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Abay, Tesfamariam Berhane; Karlsen, Dag Arild; Olaussen, Snorre & Pedersen, Jon Halvard
(2019).
Organic Geochemistry of Petroleum in the Cambro-Ordovician Succession of Ny Friesland, Spitsbergen, Norway.
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Abay, Tesfamariam Berhane; Karlsen, Dag Arild; Pedersen, Jon Halvard & Olaussen, Snorre
(2017).
Middle Triassic Source Potential and Lateral Variation in Organic Facies, Southwestern Barents Sea and Svalbard.
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Lerch, Benedikt; Karlsen, Dag Arild & Duggan, Deirdre
(2015).
Geochemical Characterization of Loppa High oils (SW-Barents Sea) and implications for regional petroleum systems.
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Lerch, Benedikt & Karlsen, Dag Arild
(2014).
Light Hydrocarbon Appraisal on Migration and Alteration Modes in Barents Sea Oils and Condensates - A Geochemical Approach to Improved Petroleum System Understanding.
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Lerch, Benedikt; Karlsen, Dag Arild & Duggan, Deirdre
(2014).
Migration and Alteration Processes in Barents Sea Oils and Condensates - A Geochemical Approach to Improved Petroleum System Understanding.
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Lerch, Benedikt; Karlsen, Dag Arild & Duggan, Deirdre
(2014).
The Light Hydrocarbon Paradox of the Barents Sea - Light Hydrocarbon Correlation- & Transformation Parameters in Barents Sea Oils and Condensates.
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Olaussen, Snorre; Abay, Tesfamariam Berhane; Karlsen, Dag Arild; Hammer, Øyvind & Pedersen, Jon Halvard
(2014).
Novel Results on Migrated Oil in several Svalbard out-crop samples. What does this tell us about the Petroleum Systems responsible for the Migrated Oils in these samples.
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Abay, Tesfamariam Berhane; Karlsen, Dag Arild; Pedersen, Jon Halvard; Lerch, Benedikt & Backer-Owe, Kristian
(2014).
Regional Variation in the Triassic Organo-Facies signatures of the Barents Sea.
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Abay, Tesfamariam Berhane; Karlsen, Dag Arild; Backer-Owe, Kristian & Ohm, Sverre Ekrene
(2013).
Geochemical comparison of oils from the Central Graben: with special emphasis on correlation and transformation of oils from the Embla Field.
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Koeverden, Jan Hendrik; Karlsen, Dag Arild & Nakrem, Hans Arne
(2009).
Migrated hydrocarbons on Novaya Zemlya, Russian Arctic - a novel petroleum system for the Barents and Kara Sea regions?
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Ohm, Sverre Ekrene & Karlsen, Dag Arild
(2005).
The Paleocene sandy Siri Fairway (2); an efficient 'pipeline' draining the prolific Central Graben.
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Conclusions
A common Paleo closure existed for the Siri-1 and Siri-2 reservoar. A regional tilt disturbed this closure and a new OWC was established, tentatively dated to Miocene.
The Siri-2 oil opposed to Siri-1 and 3 is saturated and the accumulation has a gas cap and a tar mat at and above the OWC. This hints on a communication problem (no homogenization) between individual turbidite fans/sand lobes. It does as well suggest a possible recent pulse of hydrocarbons to Siri-2.
If the GOR of the Siri-1 and 3 oils are real and not a result of phase fractionation and if this oil migrated in as a saturated phase this is modeled to have occurred when the reservoir/carrier was buried ca. 1000m more shallow. This was the case roughly 24 M.Y.b.p..
The tar mat in Siri-2 formed after the Tertiary regional tilt along the present OWC and could be a result of mixing of an original undersaturated fluid (comparable to Siri-1 and 3) with a recent saturated one. Sieving of asphaltenes in the carrier sands during migration of hydrocarbons in the more porous part of the carrier could as well lead to formation of a tar mat. A combination of these two mechanisms could as well be envisaged.
