Origin of petroleum

Relative Yield of Gas from Organic Matter in Fine-Grained Sediments 

In addition to time, the quantity of gaseous hydrocarbons formed varies with the type of organic source material, which can be broadly classified as sapropelic (marine) or humic (terrestrial). As shown in Fig. 5-1, considerably more C2-C4 and other oil-type hydrocarbons are generated from sapropelic sources than from humic sources. In addition to the different volumes and types of petroleum (oil versus gas) produced from the two source materials, their carbon isotope compositions are different terrestrial organic matter is reported to have lower C concentrations than marine organisms (Galimov, 1968 Silverman and Epstein, 1958). 

Literature review of biogenic light hydrocarbon production (C1-C4) 

Voytov et al., 1975 Swamp gases, glacial till gases, subsoil bacterial gases Ci 99% C2-C4 10- C /C2 10  

Bukova, 1959 Anaerobic bacterial decomposition, soil gases, sewage, silt C 99% C,/C2 1000 

Lomonosov was one of the first scientists to introduce a reasonable scientific concept of the origin of petroleum. In his mid-eighteenth century work on terrestrial layers , this Russian scientist wrote It is expelled from underground with heat, prepared from stone coal and brown coal, this black oily material... And this is a birth of a different grade of combustible liquid and dry hard matter. This is the essence of stone oil, liquid pitch, petroleum, and similar materi- 

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Lomonosov was not the only one who addressed the question of the origin of petroleum in the eighteenth century. However, some of the other hypotheses formed at this time were less than scientific. For example, a hypothesis credited to a Warsaw priest was that the Earth was very fertile in the paradise period. The core of the earth contained a fatty impurity. After the paradise period, this fat was partially evaporated, and the vapor partially condensed on the ground where it mixed up with a variety of materials. This was later transformed to petroleum by the world flood. 

There are many other less scientific hypotheses about the origin of petroleum even by scientists. At the end of the nineteenth century, the authoritative German geologist H. Hefer reported of an American petroleum industrialist who considered petroleum to have resulted from wet whales that existed at the bottom of polar seas. This petroleum penetrated into Pennsylvania by seeping through underground channels [5]. 

This becomes more aromatic and carbon-rich as it generates petroleum and evolves toward graphite. In contrast, the solvent-extractable lower molecular weight organic materials called bitumen or extractables increase in hydrogen content and progress through compositions typical of cmde oils to those of gas (10). 

The petroleum generation process can be dupHcated by laboratory pyrolysis. Higher temperatures are needed to produce these reactions in a few hours or days rather than the millions of years in nature (16,17). Both dry pyrolysis and hydrous pyrolysis have been used. 

Kirk-Othmer Encyclopedia of Chemical Technology (4th Edition) 

Biomarkers form a small percentage of bitumen and cmde oils, but relative distributions and complex stmctures are modified by the various processes involved during petroleum generation and accumulation. These biomarkers are widely used for correlation studies, and for recognition and documentation of the progress of generation and maturation (52,53). 

Howell, ed.. The Euture o/Enef Gases U.S. Geological Survey Professional Paper 1570, Washington, D.C., 1993, pp. 57—80. 

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A study of the origin of petroleum requires analytical capabilities for many compounds including hydrocarbons organic acids... 

The foregoing incomplete but illustrative outline of the role of analytical chemistry in the origin of petroleum makes it possible to discuss the position of a number of the other subdisciplines in connection with the genesis of oil fields. 

The chemical constraints related to physical chemistry in the origin of petroleum should be more clearly defined than in the other subdisciplines, but the complexity of the situation becomes overwhelming. Physicochemical aspects are widespread, fitting into two major areas one dealing with reaction kinetics and thermodynamics, and the other with physical relationships including colloid chemistry. 

Thermodynamics. The role of chemical thermodynamics in the origin of petroleum is concerned largely with demonstrating an almost self-evident drive from unstable biogenic molecules to stable hydrocarbons... 

Hedberg, H. D., Geologic Aspects of Origin of Petroleum, Bull. Am. 

Smith, P. V., Studies on the Origin of Petroleum Occurrence of Hydro-... 

Stevens, N. P., Origin of Petroleum—A Review, Am. Assoc. Petrol. 

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