Abstract: An underreamer for increasing the diameter of a bore. The underreamer includes a substantially cylindrical body having an axial bore therein. A mandrel may extend axially through the axial bore. One or more cutter blocks are movably coupled to the body. A ratio of a height of the cutter block to a diameter of the body is between about 0.35:1 and about 0.50:1.

Abstract: An underreamer for increasing the diameter of a bore. The underreamer includes a substantially cylindrical body. A mandrel may extend axially through the body. One or more cutter blocks are movably coupled to the body. A ratio of a height of the cutter block to a diameter of the body is between about 0.35:1 and about 0.50:1.

Abstract: A downhole tool for increasing a cross-sectional area of a wellbore is provided. The downhole tool may include a first drilling assembly including a first reaming tool for selectively increasing the cross-sectional area of the wellbore. A first ball seat may receive a first ball. At least one of the first ball seat and the first ball may deform to allow the first ball to pass through the first ball seat when a predetermined pressure is applied thereto. A first piston may be coupled to the first ball seat. The first ball seat and the first piston may stroke when the first ball is received within the first ball seat, thereby actuating the first reaming tool between an active state and an inactive state.

Abstract: An underreamer for increasing the diameter of a bore. The underreamer includes a substantially cylindrical body. A mandrel may extend axially through the body. One or more cutter blocks are movably coupled to the body. A ratio of a height of the cutter block to a diameter of the body is between about 0.35:1 and about 0.50:1.

Abstract: An underreamer for increasing the diameter of a bore. The underreamer includes a substantially cylindrical body having an axial bore therein. A mandrel may extend axially through the axial bore. One or more cutter blocks are movably coupled to the body. A ratio of a height of the cutter block to a diameter of the body is between about 0.35:1 and about 0.50:1.

Abstract: A rolling cone drill bit comprises a plurality of bottomhole cutter elements positioned in a first circumferential row, wherein at least one of the cutter elements comprises a cutting portion extending from a base portion to a point furthermost from the base portion, defining an extension height. The ratio of the cross-sectional area of the cutter element at a point equal to ninety-four percent of the extension height to the cross-sectional area of the cutter element base is greater than 0.2. Moreover, the ratio of the extension height to the base diameter is not greater than 0.75.

Abstract: A method for evaluating a cutting arrangement for a drill bit includes selecting a cutting element arrangement for the drill bit and calculating a score for the cutting arrangement. This method may be used to evaluate the cutting efficiency of various drill bit designs. In one example, this method is used to calculate a score for an arrangement based on a comparison of an expected bottom hole pattern for the arrangement with a preferred bottom hole pattern. The use of this method has lead to roller cone drill bit designs that exhibit reduce tracking over prior art bits.

Abstract: A method for evaluating a cutting arrangement for a drill bit includes selecting a cutting element arrangement for the drill bit and calculating a score for the cutting arrangement. This method may be used to evaluate the cutting efficiency of various drill bit designs. In one example, this method is used to calculate a score for an arrangement based on a comparison of an expected bottomhole pattern for the arrangement with a preferred bottomhole pattern. The use of this method has lead to roller cone drill bit designs that exhibit reduce tracking over prior art bits.

Abstract: A method for evaluating a cutting arrangement for a drill bit includes selecting a cutting element arrangement for the drill bit and calculating a score for the cutting arrangement. This method may be used to evaluate the cutting efficiency of various drill bit designs. In one example, this method is used to calculate a score for an arrangement based on a comparison of an expected bottomhole pattern for the arrangement with a preferred bottomhole pattern. The use of this method has lead to roller cone drill bit designs that exhibit reduce tracking over prior art bits.

Abstract: A method for evaluating a cutting arrangement for a drill bit includes selecting a cutting element arrangement for the drill bit and calculating a score for the cutting arrangement. This method may be used to evaluate the cutting efficiency of various drill bit designs. In one example, this method is used to calculate a score for an arrangement based on a comparison of an expected bottomhole pattern for the arrangement with a preferred bottomhole pattern. The use of this method has lead to roller cone drill bit designs that exhibit reduce tracking over prior art bits.