scholarly journals Hydrocarbon source rocks in Kazhdumi and Pabdeh formations—a quick outlook in Gachsaran oilfield, SW Iran

2021 ◽  
Author(s):  
Majid Safaei-Farouji ◽  
Mohammadreza Kamali ◽  
Mohammad Hail Hakimi
Keyword(s):  
Anoxic Condition ◽  
The Other ◽  
Source Rocks ◽  
Depth Interval ◽  
Hydrocarbon Generation ◽  
Type Ii ◽  
Petroleum Potential ◽  
Other Hand ◽  
Kazhdumi Formation ◽  
Pabdeh Formation

AbstractGeochemical study of Kazhdumi and Pabdeh Formations as potential source rocks in Gachsaran Oilfield demonstrates that the Kazhdumi Formation has a fair to good capability of hydrocarbon generation and predominately contains type II-III kerogen. On the other hand, the Pabdeh Formation has a poor to good petroleum potential and contains different kerogen types, including type II, type II-III, type III and even for one sample, type IV, indicating different depositional conditions for this formation. The geochemical log of the Kazhdumi Formation shows that there is a close correlation between different geological parameters as noticed prominently in well number 55, which suggests the more extensive the anoxic condition, the higher the petroleum potential is for Kazhdumi Formation. By contrast, a poor correlation between TOC and other Rock–Eval-derived parameters for the Pabdeh Formation at a depth of more than 2100 m may demonstrate the inert organic matter and mineral matrix effects at this depth interval. However, biomarkers show differences in lithology and depositional environment for the Kazhdumi Formation in well numbers 55 and 83. On the other hand, the Pabdeh Formation has a mixed lithology (carbonate-shale) deposited in a marine setting under suboxic–anoxic condition. Moreover, thermal maturity indicators suggest that Pabdeh and Kazhdumi Formations are immature and early mature, respectively.

scholarly journals Evaluation of hydrocarbon generation potential of source rock using two-dimensional modeling of sedimentary basin: a case study in North Dezful Embayment, Southwest Iran

2021 ◽  
Author(s):  
Ashkan Maleki ◽  
Mohammad Hossein Saberi ◽  
Seyed Ali Moallemi ◽  
Mohammad Hassan Jazayeri
Keyword(s):  
Organic Matter Content ◽  
Source Rocks ◽  
High Rate ◽  
Hydrocarbon Generation ◽  
Type Ii ◽  
Burial History ◽  
Path Modeling ◽  
Dezful Embayment ◽  
Two Systems ◽  
Kazhdumi Formation

AbstractEarly Cretaceous and Jurassic sequences in the southwestern Iran host some of the largest hydrocarbon reservoirs in the globe. This study is aimed at evaluating the maturity of hydrocarbon fluids, migration paths, and characteristics of Pabdeh, Kazhdumi, Garu and Sargelu source rocks in this region. For this purpose, 27 samples of Pabdeh and Kazhdumi Formations from wells in the northern part of Dezful Embayment were chemically evaluated by Rock–Eval pyrolysis. OpenFlow™ software was utilized to analyze the burial history, conduct 1D thermal modeling in four oilfields and perform 2D modeling on a section to estimate the maturity and extension of sediments. Results of the 1D modeling showed that the kerogens of Sargelu, Garu and Kazhdumi Formations were properly matured, leading to some hydrocarbon outflow, although the organic matter content of Pabdeh Formation was too immature to produce any hydrocarbon. Based on the plot of hydrogen index (HI) versus Tmax, it was found that the studied formations were dominated by type II kerogen and a mixed species of type II and type III kerogens. Results of the migration path modeling showed some leakage from the Kazhdumi Formation up to an overlying seal that prevented the hydrocarbons from seeping out to surface. The Early and Middle Cretaceous oil systems were found to be connected through geometrical features or faults, with the Kazhdumi Formation separating the two systems. The results further showed the migration of hydrocarbons, at a relatively high rate, into the Abadan Plate through the sub-Kazhdumi reservoirs.The Early and Middle Cretaceous petroleum systems were found to be connected through particular geometry features or possibly faults, with the two systems separated by Kazhdumi Formation. For most part, the intensity of the maturation processes was found to decrease from east to west of the study area.

