Buried mudpit delineation from electromagnetic surveys - Case history of a student project

Two deep boreholes that are used for testing well-based imaging techniques exist at a site in the northern reef trend of Michigan\u27s Lower Peninsula. Electromagnetic surveys were conducted in order to define the locations of the mudpits used in drilling the wells and to examine whether or not the materials contained were leaking into the surrounding subsurface. Part of this study was conducted as a component of a Senior Design Project for Geological Engineering students at Michigan Tech. The primary tool used to identify the mudpits was the GEM-2 broadband electromagnetic sensor from Geophex® Ltd. This tool transmits signals at a variety of programmable frequencies and receives them in a single housing carried by one person in the field. Three separate visits to the site were required before the four mudpits on the two sites were all fully and convincingly delineated. One of the mudpits had not been identified from the usual state drilling records, and was not fully covered by the initial surveys. In the end, however, all four mudpits were successfully identified, and appear to be fully contained. © 2005 Society of Exploration Geophysicists