Retention of chemical tracers in geothermal reservoirs

Conference · Fri Jan 01 04:00:00 EST 1982

OSTI ID:7369547

Horne, R N; Breitenbach, K A; Fossum, M P

The advantages and disadvantages of chemical tracers for use in geothermal reservoir monitoring are examined. Tracers are used to determine the magnitude of connectivity between injection and production wells in order to estimate the likelihood of premature fluid breakthrough. Even though chemical tracers are generally less environmentally sensitive than radioactive materials, quantities injected need to be much larger to be distinguishable by chemical analysis. As a result, a non-equilibrium concentration of tracer material is injected into the reservoir, and the tracer is susceptible to retention within the reservoir by ion exchange, diffusion into the solids or immobile reservoir fluid, adsorption or dissolution. These various reactions lead to changes in the tracer concentration as the traced fluid flows through the reservoir, and therefore reduce the capability of the experiment to distinguish concentration changes due to purely mechanical effects. Experimental observations reported here show that substantial fractions of KI tracer were retained under reservoir conditions, even though it appears that the retained material was subsequently released into more dilute fluid. The result is an apparent storage and release mechanism that will distort the later response of a tracer breakthrough.

• Research Organization: Stanford Univ., CA
• DOE Contract Number: AT03-80SF11459
• OSTI ID: 7369547
• Report Number(s): SGP-TR-60; CONF-821214-42; ON: DE83015865
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150302* -- Geothermal Exploration & Exploration Technology-- Geochemical Techniques & Surveys
152000 -- Geothermal Data & Theory
CHEMICAL ANALYSIS
FIELD TESTS
GEOTHERMAL SYSTEMS
GEOTHERMAL WELLS
Geothermal Legacy
INJECTION WELLS
ISOTOPE APPLICATIONS
MONITORING
TESTING
TRACER TECHNIQUES
WELLS