Casing deformations are common in the south-west shale regions of China and the Middle East, where the widespread use of 5.5-in., 26- and 26.8-lb/ft casing is the norm. In these regions, the majority of frac plugs are designed with an outer diameter (OD) of 4.055 in. or slightly larger, which frequently encounter restrictions resulting in the loss of bottomhole assemb…