Liquid hydrocarbon characterization of the lacustrine Yanchang Formation, Ordos Basin, China: Organic-matter source variation and thermal maturity

2017 ◽  
Vol 5 (2) ◽  
pp. SF225-SF242 ◽  
Author(s):  
Xun Sun ◽  
Quansheng Liang ◽  
Chengfu Jiang ◽  
Daniel Enriquez ◽  
Tongwei Zhang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Source Rock ◽  
Ordos Basin ◽  
Depositional Environments ◽  
Source Rocks ◽  
Type I ◽  
Hydrocarbon Generation ◽  
Type Ii ◽  
Thermal Maturity ◽  
Yanchang Formation

Source-rock samples from the Upper Triassic Yanchang Formation in the Ordos Basin of China were geochemically characterized to determine variations in depositional environments, organic-matter (OM) source, and thermal maturity. Total organic carbon (TOC) content varies from 4 wt% to 10 wt% in the Chang 7, Chang 8, and Chang 9 members — the three OM-rich shale intervals. The Chang 7 has the highest TOC and hydrogen index values, and it is considered the best source rock in the formation. Geochemical evidence indicates that the main sources of OM in the Yanchang Formation are freshwater lacustrine phytoplanktons, aquatic macrophytes, aquatic organisms, and land plants deposited under a weakly reducing to suboxic depositional environment. The elevated [Formula: see text] sterane concentration and depleted [Formula: see text] values of OM in the middle of the Chang 7 may indicate the presence of freshwater cyanobacteria blooms that corresponds to a period of maximum lake expansion. The OM deposited in deeper parts of the lake is dominated by oil-prone type I or type II kerogen or a mixture of both. The OM deposited in shallower settings is characterized by increased terrestrial input with a mixture of types II and III kerogen. These source rocks are in the oil window, with maturity increasing with burial depth. The measured solid-bitumen reflectance and calculated vitrinite reflectance from the temperature at maximum release of hydrocarbons occurs during Rock-Eval pyrolysis ([Formula: see text]) and the methylphenanthrene index (MPI-1) chemical maturity parameters range from 0.8 to [Formula: see text]. Because the thermal labilities of OM are associated with the kerogen type, the required thermal stress for oil generation from types I and II mixed kerogen has a higher and narrower range of temperature for hydrocarbon generation than that of OM dominated by type II kerogen or types II and III mixed kerogen deposited in the prodelta and delta front.

Geochemical characterization of hydrocarbon source rocks of the Triassic-Jurassic time interval in the Mandawa basin, southern Tanzania: Implications for petroleum generation potential

2020 ◽  
Vol 123 (4) ◽  
pp. 587-596
Author(s):  
A. Emanuel ◽  
C.H. Kasanzu ◽  
M. Kagya
Keyword(s):  
Source Rocks ◽  
Geochemical Data ◽  
Time Interval ◽  
Type I ◽  
Hydrocarbon Generation ◽  
Type Ii ◽  
Geochemical Characterization ◽  
Type Iii ◽  
Petroleum Generation

Abstract Triassic to mid-Jurassic core samples of the Mandawa basin, southern Tanzania (western coast of the Indian Ocean), were geochemically analyzed in order to constrain source rock potentials and petroleum generation prospects of different stratigraphic formations within the coastal basin complex. The samples were collected from the Mihambia, Mbuo and Nondwa Formations in the basin. Geochemical characterization of source rocks intersected in exploration wells drilled between 503 to 4042 m below surface yielded highly variable organic matter contents (TOC) rated between fair and very good potential source rocks (0.5 to 8.7 wt%; mean ca. 2.3 wt%). Based on bulk geochemical data obtained in this study, the Mandawa source rocks are mainly Type I, Type II, Type III, mixed Types II/III and Type IV kerogens, with a predominance of Type II, Type III and mixed Type II/III. Based on pyrolysis data (Tmax 417 to 473oC; PI = 0.02 to 0.47; highly variable HI = 13 to 1 000 mg/gTOC; OI = 16 to 225 mg/g; and VR values of between 0.24 to 0.95% Ro) we suggest that the Triassic Mbuo Formation and possibly the mid-Jurassic Mihambia Formation have a higher potential for hydrocarbon generation than the Nondwa Formation as they are relatively thermally mature.