All the analysed oils in the Siri Fairway in this study have an early mature signature. The source area in the Tail-End Graben presently expels late mature oil and gas. Consequently the Siri Fairway is believed no longer to drain this basin. The source rock (Farsund Fm) in the Søgne Basin has just entered the oil window and could maturity wise be responsible for some of the observed hydrocarbons.
There is a significant amount of biogenic gas in Siri-1 and 3, less in Siri-2. This suggests that huge quantities of hydrocarbons never passed through the Siri Fairway, which also helps explain the low maturity of the oils. The possible lower quantities of biogenic gas in Siri-2 hints on more thermogenic hydrocarbon migrating through this part of the Fairway, supporting the formation of the observed tar mat.
Possible fault movements along the Coffee Soil Fault during the time of regional tilting could have caused the connection between the Paleocene Siri Fairway sands and the Jurassic produced Tail-End Graben hydrocarbons to be cut. Alternatively influx of hydrocarbons to the Siri Fairway rests on vertical migration from Jurassic to Paleocene in the basin areas, possibly implying that the physiochemical properties of the chalk rules when it became a seal and prevented further migration through it. The Paleocene Tabita oil, located in the Tail-End Graben, has a significantly lower maturity (comparable to the Siri oils) than the underlying Jurassic Amalie oil, supporting that oil from the deep basin earlier migrated vertically, but that this now is prevented.
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Heggsum-Hubred, Jørnar & Karlsen, Dag Arild
(2005).
THERMAL EFFECTS OF BASALTIC SILL EMPLACEMENT INTO SOURCE ROCKS ON MATURITY & HYDROCARBON GENERATION.
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THERMAL EFFECTS OF BASALTIC SILL EMPLACEMENT INTO SOURCE ROCKS ON MATURITY & HYDROCARBON GENERATION
Jørnar Heggsum Hubred1,2),Dag A. Karlsen1) and Sven Dahlgren3)
1) Department of Geosciences P.O.Box 1047, Blindern, N-0316 Oslo, Norway
2) jornar@geo.uio.no
3) Norwegian Petroleum Directorate, P.O.Box 600, N-4001 Stavanger, Norway Present address: County councils of Buskerud, Telemark and Vestfold, Svend Foynsgt. 9 Fylkeshuset, N-3110 Tønsberg, Norway
In sedimentary basins sills have a tendency to become emplaced in litholgies of lower mechanical competence, like shales, which can possess source rock qualities.
In this study we have been investigating the thermal effects of thick sills on sedimentary rock units at Svalbard, Norway. We believe this study to be directly relevant for sills in large scale sedimentary basins. If sills were emplaced in contact with the source rocks at great burial depth a "source rock on a hot plate" type of situation could arise with a temperature-heat history quite unlike that of small dykes in shallow, water-rich sediments. An additional effect could be related to a regional increase in heat flow if the sills are in a sense "symptoms" of massive ingenious activity as known from other regions.
It is well proven that thin sills and dykes can locally mature source rocks, increase biomarker ratio in extractable compounds and at the same time cause systematic increases in kerogen maturity parameters. Since few organic geochemistry results on large scale sills have been published it was not clear to us if massive sills simply could be viewed as a upscalling phenomena of the smaller dyke and sill systems..
Samples were collected from eight different profiles with sills. The Triassic Botneheia black shale source rock formation, with dominantly marine kerogen, were collected from the hills of Botneheia (Central Spitsbergen), Teistberget (eastern Central Spitsbergen), Krefftberget and Høgrinden (Barentsøya Island). Samples were also collected from the Jurassic Janusfjellet black shale (with dominantly terrestrial kerogen) from Domen (eastern Central Spitsbergen) and the Wilhelmøya Island. Samples from identical black shale units in nearby sections not thermally affected by the sills were also collected and used for comparison.
Organic petrographical descriptions, vitrinite reflectance, Rock Eval, TC and TOC were determined on all 170 samples, whereas metamorphic phase petrology, EOM, Iatroscan TLC-FID, GC-FID, GC-MS and isotopic studies of C and O (in carbonates, kerogen and extracts) were conducted on 48 selected samples.
The vitrinite reflectance (%Ro) profiles show the typical inverted profile closer to the sills i.e. the vitrinite values are as low as 1.5 at 2m from a 23m thick sill, 5 at 5m, decreasing to 3.5 at 10 meters before reaching the background value of 0.8 at about 20m distance from the sill.
However, no trends in biomarker maturity of the extracts could be detected over the same profile. These results were in the beginning difficult to understand but lead us to suggest that the generative process caused violent mobilization of water, at the same time as generation of light hydrocarbons took place, transporting these light hydrocarbons away. Low maturity biomarkers have at a later stage back diffused from the lower maturity, unaffected shales into the thermally affected shales following cooling of the intrusions. The composition of generated hydrocarbons extracted from the rock samples indicates that hydrocarbon generation by sills may be a less than perfect analogue for "normal" hydrocarbon generation in subsiding basins.
Results from this study would not only be relevant for sill intruded sedimentary basins but would possibly also be relevant for deep water exploration e.g. the Atlantic volcanic margin were sediments have experienced increased heat flows due to magmatic underplating.
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Pedersen, Jon Halvard; Kristiansen, Trond & Karlsen, Dag Arild
(2005).
Degradation of oil in relation to the Barents Sea.
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Degradation of oil in relation to the Barents Sea
J. H. Pedersen1, T. Kristiansen2, D. A. Karlsen1, J. E. Lie3 & H. Brunstad3
1Department of Geosciences, University of Oslo, P.O. Box 1047 Blindern, N-0316 Oslo, Norway
2Department of Biology, University of Bergen, P. O. Box 7800, N-5020 Bergen, Norway
3RWE Dea Norge AS, P.O. Box 243 Skøyen, N-0213 Oslo, Norway
Since 1965, over 900 petroleum exploration wells have been drilled in the Norwegian North Sea, while around 70 exploration wells has been drilled in the Barents Sea since 1980. New attention to the Barents Sea as a potential oil and gas province may result in several new exploration wells to be drilled in the near future.
Major oil spills in the past have been related to transportation of oil, rather than from oil exploration activities. The biggest risk for oil spills in the Barents Sea is therefore probably leakage from oil tankers.
Oil spilled on the sea surface will within hours change composition and properties due to physical and chemical processes, such as spreading, dispersion, evaporation,
weathering, emulsification, water washing and oxidation. Wave action and temperature are key factors.
Long term biological processes include break-down of oil by bacterial oxidation of petroleum. These processes altogether increase the viscosity and gravity of the spilled oil, due to removal of the light components in the oil.
In this study we demonstrate how degradation alters the composition and properties of oil, and that some identifiable specific organic molecules are still contained in the oil residue even long time after the spill. These molecules may be used to identify the source of an oil spill.
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Pedersen, Jon Halvard & Karlsen, Dag Arild
(2005).
Maturity and organic facies of Mesozoic and Palaeozoic petroleum from off- and onshore Scandinavia.
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Maturity and organic facies of Mesozoic and Palaeozoic petroleum from off- and onshore Scandinavia
Pedersen, Jon H.1, Karlsen, Dag A.1, di Primio, Rolando2, Lie, Jan E.3 and Brunstad, Harald3
1)Department of Geosciences, University of Oslo, P.O. Box 1047 Blindern, N-0316 Oslo, Norway
2)GeoForschungsZentrum Potsdam, Telegrafenberg, D-14473 Potsdam, Germany
3)RWE Dea Norge AS, P.O. Box 243 Skøyen, N-0213 Oslo, Norway
In Lower Palaeozoic times, large parts of the Scandinavian region of the NW Europe were covered by the Iapetus Ocean. Shales, mudstones and carbonates were deposited on the mainland of Scandinavia, and in offshore areas east, south and west of the Scandinavian mainland. Some of these sediments, like the Upper Cambrian – Lower Ordovician Alum Shale, have certainly generated petroleum.
