Using a rotating inner member to drive a tool in a hollow outer member

摘要

A rotating inner member is used to drive a downhole tool housed within the hollow outer member of a dual-member drill string. The downhole tool preferably will be adapted to receive rotational energy from the inner member. In a preferred embodiment, the downhole tool is an electric generator connected to a downhole electric device. In another preferred embodiment the downhole tool is a mechanical transmission that uses the rotational energy from the inner member to drive a non-electric tool, such as a downhole hammer. This invention will increase the consistency and efficiency of downhole energy production.