ABSTRACT

The Lake Sand Project was a three-dimensional (3-D) geophysical survey conducted on the Marsh Island Wildlife Refuge as a cooperative effort by the Louisiana Department of Wildlife and Fisheries, the minerals operator (Exxon), the geophysical company (Schlumberger Geco-Prakla), and a third party environmental compliance inspector (Coastal Environments, Inc.) with the objective of using environmentally-based planning, innovative approaches, and new technology to collect high quality geophysical data in an environmentally sensitive area with a minimum of detrimental impact. Detrimental impacts to the marsh were minimized through systematic project planning and coordination, use of low, surface-pressure marsh-buggies and airboats and by limiting traverses across the survey area. Use of Vibra-Ram® technology, the Digiseis FLX® radio telemetry recording system, and slant geometry further reduced detrimental environmental impacts and also improved survey efficiency and seismic data quality. Unavoidable marsh damage was repaired using coconut fiber logs and mats pre-planted with marsh grass. A measure of effectiveness of the environmental precautions was that only 13 minor repairs were required along 146 km (92.4 mi) of shot point and receiver lines traversed during the survey. The project developed both methodology and performance standards for conducting geophysical surveys and related activities that have broad applications.