Drill string inground isolator in an MWD system and associated method

摘要

An inground isolator and associated method can provide an electrically isolated break in a drill string using electrical insulating members/isolators that are supported by a housing. During drill string operations, the isolators are subject only compressive forces responsive to both extension (pushing) and retraction (pulling) by the drill string. The isolators can be formed from an electrically insulating material such as a ceramic material. An interchangeable inground tool system is described which integrally serves to provide an electrically isolating gap in the drill string.

主权项

1. An apparatus for use in combination with a drill string that is electrically conductive and extends from an inground distal end, that includes an inground tool, to a drill rig, said drill rig configured to apply each of a push force, a pull force and a rotational force to the drill string, said apparatus comprising:
a housing assembly that is configured to support a plurality of electrical isolators to electrically isolate a downhole portion of the drill string from an uphole portion of the drill string and configured to support the electrical isolators subject to no more than compressive forces responsive to the push force, the pull force and the rotational force.