Kerogen maturation and incipient graphitization of hydrocarbon source rocks in the Arkoma Basin, Oklahoma and Arkansas: A combined petrographic and Raman spectrometric study

C. Spotl; D.W. Houseknecht; R.C. Jaques

doi:10.1016/s0146-6380(98)00021-7

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Kerogen maturation and incipient graphitization of hydrocarbon source rocks in the Arkoma Basin, Oklahoma and Arkansas: A combined petrographic and Raman spectrometric study

C. Spotl·D.W. Houseknecht·R.C. Jaques

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Abstract

Dispersed kerogen of the Woodford-Chattanooga and Atoka Formations from the subsurface of the Arkoma Basin show a wide range of thermal maturities (0.38 to 6.1% R(o)) indicating thermal conditions ranging from diagenesis to incipient rock metamorphism. Raman spectral analysis reveals systematic changes of both the first- and second-order spectrum with increasing thermal maturity. These changes include a pronounced increase in the D/O peak height ratio accompanied by a narrowing of the D peak, a gradual decrease in the D/O peak width ratio, and a shift of both peaks toward higher wave numbers. Second-order Raman peaks, though less intensive, also show systematic peak shifting as a function of R(o). These empirical results underscore the high potential of Raman spectrometry as a fast and reliable geothermometer of mature to supermature hydrocarbon source rocks, and as an indicator of thermal maturity levels within the anchizone.Dispersed kerogen of the Woodford-Chattanooga and Atoka Formations from the subsurface of the Arkoma Basin show a wide range of thermal maturities (0.38 to 6.1% Ro) indicating thermal conditions ranging from diagenesis to incipient rock metamorphism. Raman spectral analysis reveals systematic changes of both the first- and second-order spectrum with increasing thermal maturity. These changes include a pronounced increase in the D/O peak height ratio accompanied by a narrowing of the D peak, a gradual decrease in the D/O peak width ratio, and a shift of both peaks toward higher wave numbers. Second-order Raman peaks, though less intensive, also show systematic peak shifting as a function of Ro. These empirical results underscore the high potential of Raman spectrometry as a fast and reliable geothermometer of mature to supermature hydrocarbon source rocks, and as an indicator of thermal maturity levels within the anchizone.

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C. Spotl, D.W. Houseknecht, R.C. Jaques. 1998. Kerogen maturation and incipient graphitization of hydrocarbon source rocks in the Arkoma Basin, Oklahoma and Arkansas: A combined petrographic and Raman spectrometric study. https://doi.org/10.1016/s0146-6380(98)00021-7

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