Abstract: A two-cone drill bit that exhibits improved stability. In one embodiment, the two-cone drill bit has a first and a second roller cone arranged to have a cone separation angle between about 145 degrees and about 166 degrees. In some embodiments, the two-cone drill bit has a plurality of cutting elements arranged on the roller cones such that a bottom hole coverage greater than about 17 percent is achieved per revolution of the two-cone drill bit.

Abstract: The invention provides an improved drill bit and a method for designing thereof. The drill bit includes a bit body, a journal depending from the bit body, and a disc rotatably mounted on the journal. The disc of the drill bit has PDC cutting elements disposed on it. Also provided is an improved cutting structure for the discs of the drill bit. The cutting structure includes a portion that is comprised from PDC.

Abstract: A two-cone drill bit with a hydraulic arrangement that can be used for one or more of the following: cleaning roller cones, impinging on a hole bottom, or inducing a helical flow field. A two-cone drill bit having a bit body formed from two leg sections and two spacing members. Methods of manufacturing a two-cone drill bit. Methods of improving hydraulics of a two-cone drill bit.

Abstract: A two-cone drill bit that exhibits improved stability. In one embodiment, the two-cone drill bit has a first and a second roller cone arranged to have a cone separation angle between about 145 degrees and about 166 degrees. In some embodiments, the two-cone drill bit has a plurality of cutting elements arranged on the roller cones such that a bottom hole coverage greater than about 17 percent is achieved per revolution of the two-cone drill bit.

Abstract: A cutting element is disclosed having multiple cutting extensions extending from the base portion and separated by valleys. The cutting extensions of the cutting element include both crested and rounded shapes. The cutting extensions may differ in extension height, shape, extension angle, cant angle, and crest angle in other characteristics such as in material properties such as wear resistance, hardness and fracture toughness. The cutting elements have particular, but not exclusive, application in the nose portion of the cone cutters of a rolling cone bit.

Abstract: A method for designing a bit for boring earth formations includes defining parameters for a calculation, where the parameters relate to a geometry of the bit, calculating to determine interference between the bit and the earth formations, obtaining vertical displacements with respect to a bit revolution based on the interference between the bit and the earth formations and applying a criterion to the vertical displacements to evaluate bit performance.