Application of Advanced Borehole Geophysics to Managed Underground Storage of Water Projects

The performance of managed underground storage (MUS) systems, as quantified by recovery efficiency, is highly dependent upon site-specific hydrogeologic conditions. MUS systems have failed because unexpected hydrogeologic conditions were encountered, which resulted in very low recovery efficiencies. Adverse fluid-rock interactions, such as arsenic leaching, are also a major problem in some areas. The need exists for more refined aquifer characterization and accurate predictive modeling of system performance so as to allow for improved feasibility evaluations and optimization of system design and operation. Advanced borehole geophysical logging techniques, such as nuclear magnetic resonance, micro-resistivity imaging, and gamma ray spectroscopy logs, which were developed for the oil and gas industry, can provide fine-scale data on variations in porosity (type and size distribution), permeability, mineralogy, and water quality that could not otherwise be practicably obtained. Workflow software allow the geophysical log data to be incorporated into groundwater flow and solute-transport models, which allows for simulations that are based more closely on actual local hydrogeologic conditions. Advanced borehole geophysical logging was recently employed in Florida as part of exploratory well programs for ASR projects in Brighton and Daytona Beach, and as part of a 333-well system that is planned as a component of the Comprehensive Everglades Restoration Plan (CERP).