5
the ventilation system was being challenged to maintain
statutory concentrations in the airways connected to the
31 Right production section. The plot shows daily coal gas
production and the initiation of GGV production at spe-
cific boreholes on the panel with locations measured from
the start of the panel. Figure 6 demonstrates a strong corre-
lation between coal production and GGV gas output, with
increases in coal production leading to corresponding rises
in gas production. This behavior is indicative of a GGV
system functioning as expected.
Images of the two study panels are shown in Figure 7.
Each image includes gas content determinations for the
Pocahontas No. 3 for the study panels and the adjacent
panels. From left to right, Figure 7A shows panels 1 and
2 South and Figure 7B shows panels 30 and 31 Right. The
range of gas contents shown in the scale for panels 1 and 2
South show primarily values below 300 cu ft per ton and
in the lower start up end of the panel with a swath of 300
to 400 cu ft per ton above it. Towards the upper comple-
tion end of the panel, gas contents reach 400 to 500 cu ft
per ton. These variations in the amount of gas in place cre-
ate challenges for effective ventilation and methane control
design strategies. Geologic variation in both local structure
and coal bed thickness can be influential when mitigating
methane contents and gas transport in longwall mines.
In Figure 7B, panel 31 Right had a much higher rate of
methane emissions than the prior panels in this section of
longwalls and was the only panel that created consistent gas
management problems for the operator. The panel start-up
was in a region of 400 to 500 cu ft per ton gas contents
and was adjacent to an area of 500 to 600 cu ft per ton in
the bleeders. There are two regions on the panel where gas
Figure 4. Frack well locations and quality of completions for
panel 31 Right
Figure 5. Frack well locations and quality of completions for
panel 1 South
Figure 6. Cumulative gas production on a daily basis form
GGVs during the mining of panel 31 Right and daily coal
production for one month of high gas emissions. The
position relative to start up and borehole numbers are shown
at the time of exhauster start up
the ventilation system was being challenged to maintain
statutory concentrations in the airways connected to the
31 Right production section. The plot shows daily coal gas
production and the initiation of GGV production at spe-
cific boreholes on the panel with locations measured from
the start of the panel. Figure 6 demonstrates a strong corre-
lation between coal production and GGV gas output, with
increases in coal production leading to corresponding rises
in gas production. This behavior is indicative of a GGV
system functioning as expected.
Images of the two study panels are shown in Figure 7.
Each image includes gas content determinations for the
Pocahontas No. 3 for the study panels and the adjacent
panels. From left to right, Figure 7A shows panels 1 and
2 South and Figure 7B shows panels 30 and 31 Right. The
range of gas contents shown in the scale for panels 1 and 2
South show primarily values below 300 cu ft per ton and
in the lower start up end of the panel with a swath of 300
to 400 cu ft per ton above it. Towards the upper comple-
tion end of the panel, gas contents reach 400 to 500 cu ft
per ton. These variations in the amount of gas in place cre-
ate challenges for effective ventilation and methane control
design strategies. Geologic variation in both local structure
and coal bed thickness can be influential when mitigating
methane contents and gas transport in longwall mines.
In Figure 7B, panel 31 Right had a much higher rate of
methane emissions than the prior panels in this section of
longwalls and was the only panel that created consistent gas
management problems for the operator. The panel start-up
was in a region of 400 to 500 cu ft per ton gas contents
and was adjacent to an area of 500 to 600 cu ft per ton in
the bleeders. There are two regions on the panel where gas
Figure 4. Frack well locations and quality of completions for
panel 31 Right
Figure 5. Frack well locations and quality of completions for
panel 1 South
Figure 6. Cumulative gas production on a daily basis form
GGVs during the mining of panel 31 Right and daily coal
production for one month of high gas emissions. The
position relative to start up and borehole numbers are shown
at the time of exhauster start up