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7/24/2019 SPE 7774 - Noise Logs as a Downhole Diagnostic Tool.pdf
1/8
SPE
SPE7774
USEOFTHENOI SELOGASADWNHOLEDI AGNOSTI COOL
byH. B. iksmer, Jr.,and J. C. Carroll,
MembersSPE-AIME,ArabfanAmericanOil Co.
~Copyright 1979.So@ety of Pet ro leumEngineers
T f ri spapar was p r esent eda t t heM i dd l e Eas t 011Techni ca l Con f e renceo f t he c l e t y o f R? t ro l eu f i :~ I nee rshe l d I nM anama, Sahra l n, 25 . 2SM ar ch1979. Tha m ate r ia l i ssub j ec t t oco r r ec t i onby t heau t ho r .
Ie r mi ssi on t o copy I s r aat r l c t ed t o an abst r ac t o f no t m ore t han3DDwords . W ri t e SPE, 52W Nor th en lr a l Exp ressway, Da l l as , Texas 753LWUSA. Tel ax 730S6S(SPEDAL).
In all these cases the flow stream is in-
accessible,whioh rules out the use of a flow-
meter or RAT. The temperaturelog is ineffective
Flow @f aquiferwater intoa dry oil produc-
because either the flow rate is too small to
tionstream,contaminationf freshwateraquifers
effect a gradient change or the temperatut-e
due to casingleaksor orossflowbehindpipe,and
of the flowingfluidis indistinguishableromthe
loss of oil, naturalgas, or inJeotionfluidsdue
wellboretemperature.Sinoe 1976, oowever,ARAMCO
to downhole equipmentfailuresare examples of
has been using a noise logging technique to
everyday probleme in a l~~ge oil producing
successfullyevaluateproblemssimilarto these.
operation.
These problems must be detected,
oonfirmed, diagnosed and solved - quickly and
economically. Collection of useful downhole
informationis the key to meeting this require-
ment.
reoog%ec%%% Y&?S TYhcle~OE E
until 1972, however,
that the results of an
Conventional logging techniques such as
extensivelaboratoryInvestigationnt~the nature
temperature,flow-meterand radio-activetracer
(RAT)are used effectivelyfor detectingundesir-
of downhole noises were reported.
Using
these thesereeultstwo importantconclusionswere
able fluid flow in a wellbore. However, in drawn:
ARAMCO operations, situations are frequently
encounteredwhere these tec hnlquesre partially
1) That order of magnitudefl ow rates can be
or totallyinadequate,for example:
estimatedusingpeak noise;and
1) Oil producerwatersout.Temperatureprofile
2) That aertainflowsituationscan be disting-
is normal.
Tubing is set to TD. Source of
uishedfromothersif the frequencystructure
wateris questionable.
of the noisecan be obtained.
2) Producerwith tubingrun to TD developspres-
The developmentof a downholenoise logging
sure on a oashg - casingannulus,
Tempera-
techniquewas undertakenbased on these conolu-
tureprofileshowsno anomalies.
Siona.
The groundworkhas been laid for quanti-
tative interpretationof downholenoise,but, to
3) Supplywellsproduaing120 MB/D of 170 Sal-
date, most interpretationsre stillqualitative.
ine aquifer water by electrically driven
submersiblepumps hung at 500 ft on a water
columnmust be monitoredroutinelyto prevent
Oontamlnatlon of fresh water aquifers.
4) Power water inJeotionwell developea well-
Our observationsindicatethatabsolutenoise
boreobstruction.The obstructionis opposite
amplltude is the key to qualitative noise log
the top of a largeaquiferwhose temperature
interpretation, sinoe noise peaks are usually
is the same as that of the water being
deteotedoppositea noise souroe,and the energy
injected.
levels of these peaks indicate the severity
of the problem. Whereaemorepreoisequantitative
interpretationrequires additionaland improved
References and illustrations at end of paper
7/24/2019 SPE 7774 - Noise Logs as a Downhole Diagnostic Tool.pdf
2/8
rim
U 3?2 GF THY? MYME LOG AS & lYW2NHOL13 D1&GNOS CTC TOOL RPF 77711
=6
--- -- ---- ------ --- .-
.. ----------- ------------ ----
-. -,,, .
