The features of diagenetic environments of Riphean and Vendian rocks of Kuyumba oil-field group are discussed in this paper. It was established that Riphean and Vendian sections underwent diagenesis in different environments: secondary alterations of carbonates of Riphean strata were mostly subjected to folding, Vendian strata diagenesis underwent burial diagenesis in stable tectonic regimen. Dissolution and caving formation in pre-Vendian times are in charge of collector features forming, whilst earlier (even primary) pores were filled with dolomite and chalcedony before Vendian rocks were formed. Refs 14. Figs 5.