Page 74 - Geology of Carbonate Reservoirs

REVIEW QUESTIONS 55

2.3. The carbonate rock classification system in widespread use by the petroleum
industry today is the one developed by (a) Grabau, (b) Folk, (c) Embry and
Klovan, (d) Dunham, (e) Wright or (f) Riding.

2.4. Porosity and permeability are dependent rock properties. On what do they

depend?
2.5. What is a “ latent ” property?

2.6. What is the difference between total and effective porosity?

2.7. Write the expression for calculating total porosity.

2.8. Permeability has the dimensions of an area. True or false?
2.9. What is the Darcy − Ritter expression for permeability and what does each
term represent?
2.10. Can the original Darcy − Ritter expression be used as is to calculate fl ow rates
in hydrocarbon reservoirs? Explain.

2.11. How did Archie illustrate relationships between rock and petrophysical char-
acteristics in his porosity classification of carbonate rocks?

2.12. What is the basic principle behind the Choquette − Pray classification of poros-

ity in carbonate rocks?
2.13. Is there any difference between facies - selective and fabric - selective character-
istics? Explain.
2.14. How does Lucia ’ s porosity classification identify relationships between funda-

mental rock properties and pore characteristics?
2.15. What does a genetic classification of carbonate porosity provide that an objec-

tive or purely descriptive version does not?

2.16. Do wireline logs provide direct measurement of rock or pore properties?
Explain.

2.17. Which wireline logs should be most useful to detect both fractures and large

vugs?

2.18. Are electrofacies maps as reliable and easy to make for carbonate successions
as they are in sand − shale successions? Explain.
2.19. Carbonate pore types can be directly identified with the seismograph. True or

false? Explain.

2.20. Why does the seismograph detect smaller anomalies at shallow depths than
at greater depths?