A method includes receiving a drill bit design. The design specifies a design parameter for a plurality of cutter elements of a drill bit. The method also includes estimating a temperature value for the cutter elements based on the design parameter and a drilling parameter; estimating a wear value for the cutter elements based on the design parameter and the temperature value; updating a value of the design parameter for at least one of the cutter elements based on the wear value and a time period; and using the updated design parameter value, repeating the steps of estimating the temperature value, estimating the wear value, and updating the design parameter value until the design parameter value for the at least one of the cutter elements reaches a threshold value.

A downhole tool includes a cone with an outer surface, a cone axis, and a set on the outer surface thereof. The set includes first and second cutting elements. The first and second cutting elements have respective first and second grips that are different. Another downhole tool includes a body and a cone is connected to, and rotatable relative to, the body. Cutting elements on the cone are arranged in a set to vary in radial position relative to a cone axis, with a first position nearest to, and a last position farthest from, the cone axis. A first cutting element in the first position has a different cutting element geometry type than a second cutting element in the last position. First and second cutting elements may have the same cutting element geometry type and one or more cutting elements therebetween may have different cutting element geometry types.

The invention relates to a drilling tool and a method for producing a bore in the ground, in which method ground material is carried away by a removal device on the underside of a main body of the drilling tool, flushing air is supplied by a feeding device into the bore, which is filled with drilling fluid, in the area of the removal device and ground material carried away by means of the flushing air is transported away through a discharge line. According to the invention, the ground material is transported to a receiving area in an upper section of the main body. A collecting hood is provided above the receiving area, which closes off the receiving area at the top, forming an air collecting space in which air collects. An outlet valve by means of which air is discharged from the air collecting space is arranged on the collecting hood.

The invention relates to a drilling tool and a method for producing a bore in the ground, in which method ground material is carried away by a removal device on the underside of a main body of the drilling tool, flushing air is supplied by a feeding device into the bore, which is filled with drilling fluid, in the area of the removal device and ground material carried away by means of the flushing air is transported away through a discharge line. According to the invention, the ground material is transported to a receiving area in an upper section of the main body. A collecting hood is provided above the receiving area, which closes off the receiving area at the top, forming an air collecting space in which air collects. An outlet valve by means of which air is discharged from the air collecting space is arranged on the collecting hood.

The invention relates to a drilling tool and a method for producing a bore in the ground, in which method ground material is carried away by a removal device on the underside of a main body of the drilling tool, flushing air is supplied by a feeding device into the bore, which is filled with drilling fluid, in the area of the removal device and ground material carried away by means of the flushing air is transported away through a discharge line. According to the invention, the ground material is transported to a receiving area in an upper section of the main body. A collecting hood is provided above the receiving area, which closes off the receiving area at the top, forming an air collecting space in which air collects. An outlet valve by means of which air is discharged from the air collecting space is arranged on the collecting hood.

The invention relates to a drilling tool and a method for producing a bore in the ground, in which method ground material is carried away by a removal device on the underside of a main body of the drilling tool, flushing air is supplied by a feeding device into the bore, which is filled with drilling fluid, in the area of the removal device and ground material carried away by means of the flushing air is transported away through a discharge line. According to the invention, the ground material is transported to a receiving area in an upper section of the main body. A collecting hood is provided above the receiving area, which closes off the receiving area at the top, forming an air collecting space in which air collects. An outlet valve by means of which air is discharged from the air collecting space is arranged on the collecting hood.

A downhole tool includes a cone with an outer surface, a cone axis, and a set on the outer surface thereof. The set includes first and second cutting elements. The first and second cutting elements have respective first and second grips that are different. Another downhole tool includes a body and a cone is connected to, and rotatable relative to, the body. Cutting elements on the cone are arranged in a set to vary in radial position relative to a cone axis, with a first position nearest to, and a last position farthest from, the cone axis. A first cutting element in the first position has a different cutting element geometry type than a second cutting element in the last position. First and second cutting elements may have the same cutting element geometry type and one or more cutting elements therebetween may have different cutting element geometry types.

Drill bits with at least two roller cones of different diameters and/or utilizing different cutter pitches in order to reduce bit tracking during drilling operations are described. In particular, earth boring drill bits are provided, the bits having two or more roller cones, and optionally one or more cutter blades, the bits being arranged for reducing tracking by the roller cone teeth during operation by adjusting the teeth spacing, cone pitch angle, and/or the diameter of one or more of the cones. These configurations enable anti-tracking behavior and enhanced drilling efficiency during bit operation.

Drill bits with at least two roller cones of different diameters and/or utilizing different cutter pitches in order to reduce bit tracking during drilling operations are described. In particular, earth boring drill bits are provided, the bits having two or more roller cones, and optionally one or more cutter blades, the bits being arranged for reducing tracking by the roller cone teeth during operation by adjusting the teeth spacing, cone pitch angle, and/or the diameter of one or more of the cones. These configurations enable anti-tracking behavior and enhanced drilling efficiency during bit operation.