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

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.

scholarly journals Petroleum Potential of the Deep Ordovician- Lower Devonian Oil and Gas Complex in the South-East of the Timan-Pechora Petroleum Province

2021 ◽  
Vol 20 (3) ◽  
pp. 274-283
Author(s):  
E.A. Kuznetsovа ◽  
Keyword(s):  
Lower Devonian ◽  
Oil And Gas ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
The South ◽  
Reservoir Properties ◽  
Lower Paleozoic ◽  
Petroleum Potential ◽  
Middle Paleozoic ◽  
Gas Potential

The article is devoted to the assessment of the oil and gas potential of the deep Ordovician-Lower Devonian oil and gas complex in the south-east of the Timan-Pechora oil and gas province. Within the Upper Pechora Basin of the Pre-Ural trough and in the south of the Pechora-Kolva aulacogen, several wells were drilled with a depth of more than 5 km, some of which entered the Lower Paleozoic deposits. These strata are difficult to access and poorly studied, and the prospects for their oil and gas potential are unclear. The article describes the composition of the complex, gives geochemical characteristics, describes reservoir properties, and presents the results of 1D and 2D basin modeling. Models of the zoning of catagenesis are presented. The oil and gas complex includes a variety of oil and gas source rocks. It is possible to allocate collectors, as well as the seals. In the Lower Paleozoic sediments, the processes of oil, gas and gas condensate generation took place, which could ensure the formation of deposits both in the deep strata of the Lower and Middle Paleozoic, and in the overlying horizons. The generation and accumulation of hydrocarbons in deep-buried sediments occurred at a favorable time for the formation of deposits. However, it is considered that the scale of hydrocarbon generation for the Lower Paleozoic deposits is not high.

GEOCHEMICAL TOOLS FOR EVALUATING PETROLEUM GENERATION IN MIDDLE PROTEROZOIC SEDIMENTS OF THE McARTHUR BASIN, NORTHERN TERRITORY, AUSTRALIA

1994 ◽  
Vol 34 (1) ◽  
pp. 692 ◽  
Author(s):  
Roger E. Summons ◽  
Dennis Taylor ◽  
Christopher J. Boreham
Keyword(s):  
Vitrinite Reflectance ◽  
Land Plant ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Strongly Correlated ◽  
Petroleum Potential ◽  
Petroleum Generation ◽  
Early Palaeozoic ◽  
Geochemical Analyses ◽  
Rock Eval

Maturation parameters based on aromatic hydrocarbons, and particularly the methyl-phenanthrene index (MPI-1), are powerful indicators which can be used to define the oil window in Proterozoic and Early Palaeozoic petroleum source rocks and to compare maturities and detect migration in very old oils . The conventional vitrinite reflectance yardstick for maturity is not readily translated to these ancient sediments because they predate the evolution of the land plant precursors to vitrinite. While whole-rock geochemical tools such as Rock-Eval and TOC are useful for evaluation of petroleum potential, they can be imprecise when applied to maturity assessments.In this study, we carried out a range of detailed geochemical analyses on McArthur Basin boreholes penetrating the Roper Group source rocks. We determined the depth profiles for hydrocarbon generation based on Rock-Eval analysis of whole-rock, solvent-extracted rock, kerogen elemental H/C ratio and pyrolysis GC. Although we found that Hydrogen Index (HI) and the Tmax parameter were strongly correlated with other maturation indicators, they were not sufficiently sensitive nor were they universally applicable. Maturation measurements based on saturated biomarkers were not useful either because of the low abundance of these compounds in most Roper Group bitumens and oils.

Analysis and characterisation of petroleum source rocks in Queensland

2017 ◽  
Vol 57 (2) ◽  
pp. 806 ◽  
Author(s):  
Alison Troup ◽  
Justin Gorton
Keyword(s):  
Saturation Pressure ◽  
Gas Analysis ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Pyrolysis Gas ◽  
Petroleum Potential ◽  
Organic Petrology ◽  
Rock Formations ◽  
Bulk Chemical ◽  
The Stability

