Simultaneous Detection of Carbon Quantum Dots as Tracers for Interwell Connectivity Evaluation in a Pattern with Two...

Area of Science:

• Nanotechnology
• Materials Science
• Petroleum Engineering

Background:

• Traditional tracers in the oil and gas industry face limitations in assessing interwell connectivity.
• Developing novel, stable, and quantifiable tracers is crucial for enhanced oil recovery and reservoir management.
• Nanomaterials offer unique properties for advanced tracer applications.

Purpose of the Study:

• To develop and implement carbon quantum dots (CQDs) as nanotechnology-based tracers for interwell connectivity assessment in the oil and gas industry.
• To synthesize CQDs from agro-industry waste and evaluate their performance against commercial CQDs.
• To validate the use of CQDs for monitoring fluid flow and determining connectivity in producing wells.

Main Methods:

• Hydrothermal synthesis of CQDs from orange peel waste.
• Characterization of synthesized and commercial CQDs (CQDblue, CQDgreen, CQDred, CQDop) for morphology, size, and surface properties.
• Assessment of colloidal stability, zeta potential, and optical behavior of CQDs.
• Evaluation of individual quantification feasibility and interference levels in mixed CQD effluent samples.
• Field injection and monitoring of CQDs in producer wells to determine interwell connectivity.

Main Results:

• Synthesized and commercial CQDs exhibited spherical morphology, nanometric sizes (<11 nm), and high colloidal stability with negative zeta potentials (-17.8 to -49.1).
• CQDs demonstrated feasible individual quantification even in mixtures, with a maximum interference of 15.5%.
• Field application successfully determined connectivity for five producer wells, validating CQD performance under operational conditions.

Conclusions:

• Carbon quantum dots (CQDs) are a viable nanotechnology-based alternative to traditional tracers for assessing interwell connectivity in the oil and gas sector.
• CQDs synthesized from agro-waste offer a sustainable and effective option for reservoir characterization.
• This technology is particularly beneficial for intricate well arrangements requiring multi-tracer analysis for comprehensive system description.