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.

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.

A tool for drilling a borehole through a formation. The tool comprises a body, blades having rotationally leading surfaces extending from the tool body, cutting elements secured at least partially within cutting element pockets, and linear or rounded transition surfaces between the cutting element pockets and the rotationally leading surface of the blades. The rounded transition surfaces have a radius of curvature between about 3 and 150 millimeters. The disclosure also includes a method of manufacturing an earth-boring downhole tool comprising: providing a tool body and blades comprising a rotationally leading surface extending from the tool body; Forming cutting element pockets into the blades proximate the rotationally leading surface of the blades; Forming linear or rounded transition surfaces between the cutting element pockets and the rotationally leading surface of the blades, the rounded transition surfaces having a radius of curvature between about 3 and 150 millimeters; And securing cutting elements at least partially within the cutting element pockets.

A tool for drilling a borehole through a formation. The tool comprises a body, blades having rotationally leading surfaces extending from the tool body, cutting elements secured at least partially within cutting element pockets, and linear or rounded transition surfaces between the cutting element pockets and the rotationally leading surface of the blades. The rounded transition surfaces have a radius of curvature between about 3 and 150 millimeters. The disclosure also includes a method of manufacturing an earth-boring downhole tool comprising: providing a tool body and blades comprising a rotationally leading surface extending from the tool body; Forming cutting element pockets into the blades proximate the rotationally leading surface of the blades; Forming linear or rounded transition surfaces between the cutting element pockets and the rotationally leading surface of the blades, the rounded transition surfaces having a radius of curvature between about 3 and 150 millimeters; And securing cutting elements at least partially within the cutting element pockets.

Drill bits and methods relating thereto are disclosed. In an embodiment, the drill bit includes a body having a plurality of legs each having a lower section that has a leading surface and a trailing surface. A plurality of cone cutters are each rotatably mounted to the lower section of one of the legs, each having a cone axis, and including a first plurality of cutter elements arranged about the cone axis such that each is shear the formation when the body is rotated about the bit axis.

Drill bits and methods relating thereto are disclosed. In an embodiment, the drill bit includes a body having a plurality of legs each having a lower section that has a leading surface and a trailing surface. A plurality of cone cutters are each rotatably mounted to the lower section of one of the legs, each having a cone axis, and including a first plurality of cutter elements arranged about the cone axis such that each is shear the formation when the body is rotated about the bit axis.

A fixed cutting structure-composite cone drill bit includes a drill bit body, a fixed cutting structure, and at least one cone. The cone and the fixed cutting structure are disposed on the drill bit body. The cone is rotatably connected to the drill bit body by means of a bearing structure. The distance from the outermost tooth or back cone of the at least one cone to the front side surface of the fixed cutting structure La≤πR/3, and the distance from the outermost tooth or back cone of the at least one cone to the rear side surface of the fixed cutting structure Lb≤πR/3. In the composite drill bit, the distance from the cone to the front/rear side surface of the fixed cutting structure is short, the gap between the cone and the fixed cutting structure is small, transition between cutting structure is smooth.

A fixed cutting structure-composite cone drill bit includes a drill bit body, a fixed cutting structure, and at least one cone. The cone and the fixed cutting structure are disposed on the drill bit body. The cone is rotatably connected to the drill bit body by means of a bearing structure. The distance from the outermost tooth or back cone of the at least one cone to the front side surface of the fixed cutting structure La≤πR/3, and the distance from the outermost tooth or back cone of the at least one cone to the rear side surface of the fixed cutting structure Lb≤πR/3. In the composite drill bit, the distance from the cone to the front/rear side surface of the fixed cutting structure is short, the gap between the cone and the fixed cutting structure is small, transition between cutting structure is smooth.

The present invention relates to a combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation, including a joint, an outer cylinder connected to the joint by thread, a nozzle I mounted in the outer cylinder, a mechanical locking mechanism, a blade telescoping mechanism, an end cap connected to the outer cylinder by thread, a seal ring IV mounted to the end cap, and a nozzle II mounted in the end cap by threaded connection. The present invention achieves integrated operation of conventional drilling and draw-back expanding, which can effectively solve the problems that the existing hydrate drill bit cannot drill a large borehole, cannot mechanically lock an extending position of the blade to stabilize the size of the borehole, and a single crushing method is inefficient.

The present invention relates to a combined crushing super-variable-diameter drill bit for natural gas hydrate exploitation, including a joint, an outer cylinder connected to the joint by thread, a nozzle I mounted in the outer cylinder, a mechanical locking mechanism, a blade telescoping mechanism, an end cap connected to the outer cylinder by thread, a seal ring IV mounted to the end cap, and a nozzle II mounted in the end cap by threaded connection. The present invention achieves integrated operation of conventional drilling and draw-back expanding, which can effectively solve the problems that the existing hydrate drill bit cannot drill a large borehole, cannot mechanically lock an extending position of the blade to stabilize the size of the borehole, and a single crushing method is inefficient.