ABSTRACT: Thermal Maturity of Petroleum Source Rocks in the Cretaceous - Tertiary Rift Basins of Nigeria from Vitrinite Reflectance, Fluorescence and Rock-Eval Pyrolysis Studies

A relationship has been identified between the maturity level of source rocks and the stable hydrogen isotopic compositions (δD) of extracted saturated hydrocarbons, based on the analysis of nine sediments and five crude oils from the Perth Basin (WA). The sediments cover the immature to late mature range. Distinct δD signatures are observed for the immature sediments where pristane and phytane are significantly depleted in deuterium (D) relative to the n-alkanes. With increasing maturity the difference between the δD values of n-alkanes and isoprenoids reduces as pristane and phytane become progressively enriched in D. The n-alkane–isoprenoid δD signature of the crude oils, including one from a different source facies, is similar to mature–late mature sediments representative of the peak oil–generative window. Enrichment of D in isoprenoids is attributed to isotopic exchange associated with thermal maturation. Average δD values of pristane and phytane correlate well with vitrinite reflectance, as does the biomarker maturity parameter Ts/Tm. The limited data set suggests that δD values of aliphatic hydrocarbons may be useful for establishing thermal maturity, particularly when other maturity parameters are not appropriate. Furthermore, we suggest δD values may be useful over a wider maturity range than traditional parameters, particularly at very high maturity where biomarker parameters are no longer effective.

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GEOLOGY, SOURCE ROCKS AND HYDROCARBON GENERATION IN THE CLARENCE-MORETON BASIN

The APPEA Journal ◽

10.1071/aj81001 ◽

1982 ◽

Vol 22 (1) ◽

pp. 5

Author(s):

A. R. Martin ◽

J. D. Saxby

Keyword(s):

Vitrinite Reflectance ◽

Source Rocks ◽

Geochemical Data ◽

Hydrocarbon Potential ◽

Hydrocarbon Generation ◽

Tectonic Events ◽

History Of ◽

Rock Eval ◽

Coal Measures ◽

Migration Pathways

The geology and exploration history of the Triassic-Cretaceous Clarence-Moreton Basin are reviewed. Consideration of new geochemical data ('Rock-Eval', vitrinite reflectance, gas chromatography of extracts, organic carbon and elemental analysis of coals and kerogens) gives further insights into the hydrocarbon potential of the basin. Although organic-rich rocks are relatively abundant, most source rocks that have achieved the levels of maturation necessary for hydrocarbon generation are gas-prone. The exinite-rich oil-prone Walloon Coal Measures are in most parts relatively immature. Some restraints on migration pathways are evident and igneous and tectonic events may have disturbed potentially well-sealed traps. Further exploration is warranted, even though the basin appears gas-prone and the overall prospects for hydrocarbons are only fair. The most promising areas seem to be west of Toowoomba for oil and the Clarence Syncline for gas.

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Organic geochemical and palynological studies of the Maastrichtian source rock intervals in Bida Basin, Nigeria: implications for hydrocarbon prospectivity

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-020-00989-z ◽

2020 ◽

Vol 10 (8) ◽

pp. 3191-3206

Author(s):

Olusola J. Ojo ◽

Ayoola Y. Jimoh ◽

Juliet C. Umelo ◽

Samuel O. Akande

Keyword(s):

