Development of a Zonal Model for Forecasting the Oil and Gas Potential of the YUS1 Formation by Geochemical Parameters

Abstract

The distribution of geochemical properties of rocks of the Bazhenov Formation (BF) by area and section has been refined, regularities have been searched, and conclusions have been obtained that have predictive power. Due to the high cost of continuous core sampling and pyrolysis of samples from BF intervals, the fragmentation and heterogeneity of the accumulated information, as well as the high value of knowledge about the oil-generating properties of BF rocks and their changes over the area, there is a need to increase the information content of the database of geochemical core studies and adapt its application in conditions of limited data. To solve this problem, a database of results of geochemical studies was collected and analyzed, consisting of 5272 samples from 123 wells of 32 fields. As a result of the analysis, conclusions were obtained about the oil-generating properties of BF within the study area and the degree of maturity of the organic matter of the rock. Two regression models were developed to predict the geochemical parameters of free hydrocarbon content, residual generation potential and total organic carbon from well logging data. An algorithm was implemented in the Python programming language to automate the calculation process. Using this algorithm and the resulting regression equation, the calculation of geochemical parameters was carried out in 390 wells in the study area that were not presented by core data, which significantly increased the detail and information content of predictive maps of the distribution of parameters over the area. Using the data obtained, a geological and mathematical model was developed for predicting oil content by geochemical parameters. The developed model reflects the probability of oil content depending on the oil source properties of the rocks of the Bazhenov formation in the study area. The developed forecast model included the parameters of the organic carbon content in the rock, the current reservoir temperature and the thickness of the rocks of the Bazhenov formation.