Biomarker Characterization of Oil Seepages in Tomori Basin, Central Sulawesi, Indonesia

Abstract Tomori Basin is located close to the Banggai Basin which has several productive oil fields. Further investigation of the hydrocarbon potential in Tomori Basin is an important issue as potential hydrocarbon resources are indicated by the discovery of several oil seepages in the area. This study identified Tomori Basin oil seepage characteristics using a biomarker analysis approach. The Wosu and Kolo Areas were the main objectives of this study. Oil seepage characteristics were determined using Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS) methods to generate biomarker data which could be analysed to identify organic matter origin, oxic and anoxic conditions, source facies, or depositional environment. Based on the GC analysis of is oprenoids, the Pristane C19/Phytane C20 ratio (Pr/Ph) of Wosu Oil was 0.75, indicating anoxic conditions typical of a hypersaline environment. Kolo Oil had a Pr/Ph ratio of 3.37 indicative of terrestrial organic input under oxic conditions. A cross plot between Pristane/nC17 and Pr/Ph ratios indicates that Wosu Oil derives from a highly anoxic environment with algae/bacterial organic matter input whereas Kolo Oil derives from a suboxic-oxic environment dominated by terrestrial organic matter input. Trycyclic terpene analysis from C19 to C25 shows Wosu Oil seepages tend to originate from an environment of mixed terrestrial and marine organic matter (transitional environment). Overall, biomarker characteristics indicate that Wosu Oil originated from organic matter in a hypersaline and anoxic environment, whereas Kolo Oil originated from terrestrial matter in a suboxic – oxic environment.

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SEDIMENTARY AND GEOCHEMICAL EVIDENCE FOR TERRESTRIAL ORGANIC MATTER INPUT DRIVING ANOXIA EVENTS FOUND IN LATE DEVONIAN BLACK-GRAY SHALE TRANSITIONS, APPALACHIAN BASIN, NORTH-CENTRAL OHIO

10.1130/abs/2020am-357585 ◽

2020 ◽

Author(s):

Caroline A. Dunkel ◽

◽

James E. Evans

Keyword(s):

Organic Matter ◽

Appalachian Basin ◽

Late Devonian ◽

Terrestrial Organic Matter ◽

North Central ◽

Geochemical Evidence ◽

Organic Matter Input

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Terrestrial organic matter input drives sedimentary trace metal sequestration in a human-impacted boreal estuary

The Science of The Total Environment ◽

10.1016/j.scitotenv.2020.137047 ◽

2020 ◽

Vol 717 ◽

pp. 137047 ◽

Cited By ~ 2

Author(s):

Sami A. Jokinen ◽

Tom Jilbert ◽

Rosa Tiihonen-Filppula ◽

Karoliina Koho

Keyword(s):

Organic Matter ◽

Trace Metal ◽

Terrestrial Organic Matter ◽

Metal Sequestration ◽

Organic Matter Input

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Organic geochemical characteristics of coal deposits in Mae Than coal mine, Lampang Province, Thailand

10.5194/egusphere-egu2020-12894 ◽

2020 ◽

Author(s):

Patthapong Chaiseanwang ◽

Piyaphong Chenrai

Keyword(s):

Organic Matter ◽

Depositional Environment ◽

Geochemical Data ◽

Hydrocarbon Generation ◽

Thermal Maturity ◽

Terrestrial Organic Matter ◽

Normal Alkanes ◽

Lampang Province ◽

Extractable Organic Matter ◽

Organic Matter Input

<p>Fifteen samples were collected from coal mines Mae Than basins located in Lampang Province, Northern Thailand to investigate organic geochemical characterization which can provide organic matter input, thermal maturity and depositional environment. The total organic carbon (TOC) content of the coal samples ranges from 30.12 to 73.71 wt. %, while shales and mudstones value between 5.98 &#8211; 24.87 wt. %. The extractable organic matter (EOM) content of all samples, which is yielded from bitumen extraction, values in the range of 1,256 and 16,421 ppm indicating good to excellent hydrocarbon generation potential. The organic geochemical data were studied by using Gas-chromatography Mass-spectrometry (GC-MS) providincg biomarker and non-biomarker data. The thermal maturity of studied samples is represented as immature stage due to ratio of Ts/(Ts+Tm) and homohopane isomerization. The distribution of normal alkanes is predominantly long-chain normal alkanes with odd-numbered carbon. The high Carbon Preference Index (CPI) value of samples indicates terrestrial organic matter input. The depositional environment of the study area can be interpreted that the coal formation is occurred within an oxidizing condition with the majority of higher plant input, whereas shale and mudstone is slightly more anoxic-aquatic environment.</p>

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Organic geochemical characteristics of the Mississippian black shales from Wardie, Scotland

Earth and Environmental Science Transactions of the Royal Society of Edinburgh ◽

10.1017/s1755691015000225 ◽

2015 ◽

Vol 106 (1) ◽

pp. 55-65 ◽

Cited By ~ 1

Author(s):

Agata Trojan ◽

Maciej J. Bojanowski ◽

Marek Gola ◽

Oliwia Grafka ◽

Leszek Marynowski ◽

...

