Patent ID: 9416612
Filing Date: 2016-08-16
CPC Classification: E21B

Claim Text:
1. A window milling assembly for making a tubular exit at a subterranean location, comprising: a whipstock supported in the tubular; a window mill having a longitudinal axis and rotatably mounted to a delivery string while advancing on a ramp of said whipstock and initiate the forming of the window; a lower mill connected to said window mill by a mandrel having an outside dimension smaller than a peripheral surface of a plurality of blades on said lower mill for tandem movement therewith with respect to said whipstock, said blades extending generally in in the direction of a longitudinal axis of said lower mill, with said outer peripheral surfaces of said blades further comprising more than two axially spaced rows of cutters with said rows comprising multiple cutters oriented substantially perpendicularly to said longitudinal axis of said lower mill with said rows extending in circumferential alignment among said plurality of blades.