Organic matter thermal maturity

Temperature is the main "driving force" of the geochemical pro esses to a point that a thermal alteration index (an indication of the maximum temperature the sample has reached) can be used to say if the organic matter is mature to produce oil or gas. 

Schimmelmann, A., Sessions, A.L., Mastalerz, M. (2006). Hydrogen isotopic (D/H) composition of organic matter during diagenesis and thermal maturation. Annual Review of Earth and Planetary Sciences, Vol. 34, pp. 501-533. 

Radke et al. [28] described an automated medium-pressure liquid chromatograph, now commonly called the Kohnen-Willsch instrument. At present, the method is widely used to isolate different fractions of soluble organic matter (for instance, as described in Reference 29 to Reference 31). A combination of normal phase and reversed-phase liquid chromatography has been used by Garrigues et al. [32] to discriminate between different aromatic ring systems and degrees of methylamine in order to characterize thermal maturity of organic matter. 

Although the data are not plentiful, it is clear that the hydrothermal solutions of sediment-hosted ridges and back-arc basin covered by sediment (Okinawa Trough) contain high amounts of ammonium (2.8-13.6 p.molal) (Scott, 1997). This means that ammonium was derived by thermal maturation reaction of organic matter in sediments by the following reactions (Gamo et al., 1991),... 

It has been postulated that odd-carbon preference is characteristic of bulk organic matter and that its disappearance results from thermal maturation processes as petroleum is being formed. However, as these... 

Dell Abate, M. T., Canali, S., Trinchera, A., Benedetti, A., and Sequi, P. (2000). Thermal methods of organic matter maturation monitoring during a composting process. J. Ther. Anal. Cal. 61, 389-396. 

Yamamoto et al., 2007), including evaluation of the level of maturation of organic matter in composts (Dell Abate et al., 2000) and evaluation of relative soil health (Nunez-Regueira et al., 2006) through use of thermal analysis to evaluate relative microbial activity. Table 18.3 summarizes materials, methods employed, and relevant citations. 

Rowan, E. L., Goldhaber, M. B., and Hatch, R. R., 1996, Constraints on the thermal and burial history of the Illinois Basin from fluid inclusions and thermal maturity of organic matter in Geological Society of America, 28th annual meeting, p. 387. 

The Kettle Point Formation subcrops in southwestern Ontario. It is up to 60 m thick, with organic carbon values usually in the range 5%-16% and Fischer Assay oil yields up to 70 1/t (17 gal/ton). The organic matter is dominantly kerogen of marine origin and has attained only an immature thermal maturation stage. A particularly rich upper zone is present over much of the subcrop area and its thickness seems to be controlled by post-Kettle Point erosion. Although studies are still preliminary, especially for the Devonian shales, the Kettle Point Formation appears to have the most potential for shale oil production in southern Ontario. 

Table I summarizes the indicated maturation levels of organic matter from the Kettle Point, Marcellus and Whitby Formations and equivalents in various areas. Using Figure 4, these may be related to thermal maturation. Only a few samples have been ex-...

Figure 4. Thermal maturation levels and hydrocarbon generation from organic matter.

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