Page 93 - Open-Hole Log Analysis and Formation Evaluation

it
not
is
It
bed.
THE
wall.
itself.
As the
is
depth
within
be
begins.
section

involved
5.10
literature
pressure,
The
as
the
in
porous
Figure
a
for
and
control
Since
the
and
5.12
terms
pore
on-depth
the
on different trips
important
BOREHOLE
the
depth
is to
5.11).
fluid from
to

with
used
Each subsequent
In
sensor producing
along
space
that
in
various
the
evaluation
each
i
pressure
and
permeable)
reference
Sand
table
into the hole.
in
axis
1
zones
curve
the
distinguish

memorized
and
from
5.11
of well
5.1
the mud will
other.
sensors
the
ENVIRONMENT
can
that
before
the
and
of
drill bit penetrates a permeable
The
logs.
move
the
mud
only
deposit
should
between
Unless care
a
resistivity
marked A.
The
tool,
log should be placed
only

be
sensor
into
be

the
surround
main
of
logging
their
well
formation,
column
on
the
the
Higher
is taken,
flushed
logged
highest
a
an
method
mudcake
illustrates the process and the names
up
logging
insist ona repeat section that passes
on
known
resistivity
on
on-depth using
the formation
exceeds
run
the
respective
to
the
of
borehole.
is
rock/fluid
(invaded)
common
the
of assuring
tool

Sensor A.
thése surveys
tool
It
zone
made.
is
are
is
everyone
system
invasion process
formation
(provided
this repeat
the reference point for the survey is
must

used in logging
borehole
fluid
a good marker
may
good

| to. measurement when several surveys are recorded of measurement Another depth problem arises Memory Distance are on-depth on the log. simultaneously recorded [==] certain that all curves important, therefore, to make by Note the sensors). each of 2 appears at different depths for appear off depth (e.g., Sand the formations sensors, Band C.

of
to
FIGURE
:
TD-+to
<_<"
reading
5.10
Memory
Distance
first
measurement
measurement
Distance
C
A
from—>|
B
A
“se

[><]
U
Measure Points
=<]
~ head connects Logging other plus. some Dual Laterolog used for covered bridle <— Rubber Ibs 800-22000 Breaking Strength = 3/8” ~ 1/2” Diameter conductors. with 7 electrical logging cable Steel stranded *— OPERATIONS LOGGING

and
in
1”
to
This
-
bridle
100
14000
Measure
Measure
Portion
Measure
to
grappling
of
ft.
resistivity
Ibs.
2-3/8”
top
smaller
diameter.
Point
Point
of
head
point
and
Point“B”
“C”
is.
“A”
Memorization
for
devices.
portion
Length
about
Breaking
smailer
Distanc
varies
instruments.
6
provides
cable
overshots.
a
12” Jong.
or
strength
Usually3/4”
from
Upper
-
diameter
is
20
1”

feet