1887

Abstract

Summary

The lack of a predictive tool for calculating fault permeability in carbonate reservoirs has led to an increasing amount of research towards the permeability structure of carbonate-hosted fault zones. However, a better understanding of fault rock distributions and their potential petrophysical properties is required to predict the impact of faults in carbonate reservoirs. This research combines structural, microstructural and petrophysical data from a series of carbonate-hosted fault zones in Malta, enabling an understanding of the fault zone permeability structures in various lithofacies, whilst highlighting the heterogeneity on all scales of carbonate-hosted fault zones. From the studied exposures, fault displacements of 30 m are required for a continuous fault core, but 100–200 m displacement is required for a continuous cataclasite veneer. Fault rocks have reduced macro-scale heterogeneity compared to host rocks, whilst the outcrop scale heterogeneity is increased. Fault rock permeability measurements show that permeability is reduced relative to the host rock for all faulted lithofacies. Cataclasite exhibits the lowest permeability (geometric average = 10−3 mD). These reductions are large enough to have a noticeable impact on fluid flow over production scales for the c.60% of high porosity fault rocks, however less than 10% of fault rocks derived from low porosity host rocks exhibit these permeability reductions. 30% of fault rocks derived from high porosity host rocks exhibit permeability reductions sufficient to behave as a significant barrier to fluid flow.

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/content/papers/10.3997/2214-4609.201902312
2019-09-08
2020-08-05
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References

  1. Agosta, F., Prasad, M. & Aydin, A.
    2007. Physical properties of carbonate fault rocks, fucino basin (Central Italy): implications for fault seal in platform carbonates. Geofluids, 7, 19–32.
    [Google Scholar]
  2. Antonellini, M., Petracchini, L., Billi, A. & Scrocca, D.
    2014. First reported occurrence of deformation bands in a platform limestone, the Jurassic Calcare Massiccio Fm., northern Apennines, Italy. Tectonophysics, 628, 85–104, https://doi.org/10.1016/j.tecto.2014.04.034.
    [Google Scholar]
  3. Bauer, H., Schrockenfuchs, T.C. & Decker, K.
    2016. Hydrogeological properties of fault zones in a karstified carbonate aquifer (Northern Calcareous Alps, Austria). Hydrogeology Journal, 24, 1147–1170, https://doi.org/10.1007/s10040-016-1388-9.
    [Google Scholar]
  4. Cooke, A.P., Fisher, Q.J., Michie, E.A.H. & Yielding, G.
    2018. Investigating the controls on fault rock distribution in normal faulted shallow burial limestones, Malta, and the implications for fluid flow. Journal of Structural Geology, 114, 22–42, https://doi.org/10.1016/j.jsg.2018.05.024.
    [Google Scholar]
  5. Dart, C.J., Bosence, D.W.J. & McClay, K.R.
    1993. Stratigraphy and structure of the Maltese graben system. Journal of the Geological Society, London, 150, 1153–1166, https://doi.org/https://doi.org/10.1144/gsjgs.150.6.1153.
    [Google Scholar]
  6. Géraud, Y., Diraison, M. & Orellana, N.
    2006. Fault zone geometry of a mature active normal fault: A potential high permeability channel (Pirgaki fault, Corinth rift, Greece). Tectonophysics, 426, 61–76, https://doi.org/10.1016/j.tecto.2006.02.023.
    [Google Scholar]
  7. Haines, T.J., Michie, E.A.H., Neilson, J.E. & Healy, D.
    2016. Permeability evolution across carbonate hosted normal fault zones. Marine and Petroleum Geology,72, 62–82, https://doi.org/10.1016/j.marpetgeo.2016.01.008.
    [Google Scholar]
  8. Matonti, C., Lamarche, J., Guglielmi, Y. & Marie, L.
    2012. Structural and petrophysical characterization of mixed conduit/seal fault zones in carbonates: Example from the Castellas fault (SE France). Journal of Structural Geology, 39, 103–121.
    [Google Scholar]
  9. Micarelli, L., Benedicto, A. & Wibberley, C.A.J.
    2006. Structural evolution and permeability of normal fault zones in highly porous carbonate rocks. Journal of Structural Geology, 28, 1214–1227, https://doi.org/https://doi.org/10.1016/j.jsg.2006.03.036.
    [Google Scholar]
  10. Michie, E.A.H.
    2015. Influence of host lithofacies on fault rock variation in carbonate fault zones: A case study from the Island of Malta. Journal of Structural Geology, 76, 61–79, https://doi.org/10.1016/j.jsg.2015.04.005.
    [Google Scholar]
  11. Michie, E.A.H., Haines, T.J., Healy, D., Neilson, J.E., Timms, N.E. & Wibberley, C.A.J.
    2014. Influence of carbonate facies on fault zone architecture. Journal of Structural Geology, 65, 82–99, https://doi.org/https://doi.org/10.1016/j.jsg.2014.04.007.
    [Google Scholar]
  12. Rotevatn, A., Thorsheim, E., Bastesen, E., Fossmark, H.S.S., Torabi, A. & Sæen, G.
    2016. Sequential growth of deformation bands in carbonate grainstones in the hangingwall of an active growth fault: Implications for deformation mechanisms in different tectonic regimes. Journal of Structural Geology, 90, 27–47, https://doi.org/10.1016/j.jsg.2016.07.003.
    [Google Scholar]
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