Author: Rahimov, Ashraf Rasul o‘g‘li; Usmonov, Kuvonchbek Mannonovich; Buronov, Firdavsiy Eshburiyevich

Annotation: The article analyzes the mechanisms behind the formation of anomalous formation pressures (both high and low) in deep-seated (over 3,000 meters) oil and gas reservoirs, examining their hydraulic-thermodynamic nature and specific manifestations using the Alan gas field in the Kashkadarya region as a case study. The system of pressures acting within deep wells—including geostatic, hydrostatic, formation, hydrodynamic, and differential pressures—is scientifically classified, and the interrelationships between them are substantiated through mathematical expressions. The concept of the anomaly coefficient and its ranges (from 0.45 to 2.10) are explained. It is shown that while the Alan field initially operated under conditions close to normal hydrostatic pressure, more than 40 years of exploitation led to a transition to a state of anomalously low formation pressure (ALFP, with the anomaly coefficient dropping from the 1.7–1.8 range). Additionally, the article analyzes the current state of multiphase filtration theory in porous-fractured media and the limitations of existing hydraulic calculation methods.

Keywords: abnormal formation pressure, hydrostatic pressure, geostatic pressure, anomaly coefficient, carbonate reservoir, Alan gas field, non-linear filtration.

Pages in journal: 288 - 294