Prevention of the flow of clays located higher than productive formation outside and necking of production string

The paper studies the methods of prevention of necking of casings and in particular, production strings, as well as the complications occurring in the drilling process in the Caspian Sea as a result of clay flowing out and prediction of such kind of issues. Moreover, in the selection of production strings, “Stress Check” software program was used. One of the geological issues leading to the necking of casing is probably poorly cemented clay layers. In addition, the structure of the well drilled in Bulla-deniz field, formation pressure and the selection of casing for this well have been considered. In conclusion, the selection of casing to be lowered into the gas well in Bulla-deniz field has been executed via “Stress Check“ software program.