scholarly journals Colophon, contents, abstract, introduction, geological setting, previous work and material and methods

2007 ◽  
Vol 12 ◽  
pp. 1-16 ◽  
Author(s):  
Poul Schiøler ◽  
Jan Andsbjerg ◽  
Ole R. Clausen ◽  
Gregers Dam ◽  
Karen Dybkjær ◽  
...  
Keyword(s):  
North Sea ◽  
Geological Survey ◽  
Energy Research ◽  
British Geological Survey ◽  
New Members ◽  
The North ◽  
Reference Sections ◽  
Neogene Sediments ◽  
The North Sea ◽  
Constructive Criticism

Schiøler, P., Andsbjerg, J., Clausen, O.R., Dam, G., Dybkjær, K., Hamberg, L., Heilmann-Clausen, C., Johannessen, E.P., Kristensen, L.E., Prince, I. & Rasmussen, J.A. 2007: Lithostratigraphy of the Palaeogene – Lower Neogene succession of the Danish North Sea. Geological Survey of Denmark and Greenland Bulletin 12, 77 pp. + 5 plates. As a result of a lithological, sedimentological and biostratigraphic study of well sections from the Danish sector of the North Sea, including some recently drilled exploration wells on the Ringkøbing–Fyn High, the lithostratigraphic framework for the siliciclastic Palaeogene to Lower Neogene sediments of the Danish sector of the North Sea is revised. The sediment package from the top of the Chalk Group to the base of the Nordland Group is subdivided into seven formations containing eleven new members. The existing Våle, Lista, Sele, Fur, Balder, Horda and Lark Formations of previously published lithostratigraphic schemes are adequate for a subdivision of the Danish sector at formation level. Bor is a new sandstone member of the Våle Formation. The Lista Formation is subdivided into three new mudstone members: Vile, Ve and Bue, and three new sandstone members: Tyr, Idun and Rind. Kolga is a new sandstone member of the Sele Formation. Hefring is a new sandstone member of the Horda Formation. Freja and Dufa are two new sandstone members of the Lark Formation. Danish reference sections are established for the formations, and the descriptions of their lithology, biostratigraphy, age and palaeoenvironmental setting are updated. Acknowledgements: Aage Bach Sørensen (GEUS) is thanked for help with seismic interpretations. Yvonne Desezar, Johnny E. Hansen and Birthe Amdrup are thanked for preparation of microfossil and palynology samples. The referees Robert W.O’B. Knox (British Geological Survey) and Paul van Veen (ConocoPhilips Norway) are thanked for their constructive criticism of the manuscript; the editorial contributions of Adam A. Garde, Jon R. Ineson and Martin Sønderholm are gratefully acknowledged. This work was made possible through grants from the Danish Energy Authority, under the Energy Research Project Framework 2000.

scholarly journals Lithostratigraphy of the Palaeogene – Lower Neogene succession of the Danish North Sea

2007 ◽  
Vol 12 ◽  
pp. 1-77 ◽  
Author(s):  
Poul Schiøler ◽  
Jan Andsbjerg ◽  
Ole R. Clausen ◽  
Gregers Dam ◽  
Karen Dybkjær ◽  
...  
Keyword(s):  
North Sea ◽  
New Members ◽  
The North ◽  
Reference Sections ◽  
Neogene Sediments ◽  
The North Sea

As a result of a lithological, sedimentological and biostratigraphic study of well sections from the Danish sector of the North Sea, including some recently drilled exploration wells on the Ringkøbing–Fyn High, the lithostratigraphic framework for the siliciclastic Palaeogene to Lower Neogene sediments of the Danish sector of the North Sea is revised. The sediment package from the top of the Chalk Group to the base of the Nordland Group is subdivided into seven formations containing eleven new members. The existing Våle, Lista, Sele, Fur, Balder, Horda and Lark Formations of previously published lithostratigraphic schemes are adequate for a subdivision of the Danish sector at formation level. Bor is a new sandstone member of the Våle Formation. The Lista Formation is subdivided into three new mudstone members: Vile, Ve and Bue, and three new sandstone members: Tyr, Idun and Rind. Kolga is a new sandstone member of the Sele Formation. Hefring is a new sandstone member of the Horda Formation. Freja and Dufa are two new sandstone members of the Lark Formation. Danish reference sections are established for the formations, and the descriptions of their lithology, biostratigraphy, age and palaeoenvironmental setting are updated.

