Carbonates and Evaporites

, Volume 8, Issue 1, pp 90–108 | Cite as

Petrographic image analysis and petrophysics: Analysis of crystalline carbonates from the Permian basin, west Texas

  • J. Barclay Ferm
  • Robert Ehrlich
  • G. Allan Crawford
Special Papers


Classification of porosity in carbonate rocks from thin section can be performed quickly and objectively using computer-based image acquisition and classification procedures. Pore type information (size, shape and volumetric abundance) is determined with high precision, equivalent to millions of point counts. Such pore type information is always relevant because each pore type has a different distribution of associated pore throat sizes.

Five pore types occur in a sequence of highly recrystallized dolomites from the Reinecke Field in the Late Carboniferous Horseshoe Atoll Complex in the northern Midland basin. These pore types represent an expanded version of conventional classification, representing two kinds of intercrystalline porosity and three kinds of channel porosity. The channel pore types represent secondary porosity which survived cementation by dolomite, and can be classified into channel pores of three distinctly different sizes. When combined with capillary pressure data the image-based pore type data reveals that the intercrystalline pores have very small throats while the channel pores have throats which are closer in size to the pore body. The product of the numbers of pores per unit volume of each type and the fourth power of the associated mean throat diameter is an index of the relative contribution of each pore type to discharge. In the Reinecke Field rocks, the smallest type of channel pore is the major control on flow. Its relatively small throat size is compensated by its great numerical abundance. The preference of throat size for pore type in these highly recrystallized dolomites, is just as strong as previously observed in detrital sandstones. Relatively tight limestones found with the dolomites also have a strong relationship between pore type and throat size, though their maximum throat radius is 7 microns and some pore types have mean throat sizes less than 1 micron. The Reinecke Field data, coupled with data from studies on sandstones, suggests that throat size in all sedimentary rocks can be expected to be non-randomly associated with pore type. The non-random pore/throat association means that the pore types defined by image analysis represent fundamental elements of the porous microstructure and that variability in a wide range of physical properties is tied to variation in pore type abundance.


