Petroleum

Abstract

Petroleum is one of the most chemically complex materials on Earth. Its origins begin in certain depositional conditions that favors the accumulation and preservation organic matter from once living organisms. Petroleum is formed when these organic‐rich rocks are heated and the expelled fluids move into reservoirs. A petroleum system is established when key elements, and processes occur within a basin allowing for petroleum to be exploited. Petroleum is mostly composed saturated (paraffins and naphthenes) and aromatic hydrocarbons. These are the desired species most easily in refined into fuels and lubes. Petroleum also contains compounds with other elements, mostly nitrogen, sulfur, and oxygen. These heteroatomic species require additional processing, influencing the value of a crude. Although pressure continues to build to curtail the use of fossil fuels, petroleum demand is expected to remain close to current levels and there is more than enough oil reserves and resources to meet future demands. A large portion of the world's conventional reserves resides in the Middle East. However, the United States is currently the largest producer largely from the development of unconventional resources that are produced from shales and microporous carbonates using long lateral wells and hydraulic fracturing. The fear that “peak” oil production occurred in the late twentieth century has proven to be false.

Crude Oil Bioremediation: From Bacteria to Microalgae

“…Petroleum is mainly composed of aliphatic and non-aliphatic compounds, but sulfur, nitrogen and oxygen atoms are also present. Linear hydrocarbons vary their state based on the number of carbon atoms that constitute them [3]. Alkanes with a number of carbon atoms greater than five are present in a liquid state, such as heptadecane (C 17 H 36 ), while compounds with less than five carbon atoms, in a gaseous state [4].…”