Geology Reference
In-Depth Information
Taking into account genetic association of oil and gas occurrences with
the areas of alkaline water development, the Middle Jurassic sediments in
the latter three areas appear prospective from the regional position.
Most important out of the reviewed hydrogeological and hydrochemical
criteria of gas occurrences in combination with a complex of other general
geologic preconditions are the following points (Durmishyan, Muradian
and Rachinsky, 1972):
t
Duration of hydrocarbon generation and
migration
processes.
t
Increase in gas-holding capacity of traps with their subsid-
ence to great depths.
t
Thermodynamical specifics of fluid phase transformations.
t
Possibility of oil and gas migration as a single gas phase.
t
Role of overlying seals in the formation and preservation of
accumulations
from degassing and
destruction,
increase in
seal thickness down the regional dip.
t
Specifics of region's tectonic evolution and tectonic structure
specifics in external framework zones and subsided areas of
the South Caspian Depression.
t
Broad development of mud volcanism accompanied by mas-
sive release of hydrocarbon gases indicating the presence of
their large reserves in the subsurface.
t
Weakening of faulting as folding gets deeper.
t
Consistent association of gas (gas-condensate) aggregations
with the deepest traps and consistent increase in gas-satura-
tion of productive reservoirs down the regional dip.
t
Genetic association of AHFP zones with the occurrences of
gas (gas-condensate) aggregations as an identification in the
Meso-Cenozoic section of the South Caspian Depression's
west flank of the following possible zones of the predomi-
nant gas accumulation:
t
In the Productive Sequence: South Apsheron (struc-
tures Karadag, Lokbatan-More, Bahar, Zyrya, Shahdeniz,
Zevin-Petrov Bank-Apsheron) and Baku (Kobystan-
Kura) Archipelago (structures Bulla-More, Andreyev
Bank, Hamamdag-More, Svinoy Isl., Persianin Bank,
Kamen Ignatia Bank, Kornilov-Pavlov Bank Sabail,
Oblivnoy Isl., Kumani Bank, Pogorelaya Plita Bank,
Golovachev Bank, Karagedov Bank, Borisov Bank,
Kurinsky Kamen-1, Kurinsky Kamen-2, S.Kurinskaya).
