Title
The role of salt tectonics and overburden in the generation of overpressure in the Dutch North Sea area
Author
Nelskamp, S.
Verweij, J.M.
Witmans, N.
Publication year
2012
Abstract
In this paper we study the effects of timing of salt movement and mechanical compaction on the generation of overpressures in Mesozoic rocks. To that end we apply 2D basin modelling on two N-S trending cross sections in the Dutch Central Graben and Terschelling Basin, respectively. Several overpressuring scenarios were calculated by modifying the mechanical compaction of the sealing layer, the rate of sedimentation, and the timing of salt movement. Pressure and porosity measurements from several wells along the cross sections were used as calibration data. The results show that rapid sedimentation and early compaction of Pliocene to Quaternary mudstones explain most of the overpressures in the Cretaceous and Jurassic rocks. The modifications of the mechanical compaction of the Upper Cretaceous Chalk Group performed in this study could not explain the overpressure anomalies in the southern part of the Dutch Central Graben. Processes such as chemical compaction are probably more important in this respect. Overpressures in the Triassic are mainly controlled by the timing of salt movement and the closure of lateral seals. This study has lead to a better understanding of the processes that generate overpressures and those that are involved in their lateral distribution. The integration of modelling scenarios and information on the timing of seal formation enables to define new play concepts and is important for the assessment of possible drilling hazards as well.
Subject
Geosciences
Geological Survey Netherlands
Energy / Geological Survey Netherlands
Earth & Environment
PG - Petroleum Geosciences GM - Geomodelling
EELS - Earth, Environmental and Life Sciences
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http://resolver.tudelft.nl/uuid:c949a6b9-6618-414d-b9a0-ba5239275305
TNO identifier
467030
Source
Netherlands Journal of Geosciences — Geologie en Mijnbouw, 91 (91), 517-534
Bibliographical note
Commemorative volume on the centenary of KNGMG
Document type
article