1887

Abstract

Summary

In shale formations, the amount of pore space is representative of porosity and permeability, which are highly dependent on mineralogy, depth of burial, and the history of diagenesis. In the case of cemented shales, the overburden pressure can decrease permeability further than mechanical compaction such that the porosity and permeability are not proportional to the depth of burial. The impact of this process is that the cemented shales appear ‘artificially’ fast for any given depth such that the true pore pressure can be underestimated. Moreover, the uncertainties in the pore pressure model, as a direct function of the cemented shales, not only propagates into the well planning and well design stages but also into the overall de-risking of any prospect as these effective stress relationships are used as input for both rock physics modelling and geomechanical modelling. This paper demonstrates the importance of building robust pore pressure models in areas affected by cementation, such as offshore Newfoundland and Labrador. We will demonstrate the importance of identifying these intervals in rock physics modelling by integrating temperature and pore pressure data. Finally, we will attempt to explain the formation of these cemented shales by viewing the local data on a regional scale.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201413267
2015-06-01
2024-04-19
Loading full text...

Full text loading...

References

  1. Abid, I.A., Hesse, R. and Harper, J.D.
    [2004] Variations in mixed-layer illite/smectite diagenesis in the rift and post-rift sediments of the Jeanne d’Arc Basin, Grand Banks, offshore Newfoundland, Canada. Canadian Journal of Earth Science41, 401–428.
    [Google Scholar]
  2. Green, S., O’Connor, S.A., Edwards, A.P., Carter, J.E., Cameron, D.E.L. and Wright, R.
    [2014] Understanding potential pressure regimes in undrilled Labrador deep water by use of global analogues, The Leading Edge, April2014, 414–426.
    [Google Scholar]
  3. Hilterman, F.
    [1990] Is AVO the seismic signature of lithology? A case history of Ship Shoal-south addition, The Leading Edge, 09, 15–22.
    [Google Scholar]
  4. Lahann, R.W., McCarty., D.K. and Hsieh., J.C.C.
    [2001] Influence of Clay Diagenesis on Shale Velocities and Fluid Pressure, OTC #13046: Offshore Technology Conference.
    [Google Scholar]
  5. Swarbrick, R.E., Osborne, M.J. and Yardley, G.S.
    [2002] Comparison of overpressure magnitude resulting from the main generating mechanisms, In: Huffman, A.R. and Bowers, G.L. (eds.), Pressure regimes in sedimentary basins and their prediction, AAPG Memoir76, 1–12.
    [Google Scholar]
  6. Swarbrick, R. E.
    [2012] Review of pore-pressure prediction challenges in high-temperature areas, The Leading Edge, 31, 1288–1294.
    [Google Scholar]
  7. Thyberg, B., Jahren, J., Winje, T., Bjørlykke, K. and Faleide, J.I.
    [2009] From mud to shale: rock stiffening by micro-quartz cementaton. First Break, 22 (10), 170–173.
    [Google Scholar]
  8. Thyberg, B. and Jahren, J.
    [2011] Quartz cementation in mudstones; sheet-like quartz cement from clay mineral reactions during burial, Petroleum Geoscience, 17, 53–63.
    [Google Scholar]
  9. Welford, J.K., Shannon, P.M., O’Reilly, B.M. and Hall, J.
    [2012] Comparison of lithosphere structure across the Orphan Basin-Flemish Cap and Irish Atlantic conjugate margins from constrained 3D gravity inversions, Journal of the Geological Society of London, 169(4), 405–420.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201413267
Loading
/content/papers/10.3997/2214-4609.201413267
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error