Lyell Collection
Geological Society, London, Special Publications
Lyell Centre  |   Lyell Collection  |   Subscriptions   |   Geological Society  |   Email alerts  |   Online bookshop  |   Help

Keywords:
Author:
Advanced search>>
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Matchette-Downes, C. J.
Right arrow Articles by Rowland, S.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Geological Society, London, Special Publications; 1994; v. 77; p. 139-148;
DOI: 10.1144/GSL.SP.1994.077.01.08
© 1994 Geological Society of London

Case Histories

A maturity and palaeoenvironmental assessment of condensates and oils from the North Sumatra Basin, Indonesia

C. J. Matchette-Downes1,4, A. E. Fallick2, Karmajaya1,4 & S. Rowland3

1 LEMIGAS Research & Development Centre for Oil & Gas Technology Cipilur Kebayoran Lama, Jakarta, 10002 Indonesia
4 Geochem Group, Chester Street, Chester CH4 8RD, UK
2 SURRC, East Kilbride, Glasgow G75 0QU, UK
3 Petroleum & Environmental Geochemistry Group, Department of Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK

Five light oils and condensates from the wells drilled in Lower to Upper Miocene reservoir rocks of the North Sumatra Basin were analysed by gas chromatography-mass spectrometry and stable isotope ratio mass spectrometry. In conjunction with data from over 1600 well and outcrop samples the results were used to describe the character of the presumed source rocks in terms of organic matter maturity and palaeoenvironment of deposition. The source rock character was further constrained by the maturity of the drilled sections, geothermal gradient observations and re-evaluation of the geology of the region.

Dominant lacustrine with subordinate ombrogenous raised peat bog palaeoenvironments of deposition are indicated. It is envisaged that raised mires fringed large lakes in the area. Tectonic disturbance probably caused periodic flooding of the swamps and ultimately a complete marine incursion occurred.

The oils and condensates are mature to extremely mature. Some oils are mixtures of oils of different maturities and discrete terrestrial sources.





This article has been cited by other articles:


Home page
 Geological Society, London, Special PublicationsHome page
S. P. Todd, M. E. Dunn, and A. J. G. Barwise
Characterizing petroleum charge systems in the tertiary of SE Asia
Geological Society, London, Special Publications, 1997; 126: 25 - 47.
[Abstract] [PDF]