Basement reservoir plumbing: fracture aperture, length and topology analysis of the Lewisian Complex, NW Scotland
| Autor: | K. Hardman, Robert E. Holdsworth, J. Pless, Ken McCaffrey, B. S. G. Franklin |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
geography
geography.geographical_feature_category Rift 010504 meteorology & atmospheric sciences Geology Fault (geology) 010502 geochemistry & geophysics 01 natural sciences Unconformity Lewisian complex Basement (geology) Ridge Fracture (geology) Petrology 0105 earth and related environmental sciences Gneiss |
| Zdroj: | Journal of the Geological Society, 2020, Vol.177(6), pp.1281-1293 [Peer Reviewed Journal] |
| ISSN: | 2041-479X 0016-7649 |
| Popis: | Upfaulted ridges of Neoarchean crystalline basement rocks formed in the Faeroe-Shetland basin as a consequence of Mesozoic rift processes and are an active target for oil exploration. We carried out a comprehensive fault and fracture attribute study on the extensive exposures of geologically equivalent crystalline basement rocks onshore in NW Scotland (Lewisian Gneiss Complex) as an analogue for the offshore oil and gas reservoirs of the uplifted Rona Ridge basement high. Our analysis shows a power-law distribution for fracture sizes (aperture and length), with random to clustered spacing and high connectivity indices. Regional variations between the Scottish mainland and the Outer Hebrides are recognized that compare directly with variations observed along the Rona Ridge in the Faeroe-Shetland basin. Here we develop a model for the scaling properties of the fracture systems in which variations in the aperture attributes are a function of the depth of erosion beneath the top basement unconformity. More generally, the combination of size, spatial and connectivity attributes we found in these basement highs demonstrates that they can form highly effective, well-plumbed reservoir systems in their own right. Supplementary material: Additional methods and results are available at: https://doi.org/10.6084/m9.figshare.c.5017139 Thematic collection: This article is part of the The Geology of Fractured Reservoirs collection available at: https://www.lyellcollection.org/cc/the-geology-of-fractured-reservoirs |
| Databáze: | OpenAIRE |
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