scholarly journals Organic Petrology and Thermal Maturity of Dispersed Organic Matter from the Ramalhal-1 Well (Lusitanian Basin, Portugal)

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1415
Author(s):  
Paula Alexandra Gonçalves ◽  
João Graciano Mendonça Filho ◽  
Deolinda Flores
Keyword(s):  
Organic Matter ◽  
Upper Jurassic ◽  
Inorganic Materials ◽  
Mature Stage ◽  
Thermal Maturity ◽  
Solid Bitumen ◽  
Organic Petrology ◽  
Almost All ◽  
Lusitanian Basin

Organic petrology is an important tool used to characterize dispersed organic matter (DOM) in sediments and sedimentary rocks, and to assess its thermal maturity. This study was carried out on 33 cutting samples (Middle-Upper Jurassic) from the Ramalhal-1 well to characterize the particulate organic matter and to evaluate its thermal maturity. The samples were submitted to optical petrography analysis (reflected white and blue incident lights) and the mean random reflectance was measured. Microscopic observations revealed a low DOM content, characterized by the predominance of macerals of the inertinite group (including charcoal), followed by solid bitumen. Huminite/vitrinite is usually small in size and quantity. Liptinite macerals were also present, represented by sporinite, cutinite, liptodetrinite and rare bituminite. A type III-IV kerogen was defined for the Ramalhal-1 sequence. Huminite/vitrinite mean random reflectance varied between 0.38% and 0.75%, pointing to an immature-to-mature stage of the organic matter. Multi-populations of solid bitumen occurred in almost all the samples, filling voids and fractures in the inorganic materials (mainly carbonates). The bitumen populations were quite heterogeneous, concerning both the optical characteristics and distribution, displaying different thermal maturities. No relationship between vitrinite and bitumen reflectance was established, indicating that these bitumens were not generated in situ.

Geologic Characteristics of Reservoir Accumulation in Suganhu Depression in North Margin of Qaidam Basin

2012 ◽  
Vol 616-618 ◽  
pp. 19-25 ◽  
Author(s):  
Cheng Zhang ◽  
Guang Yang ◽  
Yong Shu Zhang
Keyword(s):  
Organic Matter ◽  
Middle Jurassic ◽  
Qaidam Basin ◽  
Upper Jurassic ◽  
Mature Stage ◽  
Braided River ◽  
Large Area ◽  
Reservoir Properties ◽  
Cap Rock ◽  
Low Porosity

Based on the analysis and testing data of rocks, the basic geologic characteristics of Suganhu depression is discussed. It is concluded that the 200m thickness dark mudstone of inshore shallow lake face in the middle–lower Jurassic stratum is the only source rock of this region. It has the characteristics of high abundance of organic matter and in high mature stage. And the type of organic matter is Ⅱ2.The reservoir properties is controlled by the influences of both the sedimentation and the diagenesis and belong to the low porosity and low permeability ones. The mudstone of Upper Jurassic is the local cap, the ones of braided river face and braided river delta face which existed in the up-middle of the middle Jurassic can be qualified as sealing bed between the sand bodies. Paleocene–eocene mudstone is the regional cap rock. The ability of upper Jurassic sealing bed is good because of the low porosity and permeability and high break pressure. The regional cap rock has the characteristics of big thickness and large area. Both the local and regional cap rock had been able to seal the petroleum and gas before the time of hydrocarbon accumulation of middle Jurassic. In general, Mesozoic formed reservoir–cap combination with the features of lower–generation and upper–reservoir, upper–cap.

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 Source Rock Evaluation and Lateral Changes in Thermal Maturity of the Sargelu Formation (Middle Jurassic) in Kurdistan Region-Northern Iraq

2018 ◽  
Vol 2 (1) ◽  
pp. 7-17
Author(s):  
Ayad Faqi ◽  
Ali Ali ◽  
Bahjat Abdullah ◽  
Stephen Bowden
Keyword(s):  
Organic Matter ◽  
Source Rock ◽  
Middle Jurassic ◽  
Poor Quality ◽  
Gas Chromatography Mass Spectrometry ◽  
Mature Stage ◽  
Thermal Maturity ◽  
Northern Iraq ◽  
Reducing Conditions ◽  
Rock Eval

In this study, source rock characteristics and lateral changes in thermal maturity of the Sargelu Formation (Middle Jurassic) in three outcrops were studied. The formation’s outcrops can be found in the High Folded, and Imbricated Zones of Iraqi Tectonic Division. In order to achieve the main goals of this study, the Gas chromatography mass spectrometry (GC-MS) and Rock-Eval pyrolysis were performed on the organic matter (OM) of the Sargelu sediments. Pristane/Phytane ratios for analyzed samples indicate reducing conditions (anoxic) during sedimentation. Moreover, based on  C29/C30 hopanes ratios the sediments of the Sargelu Formation associated with clay- rich source rock. Biomarker thermal maturity parameters display that all samples are thermally in Oil Window at least. The biomarker findings reveal that the samples of Walasimt and Barsarin are seem more mature than Banik section. The values for TOC% of the Sargelu Formation may show Excellent, Very Good, and Poor quality source rock. The Pyrolysis executed for studied samples revealed the kerogen in Banik section belongs to Types II and III (Probably Oil/Gas- prone), while Barsarin and Walasimt sections obtained Types III-IV Kerogen (Gas- prone). Pyrolysis parameters suggested Early Mature Stage in Banik, While Overmature in Barsarin and Walasimt. The data also shows that organic matter of the Sargelu Formation in Banik section is in Oil Widow, while in Barsarin and Walasimt is in Gas Window.

