scholarly journals Organic matter identification in source and reservoir carbonate in the Lower Cretaceous Mauddud Formation in Kuwait

GeoArabia ◽  
2005 ◽  
Vol 10 (4) ◽  
pp. 17-34
Author(s):  
Fowzia H. Abdullah ◽  
Bernard Carpentier ◽  
Isabelle Kowalewski ◽  
Frans van Buchem ◽  
Alain-Yves Huc
Keyword(s):  
Gas Chromatography ◽  
Organic Matter ◽  
Source Rock ◽  
Lower Cretaceous ◽  
Carbonate Rocks ◽  
Total Organic Matter ◽  
The South ◽  
Core Samples ◽  
The North ◽  
Kerogen Type

ABSTRACT The purpose of this study is to identify the source rock, reservoirs and nonproductive zones in the Lower Cretaceous Mauddud Formation in Kuwait, using geochemical methods. This formation is one of the major Cretaceous oil reservoirs. It is composed mainly of calcarenitic limestone interbedded with marl and glauconitic sands. Its thickness ranges from almost zero in the south to about 100 m (328 ft) in the north. A total of 99 core samples were collected from six oil fields in Kuwait: Raudhatain, Sabiriyah and Bahra in the north, and from the Burgan, Ahmadi and Magwa in the south. Well logs from these fields (gamma ray GR, sonic, resistivity, density) were correlated and used in the study. The core samples were screened for the amount and nature of the organic matter by Rock-Eval 6 pyrolysis (RE6) using reservoir mode. A set of samples was selected to study the properties of the organic matter including the soluble and insoluble organic parts. The geochemical characterisation was performed using different methods. After organic solvent extraction of rock samples, the solvent soluble organic matter or bitumen was characterised in terms of saturates, aromatics and heavy compounds (resins and asphaltenes). Then the hydrocarbon distribution of saturates was studied using gas chromatography (GC/FID) and gas chromatography-mass spectrometry (GC/MS) for tentative oil-source rock correlation. After mineral matrix destruction of previously extracted rocks, insoluble organic matter or kerogen was analysed for its elemental composition to identify kerogen type. The geology and the analytical results show similarities between the wells in the southern fields and the wells in the northern fields. Average Total Organic Matter (TOC) in the carbonate facies is 2.5 wt.% and the highest values (8.0 wt.%) are in the northern fields. The clastic intervals in the northern fields show higher total organic matter (1.3 wt.%) relative to the southern fields (0.6 wt.%). The total Production Index is higher in the carbonate (0.6) than the clastic section (0.3). This reflects the amount of extractable hydrocarbons, which are usually associated with the carbonate section in this formation, representing its reservoir section. Although the carbonate rocks are dominated by richer total organic matter, there are some intervals, with low total organic matter values (0.07 wt.%), representing its poor reservoir sections. The kerogen type varies between type II-III and III in the shales with a slightly better quality in the carbonate section. It is immature in almost all the studied fields. The composition of the rock extract has no relation with the rock type. Some sandstone show similar extract composition to the carbonate rocks in the reservoir intervals. The extracts from these intervals show different genetic nature than those in the shales. The maturity level in the reservoir extract is much higher than in the shale intervals. Thus, the oil accumulated in the reservoir might be largely related to migrated oil from a more mature source rock deposited in a clearly different environment than the associated shaly intervals. The best candidates being a more deeply buried Early Cretaceous Sulaiy Formation and Upper Jurassic Najmah Formation.

scholarly journals Petroleum system analysis of the Mishrif reservoir in the Ratawi, Zubair, North and South Rumaila oil fields, southern Iraq

GeoArabia ◽  
2009 ◽  
Vol 14 (4) ◽  
pp. 91-108 ◽  
Author(s):  
Thamer K. Al-Ameri ◽  
Amer Jassim Al-Khafaji ◽  
John Zumberge
Keyword(s):  
Source Rock ◽  
Lower Cretaceous ◽  
System Analysis ◽  
Isotopic Analysis ◽  
Upper Jurassic ◽  
Source Rocks ◽  
Core Samples ◽  
Biomarker Analysis ◽  
Sulaiy Formation ◽  
Rock Analysis

