Schumacher, Dietmar¹, Daniel Hitzman¹, Luis Clavijo¹, Daniel Malizia²
(1) Geo-Microbial Technologies, Inc, Ochelata, OK 
(2) GMT Argentina, Buenos Aires, Argentina

ABSTRACT: When Seismic is Not Enough: Improving Success by Integrating High-Resolution Surface Geochemical Data with Seismic Data

Seismic data are unsurpassed for imaging trap and reservoir geometry, however, in many geological settings seismic data yield no information about whether a trap is charged with hydrocarbons. In other settings, the quality of seismic data is poor due to unfavorable geology or surface conditions. For this presentation we will review the results of integrated seismic and geochemical surveys (1) over pinnacle reefs East Texas, (2) in the Ft. Worth basin of North Texas, (3) over a large, nearly depleted field in Venezuela, and (4) from an area of thick volcanic cover in Neuquen basin, Argentina. 
Geochemical data acquired over the pinnacle reefs clearly discriminates between hydrocarbon-charged reefs and dry or non-commercial reefs. In the Fort Worth basin, geochemical evaluation of a seismically defined Ordovician Ellenburger structural trap identified a minor seepage anomaly associated with it and an extensive microseepage anomaly over a nearby structural low. Subsequent drilling yielded a dry hole on the “high” and discovered a new Park Springs Conglomerate (Pennsylvanian) field in the area of the seismic “low.” In Venezuela, survey results identified areas of bypassed pay within the field, and several new drilling opportunities outside present field boundaries. Lastly, in the Neuquen basin microseepage data reliably imaged the extension of several fields beneath the thick basalt cover. 
Applications such as these require close sample spacing and are most effective when results are integrated with subsurface data. High-resolution microseepage surveys offer a flexible, low-risk and low-cost technology that naturally complements traditional geologic and seismic methods.

AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.