Conditions of sedimentation are considered for the Lower Permian oil-bearing complex in Timan-Pechora oil-and-gas province. All offshore oil fields of this stratigraphic level are connected with organic buildups, and each carbonate reservoir is unique by conditions of its formation, composition and, consequently, by its filtration and capacity parameters. Among them, the reservoir rocks of Prirazlomnoye oil field are represented by algal limestones, reservoirs of Southern-Dolginskoye and Northern-Dolginskoye oil-and-gas fields – by bruozoan-echinoderm grainestone-packestones and bruozoan bafflestones. Petrophysical properties of these carbonate rocks were predetermined at the earlier stages of their formation – sedimention and diagenesis; it means that facial analysis of the primary sedimention should be included as an obligatory element in the modeling of carbonate reservoirs of oil-and-gas.
