1
24-059
Mine Ventilation Pathway Simulation on a Hypothetical
Shale Gas Well Breach Utilizing the Longwall Instrumented
Aerodynamic Model (LIAM)
Robert A. Kimutis
NIOSH, Pittsburgh, PA
Marcia L. Harris
NIOSH, Pittsburgh, PA
Steven J. Schatzel
NIOSH, Pittsburgh, PA
James D. Addis
NIOSH, Pittsburgh, PA
Mark M. Mazzella
NIOSH, Pittsburgh, PA
Mayley Guitard
NIOSH, Pittsburgh, PA
Vasu Gangrade
NIOSH, Pittsburgh, PA
Abstract
Researchers from the National Institute for Occupational
Safety and Health (NIOSH) evaluated the impact of
potential shale gas well breaches and subsequent gas inflow
on selected mine ventilation systems of operating long-
wall panels using a 1:30 scaled Longwall Instrumented
Aerodynamic Model (LIAM) and Sulfur hexafluoride (SF6)
as a tracer gas. A series of tests were performed at 340, 400,
and 500 cfm inflow levels utilizing different mine ventila-
tion scenarios. Results suggest that the breached gas can be
diluted to meet statutory levels when the longwall panel is
adequately ventilated. The results enhance the understand-
ing of the gas inflow and mine ventilation system interac-
tion and provide critical information to the industry and
regulatory agencies for improving miners’ safety.
INTRODUCTION
In the tristate area of Pennsylvania, West Virginia, and
Ohio, unconventional shale gas wells have been drilled
through current and future coal reserves. Impacts on the
mechanical integrity of these wells becomes a concern
when mining occurs in and around these wells. The shale
gas wells can potentially penetrate the coal seams and the
coal seams are subsequently mined. Therefore, it is impera-
tive that the coal and shale gas industries to know what the
impacts of longwall mining may be on the shale gas wells,
what the potential deformation may be, and what stresses
are imposed on the gas wells.
In 2012, the Pennsylvania Department of
Environmental Protection (PADEP) recognized that
the 1957 Pennsylvania Gas Well Pillar Regulation
(Commonwealth of Pennsylvania, 1957) was created with
limited data from modern day longwall mining and called
for research to revise the outdated regulation. Therefore,
given the posed questions and the need for further guid-
ance given modern mining technologies and practices,
the National Institute for Occupational Safety and Health
(NIOSH) initiated research to address these issues.
To this end, several research efforts have focused on
predicting the potential quantity of methane that could
enter an underground coal mine environment if a shale
gas well casing should be breached. One such area is gas
permeability in ground strata. Measurements of the perme-
abilities of the ground strata under varying depths of cover
are being conducted. Current research shows that shallow
cover conditions (500 ft depth to the mined coal seam)
have the highest permeability compared to deep cover sites
[1, 2]. Researchers have modeled and predicted the ground
permeabilities which are well aligned with the field mea-
surements [3]. Based on the collected field measurements,
researchers modeled and predicted quantities of methane
24-059
Mine Ventilation Pathway Simulation on a Hypothetical
Shale Gas Well Breach Utilizing the Longwall Instrumented
Aerodynamic Model (LIAM)
Robert A. Kimutis
NIOSH, Pittsburgh, PA
Marcia L. Harris
NIOSH, Pittsburgh, PA
Steven J. Schatzel
NIOSH, Pittsburgh, PA
James D. Addis
NIOSH, Pittsburgh, PA
Mark M. Mazzella
NIOSH, Pittsburgh, PA
Mayley Guitard
NIOSH, Pittsburgh, PA
Vasu Gangrade
NIOSH, Pittsburgh, PA
Abstract
Researchers from the National Institute for Occupational
Safety and Health (NIOSH) evaluated the impact of
potential shale gas well breaches and subsequent gas inflow
on selected mine ventilation systems of operating long-
wall panels using a 1:30 scaled Longwall Instrumented
Aerodynamic Model (LIAM) and Sulfur hexafluoride (SF6)
as a tracer gas. A series of tests were performed at 340, 400,
and 500 cfm inflow levels utilizing different mine ventila-
tion scenarios. Results suggest that the breached gas can be
diluted to meet statutory levels when the longwall panel is
adequately ventilated. The results enhance the understand-
ing of the gas inflow and mine ventilation system interac-
tion and provide critical information to the industry and
regulatory agencies for improving miners’ safety.
INTRODUCTION
In the tristate area of Pennsylvania, West Virginia, and
Ohio, unconventional shale gas wells have been drilled
through current and future coal reserves. Impacts on the
mechanical integrity of these wells becomes a concern
when mining occurs in and around these wells. The shale
gas wells can potentially penetrate the coal seams and the
coal seams are subsequently mined. Therefore, it is impera-
tive that the coal and shale gas industries to know what the
impacts of longwall mining may be on the shale gas wells,
what the potential deformation may be, and what stresses
are imposed on the gas wells.
In 2012, the Pennsylvania Department of
Environmental Protection (PADEP) recognized that
the 1957 Pennsylvania Gas Well Pillar Regulation
(Commonwealth of Pennsylvania, 1957) was created with
limited data from modern day longwall mining and called
for research to revise the outdated regulation. Therefore,
given the posed questions and the need for further guid-
ance given modern mining technologies and practices,
the National Institute for Occupational Safety and Health
(NIOSH) initiated research to address these issues.
To this end, several research efforts have focused on
predicting the potential quantity of methane that could
enter an underground coal mine environment if a shale
gas well casing should be breached. One such area is gas
permeability in ground strata. Measurements of the perme-
abilities of the ground strata under varying depths of cover
are being conducted. Current research shows that shallow
cover conditions (500 ft depth to the mined coal seam)
have the highest permeability compared to deep cover sites
[1, 2]. Researchers have modeled and predicted the ground
permeabilities which are well aligned with the field mea-
surements [3]. Based on the collected field measurements,
researchers modeled and predicted quantities of methane