Optimization of the Gas Content Evaluation Method for Deep Coal Seams Based on Diffusion Models
ACS Omega,
Journal Year:
2025,
Volume and Issue:
10(4), P. 3967 - 3977
Published: Jan. 22, 2025
Gas
content
is
a
critical
parameter
in
coalbed
methane
(CBM)
exploration
and
development,
with
the
estimation
of
lost
gas
being
primary
source
error
when
using
on-site
desorption
method.
The
complex
occurrence
states
deep
CBM
extended
diffusion
time
before
sealing
canisters
exacerbate
these
errors
applying
traditional
evaluation
methods
to
reservoirs.
This
study
compares
performance
various
prediction
models
Following
this,
modified
method
for
calculating
loss,
capable
accurately
describing
entire
process,
proposed,
its
superiority
applicability
are
evaluated
compared
pressure-preserved
coring.
It
also
identifies
initiation
key
factors
influencing
loss.
Key
findings
include:
bidisperse
model
provides
best
fit,
exhibiting
highest
correlation
coefficient
(R2),
lowest
mean
absolute
square
error.
In
coal
seam
rope
core
testing,
start
extraction
as
zero
point
loss
more
geologically
accurate
than
midpoint.
United
States
Bureau
Mines
underestimates
adaptive
curve
fitting
(ACF)
unstable,
(MCF)
overestimates
it.
MCF20
method,
proposed
this
study,
reduces
aligns
closely
results
from
extraction,
making
it
optimal
evaluation.
A
strong
observed
between
escape
time,
Ro,
fixed
carbon
content,
vitrinite
during
extraction.
Language: Английский
Suitability Evaluation of CO2 Geological Storage in Deep Coal Seam: A Case Study in the Eastern Margin of Ordos Basin, China
Geological Journal,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Jan. 6, 2025
ABSTRACT
CO
2
coal
seam
storage
is
a
significant
component
of
carbon
capture
and
technology,
which
serves
as
pivotal
technical
instrument
for
the
reduction
greenhouse
gas
emissions.
The
Ordos
Basin
develops
considerable
number
unminable
seams,
present
an
optimal
place
storage.
This
paper
presents
investigation
into
geological
characteristics
No.4
reservoir
in
Shanxi
Formation
Permian
age
No.8
Benxi
Carboniferous
age.
To
explore
adsorption
capacity
rock
sealing
performance
caprock,
relevant
experiments
were
conducted.
results
demonstrate
that
on
samples
1.11–3.73
times
CH
4
.
breakthrough
pressure
test
mudstone
most
effective,
followed
by
dense
limestone
sandy
mudstone.
Combined
with
data
study
area,
analytic
hierarchy
process
method
was
used
to
evaluate
potential
seams.
areas
suitable
area
are
located
central
part
south‐central
part.
Language: Английский