Statistical parameter of the double electric layer as an indicator of oil-saturation of the lower-middle jurassic formation (Tomsk region)

At present, one of the strategic objectives is to develop hard-to-recover hydrocarbon reserves in Western Siberia which include, along with Bazhenov, Lower and Middle Jurassic formations. Due to high uncertainty of initial parameters, standard methods of resource exploration and evaluation are not sufficiently effective. Therefore, development of hard-to-recover oil and gas reserves located in low permeable reservoirs, Tyumen and Urman in particular, implies development and implementation of new technological approaches to resource prospecting and production. The relevance of the work is associated with the task to increase the increment of hydrocarbon reserve based on innovative technologies – statistical interpretation of old data of geophysical surveys. The purpose of the article is to analyze the relationship between secondary process of double electric layer formation in the argillaceous facies and oil-saturation of tight sand reservoir in the Lower-Middle Jurassic formation of Tomsk region. As an instrument to determine intensity of the secondary processes in tight sand reservoirs of Lower and Middle Jurassic, a new method of statistical interpretation of well logging data has been applied. Intensive secondary processes serve as indicators of hydrocarbon occurrence. Paragenesis of superimposed processes of pyritization, kaolinitization, and formation of surface conductivity in argillaceous cement in sandy intervals indicates their hydrocarbon saturation. The mathematical apparatus of estimating the perspective in reproduction of hydrocarbon resource and profitability of well logging statistical interpretation are presented. Economic feasibility and effectiveness of this technology is shown.