Hydrocarbon systems and oil and gas potential prospects of the Anabar-Lena trough

The Anabar-Lena trough is one of the least geologically studied areas on the Siberian Platform. A few wells drilled here have not yet revealed direct signs of its oil bearing. However, indirect data indicate that this region can be very prospective. This is proved by the proven oil and gas potential of the adjacent area (oil in the Khatanga saddle, bitumen of the Olenek field) and a thick sedimentary cover in the stratigraphic range from the Riphean to the Lower Cretaceous. The conducted studies show that several hydrocarbon systems are present in the section, which may be associated with the discovery in the future of industrial oil and gas fields. The most ancient of them are Upper Proterozoic and Lower Paleozoic – Riphean, Vendian and Cambrian. There are several levels enriched with organic matter in these deposits. As reservoirs can be sandy-silty units and organogenic carbonates as well. The most prospective is the Permian complex, its thickness can reach 2-3 km. It contains source rocks of good quality. The biomarker analysis shows that hydrocarbon composition of the Permian organic matter is similar to the oils and bitumens of the existing oil fields and showings in this complex. Permian reservoirs have a complex structure with an abundance of wedging and replacement zones, which was predetermined by a frequent change in sedimentation environments.