- Petroleum geochemistry
Petroleum geochemistry is the application of chemical principles to the study of the origin, migration, accumulation, and alteration of petroleum...(John M. Hunt, 1979). [Hunt, J.M., 1979. "Petroleum Geochemistry and Geology". Freeman, San Francisco ISBN 0716710056]
Petroleum is generally considered oil andnatural gas es having various compounds composed of primarily hydrogen and carbon. They are usually generated from the decomposition and/or thermal maturation oforganic matter . The organic matter originated fromplant s andalgae . The organic matter is deposited after the death of the plant insediments , where after considerable time, heat, and pressure the compounds in the plants and algae are altered to oil, gas, andkerogen . Kerogen can be thought of as the remaining solid material of the plant. The sediment - usuallyclay and/or calcareous (lime) ooze, hardens during this alteration process into rock ie.shale and/orlimestone . The shale or limestone rock containing the organic matter is called thesource rock because it is the source, having generated the petroleum.In our quest to find more oil and gas, we use numerous petroleum geochemical techniques to (1) identify source rocks and determine the amount, type, and maturation level of the organic matter; (2) evaluate the potential timing of petroleum migration from the source rock; (3) assess the potential migration pathways; and (4) correlate petroleum compounds found in reservoirs, leaks, and surface seeps to find new pools of petroleum. Some of the petroleum geochemical techniques used are:
stable isotope s; hydrocarbon analysis (fingerprinting) of specific organic compounds (biological organic markers) withgas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS); maturity indicators likevitrinite reflectance; laboratorypyrolysis and analysis; kerogen typing; and other more exotic techniques.References
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