US Patent 8720565 Tubular severing system and method of using same

A method for severing a tubular of a wellbore is provided. The method involves positioning a blowout preventer about a tubular, the blowout preventer having a plurality of rams slidably positionable therein and a plurality of blades carried by the rams for engaging the tubular. The method further involves piercing the tubular with a piercing point of at least one of the blades such that a portion of the tubular is dislodged therefrom, and raking through the tubular with a cutting surface of at least one of the blades.