Issue: 1 , Volume: 20 , Уear of publication: 2026

This study assessed the preservation of water quality in the Apt-Alb-Cenomanian aquifer complex (AAC AC) under conditions of long-term multidirectional oil and gas technogenesis. This involves two opposing processes: groundwater extraction to maintain reservoir pressure in productive horizons, and the injection of excess produced water into the complex. The scale of each of the above processes reaches hundreds of thousands of cubic metres of water per year. The AAC AC in the West Siberian oil and gas region belongs to the Mesozoic hydrogeological basin. To achieve this goal, data on the three largest oil fields were used. The research methodology involved the systematization of historical and current water quality data. The study found that, despite the significant anthropogenic load, the natural hydrogeochemical equilibrium in the system "water-rock" of the studied AAC AC remains largely intact.