Occurrence and Distribution of Carbazoles and Benzocarbazoles in Tertiary Niger Delta Source Rocks

Abstract

The distributions of carbazoles and benzocarbazoles in source rocks from the Northern depobelt of the Tertiary Niger Delta, Nigeria, have been investigated by gas chromatography-mass spectrometry (GC-MS). Biomarker compositions of the source rocks indicate that the source rocks were formed from organic matter of mixed origin (terrestrial and marine) and are either immature or at early maturity stage. The carbazoles distributions in the source rocks are dominated by C 0 -C 2 -carbazoles and strong variation was observed in their distributions with increasing maturity. Among the C 1 -carbazoles, 1-methylcarbazole shows a decrease trend at the immature stage and an increase trend at higher maturity levels. 2-and 3-methylcarbazoles display an increasing trend with increasing maturity while 4-methylcarbazole exhibits a decreasing pattern with increasing maturity. Within the C 2 -carbazoles isomers, 1,8-and 2,7-dimethylcarbazoles, show an increasing trend with increasing maturity while the partially exposed isomers 1,3-and 1,6-dimethylcarbazoles decrease with increasing maturity. The ratio of benzo [a]carbazole/benzo[a]carbazole +benzo[c]carbazole varies significantly from 0.36 to 0.55 in the entire maturity range, indicating a strong maturity dependence. These results show that maturity will have great effect on the use of carbazoles and benzocarbazoles distributions as oil migration parameter in the Niger Delta.

Production of Polyhalogenated Carbazoles in Marine Red Alga Corallina officinalis: A Possible Natural Source

“…However, studies have shown that natural origins are responsible for the widespread occurrence of carbazole in marine organisms (e.g., sponge Damiria sp. , streptomyces, and actinomycete), , source rocks (e.g., carbonate rocks and clastic rocks, , and crude oil). , For instance, carbazole in source rocks and crude oil can be formed naturally by the reaction of biphenyls with surface-adsorbed N -containing substances during sedimentary processes . Regardless of the exact source of carbazole in red algae, carbazole serves as an important precursor for the biosynthesis of PHCZs via BPO-catalyzed halogenation.…”

“…To date, it is unclear whether carbazole could be biosynthesized in red algae. However, studies have shown that natural origins are responsible for the widespread occurrence of carbazole in marine organisms (e.g., sponge Damiria sp., streptomyces, and actinomycete), 43,44 source rocks (e.g., carbonate rocks and clastic rocks, 45,46 and crude oil). 47,48 For instance, carbazole in source rocks and crude oil can be formed naturally by the reaction of biphenyls with surface-adsorbed Ncontaining substances during sedimentary processes.…”

A Simple Geotracer Compositional Correlation Analysis Reveals Oil Charge and Migration Pathways

“…Direct correlations of geotracer concentrations to oil migration distance are dependent on numerous factors, including source rock type and maturity 2 12 15 16 17 18 19 20 21 22 23 , migration channel dimension, adsorption capacity of rock matrix and volume of oil in place 11 . In reality, not all these factors can be readily established for a given study area.…”

“…The concentration of carbazoles in oils represents the difference between the initial concentration expelled from the source rock and the amount removed during oil migration and accumulation 11 . Initial concentrations of carbazoles depend on both source rock type and maturity 2 12 15 16 17 18 19 20 21 22 23 . Loss of carbazoles during migration and accumulation processes is complicated and depends on a variety of factors including migration channel size, host rock porosity, specific surface area and adsorption capacity, volume of reservoired oil and relative migration distance 11 .…”

Síntese De 11a-N-Arilsulfonil-Tetrahidro-5h-Benzo[a]carbazóis Com Ação Antitumoral

“…Os benzocarbazóis pertencem à classe de alcaloides indólicos sendo identificados em derivados de petróleo, rochas e carvão (OLIVEIRA et al, 2006;CAO et al, 2010;FABOYA et al, 2014 JOHANSSON SEECHURN et al, 2012 ;YANG et al, 2013).…”