The role of relay ramp evolution in governing sediment dispersal and petroleum prospectivity of syn-rift stratigraphic plays in the Northern North Sea
| Autor: | John R. Underhill, Ryan M. Williams, Rachel J. Jamieson |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
geography
geography.geographical_feature_category Rift Northern North Sea basin Continental shelf 020209 energy Geology 02 engineering and technology Fault (geology) 010502 geochemistry & geophysics 01 natural sciences Petroleum reservoir Sedimentary depositional environment Paleontology Fuel Technology Geochemistry and Petrology Clastic rock 0202 electrical engineering electronic engineering information engineering Earth and Planetary Sciences (miscellaneous) Echelon formation Economic Geology 0105 earth and related environmental sciences |
| Zdroj: | Petroleum Geoscience. 26:232-246 |
| ISSN: | 2041-496X 1354-0793 |
| DOI: | 10.1144/petgeo2019-096 |
| Popis: | Interpretation of a 3D seismic survey located on the western margin of the Northern North Sea Basin demonstrates how the propagation, overlap and linkage of two north–south-striking, en echelon normal fault segments exerted a powerful influence over prospective subtle stratigraphic traps. The relay ramp that formed between the segments appears to have focused sediment dispersal, controlled reservoir distribution and aided post-depositional petroleum migration. Integration of electrical well log data, root-mean-square (RMS)-amplitude analysis and biostratigraphy with seismic interpretation demonstrates that a series of elongate, linear, sand-prone (reservoir) channel complexes characterize the depositional slopes generated by fault growth. The combination of synsedimentary rotation of bedding due to fault propagation and associated footwall uplift led to erosion and truncation of a laterally extensive, older channelized system (Lower Sequence), the downdip parts of which extend beyond the relay ramp. Its subsequent drape by transgressive shales created the subtle stratigraphic trap that now hosts the Cladhan Field, with charge occurring because the sandstones belonging to the Lower Sequence extend as far as the active kitchen in the neighbouring (hanging-wall) depocentre situated downdip and to the east. In contrast, the exploration of a younger, Upper Sequence of sandstones has proven to be disappointing due to their more restricted distribution, lack of access to charge, and occurrence of faults that offset and breach the thin end of the stratigraphic wedge. The implication is that partially breached relay ramps not only provide a preferential site for synrift clastic reservoirs to develop but also form important migration pathways through which oil passed from a petroleum kitchen into a trap. Thematic collection: This article is part of the Under-explored plays and frontier basins of the UK continental shelf collection available at: http://www.lyellcollection.org/cc/under-explored-plays-and-frontier-basins-of-the-uk-continental-shelf |
| Databáze: | OpenAIRE |
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