Expandable casing employed in reservior under salt formation in Kazakhstan kenkyak oilfield

Gypsum-bearing and carbonate formation show in the same open hole section during the drilling in Kazakhstan kenkyak oilfield. expandable casing was used to prevent the leakage, overflow and breakout in the down hole of the reservoir under salt formation where the pore pressure in the below Carboniferous was only 1.5 because of development and the one in the above Permian was 1.79 originally The running depth of corrugated tube is made by formation lithology and pressure while its outer diameter and pressure grade decided by the well configurations. The inner diameter of expanded bellows is just the same of drilling hole after treatment, and it is able to endure both the fluid pressure in the hole and the extrusion force form outside strata that make the following drilling more successful. This technology can transfer from higher pressure Permian to lower pressure Carboniferous safely and successfully so it solve the complex due to formation lithology and pressure. The technology was used to not only keep drilling smoothly and successfully but also protect the reservoir. From this application in the oilfield, we accumulate some experience on bellows employ which provide reference for industry extension of thebellows.