The Benefits of Advanced Borehole Geophysical Logging for Maximizing Data Collection in Deep Ground Water Investigations

Deep groundwater investigations are becoming more common as society looks for additional fresh groundwater supplies, the development of brackish water and the disposal of desalinization brines, the extraction of deeper mineral deposits and the potential for geologic sequestration of CO2.  Advanced borehole geophysical logging employing magnetic resonance, dipole sonic, nuclear spectroscopy, and other technologies provides continuous-in-depth, high resolution, quantitative evaluation of key hydrogeologic, geologic, and geomechanical properties in all types of geologic environments, including total and effective porosity, pore and grain size distribution, hydraulic conductivity, specific yield and storage, pore water salinity, matrix geochemistry, geologic structure and texture delineation and orientation, fracture orientation and aperture, rock/substrate mechanical strength, and stress magnitude and direction.  In addition, discrete depth sidewall coring and packer hydraulic testing, in-situ pressure measurements and fluid sampling can be performed using highly modular cable-conveyed tools that do not require any pumping of the well.

Applications and case examples of advanced geophysical logging used for deep groundwater investigations in water resource, environmental, and mining projects will be provided, including a deep aquifer managed recharge project in the Mojave Desert, California; deep aquifer environmental investigation at Los Alamos National Laboratory, New Mexico; and a very deep groundwater resource investigation for a power plant in northern New Mexico.