Organic Matter ◽

Source Rock ◽

Vitrinite Reflectance ◽

Source Rocks ◽

High Yield ◽

Thermal Maturity ◽

Hydrocarbon Source Rock ◽

Moderate Amount ◽

Oxic Condition ◽

Freshwater Swamp

Abstract The Patti Formation which consists of sandstone and shale offers the best potential source beds in the Bida Basin. This inland basin is one of the basins currently being tested for hydrocarbon prospectivity in Nigeria. Fresh samples of shale from Agbaja borehole, Ahoko quarry and Geheku road cut were analysed using organic geochemical and palynological techniques to unravel their age, paleoecology, palynofacies and source bed hydrocarbon potential. Palynological data suggest Maastrichtian age for the sediments based on the abundance of microfloral assemblage; Retidiporites magdalenensis, Echitriporites trianguliformis and Buttinia andreevi. Dinocysts belonging to the Spiniferites, Deflandrea and Dinogymnium genera from some of the analysed intervals are indicative of freshwater swamp and normal sea conditions. Palynological evidence further suggests mangrove paleovegetation and humid climate. Relatively high total organic carbon TOC (0.77–8.95 wt%) was obtained for the shales which implies substantial concentration of organic matter in the source beds. Hydrocarbon source rock potential ranges from 0.19 to 0.70 mgHC/g.rock except for a certain source rock interval in the Agbaja borehole with high yield of 25.18 mgHC/g.rock. This interval also presents exceptionally high HI of 274 mgHC/g.TOC and moderate amount of amorphous organic matter. The data suggests that in spite of the favourable organic matter quantity, the thermal maturity is low as indicated by vitrinite reflectance and Tmax (0.46 to 0.48 Ro% and 413 to 475 °C, respectively). The hydrocarbon extracts show abundance of odd number alkanes C27–C33, low sterane/hopane ratio and Pr/Ph > 2. We conclude that the source rocks were terrestrially derived under oxic condition and dominated by type III kerogen. Type II organic matter with oil and gas potential is a possibility in Agbaja area of Bida Basin. Thermal maturity is low and little, or no hydrocarbon has been generated from the source rocks.

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Assessing thermal maturity beyond the reaches of vitrinite reflectance and Rock-Eval pyrolysis: A case study from the Silurian Qusaiba formation

International Journal of Coal Geology ◽

10.1016/j.coal.2017.07.006 ◽

2017 ◽

Vol 180 ◽

pp. 29-45 ◽

Cited By ~ 31

Author(s):

Stephen Cheshire ◽

Paul R. Craddock ◽

Guangping Xu ◽

Bastian Sauerer ◽

Andrew E. Pomerantz ◽

...

Keyword(s):

Vitrinite Reflectance ◽

Thermal Maturity ◽

Rock Eval

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Evaluating Molecular Evolution of Kerogen by Raman Spectroscopy: Correlation with Optical Microscopy and Rock-Eval Pyrolysis

Energies ◽

10.3390/en11061406 ◽

2018 ◽

Vol 11 (6) ◽

pp. 1406 ◽

Cited By ~ 12

Author(s):

Seyedalireza Khatibi ◽

Mehdi Ostadhassan ◽

David Tuschel ◽

Thomas Gentzis ◽

Humberto Carvajal-Ortiz

Keyword(s):

Raman Spectroscopy ◽

Organic Matter ◽

Structural Information ◽

Vitrinite Reflectance ◽

Nondestructive Method ◽

Thermal Maturity ◽

Shale Formations ◽

Reflectance Analysis ◽

Rock Eval ◽

Maturity Parameters

Vitrinite maturity and programmed pyrolysis are conventional methods to evaluate organic matter (OM) regarding its thermal maturity. Moreover, vitrinite reflectance analysis can be difficult if prepared samples have no primary vitrinite or dispersed widely. Raman spectroscopy is a nondestructive method that has been used in the last decade for maturity evaluation of organic matter by detecting structural transformations, however, it might suffer from fluorescence background in low mature samples. In this study, four samples of different maturities from both shale formations of Bakken (the upper and lower members) Formation were collected and analyzed with Rock-Eval (RE) and Raman spectroscopy. In the next step, portions of the same samples were then used for the isolation of kerogen and analyzed by Raman spectroscopy. Results showed that Raman spectroscopy, by detecting structural information of OM, could reflect thermal maturity parameters that were derived from programmed pyrolysis. Moreover, isolating kerogen will reduce the background noise (fluorescence) in the samples dramatically and yield a better spectrum. The study showed that thermal properties of OM could be precisely reflected in Raman signals.

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Petroleum Geochemistry Regional Study of Murzuq Basin: Insights from Biomarkers Characteristic, Stable Carbon Isotope and Environmental Characterization

Petroleum & Petrochemical Engineering Journal ◽

10.23880/ppej-16000215 ◽

2020 ◽

Vol 4 (1) ◽

pp. 1-14

Author(s):

Aboglila S

Keyword(s):

