Open AccessBiomarker characteristics of the adsorbed/occluded components of asphaltenes recovered from thermal degradation of kerogen
Author(s) -
Y Liu,
Bin Cheng,
Zewen Liao,
Oluwabamise Lekan Faboya
Publication year - 2019
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/360/1/012004
Subject(s) - kerogen , asphaltene , oil shale , adsorption , dichloromethane , pyrolysis , chemistry , hopanoids , source rock , reagent , mineralogy , chemical engineering , geology , chromatography , organic chemistry , solvent , structural basin , engineering , paleontology
The adsorbed/occluded components of asphaltene originate from the parent kerogen. Information on the characteristics of these components is critical to the field of oil and gas geochemistry especially in the oil and source rock correlation studies. In this work, kerogen isolated from a low-matured mudstone from Lucaogou Formation, Santanghu Basin was pyrolyzed at elevated temperature for 72 hours in a semi-open system, followed by extraction with dichloromethane and precipitation of the extract to achieve the asphaltene isolation. The asphaltene was extracted by organic solvents to recover the adsorbed components while its solid residue was oxidized to release the occluded compounds. The ratios of £C 22 7XC 23 + n- alkanes and tri/pentaterpane in the adsorbed/occluded components of the asphaltene and kerogen are similar. The distribution of C 27 , C 28 and C 29 regular steranes displayed a progressively increasing pattern from C 27 to C 29 in adsorbed/occluded fractions of both the asphaltene and its kerogen precursor. This observation is also found in the terpanes distribution of the occluded components in the asphlatene and kerogen. These results showed that the biomarkers distribution in the adsorbed/occluded components of the asphaltene to some extent exhibited some level of similarity with its parent kerogen. This also showed that the occluded components in the asphaltene macromolecule are relatively intact and stable to the thermal evolutionary conversion from its kerogen precursor.