US Patent 10151172 Pressure perforated well casing collar and method of use

Pressure perforated well casing collars have at least one pressure perforation groove cut to a consistent depth in an a sidewall of the well casing collar with sidewall bottom material at a bottom of the groove. The sidewall bottom material ruptures at a predetermined fluid pressure greater than a burst pressure rating of plain casing joints connected to the well casing collars to assemble a well casing string.