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East Siberian Oil and Gas Company, part of Rosneft, says it used a two-casing design to drill an oil well at the Yurubcheno-Tokhomskoye field in formations with a broad gas cap. Rosneft published the update on 7 October 2026.
The company says the method may shorten well construction by five days and yield an economic benefit of up to RUB 40 million per well. At the Namakara deposit, the gas-bearing interval reaches up to 100 metres thick, according to the release.
Rosneft describes the completed work as an experimental industrial operation. It says the engineering result has laid the basis for considering the design on 20 additional wells planned for drilling at Namakara; those wells are prospective, not completed.
The time and cost effects are company-reported expectations, not independently measured outcomes for every well. The release explains that an extended production casing isolated the gas-cap interval, replacing the former three-casing approach. It does not provide an independent test dataset.