Abstract: An array of cutting inserts has been invented having a plurality of adjacent inserts, each insert comprising a body having a top surface, a bottom, and a base, and a plurality of spaced-apart chipbreaking indentations in the top surface of the body, and a strengthening ridge between adjacent indentations of the plurality of spaced-apart chipbreaking indentations, and a peripheral strengthening ridge around an outer edge of the top surface of the body surrounding the plurality of spaced-apart chipbreaking indentations.

Abstract: A cutting insert for a tool for wellbore milling operations has been invented that has a body having a top, a bottom, and a base, and a plurality of cutting surfaces on the top of the body, one of the cutting surfaces at a different height above the base than the other cutting surface, each cutting surface defined by linear boundaries extending from a first edge of the cutting insert, and the linear boundaries parallel to each other, the plurality of cutting surfaces including at least two cutting surfaces including at least a first cutting surface and a second cutting surface, the second cutting surface at a height above the base which is greater than a height above the base of the first cutting surface.

Abstract: Section mills have been invented that have one or more blades one or more of whose tops are pivotably extendable outwardly from a mill body as bottoms of the blade(s) rotate about a fixed point, and one or more blades whose bottoms are pivotably extendable outwardly from the mill body, the blades pivotably secured to the mill body so that, in one aspect, in response to a downwardly moving wash tube contacting the blades, the blades move out from the mill body. In one aspect certain of the blades have a milling surface which is of such an outward extent and which is parallel to a central longitudinal axis of the mill body when the blades are fully extended so that "full sweep" milling is achieved.

Abstract: Section mills have been invented that have one or more blades whose tops are rotatably extendable outward from a mill body as bottoms of the blade(s) rotate about a fixed point, the blade bottoms rotatably secured to the mill body so that, in response to a downwardly moving wash tube contacting the blades, tops of the blades move out from the mill body. In one aspect the blades have a milling surface which is of such an outward extent and which is parallel to a central longitudinal axis of the mill body when the blades are fully extended so that the blades achieve "full sweep" milling.

Abstract: A cutting insert for wellbore milling operations is disclosed which, in certain embodiments, has two or more top milling surfaces on an insert body with the surfaces at different heights above a bottom of the insert body. In certain embodiments three top surfaces are used stair-stepped, with a central lower surface, or with a central higher surface. In one aspect all cutting surfaces have an array of chipbreaking indentations. Tools and methods are disclosed which use such inserts.