ABSTRACT Five oil samples reservoired in the Cretaceous Mishrif Formation from the Ratawi, Zubair, Rumaila North and Rumaila South fields have been analysed using Gas Chromatography – Mass Spectroscopy (GC-MS). In addition, fifteen core samples from the Mishrif Formation and 81 core samples from the Lower Cretaceous and Upper Jurassic have been subjected to source rock analysis and palynological and petrographic description. These observations have been integrated with electric wireline log response. The reservoirs of the Mishrif Formation show measured porosities up to 28% and the oils are interpreted as being sourced from: (1) Type II carbonate rocks interbedded with shales and deposited in a reducing marine environment with low salinity based on biomarkers and isotopic analysis; (2) Upper Jurassic to Lower Cretaceous age based on sterane ratios, analysis of isoprenoids and isotopes, and biomarkers, and (3) Thermally mature source rocks, based on the biomarker analysis. The geochemical analysis suggests that the Mishrif oils may have been sourced from the Upper Jurassic Najma or Sargelu formations or the Lower Cretaceous Sulaiy Formation. Visual kerogen assessment and source rock analysis show the Sulaiy Formation to be a good quality source rock with high total organic carbon (up to 8 wt% TOC) and rich in amorphogen. The Lower Cretaceous source rocks were deposited in a suboxic-anoxic basin and show good hydrogen indices. They are buried at depths in excess of 5,000 m and are likely to have charged Mishrif reservoirs during the Miocene. The migration from the source rock is likely to be largely vertical and possibly along faults before reaching the vuggy, highly permeable reservoirs of the Mishrif Formation. Structural traps in the Mishrif Formation reservoir are likely to have formed in the Late Cretaceous.

scholarly journals Organic geochemical and petrographical characteristics of the major lower cretaceous petroleum source rock (Makhul Formation) in Kuwait - Arabian Gulf

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Fatma K. Bahman ◽  
◽  
Fowzia H. Abdullah ◽  
Abbas Saleh ◽  
Hossein Alimi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sea Level ◽  
Source Rock ◽  
Lower Cretaceous ◽  
Arabian Gulf ◽  
Carbon Isotope Ratio ◽  
Middle Part ◽  
Source Rocks ◽  
Peak Oil ◽  
Rock Composition

The Lower Cretaceous Makhul Formation is one of the major petroleum source rocks in Kuwait. This study aims to evaluate the Makhul source rock for its organic matter richness and its relation to the rock composition and depositional environment. A total of 117 core samples were collected from five wells in Raudhatain, Ritqa, Mutriba, Burgan, and Minagish oil fields north and south Kuwait. The rock petrographical studies were carried out using a transmitted and polarized microscope, as well as SEM and XRD analyses on selected samples. Total organic matter TOC and elemental analyses were done for kerogen type optically. The GC and GC-MS were done as well as the carbon isotope ratio. The results of this study show that at its earliest time the Makhul Formation was deposited in an anoxic shallow marine shelf environment. During deposition of the middle part, the water oxicity level was fluctuating from oxic to anoxic condition due to changes in sea level. At the end of Makhul and the start of the upper Minagish Formation, the sea level raised forming an oxic open marine ramp depositional condition. Organic geochemical results show that the average TOC of the Makhul Formation is 2.39% wt. High TOC values of 6.7% wt. were usually associated with the laminated mudstone intervals of the formation. The kerogen is of type II and is dominated by marine amorphous sapropelic organic matter with a mixture of zoo- and phytoplankton and rare terrestrial particles. Solvent extract results indicate non-waxy oils of Mesozoic origin that are associated with marine carbonate rocks. The formation is mature and at its peak oil generation in its deepest part in north Kuwait.

scholarly journals Depositional environment and burial history of a Lower Cretaceous carbonaceous claystone, Bornholm, Denmark

