Effectively tracking mass in fluids or other materials can assist in environmental monitoring. However, in complex environments like those encountered in oil and gas mining, tracking mass can be tough. Tracing the flow of matter requires a rugged tag that can withstand harsh conditions and be measured by a unique identifiable signature.

Pacific Northwest National Laboratory (PNNL) developed silica-based, luminescent tracking particles that are resistant to harsh environments and aid understanding of environmental fate and transport. The tracers tag mass with unique luminescent particles that are capable of tracking mass through high heat, high pressure, or other challenging environments. Where historic and traditional sampling methods were rudimentary, these tags allow for improved data collection and model confirmation of mass dispersion to a degree never before achieved.

How do luminescent particle tracers work? Pigments tagged with luminescent core-shell nanoparticles provide a unique and tunable photoluminescent signature. These nanoparticles essentially “shine” at different wavelengths, illuminating the unique luminescent signature that can be used for tracking and modeling. The particles are ruggedized with a thick silica shell to protect the luminescent inner architecture in harsh conditions such as high-pressure environments experienced in drilling.

The nanoparticle tracers have luminescent nanoparticle cores coupled to a luminescent substrate. The substrate can be a large-particle-size phosphor, while the nanoparticles in the core can be photoluminescent quantum dots whose emission spectra depend on their chemical composition, size, and fabrication.

Licensees can use these particles to track mass through dispersal events where there is a need to withstand extreme environments, to detect signals for multiple zones, and to identify mass by its unique spectral or color changes. These particles check all the boxes for effective tracers: they have unique identifiers, temperature and hot gas resistance, scalable production, and they are mixable into different materials or platforms. By incorporating tracers in (or on) structures or environments of interest, valuable information on the mass distribution during flow events can be obtained, which can aid in the development or confirmation of environmental fate and transport modeling.