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^PSNon-Seismic Detection of Hydrocarbons: An Overview*

Dietmar “Deet” Schumacher¹

Search and Discovery Article #40392 (2009)

Posted May 1, 2009

*Adapted from poster presentation at 2008 AAPG International Conference and Exhibition, Cape Town, South Africa, October 26-29, 2008 

¹Terralliance Technologies, Newport Beach, CA USA ([email protected])

Abstract 

The surface expression of hydrocarbon seepage and hydrocarbon-induced alteration of soils and sediments can take many forms including (1) anomalous hydrocarbon concentrations in soils, sediments, and waters; (2) microbiological anomalies and the formation of “paraffin dirt”; (3) mineralogic changes such as formation of calcite, pyrite, uranium, elemental sulfur, and certain magnetic iron oxides and sulfides; (4) bleaching of redbeds; (5) clay mineral alteration; (6) electrochemical changes; (7) electromagnetic and telluric changes, (8) radiation anomalies; and (9) biogeochemical and geobotanical anomalies. These different manifestations have led to development of an equally varied number of geochemical and non-seismic geophysical exploration techniques. These include direct and indirect geochemical methods, magnetic and electrical methods, radioactivity-based methods, and remote sensing methods.  

What are the benefits of using geochemical and non-seismic hydrocarbon detection methods in conjunction with conventional exploration methods? In a review of more than 1100 US and International wildcat wells - all drilled after completion of geochemical or non-seismic hydrocarbon detection surveys - more than 80% of wells drilled on prospects associated with positive hydrocarbon anomalies resulted in commercial discoveries; in contrast, only 13% of wells drilled on prospects not associated with such anomalies resulted in discoveries. Although these methods cannot replace conventional exploration methods, they can be a powerful complement to them. The need for such an integrated exploration strategy cannot be overemphasized. This presentation will be illustrated with examples from geochemical surveys, aeromagnetic-micromagnetic surveys, passive and active electromagnetic surveys, and remote sensing data.

References 

Lytle, R.J., and D.L. Lager, 1976, Using the natural frequency concept in remote probing of the earth: Radio Science, v. 7/3, p. 245-250. 

MacDonald, I.R., J.F., Reilly, Jr., S.E. Best, R. Venkataramaiah, R. Sassen, N.L. Guinasso, Jr., and J. Amos, 1996, Remote sensing inventory of active oil seeps and chemosynthetic communities in the northern Gulf of Mexico, in  Hydrocarbon Migration and its Near-surface Expression: AAPG Memoir 66, p. 27-37. 

Van den Bark, E., and O.D. Thomas, 1980, Ekofisk, First of the giant oil fields in Western Europe, in Giant Oil and Gas Fields of the Decade 1968-1978: AAPG Memoir 66, p. 195-224. 

Williams, A., and G. Lawrence, 2002, The Role of satellite seep detection in exploring the South Atlantic’s ultradeep water, in Surface Exploration Case Histories: Applications of Geochemistry, Magnetics, and Remote Sensing: AAPG Studies in Geology 48, p. 327-344.