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

Energies ◽  
2018 ◽  
Vol 11 (6) ◽  
pp. 1406 ◽  
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.

scholarly journals Backtracking to Parent Maceral from Produced Bitumen with Raman Spectroscopy

Minerals ◽  
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.

scholarly journals Assessing Thermal Maturity through a Multi-Proxy Approach: A Case Study from the Permian Faraghan Formation (Zagros Basin, Southwest Iran)

Geosciences ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 484
Author(s):  
Amalia Spina ◽  
Simonetta Cirilli ◽  
Andrea Sorci ◽  
Andrea Schito ◽  
Geoff Clayton ◽  
...  
Keyword(s):  
Organic Matter ◽  
Vitrinite Reflectance ◽  
Optical Methods ◽  
Thermal Maturity ◽  
Zagros Basin ◽  
Thermal Alteration ◽  
Uv Fluorescence ◽  
Rock Eval ◽  
Southwest Iran ◽  
Microraman Spectroscopy

This study focuses on the thermal maturity of Permian deposits from the Zagros Basin, Southwest Iran, employing both optical methods (Thermal Alteration Index, Palynomorph Darkness Index, Vitrinite Reflectance, UV Fluorescence) and geochemical analyses of organic matter (Rock Eval Pyrolysis and MicroRaman spectroscopy) applied to the Faraghan Formation along two investigated Darreh Yas and Kuh e Faraghan surface sections. Furthermore, an integrated palynofacies and lithofacies analysis was carried out in order to integrate the few studies on the depositional environment. The Faraghan Formation, which is widely distributed in the Zagros area, generally consists of shale intercalated with sandstones and pebble conglomerates in the lower part, followed by a succession of sandstone, siltstone and shaly intercalations and with carbonate levels at the top. The integrated palynofacies and lithofacies data confirm a coastal depositional setting evolving upwards to a shallow marine carbonate environment upwards. Rock Eval Pyrolysis and Vitrinite Reflectance analysis showed that the organic matter from samples of the Darreh Yas and Kuh e Faraghan sections fall in the mature to postmature range with respect to the oil to gas generation window, restricting the thermal maturity range proposed by previous authors. Similar results were obtained with MicroRaman spectroscopy and optical analysis such as Thermal Alteration Index and UV Fluorescence. Palynomorph Darkness Index values were compared with Rock Eval Pyrolysis and vitrinite reflectance values and discussed for the first time in the late stage of oil generation.

scholarly journals Análisis geoquímico y petrográfico de las formaciones Los Cuervos y Molino, Subcuenca Cesar (Colombia): implicaciones en la evolución del sistema petrolero

2021 ◽  
Vol 43 (2) ◽  
Author(s):  
Gladys Marcela Avendaño-Sánchez ◽  
Mario García-González ◽  
Luis Enrique Cruz-Guevara ◽  
Luis Felipe Cruz-Ceballos
Keyword(s):  
Organic Matter ◽  
Vitrinite Reflectance ◽  
Geochemical Modelling ◽  
Maturation Stage ◽  
Petrographic Analysis ◽  
Hydrocarbon Generation ◽  
Thermal Maturation ◽  
Reflectance Analysis ◽  
Rock Eval

A geochemical characterization of Los Cuervos and Molino formations in the Cesar Sub-Basin was carried out using core samples obtained from the ANH-La Loma-1 Well. A total of 113 Rock-Eval pyrolysis analysis, total organic carbon (TOC), total sulphur content (TS) analysis, 13 vitrinite reflectance analysis (%Ro) and 30 thin-section petrographic analysis were performed. Based on these new data, it was possible to classify the quality of organic matter and the current thermal maturation of Los Cuervos and Molino formations. Additionally, a petrographic characterization of 30 samples allowed the correlation of the lithology with the geochemical results. Also, one-dimensional geochemical modelling was implemented in order to contribute to the knowledge of the evolution of the oil system in the Cesar Sub-Basin. The spatial distribution of the formations used in the modelling was obtained from 2 seismic lines two-way time. The results obtained indicate that Los Cuervos Formation presents TOC values from 0.29 to 66.55%, TS values from 0.02 to 11.29%, their organic matter consisted of type III kerogen which is consistent with an immature thermal maturation stage. In contrast, the Molino Formation presents TOC values from 0.23 to 2.28%, TS values from 0.001 to 1.39%, their organic matter consisted of type II/III kerogen this suggests an early entry to the oil window with a maximum pyrolysis temperature (Tmax) value of 442°C. The geochemical modelling tunes better with measured data from palaeo-geothermometers (%Ro and Tmax). The geochemical modelling shows that, between 60 - 40 million years ago (mya), the Cretaceous formations entered in the oil generation window and it is expected that, between 40 - 30 mya, the Lagunitas, Aguas Blancas, and La Luna formations will be at their peak of hydrocarbon generation.

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

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.

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

2017 ◽  
Vol 180 ◽  
pp. 29-45 ◽  
Author(s):  
Stephen Cheshire ◽  
Paul R. Craddock ◽  
Guangping Xu ◽  
Bastian Sauerer ◽  
Andrew E. Pomerantz ◽  
...  
Keyword(s):  
Vitrinite Reflectance ◽  
Thermal Maturity ◽  
Rock Eval

Applying Raman Spectroscopy to Modern and Palaeocharcoals Associated with Wildfire Activity

2020 ◽  
Author(s):  
Thomas Theurer ◽  
David Muirhead ◽  
David Jolley
Keyword(s):  
Raman Spectroscopy ◽  
Vitrinite Reflectance ◽  
Climatic Conditions ◽  
Thermal Maturity ◽  
Deep Time ◽  
New Approach ◽  
Composition And Structure ◽  
Determining Factors ◽  
Increasing Temperature ◽  
The Impact

<p>Evidence of wildfire activity in deep time is preserved in the rock record as fossilised charcoal. Modern wildfire temperature is often a function of fuel type, structure and availability. These three factors are reliant upon climatic conditions and offer a potential insight into palaeoenvironmental conditions through geothermometric analysis of preserved charcoals. Much like the analysis of vitrinite reflectance as an assessor of thermal maturity, similar methodology has been applied historically to charcoal in order to obtain palaeowildfire temperatures.  Raman spectroscopy has similarly been applied to organic material as an identifier of thermal maturity, via the analysis of carbon microstructure changes with increasing temperature – however very little palaeocharcoal has been analysed via Raman spectroscopy, with no apparent application to palaeowildfire geothermometry. Through the application of Raman spectroscopy, we present the first comparison of modern pyrolyzed plant material with spectra of early Danian palaeocharcoals, associated with wildfire activity. These results indicate that Raman spectroscopy of modern wildfire charcoal facilitates a correlation between charcoal microstructure change and temperature of formation. This in turn has enabled comparison with palaeocharcoal, and the generation of reliable wildfire geothermometry. With this new methodology, we intend to further the understanding of (1) changes in palaeowildfire regimes and intensity through time (2) the interaction between climate, plant community composition and structure, and palaeowildfires  (3) correlation and comparison with existing palaeowildfire interpretive approaches. Further analysis and experimentation is required to identify the impact of fire determining factors on observed spectra to target the new approach towards interpreting current and future wildfire behaviour under climatic stress. </p>

scholarly journals 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)

2012 ◽  
Vol 63 (4) ◽  
pp. 335-342 ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document