Summary

Fluorescence analysis of near-surface soils and sediments detects the Polynuclear Aromatic Compounds (PAC) associated with petroleum seepage. Transfer of PAC-containing petroleum at depth into the near-surface requires macro-fractures. Quantifying and mapping PAC displays petroleum seepage along fracture migration pathways. Therefore, mapping elevated PAC concentrations shows the approximate location of macro-fractures at the surface.

Mapped PAC data is integrated with available subsurface geology and geomorphology. The comparison of drainage patterns with elevated concentration trends often reveal a subsurface migration pathway. Macro-fractures associated with various paleo-structural features may be faults, differential loading and compaction fractures, shelf edge fractures, etc.

Integrating PAC data with available geological information helps the explorationist evaluate the hydrocarbon potential of a prospect. Areas appearing more prospective should be evaluated with additional geochemical and/or geophysical tools.

AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah