Petrophysical, geochemical and lithological features of the Domanik formation rock structure are considered. Particular attention is paid to the formation of the pore space in the pelitic carbon-enriched deposits within the depressions. The latter are characterized by low reservoir properties, heightened content of organic matter and siliceous-carbonate composition. Sedimentation and post-sedimentation factors affecting formation of pores filled with micro-oil are identified. High generation potential of rocks capable of generating and giving off liquid hydrocarbons at early stages of catagenesis is singled out. The pore space in carbonate complexes of shallow-marine origin overlapping carbon-enriched deposits is described. In spite of oil and bitumen saturation of these rocks, the predominant migratory character of hydrocarbons was noted.