Dolomite Pore Type Entry Pressure Throat Size Dolomite Cement 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. ARCHIE, G.E., 1952, Classification of carbonate reservoir rocks and petrophysical considerations.Am. Assoc. Petrol. Geol. Bull., v. 36, p. 278–298.Google Scholar
  2. ASCHENBRENNER, B.C., and CHILINGAR, G.V., 1960, Teodorovich’s Method for determining permeability from pore-space characteristics of carbonate rocks:Am. Assoc. Petrol. Geol. Bull., v. 44, p. 1421–1424.Google Scholar
  3. CHILINGAR, G.V., 1956, Use of Ca/Mg ratio in proposity studies:Am. Assoc. Petrol. Geol. Bull., v. 40, p. 2489–2493Google Scholar
  4. CHILINGAR, G.V., 1957, A short note on types of porosity in carbonate rocks:The Compass of Sigma Gamma Epsilon, v. 35, p. 69–74.Google Scholar
  5. CHILINGAR, G.V., and TERRY, R.D., 1954, Relationship between porosity and chemical composition of carbonate rocks:Petrol. Engineer, v. 26, p. 341–343.Google Scholar
  6. CHILINGAR, G.V., MANNON, R.W., AND FAIRBRIDGE, R.W., (eds.), 1972, Oil and Gas Production from Carbonate Rocks: Elsevier, New York, 408 pp.Google Scholar
  7. CHOQUETTE, P.W., and PRAY, L.C., 1970, Geologic nomenclature and classification of porosity in sedimentary carbonates:Am. Assoc. Petrol. Geol. Bull., v. 54, p. 207–250.Google Scholar
  8. CRAWFORD, G.A., MOORE, G.E., and SIMPSON, W., 1984, Depositional and diagenetic controls on reservoir development in a Pennsylvanian phylloid algal complex: Reinecke Field, Horseshoe Atoll, West Texas:Trans. Southwest Section Am. Assoc. Petrol. Geol., p. 81–90Google Scholar
  9. EHRLICH, R., CRABTREE, S.J., KENNEDY, S.K., and CANNON, R.L. 1984, Petrographic image analysis I— analysis of reservoir complexes:Jour. Sedimentary Petrology, v. 54, p. 1365–1378.Google Scholar
  10. EHRLICH, R., AND FULL, W.E., 1987, Sorting out geology— unmixing mixtures: in Mann, J., McCammon, R., and Jones, T., eds., Use and Abuse of Statistical Methods of the Earth Sciences: Oxford University Press, 275 pp.Google Scholar
  11. EHRLICH, R., CRABTREE, S.J., HORKOWITZ, K.O., and HORKOWITZ, J.P., 1991a, Petrography and reservoir physics I: Objective classification of reservoir porosity:Am. Assoc. Petrol. Geol. Bull., v. 75, p. 1547–1562.Google Scholar
  12. EHRLICH, R., ETRIS, E.L., BRUMFIELD, D., YUAN, L.P., and CRABTREE, S.J., 1991b, Petrography and reservoir physics III: Physical models for permeability and formation factor.Am. Assoc. Petrol. Geol. Bull., v. 75, p. 1579–1592.Google Scholar
  13. ETRIS, E.L., BRUMFIELD, D.S., EHRLICH, R., and CRABTREE, S.J., 1988, Relations between pores, throats, and permeability: a petrographic/physical analysis of some carbonate grainstones and packstones:Carbonates and Evaporites, v. 3, p. 17–32.CrossRefGoogle Scholar
  14. FOLK, R.L., 1959, Practical classification of limestones:Am. Assoc. Petrol. Geol. Bull., v. 43, p. 1–38.Google Scholar
  15. MCCREESH, C.A., EHRLICH, R., and CRABTREE, S.J., 1991, Petrography and reservoir physics II: Relating thin section porosity to capillary pressure, the association between pore types and throat size:AAPG Bull., v. 75, p. 1563–1578.Google Scholar
  16. PURCELL, W.R., 1949, Capillary pressures—their measurement using mercury and the calculation of permeability there from:Petroleum Trans., AIME, v. 186, p. 39–48.Google Scholar
  17. ROBINSON, R.B., 1966, Classification of reservoir rocks by surface texture:Am. Assoc. Petrol. Geol. Bull., v. 50, p. 547–559.Google Scholar
  18. SCHATZINGER, R.A., 1983, Phylloid algal and sponge-bryozoan mound-to-basin transition: a late Paleozoic facies tract from the Kelly-Snyder field, west Texas, in Harris, P.M., ed., Carbonate Build-ups — A Core Workshop: SEPM Core Workshop #4, p. 244–303.Google Scholar
  19. TOOMEY, D.F., and WINLAND, H.D., 1973, Rock and biotic facies associated with Middle Pennsylvanian (Desmoinesian) algal build-up, Nena Lucia Field, Nolan County, Texas:Am. Assoc. Petrol. Geol. Bull., v. 57, p. 1053–1074.Google Scholar
  20. TOOMEY, D.F., WILSON, J.L., and REZAK, R., 1977, Evolution of Yucca Mound complex, Late Pennsylvanian phylloid-algalbuildup, Sacramento Mountains, New Mexico:Am. Assoc. Petrol. Geol. Bull., v. 61, p. 2115–2133.Google Scholar
  21. VEST, E.L., Jr., 1970, Oil fields of the Pennsylvanian-Permian Horseshoe Atoll, West Texas, in Halbouty, M.T., ed., Geology of Giant Petroleum Fields:Am. Assoc. Petrol. Geol. Memoir 14, p. 185–203.Google Scholar
  22. WARDLAW, N.C., 1976, Pore geometry in dolomites and its influence on capillary behaviour: Symp. on Advances in Petroleum Recovery, Am. Chem. Soc., New York, Apr. 4–9, 1976, v. 21, p. 231–242.Google Scholar
  23. WARDLAW, N.C., and TAYLOR, R.P., 1976, Mercury capillary pressure curves and the interpretation of pore structure and capillary behaviour in reservoir rocks:Bull. Can. Petrol. Geol., v. 24, p. 225–262.Google Scholar
  24. WILSON, J.L., 1975, Carbonate Facies in Geologic History: Springer-Verlag, New York, 471p.CrossRefGoogle Scholar

Copyright information

© Springer 1993

Authors and Affiliations

  • J. Barclay Ferm
    • 1
  • Robert Ehrlich
    • 1
  • G. Allan Crawford
    • 2
  1. 1.Department of Geological SciencesUniversity of South CarolinaColumbia
  2. 2.Unocal Science and Technology DivisionBrea

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