MODULAR HOUSING FOR A ROTARY STEERABLE TOOL

摘要

According to one embodiment of the invention, a rotary steerable tool (36) includes a drive shaft (300) configured to be coupled to a drill string at an upper end thereof and configured to be coupled to a drilling tool at a lower end thereof. A middle portion of the drive shaft is disposed axially between the upper and lower ends and has a smaller diameter than each of the upper and lower ends. The drive shaft further includes a housing (302) rotatably coupled externally to the drive shaft and at least one housing module coupled to a respective opening in the housing at an axial location corresponding to the middle portion of the drive shaft.