The area of the Volga-Ural oil and gas basin belongs to the “old” oil and gas bearing regions. The most part of easily recoverable reserves of large and unique oil fields already have been developed within the area. Therefore, super-viscous oil reservoirs, natural bitumen deposits and shale hydrocarbons seized the attention of local petroleum geologists. Tatarstan is a classic example in that sense. The Republic of Tatarstan is a leader in the development of heavy oil resources, a leader in the degree of knowledge of natural bitumen accumulations, as well as a leader in technological readiness for their development. In the depths of Tatarstan, there are more than 450 fields of ultra-viscous oil and natural bitumen with reserves ranging from 2 to 7 billion tons of this type of hydrocarbons. However, their industrial development due to low profitability is slow. To solve the problem, it is necessary to search for and commercialize economically viable technologies for the production, transportation and processing of hydrocarbons, which take into account its features and do not require increased energy and other material costs. Therefore, the search for the right unconventional hydrocarbons production concept is an urgent problem of our time.

The article discusses the tectonics and developmental features of the Volga-Ural anteclise during the Baikalian, Caledonian, Hercynian and Alpine tectogenesis cycles. In this paper, particular attention is paid to stages and directional development during the evolution of geological structures. The main factors of the formation and destruction of Permian viscous oil and natural bitumen reservoirs are presented in the provisions of oil ontogenesis. It was noted the cyclical nature of these phenomena. Keywords: Volga-Ural anteclise; super-viscous oil; tectonic; reservoir; oil.

No abstract

No abstract

Authors of the article identified the influence of sedimentation conditions on reservoir thickness and the patterns of change in reservoir properties of superviscous oil field from the following three zones of the sandstone sequence of the Sheshminsky horizon: Northern, Southern and Central identified by PJSC Tatneft and prepared for initial development. The following relationships have been investigated: open porosity relation with bitumen content (by weight and by volume), open porosity relation with carbonate content, open porosity relation with bulk density, carbonate content relation with bulk density, bitumen content (by weight and by volume) relation with carbonate content, and also bitumen content relation with their depth. The revealed patterns of changes in reservoir properties and bitumen content within the sandstone sequence can be the result of not only changing conditions of sedimentation, but also the result of post-sedimentation processes resulting in calcitization or redistribution of carbonate cement in the rock under the influence of aggressive products (oxidation, biodegradation) of oil deposits destruction.