Advances in technology are removing the need for harmful tracer chemicals in upstream oil and gas exploration and production. New non-toxic tracing and tagging solutions feature unique spectral signatures, can be detected even in extremely low-level concentrations, and are suitable for subsurface applications.
Uzi Breier, CEO of ASX-listed tech company Dotz Limited (DTZ), said the company's innovative tracers and taggants offer a cost-effective and environmentally-friendly alternative to highly toxic fluorescent and radioactive dyes.
“Our Fluorensic tracers are water-soluble, resistant to photo-bleaching and can detect reservoir and formation damage, hydrocarbon flow paths and water dilution effects, without the potential risk of harmful chemicals or chemical presence in formations,” he said.
“Tracers are the only sure way of measuring where injected water goes within the reservoir, tracking flow paths and detecting unflushed areas. Our Fluorensic tracers are useful for quantifying contamination of downhole formation fluids, measuring reservoir production and identifying optimisation targets.”
Improved or Enhanced Oil Recovery (IOR/EOR) projects based on tracer survey results can then remodel the reservoir or reengineer wells and completions to optimise production.
“The emission spectrum of any specific Fluorensic signature used in injection fluids can be detected in tested flowback water measured at the wellsite using portable lab. Fluorensic is visible to the naked eye under UV light at 1ppm saturation. More diluted concentrations are visible using a portable lab kit.
“The signature of injected water is unique, so it positively identifies the source of water at the injection well or completion point. The retrieved injected water from any given well in the reservoir therefore reveals the unique spectral signatures and concentrations of Fluorensic when tested in the portable lab, helping to determine flow paths within the reservoir from injection points, “Breier said.
Breier added that the company's tracers can also be inserted into the injected frac water used for cracking tight reservoir rock or shales and for the transportation of proppant that hold the fractures open.
Dotz has demonstrated the benefits of its Fluorensic tracers in a successful field trial in Payne County, Tulsa Oklahoma, where its tracers were added to fracking fluids that were injected into a well. Despite extreme pressure and temperatures, Fluorensic tracers were clearly detected in parts per billion (PPB) levels and in real-time with the company's in-field detector.
Dotz's cloud-based InSpec portable readers are mobile phone-friendly and, in a world-first, allow for immediate on-site results, rather than needing to wait three days for a lab. When implemented into thousands of wells, real-time results offer substantial cost and time savings which can often mean the difference between whether a drill-hole collapses or blocks up or not.
“Fluorensic is unique in its ability to remain stable in all downhole environments and can withstand pressure and temperatures of up to 300 degrees. It does not absorb or damage the reservoir formation, nor does it cause any negative impacts to the environment.”
Meanwhile, the company's ValiDotz taggants are ideal for use in midstream and downstream areas. The non-toxic taggants can be inserted directly into crude oil and oil-based derivative products, making them ideal for security or product integrity in downstream shipping, transportation and points-of-sale.
ValiDotz have distinctive molecular signatures with four layers of security - colours, colour combinations, patterns and forensics – and cannot be reverse-engineered.
Breier said the company's markers do not affect the properties or appearance of the tagged product and can be easily integrated into existing processing, requiring minimal investment in equipment.
“ValiDotz offers product identification certainty for manufacturers as well as protection from dilution or counterfeiting. With almost infinite encoding combinations, a signature can be created for every client, batch or lot number.”
Dotz is initially targeting the US market with its end-to-end tracer, taggant and world-first, instant on-site verification solutions, which is home to more than 13,000 fracking drills. Other key markets for Dotz's Fluorensic and ValiDotz products are Australia, Canada and China.