Advertisement

Microscopic Studies

  • Vahid Tavakoli
Chapter
Part of the SpringerBriefs in Petroleum Geoscience & Engineering book series (BRIEFSPGE)

Abstract

Microscopic observations are one of the main sources of information for geological studies. This is more important in core analysis with limited macroscopic samples. Routine microscopic studies of a core sample include petrographical analysis to understand facies properties and diagenetic processes, paleontological studies for absolute age dating, X-ray diffraction for mineral identification (especially clays), scanning electron microscopy equipped with energy dispersive spectroscopy for pore and pore throat determination, mineral identification, and elemental analysis. The static reservoir properties of a sample depend completely on primary (facies) or secondary (diagenesis) characteristics of the rocks. The rock mineralogy, constituents, sedimentary environment, microscopic porosities, cements, compaction features, and many other parameters are gained by study of a rock sample under a polarizing microscope. They are recorded on standard sheets and compared with other rock properties derived from routine or special core analysis sections. Paleontological studies are used for absolute age dating and make it possible to correlate the strata in a chronostratigraphic framework. Such a framework is integrated with other microscopic and macroscopic geological data and provides the reservoir zonation scheme and understanding of reservoir geometry. Fine-size minerals, especially clays, are identified by the X-ray method. They play a vital role in reservoir properties and future drilling in the field. Pore types and pore throats determine the fluid flow properties and major rock types of the reservoir. They have a major effect on reservoir heterogeneity. Final results are combined with other sources and characterize the geological role in micro and regional scale distribution of reservoir properties.

References

  1. Ahr WM (2008) Geology of carbonate reservoirs: the identification, description, and characterization of hydrocarbon reservoirs in carbonate rocks. Wiley-Interscience, MaldenCrossRefGoogle Scholar
  2. Bebou DG, Loucks RG (1984) Handbook for logging carbonate rocks. Bureau of Economic Geology, TexasGoogle Scholar
  3. Dickson JAD (1965) A modified technique for carbonates in thin section. Nature 205:587CrossRefGoogle Scholar
  4. Dott RH (1964) Wacke, greywacke and matrix; what approach to immature sandstone classification? J Sed Res 34:625–632Google Scholar
  5. Dunham RJ (1962) Classification of carbonate rocks according to depositional texture. In: Ham WE (ed) Classification of carbonate rocks. AAPG Memoir 1, pp 108–121Google Scholar
  6. Embry AF, Klovan JE (1971) A Late Devonian reef tract on Northeastern Banks Island, NWT. Bull Can Petrol Geol 19:730–781Google Scholar
  7. Evamy BD (1963) The application of a chemical staining technique to a study of dedolomitisation. Sedimentology 2:164–170CrossRefGoogle Scholar
  8. Flugel E (2010) Microfacies of carbonate rocks, analysis, interpretation and application. Springer, BerlinGoogle Scholar
  9. Friedman GM (1959) Identification of carbonate minerals by staining methods. J Sediment Petrol 29:87–97Google Scholar
  10. Friedman GM (1965) Terminology of crystallization textures and fabrics in sedimentary rocks. J Sediment Petrol 35:643–655Google Scholar
  11. Knaust D (2017) Atlas of trace fossils in well core—appearance, taxonomy and interpretation. Springer International Publishing, ChamCrossRefGoogle Scholar
  12. Mehrabi H, Mansouri M, Rahimpour-Bonab H, Tavakoli V, Hassanzadeh M (2016) Chemical compaction features as potential barriers in the Permian-Triassic reservoirs of southern Iran. J Petrol Sci Eng 145:95–113CrossRefGoogle Scholar
  13. Pettijohn FJ (1975) Sedimentary rocks. Harper & Row, New YorkGoogle Scholar
  14. Powers MC (1953) A New Roundness Scale for Sedimentary Particles. SEPM J of Sediment Res Vol. 23Google Scholar
  15. Reading HG (1986) Sedimentary environments and facies. Blackwell Scientific Publications, OxfordGoogle Scholar
  16. Reeder RJ (1983) Crystal chemistry of the rhombohedral carbonates. In: Reeder RJ (ed) Carbonates: mineralogy and chemistry. mineralogical society of America reviews in mineralogy, vol 11. Mineralogical Society of America, pp 1–47Google Scholar
  17. Riley NA (1941) Projection sphericity. J Sed Res 11:94–95Google Scholar
  18. Scholle PA, Ulmer-Scholle DS (2006) Color guide to petrography of carbonate rocks. AAPG memoir 77, AAPG, TulsaGoogle Scholar
  19. Sibley DF, Gregg JM (1987) Classification of dolomite rock textures. J Sediment Petrol 57:967–975Google Scholar
  20. Sneed ED, Folk RL (1958) Pebbles in the lower Colorado River, Texas, a study in particle morphogenesis. J Geol 66:114–150CrossRefGoogle Scholar
  21. Tavakoli V, Jamalian A (2018) Microporosity evolution in Iranian reservoirs, Dalan and Dariyan formations, the central Persian Gulf. J Nat Gas Sci Eng 52:155–165CrossRefGoogle Scholar
  22. Tucker ME (2001) Sedimentary petrology: an introduction to the origin of sedimentary rocks. Wiley-Blackwell, OxfordGoogle Scholar
  23. Wadell H (1932) Volume, shape, roundness of rock particles. J Geol 40:443–451CrossRefGoogle Scholar
  24. Warren J (2000) Dolomite: occurrence, evolution and economically important associations. Earth-Sci Rev 52:1–81CrossRefGoogle Scholar
  25. Wentworth CK (1922) A scale of grade and class terms for clastic sediments. J Geol 30:377–392CrossRefGoogle Scholar
  26. Wiranto RS (2013) FOBEX 1: All about sandstone. Available via AAPG. http://aapg.ft.ugm.ac.id/fobex-1-all-about-sandstone. Accessed 5 Feb 2018

Copyright information

© The Author(s) 2018

Authors and Affiliations

  1. 1.School of Geology, College of ScienceUniversity of TehranTehranIran

Personalised recommendations