Post on 14-Jul-2020
IOR Centre Theme 2 – Task 5: Tracers for SOR measurements in
IW and SW application -Some recent results and future
plans
Tor BjørnstadMario Silva
Thomas BrichartAlexander Krivokapic
Sissel O. Viig
ENI, Milano 2016 Tor Bjørnstad
PITT and SWCTT• Interwell tracer injection probes the water-
contactable volume between wells. PITT measures SOR in this volume (SPE 164059)
• Single well push-and-pull (SWTT) tracer application measures SOR in a volume around a well 5-10 m from wellbore.
SWTT PITT
ENI, Milano 2016 Tor Bjørnstad
Injectionwell
Productionwell
Statified reservoir
• Preferential flow directions• Horizontal and vertical
communication between wells• Permeability strata• Sweep volumes• Large-scale heterogeneities
ENI, Milano 2016 Tor Bjørnstad
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• A passive water tracer moves only with the water water
• Phase-partitioning tracer distributes betweeen water and oil
• At residual oil saturation water moves, oil is (close to) stagnant
Passive and partitioning tracers…
K = (CTr)o/(CTr)w
ENI, Milano 2016 Tor Bjørnstad
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Passive and partitioning tracer –relative speed
Time
Conc
.
Inj.∝ SOR
ENI, Milano 2016 Tor Bjørnstad
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Volume (or time)
Rela
tive
conc
entr
atio
n
So = (Tp – Tnp)/[Tp + Tnp(K – 1)]
ENI, Milano 2016 Tor Bjørnstad
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Thermal degradation and sorption to substrates
Sealed glass ampoule
Rock substrate(sandstones, carbonates, clays etc.)
Heating bath,-thermallycontrolled
ENI, Milano 2016 Tor Bjørnstad
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2,3-Dimethylpyrazine (12 weeks)
ENI, Milano 2016 Tor Bjørnstad
4-Methoxybenzyl alcohol (12 weeks)
ENI, Milano 2016 Tor Bjørnstad
Co-operation with Cornell Univ. - C-dots
ENI, Milano 2016 Tor Bjørnstad
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C-dots and fluorescenseDue to oxygen and nitrogen functional groups on their surfaces, these carbon nanoparticles shine brightly from blue to deep red when they absorb certain wavelengths of light
ENI, Milano 2016 Tor Bjørnstad
SWCTT principle
Chemical reaction
Hydrolysis reaction
+ +
Ester Water Alcohol Acid
ENI, Milano 2016 Tor Bjørnstad
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Can a passive and a partitioning tracer be used in a SWCTT test?
See next picture frame:
ENI, Milano 2016 Tor Bjørnstad
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On backproduction……
The answer is NO!
ENI, Milano 2016 Tor Bjørnstad
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Therefore, injection of a reacting tracer is necessary
The well is shut-in for conversion of ca. 50 % of thereacting tracer into a passive water tracer
ENI, Milano 2016 Tor Bjørnstad
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Therefore, injection of a reacting tracer is necessary
On back-production, the produced water tracer starts on the same starting line as the remaining partitioning
tracer and they separate on their way back.
ENI, Milano 2016 Tor Bjørnstad
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Fluorescence of Rare Earth Compounds
Fluorescence spectra of selectedrare earths
Fluorescence colors ofselected rare earths
ENI, Milano 2016 Tor Bjørnstad
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Ester-based SWCTT = Single-WellChemical Tracer Techn.
Goal:* 3 – 5 new reacting tracers for H&P measurement of SOR
DTPA
* We synthesize new esters, for example starting with the poly-carboxylic acid DTPA etc.
ENI, Milano 2016 Tor Bjørnstad
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Promising reaction
+ Tb3+O O
O
O
O
OHOH
OHOH
OH
N N
NN
O O
O
O
O
OH
OH
OH
OHN
N
NN
OH
O
O
O
O
OOOH
OHOH
OH
N
NN
N
R
+ R-OH H2O +
Temporarilycencored
Temporarilycencored
Temporarilycencored
ENI, Milano 2016 Tor Bjørnstad
Post.docs and PhD-stud.
Thomas Brichart, post.doc.
Mahmoud Ould Metidji, post.doc.
Mario Silva, PhD-stud.
ENI, Milano 2016 Tor Bjørnstad
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New SWTT – reduction in volume and time
Present timeline – after a long production period
New timeline – after a long production period
Future timeline – beforeproduction start
ENI, Milano 2016 Tor Bjørnstad
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