scholarly journals A revised lithostratigraphy for the Palaeogene – lower Neogene of the Danish North Sea

2005 ◽  
Vol 7 ◽  
pp. 21-24
Author(s):  
Poul Schiøler ◽  
Jan Andsbjerg ◽  
Ole R. Clausen ◽  
Gregers Dam ◽  
Karen Dybkjær ◽  
...  
Keyword(s):  
North Sea ◽  
Energy Agency ◽  
Sequence Stratigraphic ◽  
Oil Companies ◽  
The North ◽  
Reference Sections ◽  
Stratigraphic Model ◽  
Lithostratigraphic Units ◽  
The North Sea ◽  
Stratigraphic Nomenclature

Intense drilling activity following the discovery of the Siri Field in 1995 has resulted in an improved understanding of the siliciclastic Palaeogene succession in the Danish North Sea sector (Fig. 1). Many of the new wells were drilled in the search for oil reservoirs in sand bodies of Paleocene–Eocene age. The existing lithostratigraphy was based on data from a generation of wells that were drilled with deeper stratigraphic targets, with little or no interest in the overlying Palaeogene sediments, and thus did not adequately consider the significance of the Palaeogene sandstone units in the Danish sector. In order to improve the understanding of the distribution, morphology and age of the Palaeogene sediments, in particular the economically important sandstone bodies, a detailed study of this succession in the Danish North Sea has recently been undertaken. An important aim of the project was to update the lithostratigraphic framework on the basis of the new data.The project was carried out at the Geological Survey of Denmark and Greenland (GEUS) with participants from the University of Aarhus, DONG E&P and Statoil Norway, and was supported by the Danish Energy Agency. Most scientific results cannot be released until September 2006, but a revised lithostratigraphic scheme may be published prior to that date. Formal definition of new units and revision of the lithostratigraphy are in preparation. All of the widespread Palaeogene mudstone units in the North Sea have previously been formally established in Norwegian or British wells, and no reference sections exist in the Danish sector. As the lithology of a stratigraphic unit may vary slightly from one area to another, Danish reference wells have been identified during the present project, and the lithological descriptions of the formations have been expanded to include the appearance of the units in the Danish sector. Many of the sandstone bodies recently discovered in the Danish sector have a limited spatial distribution and were sourced from other areas than their contemporaneous counterparts in the Norwegian and British sectors. These sandstone bodies are therefore defined as new lithostratigraphic units in the Danish sector, and are assigned Danish type and reference sections. There is a high degree of lithological similarity between the Palaeogene–Neogene mudstone succession from Danish offshore boreholes and that from onshore exposures and boreholes, and some of the mudstone units indeed seem identical. However, in order to acknowledge the traditional distinction between offshore and onshore stratigraphic nomenclature, the two sets of nomenclature are kept separate herein. In recent years oil companies operating in the North Sea have developed various in-house lithostratigraphic charts for the Paleocene–Eocene sand and mudstone successions in the Danish and Norwegian sectors. A number of informal lithostratigraphic units have been adopted and widely used. In the present project, these units have been formally defined and described, maintaining their original names whenever feasible, with the aim of providing an unequivocal nomenclature for the Palaeogene – lower Neogene succession in the Danish sector. It has not been the intention to establish a sequence stratigraphic model for this succession in the North Sea; the reader is referred to the comprehensive works of Michelsen (1993), Neal et al. (1994), Mudge & Bujak (1994, 1996a, b), Michelsen et al. (1995, 1998), Danielsen et al. (1997) and Rasmussen (2004).