1996 ◽  
Vol 43 ◽  
pp. 133-142
Author(s):  
H. I. Petersen ◽  
J. A. Bojesen Koefoed ◽  
H. P. Nytoft
Keyword(s):  
Organic Matter ◽  
Lower Cretaceous ◽  
Depositional Environment ◽  
Lower Jurassic ◽  
Plant Litter ◽  
Burial History ◽  
Transport Distance ◽  
Geochemical Parameters ◽  
Kerogen Type ◽  
History Of

A c. 1 m thick carbonaceous claystone from the type locality of the Lower Cretaceous Skyttegård Member (Rabekke Formation), Bornholm, has been investigated by organic pétrographie and organic geochemical methods in order to assess the depositional environment of the claystone and the thermal maturity of the organic matter. The claystone was deposited in a low-energy, anoxic lake which occasionally was marine influenced. The organic matter is terrestrial and can be classified as kerogen type III and lib. Detrital organic matter and cutinite are characteristic components. The organic matter is allochthonous but the transport distance was short, and the plant material was probably mainly derived from plants growing at the edge of, or nearto, the lake. Source-specific biomarkers such as norisopimarane suggest that the plant litter was derived from a gymnospermous, low-diversity vegetation. Evidence for early angiospermous plants cannot be demonstrated with any certainty. A huminite reflectance value of 0.24%Rm and several geochemical parameters indicate that the organic matter is highly immature. It has only experienced coalification corresponding to the peat stage. Estimates show that, prior to uplift, the claystone was buried to a maximum of approximately 260 m. Reflectance data further suggest that a maximum c. 550 m thick sediment package was removed by erosion prior to deposition of the ?uppermost Jurassic-Lower Cretaceous sediments on Lower Jurassic strata.

scholarly journals Mineral Composition of Subcritical Water Extracts of Saccorhiza Polyschides, a Brown Seaweed Used as Fertilizer in the North of Portugal

2020 ◽  
Vol 8 (4) ◽  
pp. 244 ◽  
Author(s):  
Cristina Soares ◽  
Jaroslava Švarc-Gajić ◽  
Maria Teresa Oliva-Teles ◽  
Edgar Pinto ◽  
Nataša Nastić ◽  
...  
Keyword(s):  
Organic Matter ◽  
Mineral Composition ◽  
Subcritical Water ◽  
Brown Seaweed ◽  
Total Organic Matter ◽  
Subcritical Water Extraction ◽  
Water Extracts ◽  
The North ◽  
Saccorhiza Polyschides ◽  
Agricultural Applications

The present work aimed at studying Saccorhiza polyschides extracts obtained by subcritical water extraction as a potential source of essential macro and trace elements, aiming for its potential application as a biofertilizer. The mineral composition, as well as sulfate, chlorine and iodine, total organic matter, and total nitrogen content, were determined on the extracts obtained from seaweeds harvested during low tide at the northern Portuguese coast. The selected parameters are important for a biofertilizer. Among the macronutrients, the most abundant was K (15.7 ± 0.2 g/L), followed by Na (5.46 ± 0.11 g/L), S (1.52 ± 0.06 g/L), Ca (1.09 ± 0.11 g/L), and Mg (1.02 ± 0.08 g/L). Several important micronutrients (Zn, B, Cl, P, Mo, V, Se, and I) have also been found in the extracts. The total organic matter was 34.1 ± 0.3 g/L. The extracts present low levels of toxic compounds such as Ni, Cd, and Pb. Considering the composition of the obtained extracts, these can find application in the development of fertilization products. The composition of subcritical water extracts of S. polyschides suggests that they may have important characteristics as a biofertilizer and can be an option in biofortification experiments with essential nutrients. The method can be easily scaled up which makes it attractive for agricultural applications.

