Accelerating Pipeline Leak Detection Quantification Solutions Through Transparent and Rigorous Scientific Validation (APpLIED)

Summary:

This project addresses PHMSA’s request for improvements in pipeline leak detection in diverse operating conditions by developing methods-centric rather than technology-specific understanding of leak detection in adverse conditions, with an emphasis on pipeline emissions in rugged landscapes. This work will:

investigate existing private and public service providers’ and operators’ LDAD methods and their applicability to complex pipeline environments;
recommend enhancements to overcome shortcomings to existing approaches;
conduct comprehensive, multi-solution controlled and field testing, including testing multiple pipeline types (e.g. flow and gathering lines), complex environments (including aerodynamics, topology, and accessibility) and varying operating conditions; and
deliver empirical analysis of enhancements to LDAQ protocols that can be realistically incorporated into operator leak detection protocols and aid developers in LDAQ solution development.

Major scope items for investigation include protocol enhancements, controlled testing and field trials, and methods performance simulation using robust test data sets. Colorado State University (CSU) and the University of Texas at Arlington (UTA) will collaborate with industry and solution providers, who will be members on a technical advisory panel, provide access to their LDAQ protocols, and, in some cases, participate in field testing. Testing will be conducted at CSU’s Methane Emission Technology Evaluation Center (METEC), on public land in collaboration with the US Forest Service and US Dept of Agriculture, and at service provider/operator test facilities.

Objectives:

Our objectives in APpLIED are to:

Develop method-centric understanding of leak detection and quantification (LDAQ) for pipelines in productions, midstream, and distribution.
Develop the science and understanding behind how to test LDAQ, not simply test a suite of current LDAQ technologies.
Put special focus on environmentally and geographically diverse conditions, including gas composition, climate, terrain, and complex urban and rural environments.

Project Plan:

In year one, we will run suites of controlled release experiments at METEC and surrounding regions with more diverse geography, including the Colorado State University Mountain Campus. Each experiment will test the validity of different LDAQ methods for the set of conditions being studied. Then in year two, we will test our developed LDAQ methods at real-world pipeline sites.

Schedule:

APpLIED kicked off in October 2023. We recruited a technical advisory board and have drafted a guidance document on leak detection applicability in adverse conditions and a survey for existing and emerging LDAQ protocols. Controlled testing is ongoing through Spring – Fall of 2023. In Spring – Summer of 2024, the teams conducted real-world field tests of pipelines. The project was completed in January 2025 and final report submitted for distribution in November 2025.

Results:

The Final Report can be found on the PHMSA site here. The main findings of this work demonstrate the importance of the relative effects of environmental and operating conditions on leak detection success, and therefore the importance of
optimizing survey parameters based on the environmental conditions. For the first time, the results presented here provide physical support for operators and solution providers to find effective values of common survey parameters over a wide range of conditions. Three potential improvements to existing LDAQ methods for better application to belowground natural gas (NG) pipeline leaks from mid and upstream include:

Consider the attributes of the belowground leak source;
Integrate the understanding of the plume evolution behavior into the deployment protocols of the current or emerging LDAQ solutions; and
Combine with modeling to inform the improvement of LDAQ methods for belowground leaks.