Insulating device and assembly

摘要

There is disclosed an electrically insulating device in the form of a sleeve (12) for a downhole tool, for electrically insulating a first threaded electrically conductive member in the form of an anchor sub (16) from a second threaded electrically conductive member in the form of an insulated sub (18). An assembly (10) including the sleeve (12) has particular use in measurement while drilling (MWD)/logging while drilling (LWD) procedures. In one embodiment, a third member in the form of a threaded electrically conductive sleeve sub (20) is coupled to the insulated sub by a second sleeve (14), to create an insulated gap between the anchor and sleeve subs (16, 20).