Surgil ESIA Report - Volume III - EKN

“O’ZLITINEFTGAZ” PC
PFS “Surgil field complex costruction with valuable
components retrieval”
charred vegetative organics and thin (0.5-1sm) rare interlayers of coal. There are widely
developed from neogenic minerals the siderite and pyrite, occurring, basically, in a view of
pseudomorphoses by the plant residues. Upwards on the cross-section the siderite
compound is decreases. Mudstones practically are impermeable, their open porosity is equal
to 2.49-4.4%, i.e. the purest, without terrigenous admixture, interlayers of mudstones can be
local fluid supports in thickness of middle Jura.
Upper Jurassic section - J 3
The deposits of upper Jura are conformability on rocks of the middle Jurassic age.
Kellovey-Oxford deposits (J 3 cl-oxf) are mainly presented by clay with interlayers of
siltstones and sandstones collecting in shallow-sea conditions.
Clay are grey, greenish-grey, in upwards of cross-section - grayish-brown, aleureic,
dense, fine-washed with the rare charred plant residues on which there are developed
pseudomorphoses of pyrite. There are widely developed iron hydroxides in upwards of
cross-section. A structure of rocks is horizontal-layered.
Siltstones are greenish-grey, clay and sandy, dense, strong.
Sandstones are greenish-grey, small-fine-grained, quite often are aleureic, dense,
strong, massive, quartz-feldspar, with clays cement, with inclusion of rare grains of
glauconite. Sandstones of upper Jura possess good filtration and capacitance properties.
Their open porosity reaches 15-16%, and of some layers to 24%, permeability fluctuates in
a wide range – 0.00-49m/darcy.
The deposits of titone (J 3 tit) without visible cross bedding, but with washout, are
bedded on deposits of kellovey-oxford.
The aggregate thickness of the Jura deposits is 811-4260m.
Cretaceous system - K
Lower Cretaceous section -K 1
Neocom uplayer (К 1 nс) includes the deposits of valangin and goteriv-barrem layers.
The deposits of neocom uplayer are opened by all drilled wells within considered territory.
In the basis of neocom uplayer there is bedded the pack of bluish-grey with tints of
green clays of valangin layer with pyritized charred plant residues.
Thickness of alternation of sandstones, siltstones and clays, greenish-grey is bedded
above.
Barrem layer is the most thickness in neocom composition. The bottom part of
barrem deposits is combined by red bed clays with the subordinated interlayers of siltstones
and sandstones; top - mainly by sandstones. Clays are dense, strong, fine-washed, in some
areas calcareous, massive, with nests of bluish-grey siltstones.
Sandstones are brown and red, small-medium-grained, quartz-feldspar, badly sorted,
with gravel grains in some areas, dense (2.05-2.509 g/sm 3 ), massive, calcareous, passing
Volume 2. Part 1. EIS Project for Surgil field construction
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