Ultra-sensitive in-situ detection of near-infrared persistent luminescent tracer nanoagents in crude oil-water mixtures.
Current fluorescent nanoparticles-based tracer sensing techniques for oilfield applications suffer from insufficient sensitivity, with the tracer detection limit typically at the several hundred ppm level in untreated oil/water mixtures, which is mainly caused by the interference of the background fluorescence from the organic residues in crude oil under constant external excitation. Here we report the use of a persistent luminescence phenomenon, which enables an external excitation-free and thus background fluorescence-free measurement condition, for ultrahigh-sensitivity crude oil sensing. By using LiGa5O8:Cr(3+) near-infrared persistent luminescent nanoparticles as a tracer nanoagent, we achieved a tracer detection limit at the single-digit ppb level (down to 1 ppb concentration of nanoparticles) in high oil fraction (up to 65 wt.%) oil/water mixtures via a convenient, CCD camera-based imaging technique without any pretreatment or phase separation of the fluid samples. This detection limit is about four to five orders of magnitude lower than that obtained using conventional spectral methods. This study introduces a new type of tracer nanoagents and a new detection method for water tracer sensing in oil reservoir characterization and management.
College of Engineering, University of Georgia, Athens, GA 30602, USA.
Yen-Jun
YJ
Chuang
College of Engineering, University of Georgia, Athens, GA 30602, USA.|Department of Physics and Astronomy, University of Georgia, Athens, GA 30602, USA.
Feng
F
Liu
Aramco Research Center-Boston, Aramco Services Company, 400 Technology Square, Cambridge, Massachusetts 02139, USA.
Wei
W
Wang
Exploration and Petroleum Engineering Center-Advanced Research Center (EXPEC-ARC), Saudi Aramco, Dhahran, Saudi Arabia.
Mazen Y
MY
Kanj
Aramco Research Center-Boston, Aramco Services Company, 400 Technology Square, Cambridge, Massachusetts 02139, USA.
Martin E
ME
Poitzsch
College of Engineering, University of Georgia, Athens, GA 30602, USA.|Department of Physics and Astronomy, University of Georgia, Athens, GA 30602, USA.
Zhengwei
Z
Pan