PLACEMENT OF CUTTING ELEMENTS ON SECONDARY CUTTING STRUCTURES OF DRILLING TOOL ASSEMBLIES

摘要

A secondary cutting structure for sure in a drilling assembly, the secondary cutting structure including a tubular body and a block, extendable from the tubular body, the block including a first arrangement of cutting elements disposed on a first blade and a second arrangement of cutting elements disposed on a second blade, wherein the second arrangement is a modified redundant arrangement. Also, a secondary cutting structure for use in a drilling assembly, the secondary cutting structure including a leading blade disposed on a first block and a trailing blade disposed on the first block adjacent the leading blade. Additionally, the secondary cutting structure includes a unique blade disposed on a second block, wherein a gage portion of at least one of the blades has a length between 30% and 45% of a total blade length.