A project to improve the understanding of petroleum source rocks across Queensland’s basins was proposed through the Industry Priorities Initiative. The study has identified new source rocks, improved characterisation of known source rocks, and examined their potential as unconventional reservoirs. Round 2 of the project sampled known source rock formations in the Adavale, Bowen, Cooper and Eromanga basins, all with proven petroleum potential. Forty-eight samples from these basins were screened through Rock-Eval and total organic carbon by LECO to determine candidates for further analysis. Pyrolysis gas chromatography was conducted on selected samples (n = 15) to understand the bulk chemical signatures of kerogens with fluids extracted to derive isotopic and biomarker signatures. Organic petrology (n = 11) examined kerogen components and reflectance. Immature samples were analysed for bulk kinetics (n = 10) to determine the stability of kerogens while some were sent for compositional kinetics (n = 7), to predict the gas to oil ratio (GOR) and saturation pressure. Some more mature samples were sent for late gas analysis (n = 6) to understand hydrocarbon generation at later stages of thermal maturation. The results indicate that the marls in the Bury Limestone may have promising potential, that the Permian coals are the principal source rocks in the Cooper and Bowen basins and that the coals and mudstones of the Birkhead Formation have potential to generate. High production index values were noted in the Bury Limestone, as well as coal and mudstone samples from the Cooper and Bowen basins, suggesting that some of these source rocks also have good retention capabilities.

Viability and Adaptability of E. coli. and Enterococcus Group to Salt Water with High Concentration of Sodium Chloride

1982 ◽  
Vol 14 (4-5) ◽  
pp. 115-126 ◽  
Author(s):  
T Omura ◽  
M Onuma ◽  
Y Hashimoto
Keyword(s):  
Sodium Chloride ◽  
Salt Water ◽  
The Other ◽  
Type I ◽  
Citrobacter Freundii ◽  
Type Ii ◽  
High Concentration ◽  
E Coli ◽  
Rapid Extinction ◽  
Other Hand

Some experiments were carried out to examine the adaptability of E. coli. and enterococcus group to salt water with high concentration of sodium chloride after the experiments on viability in this salt water. Unlike E. coli. type I, when E.coli. type II was repeatedly exposed to salt water, the survival of E.coli. type II was changed from rapid extinction to multiplication as the experiments went on. At the same time, it was also made clear by means of the IMViC test that E.coli. type II was replaced by Citrobacter freundii as E.coli. type II adapted itself to salt water. The enterococcus group was separated into four distinct types; S. faecalis, S. faecalis var. liquefaciens, S. faecium and S. durans. The results of the experiments on viability in salt water indicated that S. faecalis var. liquefaciens possessed the greatest viability, and S. faecium the weakest. From the results of the experiments on adaptability, it was found that each type of enterococcus group had a different adaptability to salt water. In spite of the weakest viability, S. faecium could adapt itself to salt water as well as S. faecalis and S. faecalis var. liquefaciens. On the other hand, S. durans could not adapt itself to salt water at all.

STUDIES ON PETROLEUM GEOLOGY AND GEOCHEMISTRY, MIDDLE PROTEROZOIC, McARTHUR BASIN NORTHERN AUSTRALIA I: PETROLEUM POTENTIAL

1988 ◽  
Vol 28 (1) ◽  
pp. 283 ◽  
Author(s):  
J- Jackson ◽  
I. P. Sweet ◽  
T. G. Powell
Keyword(s):  
Source Rocks ◽  
Coarse Grained ◽  
Hydrocarbon Generation ◽  
Petroleum Potential ◽  
Potential Source ◽  
Quartz Arenite ◽  
Abundant Evidence ◽  
Potential Reservoir ◽  
Fluvial Environments ◽  
Middle Proterozoic

Mature, rich, potential source beds and adjacent potential reservoir beds exist in the Middle Proterozoic sequence (1400-1800 Ma) of the McArthur Basin. The McArthur and Nathan Groups consist mainly of evaporitic and stromatolitic cherty dolostones interbedded with dolomitic siltstone and shale. They were deposited in interfingering marginal marine, lacustrine and fluvial environments. Lacustrine dolomitic siltstones form potential source beds, while potential reservoirs include vuggy brecciated carbonates associated with penecontemporaneous faulting and rare coarse-grained clastics. In contrast, the younger Roper Group consists of quartz arenite, siltstone and shale that occur in more uniform facies deposited in a stable marine setting. Both source and reservoir units are laterally extensive (over 200 km).Five potential source rocks at various stages of maturity have been discovered. Two of these source rocks, the lacustrine Barney Creek Formation in the McArthur Group and the marine Velkerri Formation in the Roper Group, compare favourably in thickness and potential with rich demonstrated source rocks in major oil-producing provinces. There is abundant evidence of migration of hydrocarbons at many stratigraphic levels. The geology and reservoir characteristics of the sediments in combination with the distribution of potential source beds, timing of hydrocarbon generation, evidence for migration and chances of preservation have been used to rank the prospectivity of the various stratigraphic units in different parts of the basin.

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