S.F. Khafizov1 and P.E. Syngaevsky2*
1 Project Team Leader, Department of New Exploration Ventures, TNK-BP Exploration Division, Shchepkina st., 42/2a, 129111, Moscow, Russia (e-mail: SFHafizov@tnk.ru);
2 Senior Technical Professional, Landmark (Halliburton), 9 E Greenway Plaza, 1783, Houston, TX, 77046, (correspondent author: e-mail: PSyngaevsky@lgc.com);
This paper discusses specific facies associated with deep-water slumps and sandstone intrusions in the West Siberia Basin. The slumps were formed during sea-level falls when storms caused sediment masses to be discharged into deep-water areas where they imposed a significant load on the underlying semi-consolidated black shales, deform and partially destroy them. Multiple slump/avalanche events are observed at the boundary between Lower Cretaceous (Neocomian) and Upper Jurassic (Tithonian) sequences and form potential targets for oil exploration.
High-resolution sequence stratigraphic analyses show that both
slump and distal fans are genetically related to lower slope/basin floor sediments
and were deposited during regressions and subsequent lowstands. Two key depositional
environments are recognized: (i) the proximal part of fans, where the
most prospective potential reservoirs are found; the (ii) distal parts
of slump, which are principally composed of deformed shale clasts in a silt-mudstone
matrix. A third facies (slump head) is only observed on seismic profiles and
is probably related to horizontally displaced "shingled" semi-consolidated black
shales.
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