Energy & Fuels,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Nov. 14, 2024
Minerals
in
deep
coals
contribute
to
coal
reservoir
heterogeneity
and
influence
coalbed
methane
enrichment
by
modifying
the
physical
properties
of
pore-fracture
system.
This
study
has
used
multiple
qualitative
quantitative
analytical
techniques
characterize
system
occurrences
minerals
Daji
block,
Ordos
Basin.
The
with
high
rank
medium-low
ash
yield
show
a
complex
dual
structure
obvious
cross-scale
effects.
is
genesis
diverse
morphology,
open
fractures
varying
scales
may
communicate
pores
form
networks.
Mineral
phases
consist
mainly
kaolinite,
calcite,
pyrite,
minor
other
(quartz,
Illite,
siderite,
collophanite,
bauxite
minerals,
halite).
modes
mineral
occurrence,
including
syngenetic
epigenetic
origins,
depended
on
mineralogical
associated
coal-forming
process.
Different
infilling
modified
extents.
Overall,
seams
have
reduced
porosity
but
increased
permeability
some
extent.
Higher
clay
carbonate
contents
collectively
lower
porosity;
however,
higher
sulfide
permeability.
Processes,
Journal Year:
2024,
Volume and Issue:
12(12), P. 2671 - 2671
Published: Nov. 27, 2024
Deep
coalbed
methane
(CBM)
resources
are
abundant
in
China,
and
the
last
few
years,
country’s
search
for
extraction
of
CBM
have
intensified,
progressively
moving
from
shallow
to
deep
strata
high-rank
coal
medium-
low-rank
coal.
On
other
hand,
little
is
known
about
gas
content
features
reservoirs
eastern
Junggar
Basin,
especially
with
regard
factors
that
affect
it.
Based
on
data
drilling,
logging,
seismic
surveys,
this
study
focuses
Baijiahai
Uplift’s
primary
Jurassic
seams
through
experiments
microscopic
components
coal,
industrial
analysis,
isothermal
adsorption,
low-temperature
CO2,
N2,
high-pressure
mercury
injection.
A
systematic
investigation
controlling
factors,
including
depth,
thickness,
quality
seam
pore
structure;
tectonics;
lithology
thickness
roof,
was
conducted.
The
results
indicate
Xishanyao
Formation
Uplift
usually
has
a
larger
than
Badaowan
Formation,
showing
free
adsorbed
coexist,
while
primarily
consists
gas.
generally
thick,
samples
Badawan
formations
high
vitrinite
content,
which
contributes
their
strong
generation
capacity.
Additionally,
low
moisture
ash
contents
enhance
adsorption
capacity
seams,
facilitating
storage
CBM.
pore-specific
surface
area
provided
by
micropores,
beneficial
adsorption.
Furthermore,
fault
connecting
Carboniferous
Permian
systems
(C-P)
developed
northeastern
part
allows
migrate
into
formations,
resulting
higher
seams.
roof
predominantly
mudstone
significant
effectively
reducing
dissipation
promoting
its
accumulation.
Processes,
Journal Year:
2024,
Volume and Issue:
12(7), P. 1318 - 1318
Published: June 25, 2024
The
production
of
deep-coalbed
methane
(CBM)
wells
undergoes
four
stages
sequentially:
drainage
depressurization,
unstable
gas
production,
stable
and
decline.
Upon
entering
the
stage,
recovery
rate
deep
CBM
is
constrained
by
bottom
hole
flowing
pressure
(BHFP).
Reducing
BHFP
can
further
optimize
productivity,
significantly
increasing
wells.
This
paper
optimizes
deliquification
process
for
in
Linxing
Block.
By
analyzing
wells,
an
improved
sucker
rod
pump
proposed,
a
method
considering
flow
tubing,
annulus,
reservoir
established.
Using
data
Well
GK-25D
field
as
example,
optimized
design
was
undertaken,
with
parameters
including
depth
pump,
stroke
length,
rate.
results
show
that
lowers
at
coalbed,
enhancing
well
12.24%.
enriches
technology
CBM,
offering
new
approach
its
development
helping
to
maximize
productivity.
Energies,
Journal Year:
2024,
Volume and Issue:
17(14), P. 3424 - 3424
Published: July 11, 2024
The
development
of
fractures
under
multiple
geological
tectonic
movements
affects
the
occurrence
and
efficient
production
free
gas
in
deep
coal
reservoirs.
Taking
No.8
seam
Benxi
formation
Linxing
area
as
object,
a
method
for
evaluating
favorable
fracture
areas
is
established
based
on
combination
field
joint
staging,
paleogeological
model
reconstruction
structural
leveling,
finite
element
numerical
simulation,
criteria.
results
show
that
large
number
shear
fewer
tensile
joints
are
developed
mainly
formed
Yanshanian
Himalayan
periods.
dominant
strikes
conjugate
period
NWW
(100°~140°)
NNW
(150°~175°),
with
maximum
principal
stress
magnitude
being
160
MPa
along
NW
orientation.
Those
NNE
direction
(0°~40°)
EW
(80°~110°),
100
NE
magnitudes
No.
8
between
−55
−82
MPa,
indicative
compression;
those
from
−34
to
−70
compressive
form.
Areas
high
values
distributed
central
magmatic
rock
uplift,
indicating
influence
uplift
situ
distribution
development.
Based
comprehensive
evaluation
factors
fractures,
reservoir
divided
into
five
classes
24
areas.
Fractures
Class
I
II
relatively
well
were
two
periods
movements.
not
only
significant
prediction
contents
this
but
also
has
certain
reference
value
other
Energy & Fuels,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Nov. 14, 2024
Minerals
in
deep
coals
contribute
to
coal
reservoir
heterogeneity
and
influence
coalbed
methane
enrichment
by
modifying
the
physical
properties
of
pore-fracture
system.
This
study
has
used
multiple
qualitative
quantitative
analytical
techniques
characterize
system
occurrences
minerals
Daji
block,
Ordos
Basin.
The
with
high
rank
medium-low
ash
yield
show
a
complex
dual
structure
obvious
cross-scale
effects.
is
genesis
diverse
morphology,
open
fractures
varying
scales
may
communicate
pores
form
networks.
Mineral
phases
consist
mainly
kaolinite,
calcite,
pyrite,
minor
other
(quartz,
Illite,
siderite,
collophanite,
bauxite
minerals,
halite).
modes
mineral
occurrence,
including
syngenetic
epigenetic
origins,
depended
on
mineralogical
associated
coal-forming
process.
Different
infilling
modified
extents.
Overall,
seams
have
reduced
porosity
but
increased
permeability
some
extent.
Higher
clay
carbonate
contents
collectively
lower
porosity;
however,
higher
sulfide
permeability.
