Separation and Artificial Maturation of Macerals from Type II Kerogen

Abstract

Structural characterization studies have been carried out on four commercial Saudi Arabian crude oils. The aromaticity and crystallite parameters of the asphaltenes were studied by X-ray diffraction methods and compared to the average structural parameters calculated from nuclear magnetic resonance spectra.

Geochemical evolution of organic-rich shales with increasing maturity: A STXM and TEM study of the Posidonia Shale (Lower Toarcian, northern Germany)

“…These conclusions conform to those previously reported for naturally buried as well as laboratory-heated sediments based on micro-scale sealed vessel (MSSV) pyrolysis, gas chromatography mass spectrometry (GCeMS), Fourier transform infrared (FTIR) spectroscopy, solid-state nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) investigations (Schenk et al, 1986;Behar and Vandenbroucke, 1987;Requejo et al, 1992;Patience et al, 1992;Wei et al, 2005;Lis et al, 2005Lis et al, , 2008Smernik et al, 2006;Kelemen et al, 2007;Mao et al, 2010;Horsfield and Dueppenbecker, 1991;Vandenbroucke et al, 1993;Kruge et al, 1997;Putschew et al, 1998).…”

“…Improvement in our knowledge of the geochemical evolution of such systems with increasing maturity appears necessary to improve the reliability of the kinetic models used for predicting the amount and composition of generated hydrocarbons. Artificial maturation and pyrolysis experiments performed in laboratory under well-constrained physical and chemical conditions have been extensively used for decades to better constrain hydrocarbon generation processes occurring in source rocks (e.g., Lewan et al, 1979;Lewan, 1985Lewan, , 1997Horsfield and Dueppenbecker, 1991;Horsfield et al, 1992;Larter and Horsfield, 1993;Vandenbroucke et al, 1993;Kruge et al, 1997;Schenk et al, 1997;Stasiuk, 1997;Lorant et al, 1998;Seewald et al, 1998;Putschew et al, 1998;Hill et al, 1996Hill et al, , 2003Seewald, 2001aSeewald, , 2001bTiem et al, 2008;Pan et al, 2009;Behar et al, 1992Behar et al, , 2008aBehar et al, , 2008bBehar et al, , 2010Lewan and Roy, 2011). However, temperatures and heating rates considerably higher than those encountered in nature have to be applied to the rock samples to compensate for long geological time periods.…”

Applications of Micro-Fourier Transform Infrared Spectroscopy (FTIR) in the Geological Sciences—A Review

“…Consequently, geochemical characterization of macerals has been the subject of numerous studies in recent years [ 18 , 19 , 26 , 32 , 33 , 34 , 35 , 37 , 38 , 40 , 56 ]. Purification and concentration by manual picking or physical separation is a crucial practice prior to collecting IR spectra when using conventional FTIR techniques on macerals [ 57 ]. Although useful information can be derived from the investigation of individual maceral concentrates, the physical separation process tends to cause specimen loss and introduce unexpected experimental errors [ 18 ].…”

Organic matter heterogeneities in 2.72Ga stromatolites: Alteration versus preservation by sulfur incorporation

“…Part of these primary heterogeneities might be preserved in the fossil record through selective preservation of resistant biostructures (Derenne et al, 1991b;Pacton et al, 2008). Alternatively certain heterogeneities in the chemistry of kerogens may result from concurrent secondary degradationrecondensation processes (Kruge et al, 1997). However, the initial diversity of microorganisms and associated organic matter pools remains largely unexplored in the fossil record since molecular biomarkers might be severely altered by metamorphism (Brocks et al, 2003) and because bulk kerogen isotopic compositions average potential micro-heterogeneities.…”