IOR Centre Theme 2 Task 5: Tracers for SOR measurements in IW and - - PowerPoint PPT Presentation

IOR Centre Theme 2 – Task 5: Tracers for SOR measurements in IW and SW application - Some recent results and future plans

Tor Bjørnstad Mario Silva Thomas Brichart Alexander 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

Injection well Production well Statified reservoir

• Preferential flow directions
• Horizontal and vertical

communication between wells

• Permeability strata
• Sweep volumes
• Large-scale heterogeneities

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• A passive water tracer moves
• nly with the water water
• Phase-partitioning tracer

distributes betweeen water and

• il
• At residual oil saturation water

moves, oil is (close to) stagnant

Passive and partitioning tracers…

K = (CTr)o/(CTr)w

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Passive and partitioning tracer –

relative speed

Time Conc. Inj. ∝ SOR

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Volume (or time) Relative concentration

So = (Tp – Tnp)/[Tp + Tnp(K – 1)]

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Thermal degradation and sorption to substrates

Sealed glass ampoule Rock substrate (sandstones, carbonates, clays etc.) Heating bath,- thermally controlled

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2,3-Dimethylpyrazine (12 weeks)

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4-Methoxybenzyl alcohol (12 weeks)

ENI, Milano 2016 Tor Bjørnstad

Co-operation with Cornell Univ. - C-dots

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C-dots and fluorescense

Due 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

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SWCTT principle

Chemical reaction

Hydrolysis reaction + + Ester Water Alcohol Acid

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Can a passive and a partitioning tracer be used in a SWCTT test?

See next picture frame:

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On backproduction……

The answer is NO!

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Therefore, injection of a reacting tracer is necessary

The well is shut-in for conversion of ca. 50 % of the reacting tracer into a passive water tracer

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Therefore, injection of a reacting tracer is necessary

On back-production, the produced water tracer starts

• n the same starting line as the remaining partitioning

tracer and they separate on their way back.

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Fluorescence of Rare Earth Compounds

Fluorescence spectra of selected rare earths Fluorescence colors of selected rare earths

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Ester-based SWCTT = Single-Well Chemical 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.

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Promising reaction

+ Tb3+

O O O O O OH OH OH OH OH N N N N O O O O O OH OH OH OH N N N N OH O O O O O O OH OH OH OH N N N N R

+ R-OH H2O +

Temporarily cencored Temporarily cencored Temporarily cencored

ENI, Milano 2016 Tor Bjørnstad

Post.docs and PhD-stud.

Thomas Brichart, post.doc. Mahmoud Ould Metidji, post.doc. Mario Silva, PhD-stud.

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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 – before production start

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