak and next-generation leak survey processes.

Next-generation leak-detection technology enables surveyors to cover more ground per day with exponentially better accuracy and fewer false positives. Here’s how: A two-person team can drive a survey route and test for leaks using precise methane-detection technology integrated with cellular-equipped tablet computers, telemetry tools and highly accurate GPS technology.

When integrated with technologies like 4G cellular, geographic-information systems (GIS), and asset-management systems, survey data can be collected and transmitted in real time to central pipeline-information systems, with little to no manual intervention. Leaks are plotted on digital GIS maps, and leak repair schedules can be automatically generated and sent to repair crews located nearest a leak. Surveyors armed with tablets can take advantage of applications that deliver real-time data and electronic forms, and they also can instantly transmit data and photos of completed work to the central office.

Several U.S. gas utilities are piloting an amalgam of these innovative leak-detection solutions. Among them is Pacific Gas and Electric, the first to test a new trace gas analyzer called the Picarro Surveyor, which employs cavity ring down spectroscopy (CRDS) to precisely measure and map methane detection.

Using Optical Tech To Map Methane
New optical technologies enable gas utilities to survey and repair pipelines with unprecedented accuracy and efficiency – and without a flame.