The Application of Iodine and Magnetic Susceptibility Surface Geochemical Surveys in the Lodgepole Play, Eastern Williston Basin, North Dakota: ABSTRACT

Abstract

Summary The use of surface geochemistry as a first pass exploration tool is becoming more prevalent in petroleum exploration. This is especially true due to the high cost of 2-D and 3-D seismic surveys in defining small targets such as the Waulsortion mounds of the Lodgepole Formation. Surface geochemical surveys are very effective in pinpointing specific target areas for seismic surveying and thus reducing costs. The type of survey varies from a reconnaissance type to a detail survey that focuses on specific areas for seismic exploration. Presented here are iodine and magnetic susceptibility surveys that can be used to define Heath. Mission Canyon. Lodgepole and Red River reservoirs. These type of surveys are very effective in minimizing the cost of seismic surveying and maximizing exploration effort. When the purpose of a surface geochemical survey is clearly define, properly planned and implementation is successful, the results can lead to a significant increase in new field discoveries and a decrease in the number of dry holes. Characteristically, surface geochemical surveys, when properly carried out. have been 100% accurate on predicting dry boles and when integrated with seismic have caused success rates to exceed 50% success rate over rank wildcats. Surface Geochemistry The use of iodine surface geochemistry and the current theories of vertical migration are presented in Tedesco (1994). The specific method presented in this paper is the analysis of iodine in magnetic susceptibility of soil Hydrocarbons migrating to the surface bond with iodine at the soil air interface under the influence of sunlight. Because of the stability of iodorganic compounds, iodine at the surface can be used as an exploration tool.The iodine analysis used in this survey is the most recent method and has a detection range of .004 to 20+ ppm iodine. The type of anomalous patterns for any surface geochemical methods has been termed as both halo (surrounding the reservoir) or apical (overlying the reservoir). Both types exist and most anomalies are combinations of hale and apical anomalies. Magnetic susceptibility measurements are based an the concept that migrating hydrocarbons cause the formation of magnetic minerals in the soil. The presence of these magnetic minerals are detected by changes in the magnetic signature of the soil.