US Patent 8720564 Tubular severing system and method of using same

Techniques for severing a tubular of a wellbore penetrating a subterranean formation are provided. A blade is extendable by a ram of a blowout preventer positionable about the tubular. The blade includes a blade body having a front face on a side thereof facing the tubular. At least a portion of the front face has a vertical surface and at least a portion of the front face has an inclined surface. The vertical surface is perpendicular to a bottom surface of the blade body. The blade body includes a loading surface on an opposite side of the blade body to the front face. The loading surface is receivable by the ram. The blade also includes a cutting surface along at least a portion of the front face for engagement with the tubular, and a piercing point along the front face for piercing the tubular. The piercing point has a tip extending a distance from the cutting surface.