1887
Volume 67 Number 1
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Part one of this paper reported results from experimental compaction measurements of unconsolidated natural sand samples with different mineralogical compositions and textures. The experimental setup was designed with several cycles of stress loading and unloading applied to the samples. The setup was aimed to simulate a stress condition where sediments underwent episodes of compaction, uplift and erosion. P‐wave and S‐wave velocities and corresponding petrophysical (porosity and density) properties were reported. In this second part of the paper, rock physics modelling utilizing existing rock physics models to evaluate the model validity for measured data from part one were presented. The results show that a friable sand model, which was established for normally compacted sediments is also capable of describing overconsolidated sediments. The velocity–porosity data plotted along the friable sand lines not only describe sorting deterioration, as has been traditionally explained by other studies, but also variations in pre‐consolidation stress or degree of stress release. The deviation of the overconsolidated sands away from the normal compaction trend on the / and acoustic impedance space shows that various stress paths can be predicted on this domain when utilizing rock physics templates. Fluid saturation sensitivity is found to be lower in overconsolidated sands compared to normally consolidated sands. The sensitivity decreases with increasing pre‐consolidation stress. This means detectability for four‐dimensional fluid saturation changes can be affected if sediments were pre‐stressed and unloaded. Well log data from the Barents Sea show similar patterns to the experimental sand data. The findings allow the development of better rock physics diagnostics of unloaded sediments, and the understanding of expected 4D seismic response during time‐lapse seismic monitoring of uplifted basins. The studied outcomes also reveal an insight into the friable sand model that its diagnostic value is not only for describing sorting microtextures, but also pre‐consolidation stress history. The outcome extends the model application for pre‐consolidation stress estimation, for any unconsolidated sands experiencing similar unloading stress conditions to this study.

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/content/journals/10.1111/1365-2478.12692
2018-12-26
2024-04-16
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References

  1. AvsethP., MukerjiT. and MavkoG.2005. Quantitative Seismic Interpretation: Applying Rock Physics Tools to Reduce Interpretation Risk. Cambridge University Press.
    [Google Scholar]
  2. AvsethP., MukerjiT., MavkoG. and DvorkinJ.2010. Rock‐physics diagnostics of depositional texture, diagenetic alterations, and reservoir heterogeneity in high‐porosity siliciclastic sediments and rocks – A review of selected models and suggested work flows. Geophysics75, 7531–47.
    [Google Scholar]
  3. Batzle, M.L. and WangZ.1992. Seismic properties of pore fluids. Geophysics57, 1396–1408.
    [Google Scholar]
  4. Bjørlykke, K.2010. Petroleum Geoscience‐ From Sedimentary Environments to Rock Physics. Springer.
    [Google Scholar]
  5. BreivikA.J., GudlaugssonS.T. and FaleideJ.I.1995. Ottar Basin, SW Barents Sea: A major Upper Palaeozoic rift basin containing large volumes of deeply buried salt. Basin Research7, 299–312.
    [Google Scholar]
  6. DvorkinJ. and NurA.1996. Elasticity of high‐porosity sandstones: Theory for two North Sea datasets. Geophysics61, 1363–1370.
    [Google Scholar]
  7. FaleideJ.I., VagnesE. and GudlaugssonS.T.1993. Late Mesozoic‐Cenozoic evolution of the southwestern Barents Sea in a regional rift‐shear tectonic setting. Marine Petroleum Geology10, 186–214.
    [Google Scholar]
  8. FawadM., MondolN.H., JahrenJ. and BjørlykkeK.2011. Mechanical compaction and ultrasonic velocity of sands with different texture and mineralogical composition. Geophysical Prospecting59, 697–720.
    [Google Scholar]
  9. GassmannF.1951. Über die Elastizität poröser Medien. Vierteljahrsschrift der Naturforschenden Gesellschaft in Zürich96, 1–23.
    [Google Scholar]
  10. HashinZ. and ShtrikmanS.1962. A variational approach to the theory of the elastic behaviour of polycrystals. Journal of the Mechanics and Physics of Solids10, 343–352.
    [Google Scholar]
  11. HashinZ. and ShtrikmanS.1963. A variational approach to the elastic behaviour of multiphase materials. Journal of the Mechanics and Physics of Solids11, 127–140.
    [Google Scholar]
  12. HillR.1952. The elastic behaviour of a crystalline aggregate. Proceedings of the Physical SocietyA65, 351.
    [Google Scholar]
  13. Kuster, G.T. and Toksöz, M.N.1974. Velocity and attenuation of seismic waves in two‐phase media, Part I. Theoretical formulations. Geophysics39, 587–606.
    [Google Scholar]
  14. MavkoG., MukerjiT. and DvorkinJ.2009, The Rock Physics Handbook. Cambridge University Press.
    [Google Scholar]
  15. MindlinR.D.1949. Compliance of elastic bodies in contact. Journal of Applied Mechanics16, 259–268.
    [Google Scholar]
  16. Murphy, W.F.1982. Effects of partial water saturation on attenuation in Massilon sandstone and Vycor porous glass. Journal of the Acoustical Society of America71, 1458–1468.
    [Google Scholar]
  17. NarongsirikulS., MondolN.H. and JahrenJ.2013. Possible application of friable sand model for shallow mechanically compacted overconsolidated sands. 83rd SEG Annual meeting, Houston, USA, Expanded Abstracts.
  18. NarongsirikulS., MondolN.H. and JahrenJ.2018. Acoustic and petrophysical properties of mechanically compacted overconsolidated sands: Part 1 – Experimental results. Geophysical Prospecting.
  19. ØdegaardE. and AvsethP.2003. Interpretation of elastic inversion results using rock physics templates. 65th EAGE Conference and Exhibition, Stavanger, Norway, June 2003. EAGE.
  20. OhmS.E., KarlsenD.A. and AustinT.J.F.2008. Geochemically driven exploration models in uplifted areas: Examples from the Norwegian Barents Sea. AAPG Bulletin92, 1191–1223.
    [Google Scholar]
  21. Reuss, A.1929. Berechnung der Flieflgrenze von Mischkristallen auf Grund der Plastizittsbedingungfiir Einkristalle. Zeitschrift fur Angewandte Mathematik und Mechanik9, 49.
    [Google Scholar]
  22. VoigtW.1910. Lerbuch der Kristallphysik. Leipzig–Berlin: Teubner.
    [Google Scholar]
  23. ZimmerM.A.2003. Seismic velocities of unconsolidated sands: Measurements of pressure, sorting, and compaction effects. PhD thesis, Stanford University, USA.
    [Google Scholar]
  24. ZimmerM.A., PrasadM., MavkoG. and NurA.2007. Seismic velocities of unconsolidated sands: Part 1 – Pressure trends from 0.1 to 20 MPa. Geophysics72, 1–13.
    [Google Scholar]
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