Due the high temperature and pressure conditions found in geothermal wells, tracer studies designed to elucidate properties of geothermal reservoirs are traditionally conducted by pulling liquid samples from the wellhead. These samples are then sent off for analysis in a fixed laboratory setting. Unfortunately by pulling the sample from the surface, information regarding the depth of the fractures generating the tracer flow is lost. Additionally, significant time is lost in sending the samples off for traditional chemical analysis. This presentation focuses on our efforts to develop downhole high temperature and pressure stable ion selective electrodes capable of measuring the concentration of tracers used in geothermal studies, along with pH, at various depths in the wellbore creating tracer concentration and pH depth profiles for use in geothermal reservoir analysis.
Pushing the boundaries with geothermal tool development can often necessitate exceeding manufacturer specifications for temperature and pressure of individual circuit components. Detailed here are the efforts surrounding geothermal temperature characterization of commercially available HT-Flash memory modules made by Texas Instruments (SM28VLT32-HT) and preliminary results of 3 commercial solid tantalum capacitors. Flash evaluation boards were modified for high temperature application and read, write and erase functionality were tracked as well as prolonged data retention at various temperatures well beyond datasheet specifications.
Simulation input and output files, post-processed figures and excel tables, and tecplot layout files for generating figures. These simulations were run with TOUGHREACT V4.12 by Lawrence Berkeley National Laboratory in 2021. This work was completed as part of the geologic thermal energy storage (GeoTES) research project reported in the final report for Phase I of this work, which is linked below.