Phase-Specific and Phase-Partitoning Tracer Experiment in the Krafla Reservoir, Iceland

Abstract

A field-wide tracer test was performed in the Krafla reservoir, starting in August 2013. Tracers were released into three injection wells and collected in twenty production wells. The experiment involved both phase-specific and phase-partitioning tracers. The phase-partitioning tracers were alcohols (methanol and ethanol). Naphthalene sulphonate tracers (2-, 2.6- and 2.7-naphthalene sulphonate) were used to trace the liquid phase, and perfluorocarbon tracers (PMCP, PMCH, PDMCH) were used to trace the vapor phase. The alcohols seem to have spread most widely, while the phase-specific tracers had only been detected in very few wells at the time this was written (May, 2014). The wide spreading of the alcohols is interpreted with caution however, as the tracer returns are quite volatile and high background samples were detected the just before injection took place. The results thus far are preliminary as sampling will continue through year 2014.