Easy and Rapid Synthesis of Carbon Quantum Dots from Mortiño (Vaccinium Meridionale Swartz) Extract for Use as Green Tracers in the Oil and Gas Industry: Lab-to-Field Trial Development in Colombia

Abstract

The main objective of this study is to develop nanotechnology-based materials, specifically carbon quantum dots (CQDs), as alternative nonpolluting, nontoxic, and easily manipulated tracers for the oil industry using an easy and rapid synthesis from Mortinõ (Vaccinium meridionale Swartz) extract, a process that was evaluated in the laboratory and subjected to a Colombian oil field trial. The CQDs were synthesized using an easy and rapid microwave-assisted carbonization (MWC) methodology involving aqueous natural extraction in the presence of an organic nitrogen precursor. A displacement test at reservoir conditions in a porous media was used for evaluating CQDs retention, and a breakthrough curve with a CQDs saturation of around 1 pore volume injected was obtained, indicating that the CQDs could be completely removed from the porous media with null retention due to a poor interaction with the formation and preferential affinity to the aqueous phase. Fluorescence tests showed that quantification of the synthesized CQDs could be achieved for up to 1 ng L −1 . Coreflooding tests at reservoir conditions were performed under two scenarios: (1) monophase coreflooding (the core was saturated with water) and (2) biphasic coreflooding (at residual saturation of crude oil). The results showed that the CQD S behave excellently within these outlines and are not affected by the presence of crude oil, obtaining a breakthrough that is almost ideal for a tracer. A CQDs field trial in Colombia was conducted by injecting 20 kg of the nanomaterial at a concentration of 500 000 mg L −1 . The CQDs were analyzed in 10 producer wells, showing that they are useful as interwell tracers and the different interconnections between the different wells in the field were stablished. This study places the technology at a technology readiness level (TRL) of around 8, opens a broader landscape for the use of nanotechnology in the oil industry, and maintains Colombia as a pioneer in the application of nanoparticles and nanofluids under field conditions.

Low-Temperature Molten Salts Synthesis: CsPbBr3 Nanocrystals with High Photoluminescence Emission Buried in Mesoporous SiO2

“…The CsPbBr 3 /m-SiO 2 composite was also tested under very harsh conditions, including high temperature and salinity, which characterize the underground conditions that tracers, used in oil extraction wells, have to withstand. , Such tracers are employed in order to probe the efficiency of injection wells drilled for oil extraction. To do so, tracers are inserted in the injection well, and their presence is probed at the extraction well: an amount of recovered tracer at the extraction well and the speed at which the tracer travels through the well can give precious information about the efficiency of the injection well .…”

Field Applications of Nanotechnology in the Oil and Gas Industry: Recent Advances and Perspectives

“…Concentration of the CQDs at the producer wells, as a function of time during a waterflooding operation in a Colombian field. [Reproduced from Franco et al Copyright 2020, American Chemical Society, Washington, DC. ]…”

“…Currently, many challenges arise from the use of interwell tracers in the oil and gas industry, including economic cost, environmental issues, and the difficulty of detection and quantification that requires robust equipment. However, recent studies [34][35][36]91 have shown that carbon-based fluorescent 0D nanomaterials are a reliable option for substituting conventional radioactive or FBA-like tracers. For example, Kanj et al 34 and Alaskar and Kosynkin 35 have employed "inexpensive and environmentally friendly nanoparticles" called A-Dots (Arab-D Dots) as tracers under real reservoir conditions.…”

“…Franco et al 36 reported the development of carbon quantum dots (CQDs) synthesized from Mortinõ (Vaccinium Meridionale Swartz) extract with 30 nm in diameter and 1 nm in thickness, which were evaluated as interwell tracers in a sandstone formation under laboratory and real field conditions. Coreflooding tests showed saturation after approximately one pore volume injected, suggesting null retention in the porous medium due to the preferential affinity to the aqueous phase.…”

“…In Figure 17b, it reaches a concentration of 15.4 mg/L and declines to <2 mg/L after 8 days. Franco et al 36 also stated that the costs related to the operation were 70% lower than for conventional tracers, related to the CQD manufacturing, time of analysis, and sampling. Currently, the technology is being applied in another six fields in Colombia, covering 13 different injection patterns with costs reductions higher than 90% regarding conventional tracers.…”