Keyword(s):

Organic Matter ◽

Vitrinite Reflectance ◽

Sedimentary Environment ◽

Microbial Transformation ◽

Hydrothermal Activity ◽

Black Shales ◽

Hydrocarbon Generation ◽

Terrestrial Organic Matter ◽

Water Column Stratification ◽

Biomarker Analysis

ABSTRACTCoal and hydrocarbons have been exploited from the Carboniferous rocks of the Midland Valley for over 200 years. This work characterises organic matter from the Mississippian black shales of the Midland Valley from Wardie, Scotland. Biomarker analysis allowed the estimation of the degree of microbial transformation of organic matter, type of kerogen and thermal maturity during hydrocarbon generation. Parameters based on the biomarker indicators confirm a generally mixed type II/III kerogen. However, some samples contain mostly terrestrial organic matter, whilst others contain predominantly marine organic matter, which shows that the sedimentary environment varied greatly throughout the basin. The presence of gammacerane suggests water column stratification and anoxic conditions. Organic matter was much better protected from post-depositional alteration within the concretions, where higher TOC (total organic carbon) and TS (total sulphur) contents occur, than in the surrounding sediments. This can be induced by very early diagenetic formation of these concretions which protected organic matter from late diagenetic degradation.Estimated values of vitrinite reflectance (Rc, Rcs) show that the sedimentary rocks reached the catagenesis stage. Most samples exhibit maximum organic matter maturation temperatures of around c60–90°C. However, stable isomers of phenyldibenzo[b,d]thiophene detected in some samples indicate that in some cases post-depositional hydrothermal activity affected maturation of organic matter increasing temperatures to as high as c174°C.

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Biomarker evidence for changes in terrestrial organic matter input into the Yellow Sea mud area during the Holocene

Science China Earth Sciences ◽

10.1007/s11430-016-5283-y ◽

2016 ◽

Vol 59 (6) ◽

pp. 1216-1224 ◽

Cited By ~ 10

Author(s):

Peng Wu ◽

XiaoTong Xiao ◽

ShuQin Tao ◽

ZuoSheng Yang ◽

HaiLong Zhang ◽

...

Keyword(s):

Organic Matter ◽

Yellow Sea ◽

The Yellow Sea ◽

Terrestrial Organic Matter ◽

The Holocene ◽

Sea Mud ◽

Mud Area ◽

Organic Matter Input

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The origins of paraffinic oils collected from oilfields in the western Siberian Basin, Russia: implications from geochemical and physical characteristics

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01325-9 ◽

2021 ◽

Author(s):

Mohammed Hail Hakimi ◽

Shadi A. Saeed ◽

Ameen A. Al-Muntaser ◽

Mikhail A. Varfolomeev ◽

Richard Djimasbe ◽

...

Keyword(s):

Organic Matter ◽

Sulfur Content ◽

Source Rock ◽

Environmental Conditions ◽

Saturated Hydrocarbon ◽

Source Rocks ◽

Terrestrial Organic Matter ◽

Low Sulfur Content ◽

Low Sulfur ◽

Organic Matter Input

AbstractFour oil samples were collected from oilfields in the western Siberian Basin, and analyzed using conventional geochemical and physical methods. The results of this study were used to evaluate the oil samples, focusing on the characteristics of their source rocks, including the origin of organic matter input; redox depositional conditions and degree of thermal maturity of their probable source rock were studied. The obtained SARA results show that the examined oils are paraffinic oils owing to their high saturated hydrocarbon fraction values of greater than 70% volume. The observed API gravity values (23.55° to 32.57°) and low sulfur content of less than 0.25% wt indicate that the examined oils are sweet oils and were generated from source rock containing Type-II, with low sulfur content. The low sulfur content combined with the vanadium (V) and nickel (Ni) ratios indicates that the examined oils were scoured from a mixture of aquatic and terrestrial organic matter, depositing under generally suboxic environmental conditions. The n-alkane and isoprenoid distributions, with their ratios and parameters further suggest that the examined oil samples were generated from source rock containing a mixed organic matter input and deposited under suboxic to relatively oxic environmental conditions. Bulk compositions and distributions of n-alkane and isoprenoid indicate that the oil samples were generated from mature source rock.

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Biomarker Characteristic of Kelesa Oil Shale As Evidence of The Source of Organic Matter, Depositional Environment, and Maturity Interpretation

Proc. Indon. Petrol. Assoc., Digital Technical Conference, 2020 ◽

10.29118/ipa20-sg-316 ◽

2020 ◽

Author(s):

B., M. Hartono

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Organic Matter ◽

Source Rock ◽

Oil Shale ◽

Depositional Environment ◽

Petroleum System ◽

Lacustrine Environment ◽

Biomarker Analysis ◽

Central Sumatra

Biomarker analyses can provide information about the source of organic matter, depositional environment, and maturity of source rock that is very useful for basin evaluation and understanding the petroleum system. In this paper, the study focuses on biomarker characterization of the Kelesa Formation that is situated in the Central Sumatra Basin, one of the petroliferous basins in Indonesia. This Eocene formation is equivalent to the Pematang Formation that is well known as acting as source rock in the Central Sumatra Basin. Thirty fresh outcrop samples were taken for biomarker analysis, with specification fourteen samples for gas chromatography and sixteen samples for gas chromatography-mass spectrometry. The gas chromatography analysis was done with a Perkin Elmer Clarus 600 type instrument while the mass spectrometry was done using a Perkin Elmer Clarus SQ 8C instrument. The results show that the organic matter dominantly comes from terrestrial plants with minor input from planktonic algae. Moreover, possible Botryococcus braunii input in the sediment suggests that the Kelesa Formation has been deposited in a lacustrine environment. Since the Kelesa Formation was deposited in a lacustrine environment, this formation is expected to be highly oil-prone source rock. The maturity biomarker indicators suggest that the formation does not reach appropriate maturity to expel hydrocarbon. However, the formation still has very good potential for oil shale resources. This study supports the previous study in the Kelesa Formation, and improves the understanding of the depositional history of the Kelesa Formation and the potential of the Kelesa Formation as oil shale resources. Moreover, the authors hope that this study can support recent basin evaluation and improve the understanding of the petroleum system in the Central Sumatra Basin.

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