METHODICAL APPROACHES FOR BITUMEN PROPERTIES STUDYING AND ITS CONTENT ASSESSING IN CARBONATE DEPOSIT CORE SAMPLES OF EASTERN SIBERIA

Oil and gas fields in Eastern Siberia play an important, strategic role in the development and reproduction of hydrocarbon reserves. Oil and gas-bearing carbonate rocks of the Lower Cambrian deposits are characterized by a complex structure of the pore space, which is represented by intercrystalline, interform, intraform voids, caverns and cracks, partially filled with sulfates, halite due to secondary changes. Hydrocarbons are represented by gas, oil and bitumen. Black and, less often, black-brown bitumen occurs in the form of films and smears along the contours of crystals and the walls of voids, partially or completely sealing them in some areas. Bitumen can fill almost all available void space, significantly worsening well flow rates, sometimes reducing them to a minimum. A reliable assessment of the void space of carbonate reservoirs is necessary for a correct evaluation of hydrocarbon reserves of raw materials, as well as for planning an effective development system for such objects. The largest volume of data on petrophysical and lithological-mineralogical properties of rocks, as well as their oil and gas saturation, is obtained during geophysical well logging (GWL), however, to obtain reliable results of GWL interpretation, a reliable petrophysical basis is required, which is created as a result of a comprehensive study of core and reservoir fluids. This paper examines methodological approaches to studying the properties of bitumen and assessing its content in core samples of carbonate deposits in Eastern Siberia. The objects of research are rocks of oil-saturated formations Б1 and Б5 in several fields in Eastern Siberia, located in the area of activity of Oil Company Rosneft PJSC.