Geology Reference
In-Depth Information
t
Juxtaposing across these faults of conductive and barrier
intervals.
t
Lithological and facies replacement of permeable varieties in
the section by impermeable ones.
At the same time, an assumption is justified of the lateral water flow in
strongly shaled-out members of the Neogene stage of block-steps at depths
down to 1,500-2,000 m to the adjacent faults refracting the flow. Within
the flysh-carbonate Paleogene-Triassic range, the functioning of the elision
(squeeze-out) mechanism is absolutely limited by the absence of incompe-
tent rocks capable of the modern-time compaction and by low horizontal
permeability of reservoir intervals.
The totality of data objectively indicates a large-scale presence in the
region of strong vertical, from the bottom upward, interformational
ground water cross-flow through a system of high-amplitude tectonic
unconformities (faults). These data include:
t
The present-time spatial hydrochemical zoning compat-
ible with the mechanism of mixing Mesozoic and Neogene
ground water (see Chapter 2).
t
Broad manifestation of local hydrochemical, piezometric
(Chapter 3) and geothermal (Chapter 4) anomalies associ-
ated with tectonically broken areas.
t
Numerous ascending salty thermal springs in the deep cen-
tral part of the depression near intersections of deep-seated
faults (the Steinberg, Schrattenberg, Luzhitze-Brod and
other thermal groups: Chapter 6).
This conclusion is also supported by petroleum geology data such as:
t
The presence of typically filtered oil in the Miocene horizons
(Vysotsky and Faingersh, 1959; Kalinin, 1977).
t
The presence in the section of clear-cut zones of syngenetic
and epigenetic oil and gas occurrences (Kalinin
et al
., 1967).
t
The concentration of 80% of the appraised region's
reserves in the zones of epigenetic oil and gas occurrences
(Kalinin
et al
., 1967; International Petroleum Encyclopedia,
1976).
t
The stacked nature of the fields.
t
The association of commercial oil-saturation exception-
ally with fault-related traps (Varentsov, 1948; Vysotsky and
Kucheruk, 1978; Dolenko, 1974a, 1974b; Kolesik, 1966).
