Document Type
Dataset
Source Publication Title
DOI
https://doi.org/10.32855/dataset.2024.05.017
Production/Collection Date
07/28/2021
Production/Collection Location
University of Texas at Arlington
Depositor
Kathleen Smits
Deposit Date
2-29-2024
Data Type
Survey data, Aggregate data
Abstract
Underground natural gas (NG) pipeline leakage can result in methane (CH4) buildup and migration through the soil. What is not well understood in such scenarios is how the soil conditions affect the gas migration behavior, particularly in regard to the relative contributions of specific soil properties such as soil moisture content. The objective of this study was to investigate the effects of soil properties on CH4 concentration and migration from leaking underground NG pipelines. Site characteristics such as surface cover and spatial dimensions, soil samples, and gas concentration data were collected from over 70 gas leakage sites across the United States using a standardized sampling method. Soil samples were collected from excavation sites that were 1.5′–5′ in depth. The collected soil samples were analyzed in the laboratory to measure the soil texture, permeability, and moisture. Statistical analysis was performed to evaluate the effects of soil properties on CH4 migration distance and concentration. Soil texture was consistent across geographic locations due to standardized pipeline backfill protocols, allowing for the analysis of gas concentration and transport data with respect to soil conditions. Soil moisture content was the dominant influence on the gas concentration and spreading distance. High soil moisture content was associated with reduced lateral diffusion and elevated concentrations near the leak point, whereas dry conditions were associated with reduced concentrations and greater spreading distance. Increasing soil moisture content reduced the lateral diffusion of CH4 into the soil due to water-induced tortuosity, resulting in elevated concentrations close to the leak point. Lateral migration of CH4 was suspected to be by diffusion, starting at 5 m from the leaks, while transport within the immediate vicinity of the leak was controlled by advection. These findings demonstrate a pronounced effect of soil moisture content and permeability on CH4 migration distance and concentration, providing key insight into the effects of soil conditions on NG migration and how to account for such effects in leak detection surveys.
Disciplines
Earth Sciences | Engineering | Environmental Sciences
Publication Date
8-1-2022
Language
English
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Cho, Younki; Smits, Kathleen M.; Steadman, Nathaniel L.; Ulrich, Bridget A.; Bell, Clay S.; and Zimmerle, Daniel J., "Replication Data for: A Closer Look at Underground Natural Gas Pipeline Leaks Across the United States" (2022). Earth & Environmental Sciences Datasets. 1.
https://mavmatrix.uta.edu/ees_datasets/1