Abstract: Embodiments disclosed herein relate to a method for analyzing a fixed cutter drill bit, said method including selecting a cutter; selecting an earth formation; simulating drilling performance of the fixed cutter bit having at least once cutter thereon; performing finite element analysis using outputs from the simulating; and outputting stress on the at least one cutter.

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 method of manufacturing a drill bit may include inserting an attachment end of a journal portion into a cavity of a blade portion. The journal portion includes the attachment end; a journal end opposite from the attachment end; and a journal on the journal end extending downward and radially outward from a longitudinal axis of the journal portion. The blade portion includes the cavity extending a distance into the blade portion; and at least one blade extending along the blade portion from adjacent to the cavity to a gauge region of the drill bit. Then, the method includes attaching the journal portion to the blade portion and mounting a roller cone to the journal.

Abstract: A drill bit having a bit body, at least one blade extending radially from the bit body, a plurality of blade cutting elements disposed on each blade, at least one journal extending downwardly and radially outward from a longitudinal axis of the drill bit, a roller cone or roller disc mounted rotatably to each journal, and a plurality of cutting elements disposed on each roller cone or roller disc, and methods for making the drill bit are disclosed.

Abstract: A method including of manufacturing a drill bit includes inputting bit characteristics into a simulator. The bit characteristics may include a drill bit mass, coordinates of the bit center of gravity, and an inertia tensor of the bit. The bit center of gravity and a vector of the inertia tensor may be aligned with a bit axis in the simulator. Based on the alignment of the center of gravity and the inertia tensor with the bit axis, new bit characteristics may be determined. A drill bit with the new bit characteristics may be produced.

Abstract: A method of manufacturing a roller cone drill bit may include forming a body of a single piece having an upper end and a lower end; machining at the lower end of the body at least two journals extending downward and radially outward from a central axis of the body; machining at least one of a ball passage, a hydraulic fluid passageway, a grease reservoir, and a lubricant passageway; and mounting roller cones on the at least two journals.

Abstract: A drill bit includes a bit body having a longitudinal axis extending there through, a plurality of journals extending downward and radially outward from the bit body, each journal having a journal axis extending from a base of the journal through the length of the journal, wherein the journal axis at the base is at a first radial distance from the longitudinal axis, a roller cone rotatably mounted to each of the journals, and at least one blade protruding from the bit body and extending axially and radially along the bit body from a first end to a second end, wherein the first end is at a second radial distance from the longitudinal axis greater than the first radial distance, and wherein the second end is at a gage region of the drill bit.

Abstract: A drill bit may include a bit body, comprising: at its upper end, a connection adapted to connect to a drill string; at its lower end, a plurality of journals extending downwardly and radially outward from a longitudinal axis of the bit; a plurality of roller cones rotatable mounted on the plurality of journals; and at least three rows of cutting elements disposed on each of the plurality of roller cones, wherein an outermost row has an extension height to diameter ratio greater than a mid row, and the mid has an extension height to diameter ratio greater than an innermost row.

Abstract: Embodiments disclosed herein relate to a method for analyzing a fixed cutter drill bit, said method including selecting a cutter; selecting an earth formation; simulating drilling performance of the fixed cutter bit having at least once cutter thereon; performing finite element analysis using outputs from the simulating; and outputting stress on the at least one cutter.

Abstract: A drill bit includes a bit body comprising at its upper end a connection adapted to connect to a drill string and at its lower end a plurality of journals extending downwardly and radially outward from a longitudinal axis of the bit. A plurality of roller cones are rotatably mounted on the plurality of journals and at least three rows of cutting elements are disposed on each of the plurality of roller cones. The outermost row of the at least three rows of cutting elements has an extension height to diameter ratio greater than a mid row, and the mid row has an extension height to diameter ratio greater than an innermost row.

Abstract: A drill bit having a bit body, at least one blade extending radially from the bit body, a plurality of blade cutting elements disposed on each blade, at least one journal extending downwardly and radially outward from a longitudinal axis of the drill bit, a roller cone or roller disc mounted rotatably to each journal, and a plurality of cutting elements disposed on each roller cone or roller disc, and methods for making the drill bit are disclosed.

Abstract: A method of manufacturing a roller cone drill bit may include forming a body of a single piece having an upper end and a lower end; machining at the lower end of the body at least two journals extending downward and radially outward from a central axis of the body; machining at least one of a ball passage, a hydraulic fluid passageway, a grease reservoir, and a lubricant passageway; and mounting roller cones on the at least two journals.

Abstract: A drill bit may include a bit body, comprising: at its upper end, a connection adapted to connect to a drill string; at its lower end, a plurality of journals extending downwardly and radially outward from a longitudinal axis of the bit; a plurality of roller cones rotatable mounted on the plurality of journals; and at least three rows of cutting elements disposed on each of the plurality of roller cones, wherein an outermost row has an extension height to diameter ratio greater than a mid row, and the mid has an extension height to diameter ratio greater than an innermost row.

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.