Laboratory Investigation of Chemical Tracers vs. DNA Tracers

Abstract

A new and robust tracer technology is introduced based on encapsulated Nano-sized synthetic DNA. This cutting-edge technology enables bonding of synthetic DNA strands with unique sequences to a magnetic core particle and encapsulating them with silica making it possible to have unlimited number of identifiable tracers, each with a unique signature. Each manufactured batch of DNA tracer is then coated with a special chemical to make the batch water-wet or oil-wet. The presented novel technology of encapsulated Nano-sized DNA tracers is shown to be superior to the currently used water chemical tracers, fluorobenzoic acid or FBA, in many ways both in the applications of EOR and flowback analyses in hydraulic fracturing. Unlike the chemical tracers, the DNA tracers don't partition, don't chemically react with the formation minerology, don't disintegrate with time, are stable at high reservoir temperatures and don't lag flood front velocity if used in secondary recovery projects such as waterflooding. In addition, unlike the available limited number of chemical tracers, there are unlimited number of identifiable DNA tracers. In waterflooding, the DNA tracers are used to characterize fluid flow accurately and precisely in a reservoir and to identify heterogeneity of the reservoir. The technology can also be used to evaluate flowback analyses in hydraulic fracturing to fully understand fracture behavior, pipeline leakage identification, groundwater movement, contamination tracking in water streams, etc.