GEOPHYSICAL LOG ANALYSIS FOR CARBONATE-ROCK AQUIFER INVESTIGATIONS, NEW YORK TO FLORIDA

Analysis of geophysical logs is providing critical information in the characterization of selected carbonate-rock aquifers from New York to Florida. The aquifer investigations address a wide range of ground-water problems and issues including aquifer dewatering and brine intrusion related to salt-mine collapse and flooding, drought monitoring, recharge of transboundary confined aquifers, VOC plume source and extent, aquifer storage and recovery, seawater encroachment, wellfield protection, and general resource evaluation and research. Borehole-wall image (acoustic and optical televiewer); gamma and induction; and ambient and stressed fluid property and flowmeter logs are analyzed as an integrated suite to help define the stratigraphic framework; orientation of bedding and fractures; and flow-zone transmissivity, hydraulic head, and water quality. Results of the log analysis have proven useful in the characterization of aquifer framework, design and interpretation of hydraulic tests, evaluation of cross-connection effects and water-quality samples from open holes, and installation of discrete-zone head and water-quality monitoring systems.