Passive organic cationic tracers for carbonate formations: Development and performance at oil reservoir emulating conditions

Abstract Tracers are practical tools to provide insight on reservoir heterogeneity. However, scarce is the variety of available alternatives designed specifically for carbonate oil reservoir. Through application-oriented design, directed ad hoc to carbonate oil reservoirs, a family of cationic fluorinated tracers was developed, aided by computational design. This was done through the microwave assisted, one-step synthesis of fluorinated anilines exhaustively methylated in mild reaction conditions. Stability and aging tests were carried out at reservoir-emulating conditions, confirming the structural integrity of the compounds through 19F NMR and UHPLC-MS. Moreover, the developed tracer showed low adsorption compared to a commercial anionic tracer and did not modify the water-oil-rock physical and interfacial properties, remaining preferably partitioned towards water. Finally, degree of heterogeneity characterization in a packed column of natural mineral rock was obtained with the developed tracer, and its commercially available anionic analogue commonly used in field tracer tests. The comparison showed the potential of developed tracers as prominent candidates to support the design of exploitation processes, environmentally friendly and nontoxic, in carbonate oil reservoirs.