Effect of secondary processes on the petrophysical properties of sand rock of the tanopchin formation of the Tambey field (Yamalo-Nenets autonomous okrug)

Abstract

Relevance. Finding the correlation between filtration-capacitive properties and secondary processes helps to identify missed oil and gas deposits. Traditional methods of processing geophysical information are becoming less and less effective, and accordingly there is a need to introduce new techniques for detecting missed hydrocarbon deposits. Aim. To study the effect of secondary processes on the filtration and reservoir properties of rocks in the productive lower strata of the tanopchin formation of the North Tambey license area, located within the Tambey field, using materials from geophysical surveys of wells and core data. Methods. The statistical-correlation interpretation method represents a significant breakthrough in the field of interpretation of well logging data. It allows for a more accurate interpretation of data from existing reservoir studies, which makes it possible to identify productive sections of wells where hydrocarbons could not be detected by traditional methods. Statistical correlation interpretation is carried out on the basis of data from secondary geochemical processes occurring in the formation. The scientific novelty. Identification of the relationship between the intensity of secondary processes and the petrophysical properties of the rocks of the Lower Cretaceous productive horizon of the Tambey field (Yamalo-Nenets autonomous okrug). Results and conclusions. The author has determined the dependence of the filtration-capacitive properties of rocks on the intensity of secondary geochemical processes. It was established that secondary geochemical processes such as carbonatization and pyritization worsen reservoir properties, while kaolinization and pelitization lead to an improvement in the filtration and reservoir properties of reservoir rocks. The paper explains the mechanism of effect of secondary processes on filtration-capacitive properties. Pelitization of potassium feldspars leads to the formation of three-layer clay minerals, which have the largest sorption surface area and cation exchange capacity; as a result, the reservoir capacity increases, which leads to an increase in permeability several times.