ABSTRACT: Relationship of Magnetic Susceptibility and Hydrocarbons

BARTON, ROBERT H., and WALTER D. TOMLINSON, Spectra Resources, Inc., Houston, TX

The reducing environment present over hydrocarbon deposits sets up a mechanism for the formation of magnetic mineral grain coatings on near-surface sediments. This possible relationship was first reported more than 20 years ago. Initially, aeromagnetics data was used to try and map the hydrocarbon-induced magnetic variations, but the interference problem caused by surface equipment and culture tend to mask the significant signatures. To overcome the airborne total-field data-noise problem, this study used direct-reading ground and drill sample magnetic susceptibility measurements using specially designed instruments. Profile plots of magnetic susceptibility readings taken from seismic shot hole samples reflect both the underlying geologic structure and geochemical fluorescence variati ns taken on the same samples. A significant correlation was seen between offshore direct reading magnetic susceptibility measurements and methane values from samples taken at the same sites.

AAPG Search and Discovery Article #91015©1992 AAPG International Conference, Sydney, N.S.W., Australia, August 2-5, 1992 (2009)