New Data on the Structure and Hydrocarbon Potential of the Mezen Basin

摘要

The Mezen sedimentary basin (frequently called the Mezen syneclise) situated on the northeastern Russian Platform has an area of approximately 300 000 km~2. The volume of its sedimentary filling exceeds 10~6 km~3, Riphean and Vendian sediments accounting for 75 vol % of this sequence (Fig. 1). The study of the basin and exploration of oil and gas deposits has been undertaken intermittently. Stages of intense study (the last one continuing now) have alternated with periods of calm when exploration work was stopped almost completely. In addition to geophysical work of varying quality and scale, sixteen deep wells have been drilled in the Mezen Basin to date. However, none of them have revealed reliable oil and gas manifestations. Negative exploration results have given rise to skepticism among most of the geologists who doubted the hydrocarbon potential of the Riphean sequences, which are generally considered to be the probable major productive interval of the sedimentary section. The oil and gas potential of Riphean sequences has been established for many sedimentary basins in eastern Siberia , Australia, and North Africa. However, the regional fluid trap in all of them is represented by Upper Vendian and Cambrian clayey-carbonate-evaporite sediments, which are missing from the Russian Platform. Therefore, new geological ideas are needed for the exploration of oil and gas in the Mezen Basin.