The
focus
of
global
oil
&
gas
development
is
moving
towards
the
offshore
deep
and
ultradeep
formations.
However,
well
drilling
a
changing
task
due
to
low
rate
penetration.
In
this
work,
high
efficiency
rock-breaking
idea
forming
an
isolated
M-type
rock
column
in
center
bottomhole,
that
is,
novel
convex
stepped
bottomhole
(MCSB)
new
type
central-grooved
PDC
bit
for
are
proposed.
Based
on
thermal-fluid-solid
coupling,
numerical
simulation
model
stress
field
MCSB
established,
investigated.
Meanwhile,
ROP
enhancement
mechanism
also
revealed.
research
shows
its
surrounding
area
subjected
tensile
stresses
circumferential,
radial,
axial
directions,
which
helps
improve
breaking
efficiency.
When
core
blade
length
around
70
mm
apex
angle
90°
with
diameter
215.9
mm,
reaches
maximum
MCSB.
Processes,
Journal Year:
2025,
Volume and Issue:
13(3), P. 668 - 668
Published: Feb. 27, 2025
The
accurate
prediction
and
monitoring
of
rock
drillability
are
essential
for
geomechanical
modeling
optimizing
drilling
parameters.
Traditional
methods
often
rely
on
laboratory
core
experiments
well
logging
data
to
evaluate
drillability.
However,
these
can
only
obtain
samples
sonic
in
drilled
wells.
To
enable
the
real-time
bottom-hole
during
drilling,
we
propose
following
novel
approach:
fusion
a
CNN-GBDT
framework
surface-based
monitoring.
specific
process
involves
using
1D-CNN
convolution
extract
deep
features
from
historical
wells’
log
data.
These
then
fused
with
original
passed
GBDT
framework’s
machine
learning
model
training.
validate
effectiveness
this
method,
study
conducted
case
analysis
two
wells
Missan
Oil
Fields.
models
based
XGBoost,
LightGBM,
CatBoost
were
established
compared
physical
methods.
results
indicate
that
centered
LightGBM
achieved
mean
square
error
(MSE)
0.026,
which
was
one-tenth
MSE
0.282
evaluation
method.
Furthermore,
proposed
suggests
potential
applications
other
