M.R. ZHURAEV (SE «Institute GIDROINGEO», Uzbekistan)

Refinement of hydrogeochemical setting during the formation of hydrogen-­sulfide water in the Bukhara-­Khiva artesian basin

The paper deals with the influence of the hydrogeochemical factor on conditions of hydrogen­-sulfide water formation in oil and gas fields of the Bukhara­-Khiva basin (Uzbekistan). Average temperatures of the productive horizon are taken into account, as well as the influence of the depth of occurrence of these horizons from the land surface. Processes of hydrogen­-sulfide water formation at the Bukhara and Chardzhou stages are compared. When the productive horizon is located close to the land surface (Bukhara stage), oxygen penetration enhances the sulfate reduction process in evaporite rocks resulting the formation of hydrogen­-sulfide water due to the biochemical process. When the productive horizon is submerged deeply and temperatures are high, hydrogen­sulfide waters are formed due to the thermochemical process (Chardzhou stage).
Keywords: reservoir temperature, productive horizon, gas and oil field, thermochemical process, Bukhara­-Khiva artesian basin, Uzbekistan.