MBA in petroleum geology

Oil and natural gas, commonly referred to as hydrocarbons by analogy with their essential, if not exclusive, constituents, are "sedimentary rocks", meaning they originate during sedimentation processes. The term "rock", which may initially seem shocking to designate fluids, should be taken in the broadest sense of formed deposit, like coal, ores, shales, etc., resulting from a set of geological phenomena. However, oil is obviously a very particular sediment, distinguished from all other sedimentary rocks by three remarkable qualities: it is complex and can be composed of several hundred different constituents, mostly paraffinic, naphthenic, aromatic hydrocarbons (cf. oil - Crude oil); it is mobile, just like water, and moves within the sediments that house it, under the effect of Archimedes' buoyancy, which implies that it is generally not found where it originated; it is fragile and decomposes under temperatures exceeding 200 or 300 °C or in contact with the atmosphere or meteoric waters.