Remote sensing and geochemistry for detecting hydrocarbon microseepages

Abstract

This work tests the hypothesis that chemical and mineralogical alterations in rocks and soils are related to hydrocarbon microseepages above some of the major oil fields. In this study we used Hyperion hyperspectral imaging sensors to map alterations that appear to be associated with hydrocarbon microseepages in the Patrick Draw area of Wyoming. Our mineralogical, geochemical, and carbon isotope data support the presence of hydrocarbon microseepages. Satellite imagery training classifications defined by areas of hydrocarbon microseepage have resulted in the successful identification of the areal extent of an anomalous area. Geochemical characteristics of samples that define this anomalous area were then compared to the remaining non-anomalous samples using X-ray diffraction (XRD), reflectance spectroscopy, and carbon isotope techniques. XRD analyses demonstrated the increased presence of feldspars in non-anomalous samples compared to anomalous samples. Spectroscopy results demonstrated higher proportions of clays within the anomalous samples compared to non-anomalous samples. The δ 13 C values range from −2.88‰ to as low as −45.32‰, indicating hydrocarbon sources. These methods may provide a foundation upon which further hydrocarbon exploration techniques can develop.