Carbon Isotope ◽

Vitrinite Reflectance ◽

Stable Carbon Isotope ◽

Source Rocks ◽

Crude Oils ◽

Type I ◽

Stable Carbon ◽

Potential Source ◽

Geochemical Parameters ◽

Rock Eval

This search aims to apply developed geochemical methods to a number of oils and source rock extracts to better establish the features of ancient environments that occurred in the Murzuq basin. Geochemical and geophysical approaches were used to confirm further a source contribution from other Paleozoic formations to hydrocarbon accumulations in the basin. One hundred and forty rock units were collected from B1-NC151, D1-NC174, A1-NC 76, D1-NC 151, F1-NC58, A1-NC 186, P1-NC 101, D1-NC 58, H1-NC58 and A1-NC58 wells. Seven crude oils were collocated A1-NC186, B1-NC186, E2-NC101, F3-NC174, A10-NC115, B10-NC115 and H10-NC115 wells. A geochemical assessment of the studied rocks and oils was done by means of geochemical parameters of total organic carbon (TOC), Rock-Eval analysis, detailed-various biomarkers and stable carbon isotope. The TOC values from B1-NC151 range 0.40% to 8.5%, A1-NC186 0.3% and 1.45, A1-NC76 0.39% to 0.74%, D1-NC151 0.40% to 2.00% to F1-NC58 0.40% to 1.12%. D1_NC174 0.30% to 10 %, P1-NC101 0.80% to 1.35%, D1-NC58 0.5% to 1.10%, H1-NC58 0.20% to 3.50%, A1-NC58 0.40% to 1.60%. The categories of organic matter from rock-eval pyrolysis statistics point to that type II kerogen is the main type, in association with type III, and no of type I kerogen recognized. Vitrinite reflectance (%Ro), Tmax and Spore colour index (SCI) as thermal maturity parameters reflect that the measured rock units are have different maturation levels, ranging from immature to mature sources. acritarchs distribution for most samples could be recognized and Palynomorphs are uncommon. Pristane to phytane ratios (> 1) revealed marine shale to lacustrine of environmental deposition. The Stable carbon isotope ( δ 13 C) values of seven rock-extract samples are -30.98‰ and -29.14‰ of saturates and -29.86‰ to -28.37‰ aromatic fractions. The oil saturate hydrocarbon fractions range between -29.36‰ to -28.67‰ and aromatic are among -29.98 ‰ to -29.55 ‰. The δ 13 C data in both rock extractions and crude oils are closer to each other, typical in sign of Paleozoic age. It is clear that the base of Tanezzuft Formation (Hot shale) is considered the main source rocks. The Devonian Awaynat Wanin Formation as well locally holds sufficient oil prone kerogen to consider as potential source rocks. Ordovician Mamuniyat Formation shales may poorly contain oil prone kerogen to be addressed in future studies. An assessment of the correlations between the oils and potential source rocks and between the oils themselves indicated that most of the rocks extracts were broadly similar to most of the oils and supported by carbon stable isotope analysis results.

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Backtracking to Parent Maceral from Produced Bitumen with Raman Spectroscopy

Minerals ◽

10.3390/min10080679 ◽

2020 ◽

Vol 10 (8) ◽

pp. 679

Author(s):

Seyedalireza Khatibi ◽

Arash Abarghani ◽

Kouqi Liu ◽

Alexandra Guedes ◽

Bruno Valentim ◽

...

Keyword(s):

Raman Spectroscopy ◽

Organic Matter ◽

Vitrinite Reflectance ◽

Thermal Maturity ◽

Maturity Level ◽

Production Potential ◽

Hydrocarbon Production ◽

Solid Bitumen ◽

Rock Eval ◽

Oil Gas

In order to assess a source rock for economical exploitation purposes, many parameters should be considered; regarding the geochemical aspects, the most important ones are the amount of organic matter (OM) and its quality. Quality refers to the thermal maturity level and the type of OM from which it was formed. The origin of the OM affects the ability of the deposited OM between sediments to generate oil, gas, or both with particular potential after going through thermal maturation. Vitrinite reflectance and programmed pyrolysis (for instance, Rock-Eval) are common methods for evaluating the thermal maturity of the OM and its potential to generate petroleum, but they do not provide us with answers to what extent solid bitumen is oil-prone or gas-prone, as they are bulk geochemical methods. In the present study, Raman spectroscopy (RS), as a powerful tool for studying carbonaceous materials and organic matter, was conducted on shale and coal samples and their individual macerals to show the potential of this technique in kerogen typing and to reveal the parent maceral of the examined bitumen. The proposed methodology, by exhibiting the chemical structure of different organic matters as a major secondary product in unconventional reservoirs, can also detect the behavior of solid bitumen and its hydrocarbon production potential for more accurate petroleum system evaluation.

