Methane leakage – specifically its contribution to greenhouse gas emissions – has made headlines in the news as a potential downside to the US natural gas boom. While much of the attention has been focused on the gas production process, leakage at the regulated natural gas transmission and distribution level also has the potential to raise environmental concerns.
Utilities, like gas producers, may come under increasing pressure to reduce the environmental footprint of their operations. As methane leak detection and management have emerged as critical components of realizing the emissions-reductions benefits of natural gas, the aging pipeline system is posing an obstacle to managing leaks using traditional monitoring and repair systems.
“The incumbent leak-survey process is time-consuming and essentially manual,” said accounting and advisory firm Pricewaterhouse Coopers in a report, Next-generation leak-detection technology for safe and reliable energy delivery. “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…furthermore, paper-based documentation of leaks must later be manually entered into pipeline information systems, a method that creates delay and invites human error.”
There are new methane leak detection technologies on the market that are a thousand times more sensitive than traditional systems, according to PwC. Methane detection tools can be integrated with tablet computers, global positioning system technology, and data transfer mechanisms that transmit data in real time to centralized systems, which can then communicate with the repair crews closest to leaks. This could result in dramatic efficiency improvements.
“The leak survey process could be 5 to 10 times more efficient with CRDS [cavity ring down spectroscopy] technology compared to the traditional method,” Jian Wei, Principal in PwC’s Power & Utilities practice, told Breaking Energy. CRDS is an optical measurement technique that uses a laser to detect leaks.
Costly prospect
Utilities will need to weigh the costs of methane leak detection upgrades against the benefits of improved safety and efficiency. In purely financial terms, it is unlikely that the savings from reducing gas loss could outweigh the investment required, said Wei.
“The investment in the next generation leak management process, technology and systems would be primarily justified by transmission and distribution pipeline safety and efficiency gains,” Wei said. “In the context of adopting advanced technology for natural gas transmission and distribution pipeline leak management, reduction in lost gas due to leaks was considered, but it was insignificant compared to other drivers.”
Transitioning over to a newer system would require funding not only for the technologies themselves – such as gas detection analyzers and smart phones or tablets – but for the training and integration required to link them to a utility’s existing information-technology systems. And more accurate detection of leaks could lead to substantial up-front costs to repair leaks left unidentified by less accurate systems. “This may then require additional repair and construction crews, purchase of more pipeline inventory, and increased operational spending,” the report said.
“Incremental leak repair cost is the biggest implementation cost driver,” Wei said, noting that using CRDS technology, the rate of finding leaks could rise from 50% to 100% in the first detection cycle before falling back to more traditional levels.
On the other hand, utilities stand to reduce repair costs. “While the costs associated with redesigning the processes, upgrading and integrating systems, training employees are significant, they are a fraction of the incremental repair cost,” Wei said.
