Использование вероятностно-статистических методов для анализа формирования генерационного потенциала глубокопогруженных отложений Верхнепечорской впадины

Abstract

The Upper Pechora Basin is located in the north of the Pre-Ural foredeep. The structure of the upper horizons of the sedimentary cover is well studied, but there is a poor information about deeply buried sediments confined to the eastern side of the depression. Therefore, modeling of the formation of oil and gas potential of great depths is of interest. In this paper, the problem is solved by applying probabilistic and statistical methods. The values of the total generation potential, the concentration of organic carbon, the rate of burial, the depth and the thickness of the layers were used for the analysis. In addition, since the Upper Pechora Basin is characterized by a sharply asymmetric structure, it was divided into two tectonic zones: the western (outer slope) and the eastern (inner slope). As a result, fundamental differences have been established in the conditions of generation potential formation for the studied types of organic matter and tectonic zones. Comparison of the average values of generation potential and the factors influencing its formation showed the presence of statistical differences between the types of kerogen in the deeply buried sediments of the Upper Pechora Basin, as well as between tectonic zones. Correlation analysis has determined that both positive and negative relationships with varying degrees of closeness are observed between the studied indicators. Using linear discriminant analysis, it was determined that sapropel and humus organic matter are separated quite clearly, and the mixed type practically does not stand out according to the specified characteristics, it was also revealed that the separation occurs on a tectonic basis. A step-by-step regression analysis for each of the parameters under consideration, carried out for these types of kerogen separately, confirmed a significant difference in the accumulation processes of sapropel and humus types of kerogen, as well as the western and outer sides of the depression. Thus, the conducted probabilistic and statistical analysis showed the regulatory role of tectonic factors in the processes of generation potential formation.