-f
feedbaok.
Before noise logs from different
situations are oompared~ .t is important to
know that the noise Smplitw esreoordedon the
logs are highlyaffeotedby the configurationand
fluidcontentof thewellbore.
The amplitude of a noise detected through two
stringsof pipewill be lessthanthat of the same
noisedeteotedthroughone string.
The prinoiple
is simple,the more metal,the greaterthe atten-
uationof the noise. Similarly,noiseattenuation
is greaterin gas thenit isin water. It follows
that the noise level of a 30 MBD annular flow
detectedin gas filledtubingwould be less than
if it were detected in liquid filled tubing.
Noise amplitudesin the wellboreare sometimes
distortedor maskedby noiseoarry-away.Noiseis
transmittedaway from its sourceby gas, liquid,
metal,etc. Attenuationof oarry-awaycan result
in some interesting noise log characteristics
(seeFigure1).
High frequer?ciesttenuatefaster
than lower frequencies.This faot permitsa high
energynoise sourceto be looatedwith much more
precision. A strik;nganomaly is created by a
fluid levelabove A large noisesouroe.The noise
Is c arriedawav with little attenuationin the
liquid,but when the deteotoris raisedInto the
gas,the nq selevelis reduoedconsiderably.If,
for example,a sharp changein the 200 HZ ampli-
tude ooaurs, a fluid level should be suspected.
In the lab a detailed noise spectrum of a
particular flow situation can be generated by
measuringthe noise amplitudeof numerous freq-
uenay bands (see Figure2).
In practicalfield
applicationthe noisespectrummuet be limitedto
a reasonable number of frequency bands.
Most
surfacepanels in use today have filtercircuite
for 200, 600, 1000and 20CJ0HZ.
These cuts were
selectedfor the followingreasone:
i)Noise below 200 HZ, which includes most
equipment related noises, are of limited
usefulness.
2) Large amounteof energyfrom two-phaseflow
situationsare concentratedin the 200-600
HZ band.
3) SinglephaseflowIs characterizedby maximum
amplitude in the 1000 HZ region, shifting
towards 2000 HZ as ?ressure differentials
Lnorease.
Some surfaoe units are equipped with 4000 and
6000 HZ filters.These filterspermit the isola-
tion of the high frequenoyenergycausedby sand
pinging.
The deteotion sondes used by ARAMCO were
developedand built by EXXON PRODUCTIONRESEARCH
co.
The standard sonde is I-11/16 inches in
diameter,and a speciaSaonde built for logging
throughgas lift mandrelsis 1 inoh in diameter.
Bothtoolsare about3 ft. long.
Piezoeleatrioorystalsare used to convert
noise vibrationsinto en AC signal.
This signal
Is driven up a eingle eonduator cable (with a
sheathreturn)by a transistorizedmplifier. At
the surfaaethe AC signal is amplified,filtered
and the peek-to-peakAC millivoltnoise level ie
measured, High Zidelityis a neoessity.
Extra-
ordinary oable lsngths (>10,000 ft) oan aause
exaessive attenuation or distortion of the AC
signal. Some surfaoepanelemeasurepeak milli-
volts or RMS millivoltsrather than P-P milli-
volt. Amplitudesmustbe correctedif comparisons
are beingmade or standardcorrelationsare being
ueed.
The sonde Is run in the hole with a baslo
winoh truck spooledwith 7/32 Inch monoconductor
cable. Lubricator equipment is standard for
1-11/16Inohtools. Measurementof noieelevelsie
done with the sonde stationary. The reasonfor
this should be obvioue i f you*ve ever dropped
an operating microphone.
Some of the logging
truoksavailableto us are equippedwithsophisti-
cated panelsthataveragethe noiselevelsof all
four frequencycuts simultaneouslyand provide
digital readout, while ctherv?require that
each frequenoybe measured separatelyend read
from an analogvoltmeter. Stabilizationtime for
each station will average about one minute.