On- and offshore oil and gas fields in the Baltic countries Latvia and Lithuania are sourced from Cambrian, Ordovician and Silurian marine shales. In Scandinavia, insoluble bitumen, oil stains and oils in inclusions found on the Scandinavian onshore prove that Lower Palaeozoic petroleum systems have been active in this region. Insoluble bitumen found in Upper Palaeozoic rocks in the Norwegian North Sea suggest that Lower Palaeozoic petroleum also have been present in the North Sea region.
This study presents an evaluation of Palaeozoic and Mesozoic source rocks and oil stains from Norway, Sweden, Scotland and Spitsbergen. We use established organic geochemical methods to characterise marine and lacustrine samples in order to better understand the thermal maturity and organic facies of Palaeozoic source rocks and petroleum in the Scandinavian on- and offshore region.
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Pedersen, Jon Halvard & Karlsen, Dag Arild
(2005).
Source Rocks and Petroleum of the Norwegian Barents Sea.
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Ohm, Sverre Ekrene & Karlsen, Dag Arild
(2005).
Gas expulsion from coals (Brent and Åre Fm NOCS);New proofs and understanding.
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Gas composition and isotope values of gas liberated from coals on the Norwegian Continental Shelf (NOCS) by simple crushing have been analyzed. These values were compared to those from fluid inclusion gases. The fluid inclusions were extracted from sandstones in contact with the coals. The coal gas was found to be isotopically similar to that liberated from inclusions. The methane is very light with δ13C values in the range of -58 to -72‰. For ethane, propane and butane the values were heavier and more in agreement with anticipated values. The methane is isotopically very different from most of the gas discovered on the NOCS in which methane values generally fall in the range of -42 to -45‰. Most of the coal samples have a vitrinite reflectivity of 0.8 to 1% Ro. The inclusion samples contain dominantly methane (70 to 90%) while the coal gas is much wetter. The study shows that the examined coals have expelled biogenic gas: 1) over a temperature window where quartz overgrowth formation takes place (80-1200C), 2) in sufficient amounts to become trapped in inclusions and 3) over a sufficient time interval to become trapped. This suggests that volumes of biogenic produced methane have been expelled from the investigated coals at a surprisingly high temperature (depth of burial ~4000m) and that this light methane besides being trapped in inclusions also can migrate – potentially into commercial traps and mix with thermogenic high maturity gas – which is isotopically heavy and thereby skew the overall gas isotope values towards lighter values (values in the -45 to -55‰ range).
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Alsger, Sager; Karlsen, Dag Arild & Pedersen, Jon Halvard
(2005).
Petroleum Geochemistry of the Goliath discovery compared to other fields and traps in the Hammerfest Basin.
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The Goliath discovery which is located in the Hammerfest Basin near the Troms-Finnmark fault complex is particular for its size and its content of oil and the lack of gas, whilst other traps in the Hammerfest Basin largely contains gas/condensate and generally only thin oil rims.
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Pedersen, Jon Halvard; Karlsen, Dag Arild; Lie, Jan Erik; Brunstad, Harald & di Primio, Rolando
(2005).
Petroleum Potential, Thermal Maturity and Organic Facies of Palaeozoic Sediments from the North Sea Region.
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The Palaeozoic successions in the northern North Sea are not as well mapped and understood as younger strata in the North Sea sedimentary basins. This is due to great burial depths, but also because the Palaeozoic has been regarded as of low economic interest in this area.
There are however Palaeozoic sediments with possible petroleum potential in both Norwegian and Danish wells in the northern North Sea. We also know that source rocks of Cambro-Silurian, Devonian, Carboniferous and Permian age are found in areas fringing the North Sea, i.e. in Norway, Denmark, Sweden, Poland, Germany, the Netherlands, in the UK and on East Greenland.
In the Skagerrak Sea and northern North Sea, thick sequences of marine sediments most likely accumulated in Cambro-Silurian times. Additionally, shales, coals and mudstones of Devonian to Permian age may have been deposited in Palaeozoic half-grabens and N-S trending rift basins underlying the Upper Permian Zechstein evaporites.
