Real time determination of casing resistance and wear in an Iranian oilfield based on MWD/LWD data

Abstract

Casing wear occurs when the drill pipe and the BHA contacts the inner wall of the casing tubular while rotating. Casing wear is an important and complex phenomenon in drilling oil and gas wells. This phenomenon reduces the strength of the burst and collapse resistances. If this phenomenon is not predicted correctly or considered, it will lead to the abandonment of the well. Mud logging data are used to obtain forces and then calculate the depth of casing wear. This study was performed in two wells of a Southwestern Iranian oilfield. Casing wear depth was predicted by coding MATLAB software with the slightest error. It was found that the casing wear in these wells had a more significant effect on burst strength than collapse strength. Finally, the appropriate safety factor is proposed for casing design in well planning.