Patent ID: 8443879

Claim:
A blowout preventer (“BOP”) for an oil or gas well, comprising: a BOP body having a through-bore defining a centerline and adapted to allow a tubular member to be disposed therethrough, the BOP body having at least a first guideway defining a guideway centerline formed at an angle to the through-bore centerline; a first ram slidably coupled to the BOP body along the first guideway for travel along the first guideway; a first shear blade coupled to the first ram to shear the tubular member disposed therein, the first shear blade being disposed laterally across the first ram and having a first shear blade profile that is laterally asymmetrical across the first shear blade and comprising a first stress concentrator, wherein the first stress concentrator is laterally offset from the guideway centerline; a second ram slidably coupled to the BOP body along a second guideway aligned with the first guideway; and a second shear blade coupled to the second ram, the second shear blade being disposed laterally across the second ram and having a second shear blade profile with a second stress concentrator that is laterally offset from the guideway centerline on an opposite side of the guideway centerline from the first stress concentrator on the first shear blade profile.