In this study, we investigate Palaeozoic sediments collected from wells and outcrops in the North Sea and adjacent areas. In specific, we focus on Cambro-Silurian, Carboniferous and Permian sediments, which may have petroleum source rock properties. In the northeastern North Sea and Norwegian-Danish Basin (NDB), Palaeozoic source rocks may be a crucial part of plays capped by thick Upper Permian evaporite layers.
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Svensen, Henrik; Karlsen, Dag Arild & Banks, DA
(2004).
Seep geochemistry and origin of petroleum from the Salton Sea Geothermal System, California, USA.
Geochimica et Cosmochimica Acta.
ISSN 0016-7037.
68,
p. A266–A266.
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Ohm, Sverre Ekrene & Karlsen, Dag Arild
(2004).
The Paleocene Sandy Siri Fairway; An efficient 'pipeline' draining the prolofic Danish Central Graben?
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A new petroleum charge model is presented for the sandy, Paleocene channel system known as the Siri Fairway. The Siri Fairway straddles the platform area along the Danish � Norwegian offshore border and stretches from the Norwegian paleo-shelf until the Tail-End Graben and Søgne Basin (within the Central Graben). The closest known expelling source rocks are located in the Central Graben. The discoveries of the Siri Field and later the Cecilie and the Nini Fields prove that petroleum has migrated through the sandy Paleocene deposits for distances up to 70 km. If the Siri Fairway acts as a pipeline transporting petroleum from the Graben onto the Platform area, the chemical composition of the petroleum discovered in the Graben area and within the Fairway itself should be similar. This study shows that this is not the case. The oils in the Graben area have a very mature signature whilst the oils from the Siri have an early mature signature and are mixed with in-situ derived biogenic gas suggesting Siri to represent a �dead-end for migration�. This biogenic gas signature would have been completely obliterated were the petroleum continuously introduced to the Fairway. We therefore suggest that hydrocarbon charging to the Fairway for some reason came to a halt before the source rocks in the Graben entered the main and late part of the oil window. The consequence for the Siri Fairway is that limited charging has occurred. The chemical composition of the oils in the Siri Field also led us to suggest that the Fairway has been charged from two different sub-basins with different subsidence history. The Siri-2 structure is in this context interpreted to have been initially filled with the same oil as found today in Siri-1 and Siri-3, but that it was later partly displaced with oil from a shallower buried sub-basin.
The Siri Fairway consists of sands deposited as turbidites through Late Paleocene. The deposit consists of stacked interfingering fans. These could be completely, or partly covered by layers of fine-grained clays reflecting the time lag between deposition of individual fans. Long distance migration is proven through this deposit. However, connectivity and thus migration between individual fans could represent a problem depending on the local presence and continuity of the clay. The number of dry wells drilled in the Fairway and the �dead-end� character of the analysed oils indicates that migration routes are difficult to predict.
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Pedersen, Jon Halvard; Karlsen, Dag Arild; di Primio, Rolando; Lie, Jan Erik & Brunstad, Harald
(2004).
Evaluation of extracts and pyrolysates from Palaeozoic sediments from the North Sea region.
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The Palaeozoic successions in the northern North Sea is not mapped and understood as well as younger strata in the North Sea sedimentary record. This is due to great burial depths, but also because the Palaeozoic has been regarded as of low economic interest in this area.
In this project we investigate Palaeozoic sediments collected from wells and outcrops in the North Sea and adjacent areas. In specific, we focus on Cambro � Silurian, Carboniferous and Permian sediments, which may have petroleum source rock properties.
We hope that this study will increase our understanding of the distribution, organic facies and thermal maturity of Palaeozoic sediments in the northern North Sea. We also believe that this work may help us to better evaluate the significance of Palaeozoic petroleum systems in the northern North Sea and Norwegian Danish Basin.
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Pedersen, Jon Halvard; Karlsen, Dag Arild; Lie, Jan Erik & Brunstad, Harald
(2004).
Atypical source rocks and petroleums of the Norwegian Continental Shelf.