scholarly journals Organic petrology of peak oil maturity Triassic Yanchang Formation lacustrine mudrocks, Ordos Basin, China

2017 ◽  
Vol 5 (2) ◽  
pp. SF211-SF223 ◽  
Author(s):  
Paul C. Hackley ◽  
Lixia Zhang ◽  
Tongwei Zhang
Keyword(s):  
Organic Matter ◽  
Ordos Basin ◽  
Central China ◽  
Type I ◽  
Peak Oil ◽  
Green River ◽  
Yanchang Formation ◽  
Solid Bitumen ◽  
Organic Petrology ◽  
Original Organic Matter

An organic petrology evaluation and a determination of solid bitumen reflectance [Formula: see text] were completed for organic-rich Triassic Yanchang Formation mudrocks ([Formula: see text]) from the Ordos Basin, north-central China, as part of a larger investigation of “shale gas” resources. These data were integrated with information from Rock-Eval programmed pyrolysis to show that the samples are in the peak oil window of thermal maturity and that organic matter is dominated by solid bitumen with minor amounts of type III kerogen (vitrinite and inertinite) from vascular land plants. Describing a “kerogen type” for these rocks based strictly on parameters determined from programmed pyrolysis is misleading because the original organic matter has converted to hydrocarbons (present as solid bitumen), a large proportion of which may have been expelled into adjacent reservoir facies. However, based on the comparison with immature-early mature lacustrine mudrock (Garden Gulch Member of Green River Formation) and marine shale (Boquillas Formation), we suggest that the original organic matter in the organic-rich samples examined for our study may have been type I/II kerogen with hydrogen index values of [Formula: see text] TOC.

scholarly journals Rock-Eval analysis and organic petrographical characterization of the Upper Jurassic Naokelekan Formation, northern Mesopotamian basin, Kurdistan Region-Iraq

2020 ◽  
Vol 56 (1) ◽  
pp. 187
Author(s):  
Rzger Abdula ◽  
Kamal Kolo ◽  
Maria-Elli Damoulianou ◽  
Victoria Raftopoulou ◽  
Polla Khanaqa ◽  
...  
Keyword(s):  
Organic Matter ◽  
Upper Jurassic ◽  
Thermal Maturity ◽  
Kurdistan Region ◽  
Secondary Particles ◽  
Petroleum Generation ◽  
Rock Eval ◽  
Solid Hydrocarbons ◽  
Jurassic Sequence

The aim of this study is to assess the type, thermal maturity and the petroleum generation potential of the Upper Jurassic Naokelekan Formation, occurring across the Kurdistan Region of Iraq, by applying organic petrographical methods and Rock-Eval analysis. The Rock-Eval data would indicate the presence of kerogen types III, IV and II as the main constituents. However, the qualitative petrographical evaluation revealed that the main organic constituents are solid hydrocarbons, in the form of microgranular migrabitumens, with minor amounts of pyrobitumens. These secondary particles have affected the results of the Rock-Eval analysis and would have led to misinterpretation of organic matter typification based on pyrolysis results only. The combined results of petrography and pyrolysis indicate an active petroleum system within the Upper Jurassic sequence, where hydrocarbons are generated and reservoired within suitable lithologies.

scholarly journals Diversity of Biodeteriorative Bacterial and Fungal Consortia in Winter and Summer on Historical Sandstone of the Northern Pergola, Museum of King John III’s Palace at Wilanow, Poland

2021 ◽  
Vol 11 (2) ◽  
pp. 620
Author(s):  
Magdalena Dyda ◽  
Agnieszka Laudy ◽  
Przemyslaw Decewicz ◽  
Krzysztof Romaniuk ◽  
Martyna Ciezkowska ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Microbial Community Composition ◽  
Fungal Communities ◽  
Bacterial Strains ◽  
Microbial Biodiversity ◽  
Acidophilic Bacteria ◽  
Almost All ◽  
Generation Sequencing ◽  
King John

The aim of the presented investigation was to describe seasonal changes of microbial community composition in situ in different biocenoses on historical sandstone of the Northern Pergola in the Museum of King John III’s Palace at Wilanow (Poland). The microbial biodiversity was analyzed by the application of Illumina-based next-generation sequencing methods. The metabarcoding analysis allowed for detecting lichenized fungi taxa with the clear domination of two genera: Lecania and Rhinocladiella. It was also observed that, during winter, the richness of fungal communities increased in the biocenoses dominated by lichens and mosses. The metabarcoding analysis showed 34 bacterial genera, with a clear domination of Sphingomonas spp. across almost all biocenoses. Acidophilic bacteria from Acidobacteriaceae and Acetobacteraceae families were also identified, and the results showed that a significant number of bacterial strains isolated during the summer displayed the ability to acidification in contrast to strains isolated in winter, when a large number of isolates displayed alkalizing activity. Other bacteria capable of nitrogen fixation and hydrocarbon utilization (including aromatic hydrocarbons) as well as halophilic microorganisms were also found. The diversity of organisms in the biofilm ensures its stability throughout the year despite the differences recorded between winter and summer.

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