Biomarkers: Review and application to the Eagle Ford shale formation

Biomarkers have become an integral part of oil exploration. Gas Chromatography (- Mass Spectrometry) was performed to an oil sample to acquire biomarkers from the sample. The presence, lack of, or abundance of a given compound (or biomarker) in the geochemical results of an oil sample depict(s) a property or properties of the source rock and the oil. For example, the abundance of pristane and lack of phytane in an oil sample are characteristic of shale source rock, and the results from the Eagle Ford shale formation show a high pristane to phytane ratio.;The Eagle Ford shale formation is cretaceous in age; the presence and absence of certain biomarkers like oleanane suggest age ranges. The oil sample tested from the Eagle Ford shale formation support a source rock from the cretaceous period. The results from the Eagle Ford shale formation also suggest the thermal maturity of oil samples tested. The Eagle Ford shale formation produces both gas and oil. This unique property ensures that the biomarkers detected can be used to study thermal maturity. The results from the Eagle Ford shale formation show a thermal maturity that is between peak and late stages of oil generation which supports continued exploration from the reservoir of the oil sample.;Results are affected by many variables; therefore, there will be considerable variations in the ensuing interpretations. The use of multiple biomarkers in the results from the Eagle Ford shale formation and comparing and contrasting those results with other available results will produce more accurate conclusions.