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***This poster won the Best Student Poster Award at the 21st Annual Meeting of TSOP , Sydney, 26 September - 1 October, 2004***
In one of the world�s most important oil and gas provinces, the North Sea and NE Atlantic margin of the NW Europe, the dominating source rock is the Upper Jurassic marine Kimmeridge Clay. Up to 1 km of this excellent source rock was deposited in extensive Jurassic rift systems developed along almost the entire Norwegian continental shel,f from the Central Graben in the south to the Barents Sea in the north.
21 hydrocarbon samples, including some highly atypical oils, were analysed geochemically to determine their source rock facies and maturity relationships. While most of the samples are from the Norwegian Offshore Continental Shelf (NOCS), oils and condensates from onshore Scandinavia are also analysed, debated and attempted interpreted in relation to source facies and thermal maturity.
It was hoped that this work might help in providing evidences that the NOCS and neighbouring regions may contain additional source rocks besides the widespread Upper Jurassic Kimmeridge Clay formation and its equivalents.
Another goal was to seek out and point to potential atypical petroleums and bitumens on and offshore Norway and Fennoscandia, by using organic geochemical analytical procedures and parameters obtained from these. The molecular parameters are used to illustrate the differences between the typical and atypical petroleums, and to show the variation in NOCS source rock depositional facies and maturity.
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Pedersen, Jon Halvard; Karlsen, Dag Arild; Lie, Jan Erik & Brunstad, Harald
(2004).
Petroleum potential and thermal maturity of Palaeozoic sediments from the North Sea region.
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The dominating oil and gas source rocks in the northern North Sea are of Mesozoic age. Especially important are the Upper Jurassic marine clays of the Kimmeridge Clay Formation, deposited in the Jurassic Central and Viking Graben rift structures.
There are however Palaeozoic sediments with possible petroleum potential in both Norwegian and Danish wells in the northern North Sea. We also know that source rocks of Cambro-Silurian, Devonian, Carboniferous and Permian age are found in areas fringing the North Sea, i.e. in Norway, Denmark, Sweden, Poland, Germany, the Netherlands, in the UK and on East Greenland.
In the northern North Sea, thick sequences of marine sediments most likely accumulated in Cambro-Silurian times. Additionally, shales, coals and mudstones of Devonian to Permian age may have been deposited in half-grabens and N-S trending rift basins underlying the Upper Permian Zechstein evaporites.
In this study, we investigate the kerogen types, petroleum potential and thermal maturity of some of these Palaeozoic sediments, and look for traces of Palaeozoic petroleum in reservoir rocks in the North Sea. In the northeastern North Sea, Palaeozoic source rocks may be a crucial part of plays capped by thick Upper Permian evaporite layers.
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Skeie, Jon Erik; Karlsen, Dag Arild; di-Primio, Rolando; Backer-Owe, Kristian; Lie, Jan Erik & Brunstad , Harald
[Show all 8 contributors for this article]
(2003).
How an integrated study combining basin modelling, geochemical data and petroleum properties can constrain the timing of petroleum migration and evolution of overpressures in sedimentary basins. An example utilizing the distribution of petroleum in Mesozoic sediments in the Haltenbanken area, offshore Norway.
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Skeie, Jon Erik; di-Primio, Rolando & Karlsen, Dag Arild
(2003).
An integrated basin modelling study applying asphaltene kinetics from reservoired petroleum in the Snorre Area, Northern North Sea.
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Skeie, Jon Erik; Karlsen, Dag Arild & di-Primio, Rolando
(2002).
The release of petroleum from source rocks; implications for basin modelling.
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Karlsen, Dag Arild
(2000).
Primary migration of hydrocarbons and hydrocarbon generation.
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Hydrocarbon generation from organic matter in shales and carbonates occur by thermocatalytic cracking of a polymer called kerogen. The thermal response of the kerogen during progresive burial of the source rocks will produce specific types of petroleum (oil and gas) depending on the type of organic matter making up the kerogen, the degree of anoxic conditions in the palaeo-depositional environment, the termal profile, and the organization of the organic matter in the source rocks. Oil moves out of good quality source rocks as a singel phase whilst diffusive type mechanisms operate in lean source rocks.
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Karlsen, Dag Arild; Backer-Owe, Kristian & Helland, Reidar
(2000).