scholarly journals A Cretaceous dinoflagellate cyst zonation for NE Greenland

2019 ◽  
Vol 157 (10) ◽  
pp. 1658-1692 ◽  
Author(s):  
H. Nøhr-Hansen ◽  
S. Piasecki ◽  
P. Alsen
Keyword(s):  
North Sea ◽  
Lower Cretaceous ◽  
Upper Cretaceous ◽  
Barents Sea ◽  
The South ◽  
Norwegian Sea ◽  
Dinoflagellate Cyst ◽  
The North ◽  
Northern North Sea ◽  
First Time

AbstractA palynostratigraphic zonation is for the first time established for the entire Cretaceous succession in NE Greenland from Traill Ø in the south to Store Koldewey in the north (72–76.5° N). The zonation is based on samples from three cores and more than 100 outcrop sections. The zonation is calibrated to an updated ammonite zonation from the area and to palynozonations from the northern North Sea, Norwegian Sea and Barents Sea areas. The palynozonation is primarily based on dinoflagellate cyst and accessory pollen. The Cretaceous succession is divided into 15 palynozones: seven Lower Cretaceous zones and eight Upper Cretaceous zones. The two lowermost zones are new. The following five (Lower Cretaceous) zones have already been described. Two of the Upper Cretaceous zones are new. The zones have been subdivided into 20 subzones, 11 of which have been described previously and one of which has been revised/redefined. Nine subzones (Upper Cretaceous) are new. More than 100 stratigraphical events representing more than 70 stratigraphic levels have been recognized and presented in an event-stratigraphic scheme.

THE SOUTH AUSTRALIAN CONTINENTAL SHELF AS A HABITAT FOR PETROLEUM

1964 ◽  
Vol 4 (1) ◽  
pp. 53
Author(s):  
Reg. C. Sprigg
Keyword(s):  
Continental Shelf ◽  
Lower Cretaceous ◽  
Structural Break ◽  
Continental Drift ◽  
South Australia ◽  
The South ◽  
The North ◽  
Preferred Habitat ◽  
Murray River ◽  
Petroleum Generation

The Continental Shelf off South Australia is predicted to be a preferred habitat of petroleum. Non-metamorphosed sediments which are known or presumed to extend onto this shelf include Permian, Cretaceous and Cainozoic sediments. A single presumed Permian trough lying seaward of, and sub-parallel to, the Coorong is interpreted (aeromagnetic data) to extend to possibly 4,000 feet. As part of the Permian fossil valley system of central-eastern South Australia is is predicted to be filled by shales and sands with limited marine facies, and by glacigene sediments. The north-south orientation of the trough would require a landmass to the south from which the Permian glaciers originated. Some form of continental drift may be required to satisfy this requirement.An east-west graben or geosyncline (Gambier-Otway Basin) choked with Cretaceous mudstones and sub-greywackes projects across the shelf in the extreme south-east. Landward dips at depth extending well out beneath the shelf, may suggest a southerly boundary to the basin consistent with a pre-existing landmass in this direction.Extensive erosion at the close of Lower Cretaceous times accords with major geological change at least in more southerly shelf areas. Marine sedimentary onlap and overlap become conspicuous elements, and the accumulation of oceanward thickening sedimentary deposits is more in keeping with outbuilding terrace development. A major structural break accordingly is indicated at the end of the Lower Cretaceous, at which time development of the modern continental shelf began.The Murray River had its principal outlets in the extreme south-east zone during mid-Cretaceous to early Tertiary times, but shifted to its present position during late Cainozoic at which time its sediments were swept across the developing shelf south of Kangaroo Island. Thick sedimentary developments in each of these areas provide promising environment for petroleum generation. These are areas of extensive coastal bitumen activity.Principal petroleum prospects are to be expected within the Middle Cretaceous to Tertiary developments, but older Cretaceous and Permian deposits are potentially prospective.

