The Distribution of Triaromatic Steroids and Oil Group Classification of Ordovician Petroleum Systems in the Cratonic Region of the Tarim Basin, NW China

Yang, Fengli; Wang, T.; Li, M.

doi:10.1080/10916466.2015.1092984

Cited by 15 publications

(5 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Allowing for the biodegradation of higher than PM 6, the diasterane and TAS-related maturity parameters (C 27 -DS 20S/(20S + 20R), C 28 -TAS 20S/(20R + 20S)) can effectively define the petroleum thermal maturity here for their high bioresistance (Mackenzie et al., 1980, 1981; Peters et al., 2005; Yang et al., 2015). As for the eastern Chepaizi Carboniferous oils, the C 27 -DS 20S/(20S + 20R) value was 0.50–0.58, close to that of the western oil (0.51).…”

Section: Discussionmentioning

confidence: 99%

Geochemistry of severely biodegraded oils in the Carboniferous volcanic reservoir of the Chepaizi Uplift, Junggar Basin, NW China

Chang

Shi

et al. 2018

Energy Exploration & Exploitation

View full text Add to dashboard Cite

A substantial amount of petroleum was recently discovered in the Carboniferous volcanic reservoir of the Chepaizi Uplift in the western Junggar Basin, yet the source is still indefinitive. Geochemical investigation indicates that the Carboniferous oils from the eastern and western Chepaizi Uplift are characterized by different source facies, although they are all typically of lacustrine origin. The eastern oils exhibit a restricted, clastic starved, highly reducing hypersaline condition during source rock deposition, which is distinct from the western oils. The Carboniferous oils were subjected to biodegradation ranging from rank 6 to rank 9, as indicated by the presence of 25-norhopane, evident depletion of hopanes and regular steranes, and even selective reduction of tricyclic terpanes. The maturities for the Carboniferous oils correspond to the onset of oil generation. The eastern oils contain lower (C 19 þ C 20)TT/ (C 23 þ C 24)TT and C 19 TT/C 21 TT, and lighter stable carbon isotopes than the western ones, correlating well with the Middle Permian Wuerhe (P 2 w) source rocks and the Jurassic source rocks, respectively. The good correlation of tricyclic terpanes source-related parameters further implies less contribution to the eastern oils by the Carboniferous source rocks.

show abstract

Section: Discussionmentioning

confidence: 99%

Geochemistry of severely biodegraded oils in the Carboniferous volcanic reservoir of the Chepaizi Uplift, Junggar Basin, NW China

Chang

Shi

et al. 2018

Energy Exploration & Exploitation

View full text Add to dashboard Cite

show abstract

“…The prominent peaks present in the TIC and ion m/z 57 are interpreted to represent terpane and sterane biomarkers, which are relatively resistant to biodegradation. The near-absence of tricyclic terpanes (represented only by the C 23/3 ) on the m/z 191 chromatogram (Figure 5) cannot be attributed to biodegradation because these compounds are very resistant to biodegradation [38,39].…”

Section: Bulk Bitumen Composition: Clues To Its Originmentioning

confidence: 99%

Meteoric Water Incursion, Crude Oil Degradation and Calcite Cementation of an Upper Cretaceous Reservoir in the Zagros Foreland Basin (Kurdistan Region of Iraq)

