Fracture attribute scaling and connectivity in the Devonian Orcadian Basin with implications for geologically equivalent sub-surface fractured reservoirs

Dichiarante, Anna M.; McCaffrey, Ken J. W.; Holdsworth, Robert E.; Bjørnarå, Tore I.; Dempsey, Edward D.

Abstract

Fracture attribute scaling and connectivity datasets from analogue systems are widely used to inform sub-surface fractured reservoir models in a range of geological settings. However, significant uncertainties are associated with the determination of reliable scaling parameters in surface outcrops. This has limited our ability to upscale key parameters that control fluid flow at reservoir to basin scales. In this study, we present nine 1D-transect (scanline) fault and fracture attribute datasets from Middle Devonian sandstones in Caithness (Scotland) that are used as an onshore analogue for nearby sub-surface reservoirs such as the Clair field, west of Shetland. By taking account of truncation and censoring effects in individual datasets, our multiscale analysis shows a preference for power-law scaling of fracture length over 8 orders of magnitude (10−4 to 104 m) and kinematic aperture over 4 orders of magnitude (10−6 to 10−2 m). Our assessment of the spatial organization (clustering and topology) provides a new basis for up-scaling fracture attributes collected in outcrop- to regional-scale analogues. We show how these relationships may inform knowledge of geologically equivalent sub-surface fractured reservoirs.

Citation

Dichiarante, A. M., McCaffrey, K. J. W., Holdsworth, R. E., Bjørnarå, T. I., & Dempsey, E. D. (2020). Fracture attribute scaling and connectivity in the Devonian Orcadian Basin with implications for geologically equivalent sub-surface fractured reservoirs. Solid Earth, 11(6), 2221-2244. https://doi.org/10.5194/se-11-2221-2020

• Journal Article Type: Article
• Acceptance Date: Sep 28, 2020
• Online Publication Date: Nov 23, 2020
• Publication Date: 2020
• Deposit Date: Jan 20, 2021
• Publicly Available Date: Jan 20, 2021
• Journal: Solid Earth
• Print ISSN: 1869-9510
• Publisher: European Geosciences Union
• Peer Reviewed: Peer Reviewed
• Volume: 11
• Issue: 6
• Pages: 2221-2244
• DOI: https://doi.org/10.5194/se-11-2221-2020
• Keywords: Earth-Surface Processes; Stratigraphy; Palaeontology; Soil Science; Geology; Geochemistry and Petrology; Geophysics
• Public URL: https://hull-repository.worktribe.com/output/3697259
• Publisher URL: https://se.copernicus.org/articles/11/2221/2020/se-11-2221-2020.html