Source rock, hydrocarbon, petroleum

Brooks J., Cornford C., and Archer R. (1987) The role of hydrocarbon source rocks in petroleum exploration. In Marine Petroleum Source Rocks (eds. J. Brooks and A. J. Fleet). Blackwell, Oxford, pp. 17-46. 

Parnell, J. (1992) Burial histories and hydrocarbon source rocks on the North West Seaboard. In Basins on the Atlantic Seaboard Petroleum Geology, Sedimentology and Basin Evolution (Ed. Parnell, J.). Spec. Publ. Geol. Soc. London, 62, 3-16. 

Tainter PA (1984) Stratigraphic and paleostructural controls on hydrocarbon migration in Cretaceous D and J Sandstones of the Denver Basin. In Woodward J, Meissner FF, Clayton JL (eds) Hydrocarbon source rocks of the Greater Rocky Mountain Region. Rocky Mountain Assoc Geol, Denver, CO, pp 339-354 Tissot BP, Welte DH (1978) Petroleum formation and occurrence. Springer, Berlin Heidelberg New York, 538 pp... 

Fig. 3 Petroleum-type curves of different oU components from the North Sea showing a positive oU-oU correlation and a negative source rock - oU correlation (SAT saturated hydrocarbons, AROM aromatic hydrocarbons, NOSS heterocomponents, AS PH asphaltenes (Stahl, 1977)...

Liquid hydrocarbons derived from coal have a composition that is somewhat distinctive, and that distinguishes them from oils derived from algal-dominated type I and II source rocks. For example, petroleum derived from coal tends to have high pristane/phytane ratios a ratio >4 is... 

Boreham C. J. and PoweU T. G. (1993) Petroleum source rock potential of coal and associated sediments qualitative aspects. In Hydrocarbons from Coal (eds. B. E. Law and D. D. Rice). American Association of Petroleum Geologists, AAPG Smdies in Geology 38, American Association of Petroleum Geologists, Tulsa, OK, pp. 133—157. 

Water temperature is one factor that can influence the concentration of dissolved CO2 and, thereby, the isotopic fractionation encoded during photosynthetic carbon assimilation. This has been suggested as a means through which paleolatitude could be reconstructed from the carbon-isotopic composition of petroleum hydrocarbons sourced from rocks laid down during time intervals when significant pole to equator temperature gradients prevailed (Andrusevich et al., 2001). 

The molecular distribution and compound-specific carbon-isotopic composition of hydrocarbons can be used to qualify and quantify their sources and pathways in the environment. Molecular source apportionment borrows from molecular methods that were developed and applied extensively for fundamental oil biomarker studies, oil-oil and oil source rock correlation analysis. Additionally, petroleum refinement produces well-defined mass and volatility ranges that are used as indicators of specific petroleum product sources in the environment. Compound-specific carbon-isotopic measurement is a more recent addition to the arsenal of methods for hydrocarbon source apportionment. Carbon isotopic discrimination of i-alkanes, biomarkers, and PAHs has shown that the technique is highly complementary to molecular apportionment methods. 

Figure 3.12 Schematic illustration of likely sites and directions of light hydrocarbon diffusion in shale source rocks (after Leythaeuser et al., 1982. Reprinted Iqr permission of the American Association of Petroleum Geologists).

After primary migration has taken place, a certain proportion of the generated hydrocarbons remains in the pore system of the source rock (Hunt, 1979). The oil fraction that remains in the source rock will be cracked to gas as the source rock is buried to greater depths and temperatures (Section 3.1.5). The effect of primary migration of hydrocarbons can be indicated by the expulsion efficiency. The petroleum expulsion efficiency is the ratio of the expelled petroleum and the sum of the generated and initial petroleum and can vary from zero (no expulsion) to 1.0 (complete expulsion) (Cooles et al., 1986). The expulsion efficiencies are not uniform in time and space (Leythaeuser et al. 1987b). They depend on the tsrpe of source rock, its richness and thermal maturity and the primary migration mechanism. 

Figure 3.16 Schematic representation of amount of hydrocarbons generated in, and expelled from a type II kerogen-bearing source rock as a function of organic matter maturity for the initial part of the oil window (after Leythaeuser et al., 1987. Reprinted with permission from the Proceedings 12th World Petroleum Congress, Houston, Vol. 2, Fig. 2a, p. 229).

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