Triassic Palynology of the Central North Sea: Correlation and Environmental Reconstruction of a Fluvial System

Abstract

The Skagerrak Formation is a mid-late Triassic clastic succession from the Central North Sea comprising alternating fluvial sandstone dominated and playa/lacustrine mudstone dominated members. The Sandstone members form important primary and secondary reservoirs in the UKSC whilst the mudstone members can act as potential baffles/seals and lead to the compartmentalisation of these reservoirs. Hydrocarbon extraction has been hampered by a lack of knowledge regarding correlation at a basinal, sub-basinal and field scale and to date the identification; distribution and correlation of the different members is still poorly understood. Palynology is powerful tool for well correlation, age assessment and environmental reconstruction and is routinely used within the Petroleum industry. However previous attempts at utilizing palynology from Triassic sediments within the Central North Sea have generally yielded poor recovery due to a combination of PDC drilling techniques, oil based muds, poor preservation and the heavily oxidised nature of these sediments. By utilising state of the art palynology processing techniques this study shows it is possible to maximise and concentrate palynomorph content from drillcore and well cuttings to construct a robust age model providing the chronostratigraphic framework needed to accurately correlate the different members within the Skagerrak formation as well as allowing for accurate environmental reconstruction. The focus of this study is on quadrants 22, 29 & 30 from the Central North Sea with further worked planned to extend the study area into the Norwegian North Sea and Northern North Sea. This will then allow for a better regional understanding of the Skagerrak formation within North Sea and help aid further hydrocarbon exploration and exploitation.

AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017