Patent attributes
Present embodiments of the disclosure are directed to a blowout preventer having a ram unit designed to shear wellbore tubulars with a range of diameters. The ram unit may include a first shear block having a first blade profile, and a second shear block having a second blade profile. The blade profiles may each feature an angled portion for contacting the wellbore tubular. The angled portion of the first blade profile may be a different size (e.g., width dimension) than the angled portion of the second blade profile. This may enable the larger angled portion to support a smaller tubular while contact points on the smaller angled portion apply a force for shearing the tubular. With larger tubulars, an initial edge of the blade profile with the smaller angled portion may support the tubular while contact points on the larger angled portion apply a force for shearing the tubular.