PGK Monthly Lecture
Stefan Peeters (TNO) will talk about:
“Seismic and petrographic characterisation of the Zechstein Hauptdolomit around the Dutch Elbow Spit High”
The Zechstein Supergroup (German for “mine stone”) is a succession of Upper Permian evaporites, carbonates and siliciclastics that were deposited in the Southern Permian Basin. The Zechstein Supergroup was deposited into 4 cycles under warm and arid conditions (Patruno et al., 2017; Grant et al., 2019). Each Zechstein cycle is characterized by an initial transgression, followed by a phase of regression during which vast amounts of halite were deposited in the central parts of the basin (Geluk, 2007). Meso-, and Cenozoic halokinesis later formed the typical salt pillows, salt diapirs and salt walls that today make the Zechstein instantly recognisable on seismic data in the Southern North Sea area. Towards the paleo basin margins of the Southern Permian Basin, the Zechstein is thinner and mainly consists of fringe deposits, including carbonates, anhydrites and siliciclastics. For several decades, in particular the Hauptdolomit (ZEZ2C) platforms have been known as proven hydrocarbon reservoirs, especially on the southern margin of the Southern Permian Basin in the onshore parts of the Netherlands, Germany and Poland. More recently, discoveries south of the Mid North Sea High on the British side have highlighted the relevance of this play also around the northern margin of the Southern Permian Basin. The reservoir quality of the Hauptdolomit is strongly correlated with the depositional setting. On the edge of the carbonate platforms, porosity may exceed 20% in oolitic grainstones, whereas microcrystalline basinal deposits can be considered completely tight (Patruno et al., 2017). Earlier work performed by Geluk (2007) and Tolsma (2014) has led to a general understanding of Hauptdolomit platform occurrences around the Dutch Elbow Spit High, which can be considered as the eastward extension of the Mid North Sea High. However, major knowledge gaps still exist regarding the paleogeography and the exact configuration of Hauptdolomit platforms in this area. By using a multidisciplinary approach of seismic-, and well log interpretation, combined with new petrographic analyses from cores and cuttings, a better understanding was obtained regarding the Hauptdolomit paleogeography and the distribution of Hauptdolomit platforms around the Elbow Spit High. Because of the importance of (domestic) natural gas in the energy transition, understanding the Hauptdolomit facies around the Elbow Spit High is crucial in assessing the remaining hydrocarbon potential for this under evaluated play in the northern Dutch offshore.
The work that will be presented to you, was a joint effort between TNO and Cambridge Carbonates and was commissioned by EBN as part of the ZEPHYR project.
About the presenter
Stefan Peeters is a structural geologist by background and graduated from Utrecht University in 2016. For the last 3.5 years, he has been working at TNO, where he conducts tectonostratigraphic analyses and creates geological models by making use of seismic- and well log data. In the past few years, he has been involved in several TNO multi-disciplinary studies that have focussed on various intervals in the Dutch offshore, such as ZEPHYR (Zechstein), MAXIM (Upper Jurassic) and CREST (Upper Cretaceous).
Millers, Plein 10, Den Haag.