Hole making in rock salts at Astrakhan gas condensate field is accompanied by emerging of high-pressure concentrated brine, which results in problems during the drilling. Analysis of causes of complications in well development in 2000–2018 revealed that 80 % of upset scenarios flow from lack of data on the localization of brine-risky levels in the area and sequence.
The study proposes the novel hypothesis on the geomorphological correlation of salt domes with the spatial arrangement of brine-bearing formations. The mechanism is proposed to explain the anomalously high and low formation pressures. Also, the new geological model is created to find the brine-risky formations remotely. The model will use the seismic data to reveal the zones where the brine is likely to emerge during well drilling at the Astrakhan gas condensate field.
The results are advised to use when planning and managing the design and subsalt drilling activities at productive sediments of Astrakhan, Kovyktinskoye, and some other oil and gas fields, which will enhance the feasibility of design and engineering decisions.
Keywords: BRINE, BRINE-BEARING FORMATION, BRINE EMERGING, INTRASALT FORMATION, DRILLING, MODEL, FORECAST, ASTRAKHAN GAS CONDENSATE FIELD.