Steerable modular drilling assembly

摘要

The present invention provides a modular drilling assembly having a module (520) for contactless power and data transfer over a nonconductive gap (113) between rotating (110) and non-rotating (120) members of a steering module. The downhole tool is a modular drilling assembly wherein a drive shaft (110) is rotated by a downhole motor to rotate a drill bit attached to the bottom end of the drive shaft (110). A substantially non-rotating sleeve around the drive shaft includes at least one electrically-operated device. The drilling assembly is modular in that it includes at least one steering module (510) at the bottom end of the drilling assembly that has at least one steering device module that provides power to the force application member. A number of additional modules can be provided to make up the entire drilling assembly, said modules being interchangeable.