The justification of zonal oil and gas potential of the territory of Visimskaya monocline by geochemical criteria

Abstract

The paper presents a zonal probability and statistical assessment of the generation potential of deposits that form oil and gas potential of the territory of Visimskaya monocline. Databases on geochemical and bituminological characteristics of dispersed organic matter (DOM) in Domanicoid type deposits of the Upper Devonian-Tournaisian formation were used. The following indicators were used: content of organic carbon Sorg, %; organic matter OM, %; composition of DOM (content of bitumoids: % – chloroform – CBE, petroleum – PB, alcohol-benzene – ABB, humic acids – HumA, %, insoluble residue – IR, %) and characteristics of DOM conversion (ratio of chloroform bitumen to alcohol-benzene one – CBE/ABB, bitumoid coefficient – β), as well as the conversion factor for Sorg – Kc. In order to determine the informativeness of these characteristics, the Student’s and Pearson's statistical criteria were used. When building models for predicting the zonal oil and gas potential of the territory of Visimskaya monocline, one-dimensional and step-by-step multidimensional regression analyzes were used, which allowed to construct one-dimensional and multidimensional regression linear models. Using the step-by-step multidimensional regression analysis a complex criterion was developed taking into account influence of each geochemical indicator separately and their combinations. This made it possible to construct a scheme for distribution of probability of petroleum potential of the territory of Visimskaya monocline. Analysis of the scheme showed that the most favorable geochemical conditions for the formation of petroleum potential due to DOM are observed in the central part of Visimskaya monocline (within the Maykorskoye field and surrounding area, bounded by the likelihood more than 0.5). Besides, areas in the south of Visimskaya monocline in the territories where Pcompgh > 0.5 are of particular interes in terms of zonal oil and gas potential. North of Visimskaya monocline probably has a certain interest as well.

Keywords

• probability
• linear statistical model
• multidimensional statistical model
• correlation coefficient
• oil and gas potential
• statistical criteria
• geochemical and bitumen characteristics
• organic matter
• geochemistry.