Mansurbeg

Mohialdeen

Al-Juboury

et al. 2023

Water

View full text Add to dashboard Cite

Field observations, together with the results of gas chromatography–mass spectrometry (GC-MS) and stable carbon isotope analysis of bitumen, coupled with fluid inclusion microthermometry and stable isotope analyses of closely associated vug- and fracture-filling columnar calcite in the Upper Cretaceous Bekhme Formation, Kurdistan Region of Iraq, suggest that the degradation of crude oil was caused by the regional incursion of meteoric waters. This incursion, which is interpreted to have occurred during tectonic uplift during the Zagros Orogeny, is evidenced by: (i) the depletion of n-alkanes and acyclic isoprenoid alkanes (pristane and phytane) in the bitumen; (ii) low δ13CVPDB values (−8.5‰ to −3.9‰) and δ18OVPDB values (−22.9‰ to −15.0‰), with more radiogenic Sr isotopic ratios (0.70771–0.70772) compared to Cretaceous seawater; and (iii) low salinity and low temperatures (20 to 40 °C) in fluid inclusions of the columnar calcite. This study demonstrates that regional meteoric water incursion into sedimentary basins can be linked to crude oil degradation accompanied by calcite cementation events in carbonate reservoirs.

show abstract

“…Triaromatic steroids (TAS) are the most degradation-resistant aromatic components and are only removed to any significant extent in extremely biodegraded oils (PM 10). They are formed by the aromatization of their corresponding regular steranes (Peters et al, 2005;Yang et al, 2015;Zhang et al, 2016). TAS are believed to be effective molecular markers for oil-to-oil correlation of heavily to severely biodegraded petroleum (Li et al, 2012;Lin et al, 1989;Peters et al, 2005).…”

Section: Classification Of Oil Familymentioning

confidence: 99%

Geochemical characteristics and origins of biodegraded oils in the Bongor Basin (Chad) and their implications for petroleum exploration

Deng

Dou

Chen

et al. 2022

Energy Exploration & Exploitation

View full text Add to dashboard Cite

The Bongor Basin is a typical lacustrine passive-rifted basin situated in the West and Central African Rift System (WCARS). It has experienced two phases of tectonic inversion and features a complex process of petroleum generation and accumulation. A total of 41 crude oil samples from the basin were geochemically analyzed to investigate their compositions of molecular markers. The results show that the oils have similar origins and are likely to belong to the same oil population. However, there are significant differences in geochemical characteristics and physical properties, caused by the secondary alteration. The relative contents and distribution patterns of normal alkanes and acyclic isoprenoids indicate that some of the oils have suffered biodegradation to varying degrees. The samples can be divided into three categories according to their relative degrees of degradation: normal oil, slightly biodegraded oil (PM 1–3), and severely biodegraded oil (PM 5–7). The burial depth of oil reservoirs in this area is the predominant factor impacting on the level of biodegradation. Crude oils in reservoirs with burial depths of less than 800 m are all severely biodegraded, while oils in reservoirs with burial depths greater than 1300 m have experienced no evident biodegradation. In reservoirs with burial depths between 800 m and 1300 m, the biodegradation degrees vary from normal to severely biodegraded. Oil reservoirs with burial depths less than 1300 m and adjacent to major faults are readily subject to biodegradation, while reservoirs with similar burial depths, but a certain distance away from major faults, have suffered no evident biodegradation. Moreover, if primary reservoirs have been modified by tectonic activity after accumulation, the crude oils are more likely to be biodegraded. Faulted anticline traps may create more favorable geological conditions for preservation of crude oil than reverse extrusion anticline reservoirs. This study may provide practical guidance for the assessment and prediction of oil quality in future oil exploration.

show abstract

The Distribution of Triaromatic Steroids and Oil Group Classification of Ordovician Petroleum Systems in the Cratonic Region of the Tarim Basin, NW China

Cited by 15 publications

References 12 publications

Geochemistry of severely biodegraded oils in the Carboniferous volcanic reservoir of the Chepaizi Uplift, Junggar Basin, NW China

Geochemistry of severely biodegraded oils in the Carboniferous volcanic reservoir of the Chepaizi Uplift, Junggar Basin, NW China

Meteoric Water Incursion, Crude Oil Degradation and Calcite Cementation of an Upper Cretaceous Reservoir in the Zagros Foreland Basin (Kurdistan Region of Iraq)

Geochemical characteristics and origins of biodegraded oils in the Bongor Basin (Chad) and their implications for petroleum exploration

Contact Info

Product

Resources

About