Features of modern interpretation of seismic data on the example of a site in the Middle Caspian waters

The oil and gas industry is a key economic driver of Kazakhstan’s development. The current reality is that the country's GDP growth rates, the level of digitalization in science and its technological advancement, a significant portion of national revenues are still directly dependent on the discovery of new hydrocarbon fields. In this context, the most promising regions for oil and gas exploration are the Pre-Caspian Basin, South Mangyshlak, and the Caspian Sea offshore areas. Particular attention from both domestic and foreign oil companies is focused on the North and Middle Caspian offshore zones. It is worth noting that between 2000 and 2008, 13 fields were discovered in the study area, 6 of which are located in the North Caspian (Kashagan, Kairan, Aktoty, Kalamkas-Sea, Auezov, Khazar). In the Middle Caspian, the following fields have been discovered: Khvalynskoye, Sarmatskoye, Shirotnoye (named after Korchagin), Rakushechnoye, named after Filanovsky, and Rakushechnoye West. The hydrocarbon potential of the region is substantiated not only by the significant thickness of sediments but also by the presence of extensive subsidence zones within the sedimentary cover, characterized by the widespread development of reservoir rocks, cap rocks, and oil-source rock formations. It should be noted that, along with discoveries, there have also been unsuccessful drilling results in several explored structures in the region, including Tub-Karagan-1 (2005), Kurmangazy-1 (2006), Atash-1 (2008), Laganskaya-1 (2008), Kurmangazy-2 (2009), Petrovskaya-1 (2009), and Zhenis (2023). On the other hand, more than 30 local structures, predominantly of Mesozoic age, remain unexplored within the studied area. All these factors are observed against the backdrop of relatively low geological and geophysical study coverage. This leads to the conclusion that there is a critical need to significantly improve the efficiency of geological exploration, which could substantially enhance the research foundation and facilitate the development of a modern geological model of the region. This study demonstrates various technological approaches to seismic data interpretation. To date, a range of technical and software solutions for seismic data processing and interpretation have been developed to address the challenges of hydrocarbon reservoir prediction. Moreover, the analysis has reached a stage where unstacked seismic data are increasingly used as input. The study analyzes the effectiveness of seismic attributes and performs dynamic interpretation of seismic data in one of the areas of the Middle Caspian hydrocarbon basin. This approach has refined the geological structure of the study area, enabled the mapping of clay content zones and reservoirs, and assessed the advantages of the applied interpretation methods in the exploration and prediction of hydrocarbon-bearing targets, where the lithological factor significantly influences the formation of hydrocarbon accumulations. As a result, volumetric models of reservoir distribution, clay content, and hydrocarbon saturation have been constructed.