Laboratory Experiments to Characterize Cation-Exchanging Tracer Behavior at Newberry Crater, OR

Abstract

Laboratory experiments were conducted to estimate cation exchange parameters for lithium and cesium ion to facilitate interpretations of tracer tests at Newberry Crater, OR in which these tracers will be used to interrogate fracture surface area generated during reservoir stimulation. The materials used in the experiments included a crushed (250-500 μm) and annealed (450ºC for 48 hr) mineral assemblage representing reservoir fracture coatings comprised of roughly equal fractions of chlorite, albite, calcite, epidote and quartz and a synthetic water having chemistry matching that of Newberry Crater injection water. Batch sorption experiments using lithium and cesium were performed at room temperature and at ~275ºC in a high-pressure, high temperature assembly to obtain estimates of site-specific cation-exchange parameters and to do a cursory evaluation of the temperature dependence of these parameters. In addition, high-pressure, high-temperature flow-through column transport experiments using the synthetic Newberry water and mineral assemblage at 275ºC were conducted to study cation-exchanging tracer transport relative to that of conservative tracers bromide and 1,5 naphthalene disulfonate. These experiments were conducted to verify that the parameters determined in the batch experiments can be effectively applied under the dynamic flow conditions expected in the field tracer tests.