Cretaceous Stratigraphic Patterns and Exploration Concepts on the Arabian Plate

Abstract

The search for remaining reserves in mature basins, such as on the Arabian Plate, demands an increasingly detailed understanding of the stratigraphic architecture and basin history. This effort requires the full integration of different subsurface datasets, as well as the application of geological concepts, (outcrop-) analogues and a range of modelling techniques. In this presentation we will focus on the Cretaceous and demonstrate how a re-evaluation of eustatic fluctuations in sea-level, combined with a plate-wide dataset, allows us to improve our prediction at the exploration and production scale and identify potentially new play concepts. A literature based synthesis has provided evidence for significant variations in the magnitude of short-term eustatic sea-level changes during the Cretaceous, which vary from a few meters to over 60m. These variations appear to be organised in four broad trends (I: Berriasian to early Hauterivian; II: late Hauterivian to Aptian; III: Albian to Coniacian; IV: Santonian to Maastrichtian) that represent general increases (I, II and IV) and a decrease (III) in magnitude. Due to the relatively stable tectonic nature of the Arabian Plate during the Early and Mid Cretaceous eustatic sea-level fluctuations have been recognised as a key driver for stratigraphic heterogeneity and architecture. Based upon our newly acquired knowledge of global trends in sea-level magnitudes the hierarchy of different orders of sequences and the resulting stacking patterns has been re-assessed for the Arabian Plate. The stacked 3rd and 2nd order sequences provide an excellent time framework to document and predict stratigraphic patterns in different depositional settings, such as carbonate, siliciclastic, evaporitic and mixed systems. The added value of establishing an overview of these sedimentation patterns lays in the recognition of the local variation – due to e.g. lithology, climate, oceanography – on the overall global pattern. This, in turn, allows us to interrogate less studied local stratigraphic records elsewhere with global concepts in mind, which may lead to the introduction of new play concepts.

AAPG Datapages/Search and Discovery Article #90364 © 2019 AAPG Middle East Geoscience Technology Workshop, Integrated Emerging Exploration Concepts: Challenges, Future Trends and Opportunities, Dhahran, Saudi Arabia, December 2-4, 2019