Skip to Main Content
Book Chapter

Source rock quality and maturity and oil types in the NW Danish Central Graben: implications for petroleum prospectivity evaluation in an Upper Jurassic sandstone play area

By
H. I. Petersen
H. I. Petersen
Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark (e-mail: hip@geus.dk)
Search for other works by this author on:
H. P. Nytoft
H. P. Nytoft
Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark (e-mail: hip@geus.dk)
Search for other works by this author on:
H. Vosgerau
H. Vosgerau
Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark (e-mail: hip@geus.dk)
Search for other works by this author on:
C. Andersen
C. Andersen
Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark (e-mail: hip@geus.dk)
Search for other works by this author on:
J. A. Bojesen-Koefoed
J. A. Bojesen-Koefoed
Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark (e-mail: hip@geus.dk)
Search for other works by this author on:
A. Mathiesen
A. Mathiesen
Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark (e-mail: hip@geus.dk)
Search for other works by this author on:
Published:
January 01, 2010

Abstract

The principal exploration targets in the northwestern part of the Danish Central Graben have been Upper Jurassic sandstone reservoirs. The presence and effectiveness of the oil-generating rocks of the Upper Jurassic–lowermost Cretaceous marine shales of the Farsund Formation has generally not been considered as a significant risk. This study provides an evaluation of the source rock quality, maturity and distribution and of the oils in this area. The kerogen in the Farsund Formation is algal-derived, and kerogen type ranges from Type II to Type III. Generally the source rock quality is fair to excellent, but the petroleum generation potential varies considerably. In most wells the uppermost part of the Farsund Formation (Bo Member) consists of highly oil-prone shales. However, the presence of oil-prone kerogen may be masked by kerogen of poorer source quality. Favourable conditions for oil-prone kerogen preservation were present during the time of deposition of upper parts of the Farsund Formation, but exceptions are not unusual. Similar vitrinite reflectance gradients indicate a uniform thermal regime over the area. The oil window occurs from c. 3800–4000 to 4800 m, i.e. spanning approximately 800–1000 m. A general decrease in the generation potential from the top towards the base of the formation is caused by both generation and deterioration of kerogen quality. The Gertrud Graben and Feda Graben constitute the main kitchen areas, and oil compositions indicate sourcing from marine shales. In the shallow parts of the Outer Rough Basin the shales are mostly immature and the sourcing is dependent on kitchen areas outside the area or on Palaeozoic rocks. Mature Zechstein is indicated by a minor oil show probably locally sourced.

You do not currently have access to this article.
Don't already have an account? Register

Figures & Tables

Contents

Geological Society, London, Petroleum Geology Conference series

Petroleum Geology: From Mature Basins to New Frontiers – Proceedings of the 7th Petroleum Geology Conference

B. A. Vining
B. A. Vining
Baker Hughes, UK
Search for other works by this author on:
S. C. Pickering
S. C. Pickering
Schlumberger, Gatwick, UK
Search for other works by this author on:
Geological Society of London
Volume
7
ISBN electronic:
9781862394131
Publication date:
January 01, 2010

GeoRef

References

Related

A comprehensive resource of eBooks for researchers in the Earth Sciences

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

View Article Abstract & Purchase Options

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

Subscribe Now