Characterization of thin-bedded turbidites in the North Brae Field, South Viking Graben, North Sea

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

Heterogeneity in hydrocarbon reservoirs has significant impact on fluid flow during production and may lead to oil being trapped in low-permeability reservoir compartments. This is particularly true for producing turbidite fields with significant thin-bedded turbidite (TBT; 3-10 cm [1.2-3.9 in.] sand and silt unit) and very thin-bedded turbidite (VTBT; 1-3 cm [0.4-1.2 in.] sand and silt unit) successions. The principal geological attributes used to characterize TBT-VTBT include facies and facies associations, sandstone/mudstone ratio, bed geometry, sand connectivity, sediment texture, sedimentary structures, and vertical sequences of bed thickness. Their combination enables definition of four fundamental attribute indices that reflect the reservoir quality of TBT-VTBT successions. The attribute indices are sand connectivity index, sediment textural index, facies ratio index, and facies net-to- gross index. Twenty TBT and VTBT facies are recognized in cores from North Brae field wells. The combination of results from the application of the attribute indices approach to core data from the field reveals six facies associations (FA), which may also be applicable elsewhere, each characterized by different attribute indices. FA1 has high-to- very-high sand connectivity and textural indices (mature, fine-medium- grained, well-sorted sand). Its core-based porosities and horizontal and vertical permeabilities indicate that it possesses the most favorable reservoir properties. For FA2, a lower sand connectivity index because of extensive mudstone lamination signals poorer quality reservoir features. FA3 and FA4 show moderate attribute indices and mixed reservoir quality facies, whereas more studies are needed to determine the suitability of FA5 and FA6 for potential shale gas exploitation in other areas.

Original languageEnglish
Title of host publicationRift-Related Coarse-Grained Submarine Fan Reservoirs; the Brae Play, South Viking Graben, North Sea
EditorsColin C. Turner, Bryan T. Cronin
PublisherAmerican Association of Petroleum Geologists
Pages257-281
Number of pages25
ISBN (Electronic)9780891813958
DOIs
Publication statusE-pub ahead of print - 2018

Publication series

NameAAPG Memoir
Volume115
ISSN (Print)0271-8529

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ASJC Scopus subject areas

  • Economic Geology

Cite this

Omoniyi, B. A., Stow, D. A. V., & Gardiner, A. R. (2018). Characterization of thin-bedded turbidites in the North Brae Field, South Viking Graben, North Sea. In C. C. Turner, & B. T. Cronin (Eds.), Rift-Related Coarse-Grained Submarine Fan Reservoirs; the Brae Play, South Viking Graben, North Sea (pp. 257-281). (AAPG Memoir; Vol. 115). American Association of Petroleum Geologists. https://doi.org/10.1306/13652184M1153811