Why are Surface Geochemical Exploration Techniques Regarded as Unconventional? Home

I find it interesting that the use of surface geochemical exploration still comes under such scrutiny. I recently received an email that stated “I like unconventional tools. Anything that can reduce risk at a reasonable cost is a good idea. Unfortunately most investors are skeptical and don’t want to spend the money.” Another exclaimed that “all the talk needs proof.” The interesting thing about the authors of these emails is that both use and promote non-seismic methods of detecting geochemical alteration anomalies via micromagnetics, radar, and radiometrics.

According to the first author’s webpage, micromagnetic “surveys detect large blooms of magnetotactile bacteria that consume hydrocarbons which seep from hydrocarbon traps.” These anomalies are produced by the same hydrocarbon seepage plumes that are detected using various geochemical tools, yet the magnetic method is deemed conventional while surface geochemistry is termed as “unconventional.”

Seismic companies are currently developing methods to detect seepage anomalies. One such method is the “chimney cube.” Furthermore, shallow seismic anomalies related to seepage have been detected but discarded due to not being at the depth of interest and processing issues. According to a paper presented at the EGM 2007 International Workshop, Innovation in EM, Grav and Mag Methods: A New Perspective for Exploration, “Non-seismic geophysical exploration techniques are important strategic components of the exploration toolkit when properly calibrated and applied.” From my application of non-seismic methods (EM and magnetics) I know I am detecting alteration related to near surface geochemical processes. Yet the geochemistry is still regarded as “black box” or unconventional.

Regarding “proof.” Article after article have been published with reference to success rates using geochemical methods, yet proof is still required. Geochemistry will find hydrocarbons at depth when properly applied. Whether a producing well results from drilling a geochemical anomaly is beyond the scope of the tool, in fact most tools, geochemical or geophysical. Hence the disclaimer which I found on a legitemate producers website. “The oil and gas exploration business is a very risky and is subject to a number of uncertainties including but not limited to: 1) reserve quantities discovered, 2) dry holes, 3) volatile oil and gas prices, 4) the effects of inclement weather, 5) federal and state regulations of the oil and gas industry and 6) general economic conditions.”

So if the problem is that surface geochemical methods are considered riskey and other methods are not, then why post such a disclaimer. All methods have their place in an exploration project. Use of a particular method is primarly based on economics and whether it can be interpreted to fit the prospect. Surface geochemical tools should be applied early in the exploration process to determine whether hydrocarbons are in place prior to the application of othe, potentially more expensive, methods which may provide additional verification.