Patent ID: 8579050
Filing Date: 2013-11-12
Classification: E21B

Abstract:
1. A reamer bit for downhole earth boring operations comprising: a reamer body having a longitudinal axis; first through fourth cutter mounts attached to the body at about the same distance from the axis and spaced sequentially around the axis; cutters rotatably secured to each mount, each cutter having a gage surface for engaging a wall of a borehole and a nose on an inner side of each of the cutters; a heel row of cutting elements adjacent the gage surface on each of the cutters for engaging an outer portion of the bottom of the borehole, the heel rows on the cutters being the same distance from the axis; inner rows of cutting elements on the cutters inward from the heel row, wherein the inner row include: a first inner row next to the heel row on the first cutter and farther from the axis than any other inner rows on any of the cutters; a first inner row on the third cutter that is the second farthest from the axis of all of the inner rows of the cutters; a first inner row on the second cutter that is the third farthest from the axis of all of the inner rows of the cutters; and a first inner row on the fourth cutter that is the fourth farthest from the axis of all of the inner rows of the cutters.