Millivolt readingsare plottedon a log scalevs
depth. Stationsare predetermine~.Any anomalies
are repeatedand further defined by additional
stopeif necessary.
Our use of noise logginghas been strictly
qualitative.Any quantitativework hae been for
academicpurposesonly. Most of our problemscan
be solvedby recognizinganomalousnoisepeaksand
describingthe flow situationbased.onthe loca-
tLonand smpl~tudeof thesepeaks.
Few wells in Saudi Arabia will provide a
noiselog llkethe one presentedin Figure3. It
is probablysafe to say that therewas no uncon-
trolledfluidflowin this well when the log was
recorded. Manywellsexhibitcomenoisecharacter
whether or not a problem existe.
It iS 108S
like the one in Figure 4 that test an inter-
preters knowledgeand ability.
This noise log
was an unsuccessfulattemptto confirma suspected
liner lap leak which had been indicated by a
continuousflowmeter.
The well, used to indeot
desaltingwaste water,was workedover to ensure
that contaminationof aquiferswas not occurring.
Tressure teetingdid not revealthe exlstenoeof
any leaks.
The resultsof many successfulapplications
of noise loggingby ty rest of the oil induetry
have been documented.
Presented here are four
examples taken from our files that illustrate
ARAMCOIS use of the noise log as a downhole
diagnostict?ol. Theee examplesalso show that
major problems,the ones thatneed to be deteoted
and solvedquickly,are easilydeteotedusingthe
noiselog.
7/24/2019 SPE 7774 - Noise Logs as a Downhole Diagnostic Tool.pdf
3/8
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n.rknfi, r
4 n,
WE 7774
11.n.Ul IINhn
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IVI
however, detest a standing fluid level in the
tubingjustbelow3494 ft. and indicatedthat the
fluidwas 0%1.
The firstexample(seeFigure5) was recorded
in the tubingof an openhole 011 producerin the
The noise log presented in Figure 6 was
Ghawar Field.
The oompletlonis typical- 9-5/8
inchintermediateeasingcementedin two stages,a
recordedwith the 9-5/8 In. X 13-3/8in. annulus
flowinggas to flareat 15 psig. The interpreta-
7 inchlinerto the top of the produainginterval,
t.~~fif this
log stated
that leaks existed
and 2-3/8 inch tubing run just off bottomas a
kill string.
This well producedapprezirzately
oppositethe noisepeeksat 1600 ft. and 3500 ft.
5000 BID of dry oil through the tu5ing casing
During the workover to eliminate the annulus
pressure,
the only leak detectedwas at 1600 ft.
annulusuntilit died in 1976.
After the well died, the followinglnforma-
The noise peak at 3500 ft was due to the
exissenceof a fluid leveland gas roilingat the
tionwas collected:
gas/oilinterface. The gas evolvingfrom the oil
1) Shut in wellheadpressurewas zero psig.
was flowingup the wellboreto 1600 ft where it
was enteringthe 9-5/8 in. X 13-3/8 in. annulus
through a failed DVn tool. From there it
2) PressureprofileIndicateda water/oiloon-
flowedup theannulusto flare.
tactin the tubingat 5800 ft.
3) Temperaturesurvey ~howedno anomalles.
Availableevidenceshouldhave indicatedthat
a leek did not exist at 3500 ft.
The pressureof
4) Bailersampletakenat 6700 ft was 98% water
theaquiferat thisdepthwas 1460psig,whilethe
(TDS=76,000ppm).
pressure measured in the wellbore
during a
gradientsurveywas 1259 pslg. The potentialfor
flow was towar~s the wellbore, however, oil
5) Swabbingrecovered200 bb%s fluid,10% oil
productionwas dry.
- 905 water.
6) Finalfluidlevelafterswabbingwas about
2500 ft.
Much of the aquiferwaterfarhaterinjection
It was suspectedthat thewaterscurcewas s.n
projeatais euppliedby waterwellsequippedwith
submersiblepump installations.
A typicalwater
aquiferdumping from a casing leak.
