The main factors of formation and industrial gas content criteria of Silurian shale deposits in Volyn-Podillia area

Abstract

The main formation factors and criteria of industrial gas content were identified and based on a systematic
analysis of known shale gas fields of various oil and gas basins of the world. As a result of study of lithological,
mineralogical and petrographic, petrophysical, geochemical, thermobaric characteristics of rocks by laboratory
studies of cores, slabs, industrial and geophysical data the main most important formation factors and criteria
for shale gas content of Silurian sediments of Volyn-Podillia were established: shale basin area – more than
10 thousand. sq. km; The depth of occurrence of the shale - no more than 3-4 thousand. m; the thickness of the shale
deposits – more than 15 m; sedimentation conditions – mostly low-energy marine environment; mainly sub horizontal
bedding of prospect shale strata; facies and lithology of shale strata – mainly fine grained shaly dark coloured
due to organic substance of rock with layered clay minerals; organic matter content - more than 1-3%; the age of
prospective strata – mainly Paleozoic; degree of metamorphism (% RO) -1,5-2,0%; thermal maturity of organicrich
rocks – MK2-AK2; porosity – more than 4%, permeability – more than 0.1 mD; availability of fracture: a high
silica content. They uniquely allow stating that the study area belongs to the prospective territory for shale gas. The
most prospective are black shale deposits of yadlovsky stage of upper Silurian, which is a priority target for further
research.