The problem of assessing the core saturation of rocks, which existed in the development of the Sakha (Yakutia) Republic deposits, caused this research work, the elaboration of methods and the search for objective dependencies for solving it. One of the found and possible in the implementation was the method of pyrolysis and subsequent oxidation. Depending on the degree of oxidation, bitumens retain the ability to be partially (and sometimes completely) extracted when using core extraction methods with organic solvents (hot and even cold). In this case, uncontrolled overestimation of the total porosity and distortion of the parameters of absolute gas permeability occurs. To study the bituminous nature of reservoir rocks, it is possible to use thermal analysis methods that do not require special sample preparation and allow analysis of organic matter directly in the core material. One of the thermal methods of analysis is pyrolysis in the Rock Eval 6 installation. Pyrolytic analysis provides a quantitative assessment of organic matter components (oil and bitumen) contained in the reservoir rock. The study was conducted according to the method of Reservoir. The main goal of the study is to determine the boundaries of the mobility of organic matter and the criteria for oil-bitumen differentiation in the core.
The paper proposes the use of a pyrolytic method for estimating the structure of hydrocarbon saturation with respect to the core. Based on a comparison of laboratory studies with test data, the criteria for estimating the oil-saturated intervals for the core are identified. The criteria for estimating bitumenization of reservoirs are proposed.
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