The noise-
loggerwas run in the hole to attemptto pinpoint
supplywell is completedopen hole with 20 inch
the water source. Stops were made at 100 ft.
casingoementedat 1000ft, 13-3/8inchlinerfrom
800 ft. to 3450 ft. and a 9-5/8 inch liner from
stations to measure the amplitudescf the four
3000 ft to the top of the produoing aquifer.
standardfrequencycuts.
The submersiblepump and electricdriverare hung
on 10 inch water columna~5000ft.
These pumps
There is an obvious noise peak at 4800 ft.
The peak is oppositea large, prolificaquifer.
will lift 120 MBD of 160 -170F saline aquifer
The evenspacingcf the frequencycurvesindicates
waterat 120 psigFWHP,and the wellswill flow90
MBD to the atmosphere.
that the leak was singlephase.
No attemptwas
made to calculatethe leakrate.
The absenceof a
All supplywells are compietedwith major,
temperature anomaly indicated that the leak fresh-wateraquifersbehind the surface casing.
ratewas small.
Many of the wells are locatedon the edge of a
large oasis that depends on the fresh water
A workover to repair the 7 inch liner waa
produced from these aquifers.
Protecting the
recommendedbased on the informationsuppliedby
the noise log. Subsequentpressuretestingwith
aquifers from contamination requires that the
drillpipeand a peckerconfirmedthe existenceof
wells be m~nitored routinelyfor shallow casing
leaks.
a leak at 4800 ft.
The casing was repaired,
and thewell returnedto production.
A radioactivetracersurveyis made wher%s?er
1200 nSIR ON THE 9-5/8 X 1?-?/8 A~
a failedsubmersiblepump assemblyIs pulletifrom
n
a well. Recently,hcwever,we have increasedthe
The well in this example (see Figure 6) is
average run life of these pumps so that it now
exceeds the acoepted routine survey period.
also an oil producerin the Ghawar Field.
The
Pulling water columns, changingout submersible
completionis typicalwith the DV stagetool in
the 9-5/8inchcasingat 1601ft.
pumps and especially electric drivers is an
expensive,time-consumingoperation.
Therefore,
A routineannulisurveydetected3 pressure
an alternativemethod for surveyingthese wells
was required.
of 1200 paig on the 9-5/8 X 13-3/8n annulus.
Shut-in tubing pressure was 1200 psig, while
Historically, nearly all casing leaks in
ehut-incasingpressurewas 1150 psig.
these water supply wells occur at or above the
pumpsuction. Aftershuttingdown the pump,it is
Attemptsto eliminatethe annuluspressureby
reworkingand repackingthe wellheadwere unsua-
possibleto run the noise sonde down the water
columnand recorda noieelog (seeFigure7). All
cessful.Temperatureand pressureprofilesmade
frequencycuts on this log increasefrcm surface
with the well shut in failedto revealthe source
to a peak at 150 ft. then remain constant or
of the problem.
The pressure profile did,
deoreaseslowly to 500 ft.
The absolutenoise
amplitudeis an indicationof fluid movementin
7/24/2019 SPE 7774 - Noise Logs as a Downhole Diagnostic Tool.pdf
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194
USE OF 92SE
NOISELOG AS A ~WNHOLE DIAGNOSTICTOOL
SPE77?
-
-. .. .
I
the wellboreand the peakat 150 ft. was probably
been adequatelyresearchedand.documented.Three
caused by fluid aooeleratingaorose a restrio-
yesrsofoperationalexperiencewith the technique
tion. This well was worked over and a large
have providedus with an extensivebackgroundand
leakat 150 ft. repaired.
database; and basedon thieinfonnatlon,oonolu-
sionsare as follows:
~
1) Noise loggingcan be used effectivelyto
Figure8 is a noise log thatwas recorded in
deteot, confirm and diagnose downhole
a typioalpowerwater indeotionwell. ,Thiswell
problemsthathave reiadaredtherlogging
is a perforatedcompletionwith 9-5/8 Inoh casing
techniquesInadequate.
oementedat 4794 ft. and a 7 inoh linerrun from
3642 ft. to TD.
