Geology Reference
In-Depth Information
A convincing factual confirmation of the above consideration is provided
by the areal variability in the geobaric field of the Upper Cretaceous reser-
voir, which should not have happened in case of a large-scale lateral elision
water flow. As an example, the following formation pressure gradients were
discovered in the course of drilling. At the Staro-Groznensky prospect, 18
MPa on the south flank of the structure and 11 MPa on the north one. In
the Khayat-Kort-Mineralnaya area, 13 MPa; between the Yastrebiny pros-
pect and Khayat-Kort east area, 6 MPa. In the area of the west plunge of the
October structure, 13 MPa; between the Bragun and Gudermes prospects,
5 MPa; between the Bragun and West Gudermes prospects, 7 MPa, etc.
(Anikeyev, Bronovitsky and Taliyev, 1985; Volobuyev, 1986; Durmishyan,
Muradian and Rachinsky, 1976; Kissin, 1964; Orlov and Kornilov, 1986;
Sidorov
et al
., 1987).
Geologic data indicate that the main water-exchange form in the Tersk-
Caspian Trough sediment cover is the interformational vertical fluid
cross-flow from the lower to the upper hydrogeologic stage through the
system of regional and local tectonic unconformities. This statement is
supported by:
t
Broad development in all Meso-Cenozoic intervals of high
salinity hydrochemical anomalies of the cross-flow-injec-
tion type (Chapter 2).
t
Identicality of ground waters in the Lower and Upper
Cretaceous.
t
Similar contents in them of radium, deuterium, tritium
and oxygen isotopes (Nikanorov, Volobuyev and Bartsev,
1975).
t
Direct migration traces in the form of calcite formations
left by ground water circulating through fractures and
faults (Volobuyev, 1986; Nikanorov, Tarasov and Fedorov,
1983).
t
Bitumen-gas, bitumen-water and solid bitumen inclusions
in hydrothermal calcite crystals (Nikanorov, 1977).
t
Clear match with the current vertical hydrochemical zon-
ing under the mixing model of syngenetic with the enclosing
rocks and foreign waters (Chapter 2).
t
The patterns in spatial distribution of normalized formation
pressure gradients (Chapter 3).
t
Geothermal distortions of the regional background
(Chapter 4).
