1887

Abstract

Summary

Methods for determining properties of shales from cuttings samples are beneficial as they provide a fast and cost-efficient way for evaluating potential shale reservoirs for which often core sample data and modern wireline logs are missing. A case study is performed on 80 cuttings samples from the radioactive Silurian shales of a Palaeozoic basin in SW Algeria. In this study geochemical (Rock-Eval pyrolysis and LECO carbon analysis), mineralogical (QEMSCAN analysis), structural (CT scanning) and geomechanical (nanoindentation) analyses are performed on cuttings samples to characterize the heterogeneity of the shales and predict shale gas sweet spots. Using these innovative analysis methods reliable values for the properties of the radioactive Silurian shales are obtained. By integrating TOC content values and QEMSCAN data with wireline logs, clear vertical trends/cycles are identified and the strong vertical and lateral heterogeneity of the shales is demonstrated. Using CT scanning different fractural networks are observed and Young’s modulus values obtained from nanoindentation measurements are in the range expected for shales (± 33 GPa) and are appropriate for shale gas production. The shale gas opportunity is confirmed for the radioactive Silurian shales and sweet spots are indicated by high TOC contents and favorable mineralogical compositions and geomechanical properties.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.20140233
2014-04-07
2024-04-27
Loading full text...

Full text loading...

References

  1. Gebrande and Alexandrov et al. in Schon, J.
    [1996] Physical properties of rocks: Fundamentals and principles of petrophysics. Elsevier Science, Oxford, UK.
    [Google Scholar]
  2. Hofmann, A., Rigollet, C., Portier, E. and Burns, S.
    [2013] Gas shale characterization – Results of the mineralogical, lithological and geochemical analysis of cuttings samples from radioactive Silurian shales of a Palaeozoic basin, SW Algeria. North Africa Technical Conference & Exhibition, Cairo, Egypt, 15–17 April 2013.
    [Google Scholar]
  3. Kumar, V., Sondergeld, C. and Raj, C.
    [2012] Nano to macro mechanical characterization of shale. SPE Annual Technical Conference and Exhibition, San Antonio, USA, 8–10 October.
    [Google Scholar]
  4. Rigollet, C., Hofmann, A., Burns, S., Portier, E., Paul, A. and Koolschijn, M.
    [2013] Hot shales facies heterogeneity: Highlights from the mineralogical and geochemical analyses of the Lower Silurian source rock of a Palaeozoic basin (SW Algeria). North Africa Technical Conference & Exhibition, Cairo, Egypt, 15–17 April 2013.
    [Google Scholar]
  5. Simmons, G. and Wang, H.
    [1971] Single crystals elastic constants and calculated aggregate properties. A Handbook. Cambridge: The MIT Press.
    [Google Scholar]
  6. Sondergeld, C., Newsham, K., Comisky, J., Rice, M. and Rai, C.
    [2010] Petrophysical considerations in evaluating and producing shale gas resources. SPE Unconventional Gas Conference, Pittsburgh, USA, 23–25 February 2010.
    [Google Scholar]
  7. Zhang, G., Wei, Z. and Ferrel, R.E.
    [2009] Elastic modulus and hardness of muscovite and rectorite determined by nanoindentation. Applied Clay Science, 43(2), 271–281.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.20140233
Loading
/content/papers/10.3997/2214-4609.20140233
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