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Burial history, thermal history and hydrocarbon generation modelling of the Jurassic source rocks in the basement of the Polish Carpathian Foredeep and Outer Carpathians (SE Poland)

Geologica Carpathica ◽

10.2478/v10096-012-0026-2 ◽

2012 ◽

Vol 63 (4) ◽

pp. 335-342 ◽

Cited By ~ 3

Author(s):

Paweł Kosakowski ◽

Magdalena Wróbel

Keyword(s):

Organic Matter ◽

Thermal History ◽

Vitrinite Reflectance ◽

Source Rocks ◽

Hydrocarbon Generation ◽

Thermal Maturity ◽

Burial History ◽

Se Poland ◽

Carpathian Foredeep ◽

Outer Carpathians

Burial history, thermal history and hydrocarbon generation modelling of the Jurassic source rocks in the basement of the Polish Carpathian Foredeep and Outer Carpathians (SE Poland)Burial history, thermal maturity, and timing of hydrocarbon generation were modelled for the Jurassic source rocks in the basement of the Carpathian Foredeep and marginal part of the Outer Carpathians. The area of investigation was bounded to the west by Kraków, to the east by Rzeszów. The modelling was carried out in profiles of wells: Będzienica 2, Dębica 10K, Góra Ropczycka 1K, Goleszów 5, Nawsie 1, Pławowice E1 and Pilzno 40. The organic matter, containing gas-prone Type III kerogen with an admixture of Type II kerogen, is immature or at most, early mature to 0.7 % in the vitrinite reflectance scale. The highest thermal maturity is recorded in the south-eastern part of the study area, where the Jurassic strata are buried deeper. The thermal modelling showed that the obtained organic matter maturity in the initial phase of the "oil window" is connected with the stage of the Carpathian overthrusting. The numerical modelling indicated that the onset of hydrocarbon generation from the Middle Jurassic source rocks was also connected with the Carpathian thrust belt. The peak of hydrocarbon generation took place in the orogenic stage of the overthrusting. The amount of generated hydrocarbons is generally small, which is a consequence of the low maturity and low transformation degree of kerogen. The generated hydrocarbons were not expelled from their source rock. An analysis of maturity distribution and transformation degree of the Jurassic organic matter shows that the best conditions for hydrocarbon generation occurred most probably in areas deeply buried under the Outer Carpathians. It is most probable that the "generation kitchen" should be searched for there.

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Geochemistry and petrology of selected sediments from Bukit Song, Miri, Sarawak, Malaysia, with emphasis on organic matter characterization

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01275-2 ◽

2021 ◽

Vol 11 (10) ◽

pp. 3663-3688

Author(s):

Amin Tavakoli

Keyword(s):

Organic Matter ◽

Depositional Environment ◽

Vitrinite Reflectance ◽

Xrd Analysis ◽

Source Rocks ◽

Hydrocarbon Generation ◽

Thermal Maturity ◽

Petroleum Potential ◽

Type Iv ◽

Two Samples

AbstractThe aim of this study is to provide a better understanding of the type of source input, quality, quantity, the condition of depositional environment and thermal maturity of the organic matter from Bukit Song, Sarawak, which has not been extensively studied for hydrocarbon generation potential. Petrological and geochemical analyses were performed on 13 outcrop samples of the study location. Two samples, having type III and mixed kerogen, showed very-good-to-excellent petroleum potential based on bitumen extraction and data from Rock–Eval analysis. The rest of the samples are inert—kerogen type IV. In terms of thermal maturity based on vitrinite reflectance, the results of this paper are akin to previous studies done in the nearby region reported as either immature or early mature. Ph/n-C18 versus Pr/n-C17 data showed that the major concentration of samples is within peat coal environment, whilst two samples were associated with anoxic marine depositional environment, confirmed by maceral content as well. Macerals mainly indicated terrestrial precursors and, overall, a dominance of vitrinite. Quality of the source rock based on TOC parameter indicated above 2 wt. % content for the majority of samples. However, consideration of TOC and S2 together showed only two samples to have better source rocks. Existence of cutinite, sporinite and greenish fluorescing resinite macerals corroborated with the immaturity of the analysed coaly samples. Varying degrees of the bitumen staining existed in a few samples. Kaolinite and illite were the major clays based on XRD analysis, which potentially indicate low porosity. This study revealed that hydrocarbon-generating potential of Bukit Song in Sarawak is low.

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