Organic Geochemical Characteristics of Core Samples from Central Primorsk-Emba Province, Precaspian Basin, Kazakhstan

2021 ◽  
Author(s):  
Tolganay Jarassova ◽  
Mehmet Altunsoy
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Organic Matter ◽  
Aromatic Hydrocarbons ◽  
Oil And Gas ◽  
Gas Chromatography Mass Spectrometry ◽  
Type Ii ◽  
Core Samples ◽  
Chromatography Mass Spectrometry ◽  
Potential Type

Abstract The Primorsk-Emba province is one of the main oil and gas region of the Precaspian basin. The resources of the Primorsk-Emba oil and gas region range from 5 to 12 billion tons of oil and from 2 to 6 trillion m³ of natural gas. This study primarily concentrates on investigating the organic geochemistry and petroleum geology characteristics of sedimentary units that generated oil in the central Primorsk-Emba province. 20 core samples taken from the Jurassic units in the western part of the study area are characterized by organic matter amount, hydrocarbon production potential, type of organic matter, maturity of organic matter. According to the Rock-Eval results Jurassic aged rocks generally have a petroleum potential ranging from weak to excellent, the organic matter is between Type II (oil prone), Type II-III (gas-oil prone) and Type III (gas prone), and the degree of maturation is immature-mature stage. Oil extracts were characterized by geochemical methods including Gas Chromatography (GC) and Gas Chromatography–Mass Spectrometry (GC–MS). n-alkanes and isoprenoids were evaluated by High-Resolution Gas Chromatography (GC-HR), aromatic hydrocarbons were evaluated by Low Thermal Mass Gas Chromatography (GC-LTM), terpanes (hopanes), steranes / diasteranes and aromatic hydrocarbons were evaluated by Gas Chromatography-Mass Spectrometry (GC-MS). The GC and GC-MS data obtained, it has been determined whether the paleoenvironment characteristics of the study area, hydrocarbon potential, type of kerogen, maturity level of organic matter and whether it is affected by biodegradation. Distribution of n-alkanes in the GC showed that no biodegradation was observed in analyzed samples, source rock deposited in a marine environment under reducing conditions and an organic matter that occurred were generated by marine carbonates. Based on maturity parameters, studied oils are mature and located on the oil generation window. According to biomarker age parameters C28 / C29 and norcholestane (NCR)/nordiacholestane (NDR) samples are generally Mesozoic (Triassic-Jurassic- Cretaceous) origin, nevertheless there are also levels corresponding to the Paleozoic (Permian) late stages.

scholarly journals Upper Jurassic–Lower Cretaceous Source Rocks in the North of Western Siberia: Comprehensive Geochemical Characterization and Reconstruction of Paleo-Sedimentation Conditions

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 320
Author(s):  
Evgeniya Leushina ◽  
Timur Bulatov ◽  
Elena Kozlova ◽  
Ivan Panchenko ◽  
Andrey Voropaev ◽  
...  
Keyword(s):  
Organic Matter ◽  
Lower Cretaceous ◽  
Organic Matter Content ◽  
Upper Jurassic ◽  
Matter Content ◽  
Source Rocks ◽  
Organic Carbon Content ◽  
Sea Level Changes ◽  
The North ◽  
Terrigenous Sedimentation

The present work is devoted to geochemical studies of the Bazhenov Formation in the north of the West Siberian Petroleum Basin. The object is the Upper Jurassic–Lower Cretaceous section, characterized by significant variations in total organic carbon content and petroleum generation potential of organic matter at the beginning of the oil window. The manuscript presents the integration of isotopic and geochemical analyses aimed at the evaluation of the genesis of the rocks in the peripheral part of the Bazhenov Sea and reconstruction of paleoenvironments that controlled the accumulation of organic matter in sediments, its composition and diagenetic alterations. According to the obtained data, the sediments were accumulated under marine conditions with a generally moderate and periodically increasing terrigenous influx. The variations in organic matter composition are determined by redox conditions and terrigenous input which correlate with the eustatic sea level changes during transgressive/regressive cycles and activation of currents. Transgression is associated with an intensive accumulation of organic matter under anoxic to euxinic conditions and insignificant influence of terrigenous sources, resulting in the formation of rocks with oil-generating properties. During the regression periods, the terrigenous sedimentation increased along with the dissolved oxygen concentration, and deposits with low organic matter content and gas-generating properties were formed.

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