Porosity estimates from marine controlled source electromagnetic dipole-dipole data at the Scanner Pockmark in the North Sea

2020 ◽  
Author(s):  
Romina Gehrmann ◽  
Giuseppe Provenzano ◽  
Christoph Böttner ◽  
Naima Yilo ◽  
Gaye Bayrakci ◽  
...  
Keyword(s):  
North Sea ◽  
Seismic Data ◽  
Sediment Cores ◽  
Dipole Source ◽  
Inversion Algorithm ◽  
British Geological Survey ◽  
Controlled Source ◽  
The North ◽  
Rock Drill ◽  
The North Sea

<p>As part of the EU Horizon2020 ‘STEMM-CCS’ project, controlled source electromagnetic (CSEM) and seismic data were acquired in 2017 at the Scanner Pockmark in the UK sector 15/25 of the North Sea, which is actively venting methane gas, to contribute to the evaluation of risk from potential fluid pathways to the sequestration of carbon dioxide in geological formations. We will present some preliminary results and relate electrical resistivities to sediment properties such as porosity and gas saturation.</p><p>The CSEM data presented were acquired with a University of Southampton deep-towed electric dipole source and two towed three axis dipole receivers (Vulcan, Scripps) along 12 profiles across an active pockmark. The data were processed in the frequency domain and the electrical resistivity structure was inferred with a 2D regularized inversion algorithm (MARE2DEM, K. Key).</p><p>To estimate porosities and their uncertainties to about 200 m below the seafloor, we use the empirical Archie’s law and calibrate Archie’s coefficient using physical properties measured with the multi-sensor core logger on gravity cores and sediment cores from the British Geological Survey Rock Drill 2 rig. Geological horizons identified on reflection seismic data are used as constraints in the resistivity model. The resulting porosity profile decreases with depth due to compaction and can be related to marine and glacial deposition environments.</p>

scholarly journals A new method for bulk palynological processing of oil-contaminated chalks

1991 ◽  
Vol 10 (2) ◽  
pp. 202-202 ◽  
Author(s):  
Ingerlise Nørgaard ◽  
Anne-Marie Rasmussen ◽  
Poul Schiøler ◽  
Svend Stouge
Keyword(s):  
North Sea ◽  
Hydrofluoric Acid ◽  
Acid Treatment ◽  
Upper Cretaceous ◽  
Treatment Process ◽  
Reaction Vessel ◽  
Geological Survey ◽  
Large Sample Size ◽  
The North ◽  
The North Sea

Abstract. INTRODUCTIONThe application of palynomorphs in well-site dating and correlation within the Upper Cretaceous—Danian Chalk Group of the North Sea, is currently being investigated at the Geological Survey of Denmark. Due to the relatively low abundance of palynomorphs in the chalks, a large sample size (100–300g) is often needed to obtain representative microfloras. Palynological preparation of large chalk samples does, however, create processing problems, especially if the samples derive from oil bearing intervals. The aim of this note is to describe a method developed at the Geological Survey of Denmark to overcome these processing problems.PROBLEMS IN THE PREPARATION OF LARGE CHALK SAMPLES.The problems during the preparation process comprise the following factors: The dissolution of carbonates from 100—300g sized chalk samples with hydrochloric acid causes a vigorous reaction that developes vast amounts of foam. The foam development is usually controlled by spraying alcohol or the more hazardous acetone into the reaction vessel; these solvents reduce the vigorous expansion of the foam by reducing the surface tension of the acid. This procedure, however, demands constant surveillance of the acid treatment, because the effect of the solvents is of short duration. Furthermore, the initial vigorous reaction restricts the use of stronger, more effective hydrofluoric acid concentrations to later parts of the acid treatment process, where the reaction is more calm. In the Danish sector of the North Sea, the main producing reservoir is situated in the Chalk Group. Core samples from the Chalk Group are therefore usually usually oil bearing . . .

scholarly journals Preface

1991 ◽  
Vol 16 ◽  
pp. 5-5
Author(s):  
Nils Frandsen
Keyword(s):  
North Sea ◽  
Working Group ◽  
Geological Survey ◽  
The North ◽  
Central Trough ◽  
Southern Central ◽  
The North Sea ◽  
Lithostratigraphic Correlation