Defining dynamics of hydrocarbon zones in reservoir strata using petroleum inclusions distribution and geochemistry.
Show summary
Oil reservoir compartmentalisation is deliniated using geochemical tools and examples from 5 wells in the Gullfaks Sør and the nearby Gullfaks Gamma structure illustrate this approach. The results obtaine does not only help in optimizing field production but do also provide data relevant for understanding better basin scale hydocarbon migration patters. Thus, the methods we illustrate have a clear impact for reservoir production and exploration for hydrocarbon resources.
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Karlsen, Dag Arild; Dahlgren, Sven; Jamtveit, Bjørn & Kjærnet, Torfinn
(2000).
Thermal effects of basaltic sill emplacement in source rocks for maturation & hydrocarbon generation.
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Emplacement of basaltic sills into sedimentary strata may represent a heat source for hydrocarbon generation from shallow source rocks. Mathematical modeling of this phenomena and studies of thin intrusive boddies suggest that the heat impact can be favourably for oil generation. Our studies of real rock systems from Svalbard and nearby islands do, however, suggest the heatimpact to be destructive for oil generation generation.
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Karlsen, Dag Arild; Backer-Owe, Kristian; Bjørlykke, Knut; Berge, Kari & Schaefer, Rainer G.
(2000).
Faults, Oil Migration Overpressure and Dismigration - Dating Events. A case History from the Halten Vest High Pressure Region, Offshore Norway.
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Geochemical evidences from core extracts and fluid inclusions in diagenetic mineral is used to shed light on the overpressure development and palaeo-leakage from currently dry structures in the Haltenbanken area. A new model is presented for the role of faults during hydrocarbon migration and for determining the time for overpressure development
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Brekke, Trond; Karlsen, Dag Arild; Bhullar, Abid Ghafoor; Holm, Kristine; Melberg, Nina & Kvinnsland, Steinar R.
(2000).
Variability in organic extracts from cores from the Frøy reservoir.
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Principal component analysis of organic core extracts from the Frøy oil field reservoir section was used to detail the different potential origins of the organic matter from i.e. to isolate contributions from in-situ generated bitumen from migrated oil from distant source rocks. In-situ contributions can greatly mask the proper origin of migrated oil.
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Khoshbakht, Payam; Karlsen, Dag Arild; Backer-Owe, Kristian & Ohm, Sverre
(2000).
Variations in source facies and matuirty in Central Garaben Oils, Norwegian continental Shelf.
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The poster describes detailed geochemical characteristics of oils in the Central Graben Area. Clear trends in terms of increasing terrestrial contributions to oils from more proximal positions in the basin is demonstrated and oils are grouped into families.
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Karlsen, Dag Arild; Backer-Owe, Kristian & Helland, Reidar
(2000).
Defining Dynamics of Hydrocarbon Zones in reservoir Strata Using petroleum Inclusion - distributions and Geochemistry - Elucidating petroleum migration into the Gullfaks Sør Field and the nearby Gullfaks Gamma Structure, Norwegian Continental Shelf.
Show summary
Examination of core extracts, drill stem tests and fluorescent petroleum inclusions in 5 wells from the Gullfaks Sør and the Gullfaks Gamma structure has showed that these structures have experienced dramatic shift in their gas/oil zones during filling. The structures closest to the filling direction have experienced larger shifts in the contacts as the field filled. The presently gas filled Gamma structure is proved to ahve ealier contained oil. We illustrate how geochemical data are used to construct a filling direction model for the Gullfaks Sør and the Gullfaks Gamma structure.
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Pinturier-Geiss, Laurence; Dale, Barrie; Abdullah, Mohamed I & Karlsen, Dag Arild
(2000).
Lipid composition and cultural eutrophication in the oslofjord (Norway).
