Determination of temperatures and cooled fractions by means of hydrolyzable thermo-sensitive tracers

This work presents the development of improved tracer techniques for monitoring internal temperatures and cooled fractions in water saturated porous media. The analysis is based on reactive chemical compounds whose hydrolysis reactions allow for accurate temperature measurements. The tracers are designed to improve geothermal reservoir management procedures. Thermo-sensitive tracers will provide valuable information about the thermal state of the examined permeable media. This is demonstrated by means of laboratory experiments with sand-packed columns. The special heating/cooling setup provides a defined internal temperature distribution. In 70 independent experiments, tracer sensitivity was examined. Practical limitations in three different experimental schemes, flow-through, moving thermal front and push-pull, were investigated. The results show that thermo-sensitive tracers can be used to measure temperatures and cooled fractions with high precision and accuracy.