A lithofacies description of Jurassic sediments in the south of the Predyenisei petroleum subprovince, West Siberia

Abstract

We have studied Jurassic sections in the Predyenisei subprovince of the West Siberian petroleum basin, which were penetrated in the Vostok-1, Vostok-3, and Vostok-4 stratigraphic wells. The Urman, Togur, Ilan, Peshkovo, Tyumen’, Naunak, and Mar’yanovka Formations are described from a detailed comprehensive core analysis and log data. The depositional environment for these sediments was predominantly continental. There is evidence for short transgressions in the Ilan (Lower Toarcian) and Peshkovo (Upper Toarcian) Formations, as well as the Upper Urman (Upper Pliensbachian) and the Upper Tyumen’ (Bajocian) Subformations. In the Upper Naunak Subformation (Oxfordian), there was a change of facies from continental to littoral continental and littoral marine. The Mar’yanovka Formation developed in normal marine shallow- or moderately deep-water environments. Although good reservoirs are common throughout the Jurassic section in the southeast of West Siberia, only small, lithologically screened deposits are predicted here.

Sequence Stratigraphy of Fluvial Facies: A New Type Representative from Wenliu Area, Bohai Bay Basin, China

“…The lithofacies characteristic analysis is also very important for depositional environment analysis [49][50][51][52]. The lithofacies recognition and categorization is based on lithology, grain size, physical and biogenic sedimentary structures, and stratification from core observation and description.…”

Sedimentology and sequence stratigraphy of the Paleogene lower second member of the Shahejie Formation, W79 Block, Wenliu Oilfield, Bohai Bay Basin, China

“…The categorization is based on lithology, grain size, physical and biogenic sedimentary structures, and stratification, which reveal the depositional processes that produced them. Lithofacies and lithofacies associations (groups of related lithofacies) are the basic units for the interpretation of depositional environments (Eltom, 2014;Holz et al, 2000;Srivastava and Mankar, 2015;Vakulenko et al, 2010;Zhang and Xie, 2008). Seventeen lithofacies have been recognized within the study interval, ranging from fine-grained sandstones of parallel bedding to mudstones of lenticular structures (Fig.…”