Geology Reference
In-Depth Information
>120 MMY
120-115 MMY
115-100 MMY
100-90 MMY
90-80 MMY
Figure 6.1-b
South Caspian Depression (west flank). Geochemical age of the Productive
Series condensates. 1. Begimdag-Tegchay; 2. Keshchay; 3. Apsheron Bank; 4. Garabagly;
5. Gyursangya; 6. Galmas; 7. Duvanny; 8. Pirsagat; 9. Dashgil; 10. Kyanizadag;
11. Sangachal-Deniz; 12. Duvanny; 13. Bulla; 14. Bulla-Deniz; 15. Garadag; 16. Lokbatan
South; 17. Govsan; 18. Gum Adasy; 19. Bakhar; 20. Zyrya; 21. Dzhanub; 22. Gyuneshli;
23. Chirag; 24. Azeri.
This directional change in the age of fluids over the basin leads to a
conclusion that there is a progressive (from the flanks to the central zone
of basin) present-day participation of fluids generated in the Paleogene-
Miocene sequence in saturating with oil and gas the overlying Pliocene
reservoir sequence.
By the present period of geological evolution, the syngenetic Mesozoic
oils resided in the temperature range of 167-424
C (depths of 6 to 21.5 km).
Over a long period of Post-Mesozoic time they underwent thermocatalytic
transformations in the environment of prevailing gas generation. In this
environment they could have hardly remained phase-preserved and should
have transformed into a vapor-gas fluid saturating practically all natural
reservoirs of the section.
Prior to being buried underneath the Pliocene reservoir sequence capa-
ble of capturing the generated products of catagenic reactions, the dispersed
organic matter in the Paleogene-Miocene complex had been transforming
mainly by way of bituminization (formation of oil shales). Only in the Post-
Miocene time, the environment conducive to oil generation were created,
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