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The aim of this work is to evaluate variations in chemical signals extracted from sediments as a mean of tracing out the development of eutrophication, and to compare this with potential parallel variations in the dinocyst assemblages. The lipid fraction of the organic matter was analysed by TLC-FID, GC-FID and GC-MS.Particular attention was given to the polar fraction (phospholipids, glycolipids) and hydrocarbons. The down-core distribution of lipids is strongly correlated with the dinocyst signal.The highest concentrations as well as a marked increase in the HC concentration are observed during the period of intensive eutrophication.The molecular composition of HC and fatty acid methyl esters of the polar fraction enables identification of the predominant source of the Om: bacteria and dinocyst.
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Storvoll, Vidar; Bjørlykke, Knut; Karlsen, Dag Arild & Girish, Saigal
(2000).
Diagenesis and reservoir quality in the Garn Formation from deep wells in the Halten Area.
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Although we would expect extensive quartz cementation and low porosity and permeability values in sandstones buried below 4 km, it is sometimes found that the reservoir quality in the Garn Formation is remarkably good. This study focuses on the diagenetic differences in the Kristin and Lavrans fields and the variations in the reservoir properties. The effect of chlorite coatings are well known from several publications, but this study suggests that illite- and illite/chlorite-coatings also have been most effective in preventing precipitation of quartz. Many of the studied samples contain a more or less continuos fluorescent coatings around the detrial sand grains. A green and "fibrous" coating has been observed in the samples from one of the studied wells, but it is completely absent in the other wells from this area. We conclude that it is mainly the illite- and illite/chlorite-coatings that are responsible for the good reservoir quality in the Garn Formation. The occurance of the fluorescent coatings, the green "fibrous" coatings and the black "asphalt-rich" material found in the pores does not seem to have had any positive influence with respect to the reservoir quality in the Garn Formation from the studied wells. The absence of the clay coatings in the extensively cemented wells is most likely due to variations in the depositional environment.
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Karlsen, Dag Arild; Backer-Owe, Kristian; Bjørlykke, Knut; Scjaefer., R.G.; Bhullar, Abid Ghafoor & Angard, K.
[Show all 11 contributors for this article]
(1999).
Faults and Oil Migration in the Halten Vest High Pressure and Haltenbanken Normal Pressure Regimes, Offshore Norway.
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Karlsen, Dag Arild; Backer-Owe, Kristian; Bjørlykke, Knut; Angard, K.; Steinhoff, Inga & Olstad, Richard
[Show all 9 contributors for this article]
(1999).
Differential pressure across a fault zone and oil migration - an ezample from Haltenbanken offshore, Norway.
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Karlsen, Dag Arild; Dahlgren, Sven; Jamtveit, Bjørn & Kjærnet, Torfinn
(1999).
Thermal effects of basaltic sill emplacement in source rocks maturation and hydrocarbon generation.
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Karlsen, Dag Arild; Dahlgren, Sven; Jamtveit, Bjørn & Kjærnet, Torfinn
(1999).
Thermal effects of basaltic sill emplacement in source rocks for maturation and hydrocarbon generation.
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Bhullar, Abid Ghafoor; Karlsen, Dag Arild; Johansen, H.; Backer-Owe, Kristian; Holm, Kristine & Primio, R. de
(1999).
"The filling history of the Rind and Froy petroleum accumulations, North Sea, using petroleum geochemical, fluid inclusion and PVT data to geological dating".
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Bhullar, Abid Ghafoor; Karlsen, Dag Arild; Holm, Kristine & Primio, R. de
(1999).
"Characterizationn of petroleum fluids in the Frøy Fields and Rind Discovery, NOCS, using petroleum geochemical, fluid inclusion and PVT data. Poster presentation at AAPG Hedberg Conference, Multi-Dimentional Basin Modeling.".
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Bhullar, Abid Ghafoor; Karlsen, Dag Arild; Johansen, H.; Holm, Kristine & Seland, R.T.
(1999).
"The filling history of the Rind and Frøy petroleum accumulations, North Sea - Application of fluid inclusions, core extracts and oils to geological dating".
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Bhullar, Abid Ghafoor; Karlsen, Dag Arild; Holm, Kristine & Lacharpagne, J.C.
(1999).
"Filling history and petroleum characterisation of the Frøy Field and Rind discovery, Nocs, using petroleum geochemical, fluid inclusion and PVT data.".