Oil and gas operators have explored in the Arctic regions of Russia for more than 40 years. Early drilling campaigns encountered significant problems drilling through the shallow permafrost sections due to degradation of drilling conditions as a result of permafrost thaw. Experience from these earlier operations and experiments conducted by Kutasov et al (1988) has highlighted the need to maintain chilled drilling mud to minimize permafrost thaw during the well construction process. After time technologies made step forward and casing drilling is in addition option with Kutasov technology to improve drilling process. This technology is one of the greatest developments in drilling operations. Casing drilling involves drilling and casing a well simultaneously.
Casing drilling system has been designed primarily for multi-well offshore platforms, multiwell operations on land, deep-water operations, and for situations requiring operators to drill through and place casing across problem formations quickly. This technology was applied successfully to drill through depleted reservoir (problems: wellbore instability, mud losses into the depleted zones) as an alternative to the underbalanced drilling, which requires special equipment.
