IMPROVEMENT OF THE METHODOLOGY FOR INTEGRATED ACCIDENT RISK ASSESSMENT AT HYDROGEN SULFIDE-CONTAINING OIL AND GAS FIELDS (A CASE STUDY OF THE KOKDUMALAK FIELD)

This article examines the development of an integrated approach to assessing accidental risk at oil and gas facilities containing hydrogen sulfide (H₂S), accounting for release duration, heavy-gas cloud formation, toxic exposure, and expected damage. The methodological framework encompasses hazard identification, scenario-based modeling of H₂S releases, and estimation of accident frequency, exposure probability, and total damage. A methodological scheme designated OGT–IXB is proposed, integrating source isolation, heavy-gas dispersion, spatiotemporal concentration, toxic load, and integrated risk. Using a hypothetical depressurization scenario for a high-pressure gas-condensate manifold at the Kokdumalak field, initial and residual expected annual damage are assessed. Under the assumed scenario parameters, expected annual damage decreases from 0.1725 to 0.0263 billion Uzbek soums per year, or approximately 84.7%. Limitations of the input data and the need for independent validation are discussed. The findings can support comparative prioritization of preventive measures; the numerical estimates should not be regarded as verified results of industrial operation.