Injectionratewas 50 MBD at 1150
2) Correot interpretationof any but the
pslg wellhead pressure.
The flowing wellhead
simplestnoise logs requires& thorough
temperaturewas 155 F.
understanding of noise logging funda-
mentals and a oompleteknowledgeof the
While running an ETT log In the hole an
problembeinginvestigated.
obstructionwaa encounteredat 4010 ft. Attempts
to get belowthe obstructionwitha flowmeterwere
unsuccessful.A temperatureprofilewas obtained
from the obstructionto aurfaoe.The anomolyat
200-850 ft. was not related to this problem,
The authors wish to thank the Arabian
and there were no anomaliesin the area of the
AmericanOil Company for pc.missionto publish
obstruction.Tools were run to 3800 ft. only to
thispaper.
prevent them from
getting
oaught up in the
obstruction.
The noiselogwas recordedwith thewell shut
in. Stations were every one hundred feet from
1. Enright, R. J.:
Sleuthfor Down-HoleLeakstt
surfaoeto the obstruction. The amplitudesnear ~ (Feb. 28, 1955) 78-79.
surfac eere quite high and they increaseddrama-
ticallyas the tool approachedthe obstruction.
2. Korotaev,Yu. P. and Babalcw,M.A.:
lAcous-
It was known that the reservoirpressureof the
tio Method of DelineatingOperatingIntervals
injeotlon zone was high enough to baokflow to
in Gas Bearing Formationsn, ~azovava PrQM
aquifersin the vicinity
of
the obstruction
f a
Nov., 1970).
leakexisted.
3. Stein, N., Kelly, J., Baldwin, W. F., and
The extremely high noise levels (200 HZ
McNeely, W. E.:
Sand ProductionDetermined
overranged)
aonflrmed that flow was ooourring
from Noise Measurementst , J. Pet. Tea~.
below the obstruction.(No additionalinformation
(July,1972)803-806.
can be obtainedfromthis log).
4. McKinley,R.M.,Bower,F.M.,and Rumble,R.C.:
Duringworkoveroperationsit was determined
The Struoture and Interpretation of Noise
that the well was baokflowing30 MBD into a leak
From Behind Cemented Casingff,J. Pet.Teti.
just belowthe obstruction.The leakwas repaired
Teoh. (Maroh 1973) 329-338; Trans., AtME,
and thewellreturnedto indeotionstatus.
255.
5. Robinson,W.S., FieldReeultsFrom The Nolse-
Logglng Technique ,
.,Nov. 1976)
The basicfundamentalsof noiselogginghave
1370-1376.
...
7/24/2019 SPE 7774 - Noise Logs as a Downhole Diagnostic Tool.pdf
5/8
1000
2000
3000
4000
5000
7000.
(
~
NOISE SOURCE AT 48Z0,
\
FLUID LEVEL AT 2050
-----------
512
-
-----------
J
1 8
t
I 1 1111 I t 1 I 1 I 111 I 1 1 1 I 11 1 1 I r
1.0
1 1 t 1 1
NOI SEAMPLki OE,MLLIVOLTS
foo. o
foo
FI G, 1 -
CARRY AWAY
OF NOI SE FROM SOURCE AND FLUID LEVEL EFFECT.
FI G, 2-
--+--
I I ATER
L
10, 9
00
FREQUENCY HZ
t o
NOI SE SPECTRUM GENERATED BY WTER THROTTLING ACROSS l o
rf
SI / IN PRESSURE DROP, tROM , IKINLEY, ET, AL, [ ,
7/24/2019 SPE 7774 - Noise Logs as a Downhole Diagnostic Tool.pdf
6/8
DEPTH, FT
O*
1000-
2000-
3000-
4000-
5000
6000
7000
7500
2US1EC7027
I
lH3/s2519
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95/84295A
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PEAKOPEAt fOI SEMPI I TUDE, M 1l I VOI TS
FIG,
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DEAD-WELL RESPONSE, SHUT-I N OI L PRODUCER,
o
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95/0
2000.
3000.
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