Subsurface methane migration from natural gas distribution pipelines as affected by soil heterogeneity: field scale experimental and numerical study
type: CreativeWork
description: With the increased use of natural gas as a transition fuel on the path toward low-carbon energy, safety and environmental concerns from leaking underground natural gas pipelines are becoming more widespread. Pipeline leakage can be catastrophic when flammable mixtures of methane and air accumulate and ignite. Methane is additionally a powerful greenhouse gas thus; leakage also poses adverse climate impacts. What is not well understood in leakage incidents is how the environmental conditions (i.e. soil type and moisture, competing utilities, ground surface cover) affect gas migration behavior (including the migration rate and extent). To mitigate these concerns, an increased understanding of gas migration through soil is necessary to support efficient leak response, improve leak detection technology, and inform policy and regulations. This study investigates the effects of various soil conditions including soil moisture, heterogeneity, gas leakage rate, and pipeline depth on natural gas migration caused by leaking pipelines. Eight field-scale experiments were performed in custom designed test beds with different soil textures, pipeline burial depths, and alterable leak rates and soil moistures. Subsurface and surface methane concentrations in addition to soil moisture, temperature, and meteorological data were collected over time under transient and steady state conditions. Results found pronounced effects of soil heterogeneities and to a lesser degree of soil moisture on the shape and travel distance of the subsurface methane plume. Leaks from shallow pipelines were found to produce higher surface methane concentrations than from pipelines buried deeper. Advection and buoyancy played a large role on methane concentrations close to the leak, whereas diffusion dominated as the plume moved farther away from the source. Although the conditions explained above were considered separately, they affect each other, yielding a combined and complicated effect on gas distributi…
abstract: With the increased use of natural gas as a transition fuel on the path toward low-carbon energy, safety and environmental concerns from leaking underground natural gas pipelines are becoming more widespread. Pipeline leakage can be catastrophic when flammable mixtures of methane and air accumulate and ignite. Methane is additionally a powerful greenhouse gas thus; leakage also poses adverse climate impacts. What is not well understood in leakage incidents is how the environmental conditions (i.e. soil type and moisture, competing utilities, ground surface cover) affect gas migration behavior (including the migration rate and extent). To mitigate these concerns, an increased understanding of gas migration through soil is necessary to support efficient leak response, improve leak detection technology, and inform policy and regulations. This study investigates the effects of various soil conditions including soil moisture, heterogeneity, gas leakage rate, and pipeline depth on natural gas migration caused by leaking pipelines. Eight field-scale experiments were performed in custom designed test beds with different soil textures, pipeline burial depths, and alterable leak rates and soil moistures. Subsurface and surface methane concentrations in addition to soil moisture, temperature, and meteorological data were collected over time under transient and steady state conditions. Results found pronounced effects of soil heterogeneities and to a lesser degree of soil moisture on the shape and travel distance of the subsurface methane plume. Leaks from shallow pipelines were found to produce higher surface methane concentrations than from pipelines buried deeper. Advection and buoyancy played a large role on methane concentrations close to the leak, whereas diffusion dominated as the plume moved farther away from the source. Although the conditions explained above were considered separately, they affect each other, yielding a combined and complicated effect on gas distributi…
author: Mitton, Melissa
language: eng
language: English
keywords: experimental study, natural gas, diffusion, pipeline leakage, methane
identifier: T 8574
date published: 2018
date modified: 2026-07-24T01:43:54Z
provider: Colorado School of Mines
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Colorado School of Mines. Arthur Lakes Library

PropertyValue
property ID: Handle
value: https://hdl.handle.net/11124/172530