Page 69 - Open-Hole Log Analysis and Formation Evaluation

in
mud
shows
require
turn,
a
Figure
also
oras
drillstring
mud-pulse
electric
be
that
3.1
accumulated
measurement
circulation
in
the
or
telemetry
consists
a
current)
of
The
or
turn,
recorded
a
generator
transmitter,
signal-processing
connections
system
“word”
drilling
illustrates
buffer
on
is
it.
held motionless
data-transmission
output
an
a hard-copy listing,
and
located
h-mode
requires
turbine
recommences.
for
process
hardware
from
between
a
a
magnetic
Coded
MWD
or log,
be
the
either
and
transmitted
synchronization
short
as
commonly
(magnetic
generator,
transmitted
specific
for
MWD
for
to
special
word
part
underpressure
and
used
surface
downhole
and/or tubing in straight hole,
period.
the
temporarily
drill
is
mud-pressure
and
future
sensor
MWD.
and
that
sensor
of the parameters
15
which
drillpipe
use.
collar.
surface
the
anomalies
pulses
sub.
acoustic
assembly
Readings
or through
suspended
an
This
frame,
only
Typically,
of coded
the
are
converted
together
in
with
and
Figure
not
earth
Data
then
when
pro-
which,
measurement
3.2
each
the
its
downhole
the
together
electric
turn
from
telemetry

on
Bit
Bir
Torque
7
one
Weight:
» | Mud of hole deviation and azimuth may For example, a measurement is selective. — the transmission of data to the surface In most systems Temperature tape may Mud i) recorded: site) rig floor orata remote be in the form ofa visual display (either on the Pressure to use. Output may that the drilling engineer wishes duce the output software with in use) o
Resistivity :
. Conditioning a Signal Conditioning |_| _ Signal Grosso the SPE-AIME from 3.1 Drill Collar Sensor Electrical Turbine Generator Transmitter Flow Mud MEASUREMENTS WHILE
FIGURE 3.2
| |
[|
| |

.
MWD
Signal
of a data
Signal
Signal
4 content.
the SPE-AIME from
Conditioning
Conditioning
nditioning
Conditioning

Data
}_]
[——]
Grosso

et al.
1983, Jig.
: * fe x e ¢ i ’ Converter Analog/Digital 1 —, M 1, p. 1983, Jig. et al. Typical MWD Downhole Assembly. Package Cable DRILLING
2, p.
. - Valve ud- Mud-Pulse PS in Control : 2] Data SPE-AIME. 900. © 1983 of Reprinted by permission
ae}
901.
eee
©
1983

1
SPE-AIME.

Transmission Schematic. Reprinted by permission of

schematic