8/12/2019 Bond Log Quick Reference Handout[1]
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Transmitter
12
345
6
7 8
2 Radial Receiver Array
3 Receiver
5 Receiver
Bow Spring Centralizer
Bow Spring Centralizer
Collar Locator
Gamma Ray & Telemetry
CBL
RBL
Cement Bond Log Quick Reference
Good Bond To Pipe & Formation
Good Bond to Pipe & Poor Bond to FormationFree Pipe
Example Bond Tool
Good Bond To Pipe & Formation - Good bond to pipe is
characterized by
a low 3 amplitude, transit times of something other than pipe
arrivals (whic
are consistent), lack of pipe arrival in the VDL and low 2
radial amplitudes
(if RBL). Good bond to formation can be assumed if the VDL
exhibits stron
formation arrival suggesting good acoustic coupling between
cement an
the surrounding formation. Travel time will also track
lithology.
Brooks - 403.501.8474Red Deer - 888.309.3055
Whitecourt - 780.778.4505Grande Prairie - 780.538.1108
Cased Hole LoggingTCP and Conventional
PerforatingSwabbingSpecialty Services
Low 3 amplitude
Late, inconsistent
3 travel time
No pipe arrival in
the VDL
Good Bond
To Pipe
Low radial
amplitudes
Good Bond
To Formation
Good Formation
arrival in VDL
Travel time tracks
changes in lithology
CBL - Cement Bond Log (GR-CCL, 3 & 5 receivers)
RBL - Radial Bond Log (CBL + Array of 8 Radials)
Good Bond To Pipe & Poor Bond to Formation- Good bond to
pipe is
characterized by a low 3 amplitude, transit times of something
other than
pipe arrivals (which are consistent), lack of pipe arrival in
the VDL and low
2 radial amplitudes (if RBL). Poor bond to formation may be
assumed if
the VDL does not exhibit strong formation arrivals (may not be
present at a
Must be aware if VDL is from 3 or 5 as mud may be confutes with
formatio
Low 3 amplitude
Late, inconsistent
3 travel time
No pipe arrival in
the VDL
Good Bond
To Pipe
Low radial
amplitudes
Poor Bond
To Formation
Little to no Formation
arrival in VDL
Travel time arrives
late (in this caseoff scale)
suggesting
something other
than pipe or
formation.
Free Pipe- No bond to pipe (free pipe) is characterized by a
high, consistent
3 amplitude, consistent 3 travel time, high radial amplitudes,
strong pipe
arrivals (train tracks) and chevron patterns in VDL. No
formation arrivals are
present in the VDL as no cement is present to carry acoustic
signal to
formation and back to the receivers.
High, consistent3 amplitude
Consistent 3
travel time
No Bond To Pipe
Straight collar
effect surrounded
by chevron pattern
Pipe arrivals in
VDL - train tracks
Formation Bond?
No formation
arrivals in VDL
High radial
amplitudes
8/12/2019 Bond Log Quick Reference Handout[1]
2/2
Cement Bond Log Quick Reference
Brooks - 403.501.8474Red Deer - 888.309.3055
Whitecourt - 780.778.4505Grande Prairie - 780.538.1108
Cased Hole LoggingTCP and Conventional
PerforatingSwabbingSpecialty Services
Fast Formation
Fast Formation - to get formation arrivals there must be good
bond from
cement to pipe and cement to formation. Thus, if there is fast
formation
arrival there is good bond on both sides of cement. The problem
arises w
the formation arrival appears like pipe arrival. Look for
earlier arrival times in VDL and travel time, , wavy
appearance
in VDL and lack of chevrons in VDL. 3 amplitude may be high or
low.
clean GR (hard roc
carbonates)
Earlier-than-pipe
arrival time
Fast Formation
Earlier arrival time
on the VDL
Wavy VDL.
No chevrons
in VDL
Low radial
amplitudes
Channel
Light Weight Cement Microannulus
Microannulus- Micro-seperation of pipe from cement that reduces
the
cements ability to support the pipe in shear and thus allows for
some pipe
To test for a microannulus, the pipe is logged under pressure to
see a
reduction in 3 amplitude, loss of pipe arrival in VDL and
improved radials.
The presence of a microannulus indicates cement present.
Light Weight Cement- VDL exhibits a straight line collar effect
with no
chevron patterns. First arrival in VDL and 3 Travel Time is pipe
as cement
does not fully attenuate signal. 3 amplitude may baseline up to
10 mV
(new 100% bond). Formation arrival may be weak if present.
Channel - a channel is a potential conduit for formation fluids
from one zone
to communicate with another, contaminate groundwater or allow
for fluid/gas
communication to surface in the form of surface casing vent flow
or gas
migration. Radial bond logging allows for the identification of
channels not
readily identified on basic cement bond logs.
Channel
Channel may not
be identified on
3 amplitude
(average of 3section).
Mapping of 2
radials identify
channel.
Channel may
appear as a
spiral due to the
tool spinning out
of the hole.
Light Weights
Amplitude may not
reach 0 mV butwill flat-line at a
new 100% bond -
up to +/- 10 mV.
First arrival in VDL
and travel time
will be pipe as
signal not fully
attenuated.
No chevrons
present. Under
good bond
collars show
straight-line
collars patterns.
Formationarrivals may be
weak or not
present at all.
Microannulus
Reduction in 3
amplitude underpressure.
Loss of pipe arrival
in VDL under
pressure
Reduction in 2
radial amplitudes
under pressure
