The analysis of oil reserves distribution in the territory of permafrost of different types showed that the zone of discontinuous spread of permafrost is much richer than the oil-and-gas bearing territories of insular and continuous permafrost propagation. A comparison analysis of the Russia crude oil chemical composition in the zones of continuous, discontinuous fnd insularpermafrost propagation is made. It is shown that in the territory of discontinuous spread of permafrost the content of sulfur, paraffins, resins and asphaltens in average is less, and the content of fractions with boiling temperature 350 oC is higher in comparison with their content in the pеrmafrost territory of insular and continuous types. Fig. 6, table 3, ref. 7.

The distribution and composition of nitrogen-organic compounds in heavy pils of Usinsk field produced without applying oil recovery enhancement methods and using steam thermal treatment are studied. The specific feature of crude oil nitrogen compounds undergone the impact of steam is an increase in the content of weak-base components, in a quantity of low-molecular bases including nitrogen compounds. The composition of weak and strong bases of such oil is characterized by an increased fraction of polycyclic naphteno-aromatic structures. Fig. 1, table 4, ref. 8.

Представлена детализированная классификация трудноизвлекаемых нефтей с высоким содержанием парафинов. Проведен анализ пространственного распределения таких нефтей по нефтегазоносным бассейнам России и мира в зависимости от изменения распределения парафинистых нефтей могут быть использованы при совершенствовании геохимических методов поиска месторождений, определении оптимальных схем добычи и транспортировки нефтей.