In June 1989, Dansk Olie- og Gasproduktion A/S (DOPAS) sponsored a well-attended symposium on the Jurassic in the Southern Central Trough held at the DOPAS premises in Hørsholm, Denmark. The background for the symposium was a desire among geologists working in the Dutch, German and Danish sectors of the North Sea to establish a forum to discuss problems of lithostratigraphic correlation across the sector boundaries and eventually arrive at a common nomenclature. A number of lectures were held at the symposium and an informal working group was established to deal with the details of lithostratigraphic correlation. The present publication, sponsored partly by DOPAS and partly by the Geological Survey of Denmark (DGU), contains extended abstracts of the lectures.

scholarly journals Increased oil recovery from Halfdan chalk by flooding with CO2-enriched water: a laboratory experiment

1969 ◽  
Vol 17 ◽  
pp. 17-20
Author(s):  
Dan Olsen
Keyword(s):  
North America ◽  
Laboratory Experiment ◽  
North Sea ◽  
Oil Recovery ◽  
Oil Field ◽  
Geological Survey ◽  
Low Permeability ◽  
The North ◽  
The North Sea ◽  
Increased Oil Recovery

Injection of CO2 is a method that may increase the recovery of oil from Danish chalk reservoirs in the North Sea. The method is used elsewhere, particularly in North America, but has so far not been used in the North Sea and has nowhere been used for chalk reservoirs, and the performance of the method when used for North Sea chalk is therefore uncertain. A laboratory flooding experiment was conducted at the Geological Survey of Denmark and Greenland on a sample from the Nana-1X well of the Halfdan oil field in the Danish North Sea in order to test the efficiency of CO2-enriched water to produce additional oil from chalk. The sample is a low-permeability chalk from the Ekofisk Formation and represents rocks that are marginal to the Halfdan reservoir in an economical sense.

scholarly journals Some geological results from the first five Danish exploration wells in the North Sea. Dansk Nordsø A-1, A-2, B-1, C-1, and D-1

1974 ◽  
Vol 42 ◽  
pp. 1-46
Author(s):  
Leif Banke Rasmussen
Keyword(s):  
Continental Shelf ◽  
North Sea ◽  
Main Part ◽  
Geological Survey ◽  
Upper Miocene ◽  
Subsurface Geology ◽  
The North ◽  
The North Sea

After an introducing survey of the exploration for hydrocarbons on the Danish continental shelf during the period from 1963 to 1968 a lithological and chronostratigraphical description of the first five exploration wells is given. The results are preliminary and they are based on investigations carried out by the staff of the Department of Subsurface Geology at the Geological Survey of Denmark.Deposits of Permian, Triassic, Jurassic, Cretaceous, Tertiary and Quaternary age are proved to occur in the borings. Stratigraphical investigations of the very thick Tertiary sequence in the central part of the North Sea show, that the main part of the sedimentation took place during the younger Miocene (Upper Miocene).

scholarly journals Aero-elastic loads on a 10 MW turbine exposed to extreme events selected from a year-long Large-Eddy Simulation over the North Sea

2020 ◽  
Author(s):  
Gerard Schepers ◽  
Pim van Dorp ◽  
Remco Verzijlbergh ◽  
Peter Baas ◽  
Harmen Jonker
Keyword(s):  
Large Eddy Simulation ◽  
North Sea ◽  
Practical Importance ◽  
Research Centre ◽  
Energy Research ◽  
Eddy Simulation ◽  
The North ◽  
Large Eddy ◽  
The North Sea ◽  
A Site

Abstract. In this article the aero-elastic loads on a 10 MW turbine in response to unconventional wind conditions selected from a year long Large Eddy Simulation on a site at the North Sea are evaluated. Thereto an assessment is made of the practical importance of these wind conditions within an aero-elastic context based on high fidelity wind modelling. Moreover the accuracy of BEM based methods for modelling such wind conditions is assessed. The study is carried out in a joint effort by the Energy Research Centre of the Netherlands ECN part of TNO and the Dutch meteorological consultancy company Whiffle.

Sign in / Sign up

Export Citation Format

Share Document