Abstract: Milling systems, tools, and methods include using a mill with secondary attrition system to re-mill cuttings and other debris away from the face of the mill. The secondary attrition system may be located uphole of the mill may be used to stage conditioning and re-sizing of debris. After debris is generated by the mill, the secondary attrition system may re-mill the debris to a finer size before allowing the debris to pass out of the sleeve. The debris may be re-milled by secondary cutting elements while within an annular gap positioned radially between the sleeve and a drive shaft for the mill. The annular gap may have a variable width as a result of a tapered outer surface of the drive shaft and/or a tapered inner surface of the sleeve. The variable width may cause debris to be re-milled into increasingly finer sizes.

Abstract: Milling systems, tools, and methods include using a mill with secondary attrition system to re-mill cuttings and other debris away from the face of the mill. The secondary attrition system may be located uphole of the mill may be used to stage conditioning and re-sizing of debris. After debris is generated by the mill, the secondary attrition system may re-mill the debris to a finer size before allowing the debris to pass out of the sleeve. The debris may be re-milled by secondary cutting elements while within an annular gap positioned radially between the sleeve and a drive shaft for the mill. The annular gap may have a variable width as a result of a tapered outer surface of the drive shaft and/or a tapered inner surface of the sleeve. The variable width may cause debris to be re-milled into increasingly finer sizes.

Abstract: Milling tools, systems, and assemblies may have an adjustable gauge diameter. An example mill may include a body with tracks thereon. The tracks may slope in an axial direction and may be configured to couple to multiple blades. A locking collar may be positioned on the body and may be movable between multiple locking positions. Each locking position may be axially offset from another. At each locking position, the blades may be located at a different axial position on the body. Where the tracks slope, each different axial positions of the blades may also correspond to a different radial position for the blades. A gauge diameter of the blades may be based on the locking positions of the locking collar.

Abstract: Milling systems, tools, and methods include using a mill with secondary attrition system to re-mill cuttings and other debris away from the face of the mill. The secondary attrition system may be located uphole of the mill may be used to stage conditioning and re-sizing of debris. After debris is generated by the mill, the secondary attrition system may re-mill the debris to a finer size before allowing the debris to pass out of the sleeve. The debris may be re-milled by secondary cutting elements while within an annular gap positioned radially between the sleeve and a drive shaft for the mill. The annular gap may have a variable width as a result of a tapered outer surface of the drive shaft and/or a tapered inner surface of the sleeve. The variable width may cause debris to be re-milled into increasingly finer sizes.

Abstract: Milling tools, systems, and assemblies may have an adjustable gauge diameter. An example mill may include a body with tracks thereon. The tracks may slope in an axial direction and may be configured to couple to multiple blades. A locking collar may be positioned on the body and may be movable between multiple locking positions. Each locking position may be axially offset from another. At each locking position, the blades may be located at a different axial position on the body. Where the tracks slope, each different axial positions of the blades may also correspond to a different radial position for the blades. A gauge diameter of the blades may be based on the locking positions of the locking collar.