Lithogenetic aspects of oil and gas systems formation in the Volyno-Podolia Silurian deposits
Journal Title: Геодинаміка - Year 2018, Vol 25, Issue 2
Abstract
Objective. To elucidate the dynamics of catagenetic processes that occurred in the Silurian sediments against the background of an oil and gas systems formation. Method. The method includes lithology-facies, mineralogical-petrographic, catagenetic, and litho-fluido-dynamic analyses. Results. The spatial-temporal development features of carbonate (bank-reefal facies), argillite (outer and inner shelf), and argillite-carbonate (transition facies) complexes located in the Silurian sediments (profile of boreholes: Lishchynska-1 – Peremyshlyany-1 – Baluchin-1 – Olesko-1) have been determined. The main post-sedimentary transformations of clayey compound rocks consistent in the formation of quartz, calcite, pyrite, as well in the formation of caverns and fractures, which in most cases are combined with thin channels forming a single system, have been studied. It has been established that during the Palaeozoic and Early Mesozoic, the regime of catagenesis of the Silurian sediments of the considered structures was identical. Its further differentiation caused by the individualization of various tectonic block development occurred. In the first catagenetic cycle, the Silurian deposits reached the temperature conditions of the main zone of gas formation. The hydrocarbon (HC) generation centre was located in the western part of the studied profile (the Lishynskaya area), and within the zone of hydrocarbon accumulation a number of lithogenetic reservoirs were localized, the formation of which took place at different catagenetic substages. The main phase of hydrocarbon accumulation is confined to the Late Cretaceous. At this time in the Lishchino-Peremyshlyanskaya area there was a knot of reservoirs pertaining to the heterogeneous morphology, genesis, and the time of their formation. The spatial superposition of these reservoirs and the presence of a multi-directional system of fractures led to the formation of a single fluid system. In the Palaeogene, the accumulated oil and gas accumulations were destroyed as a result of the regional fracture zone development. Hydrocarbon fluids migrated both laterally and vertically with their possible accumulation in structural or lithological traps in the Silurian and Devonian sediments. Scientific novelty. The novel periodization of the Silurian deposits catagenesis has been determined, and the difference in the regime of catagenesis which occurred in various tectonic structures has been established. Practical relevance. The hydrocarbon fluids migration stages and the history of conditions during the formation of the lithogenetic reservoirs have been determined, which allowed assessing specific aspects of the oil-and-gas potential of the Silurian and adjacent sedimentary complexes.
Authors and Affiliations
K. Hryhorchuk, V. Hnidets, L. Balandiuk
Modeling stress-strain state bases of engineering constructions for evaluation of seismic hazard
Purpose. The aim of this work was to evaluate changes in the transfer characteristics of the seismic environment with additional loading of massive engineering structures. This analysis will help to more accurately asses...
Anoxic sedimentogenesis of ediacaran and silurian strata of south-western slope of the East-European platform
Purpose. The objective of this study was to investigate the depositional environments of organic-rich Ediacaran and Silurian strata on the south-western slope of the East-European platform. In particular, the factors fac...
Study of horizontal displacements of the channel of Dniester river using remote sensing data and GIS-technologies
Aim. The aim of the work is to research the method of studying horizontal displacements in the channel of the Dniester river from town Galich to town Zalishchiki using topographic maps of different periods, special maps,...
Triggering of earthquakes of Azov-Black Sea basin by seiche deformation of the ground
Purpose. Evaluation of possible causes of earthquakes in the area of waters by comparing the Earth's surface deformations, caused by their own variations of water, with deformations, caused by stress from pressure create...
Thermodynamic and hydrogeological conditions of forming the hydrocarbon deposits of the Pre-Black Sea aquiferous basin
Purpose. Finding the connection between the thermodynamic conditions of hydrocarbon mixtures synthesis and zones of oil and gas accumulation. Methodology. The thermodynamic eguilibrium depths of gas and gas-condensate de...