Geophysical Solutions: Environmental Geophysics, Geophysical Contracting & Consulting, Mineral & Geothermal Exploration


	CERRO NEGRO VOLCANO ROGUE ROBOT MAPPING OF PETROLEUM STORAGE RESERVOIR		Mapping Of A Hydrocarbon Plume And The Geometry Of An Abandoned Petroleum Storage Reservoir Geophysical data were collected over an abandoned petroleum storage reservoir in Norwalk, California. The storage tank is a bowl shaped structure approximately 600 feet in diameter with the walls of the structure 4 to 8 feet below the ground surface and a maximum depth of 25 feet. The reservoir was used as a storage facility in the 1920s and has since been back-filled. Geophysical methods used to delineate the location, depth, and structural integrity of a buried circular tank, and to determine if significant pockets of petroleum could be located using geophysical methods included electromagnetic terrain conductivity, and magnetics. Positioning was obtained using differential GPS. Concentrations of hydrocarbons were detectable with a horizontal loop electromagnetic system 3.77 meter intercoil spacing operated in the vertical dipole configuration. Magnetics and electromagnetics were used to map the perimeter of the reservoir and locate any possible breaches in the wall of the structure. Magnetic data were collected remotely with GPS position and magnetic field data collected continuously (5Hz) and transmitted to a remote data acquisition system and compared favorably to data collected in discrete mode. Magnetic data were modeled at locations along the perimeter of the reservoir to estimate the depth to the top of the structure's wall. Monitor wells were properly placed at the contaminant plume and depth to the perimeter of the tank was effectively modeled.