Method and apparatus for a downhole NMR MWD tool configuration

摘要

A NMR device is presented that includes a drill collar having non-rotating sleeve containing permanent magnets. The non-rotating sleeve is clamped against a borehole wall and decoupled from drilling vibrations during NMR measurements. The transmitter and receiver are located on the rotating part of the drill collar. Alternatively the permanent magnets and the RF receiver antenna and/or receiver electronics are placed on the non-rotating sleeve which is clamped against the borehole wall and decoupled from drilling vibrations, with the transmitting antenna located on the rotating drill collar. Alternatively a non-rotating stabilizer is provided above or below a NMR sensor. A stabilizer is activated to stabilize the rotating NMR sensor located on the drilling collar in the bore hole. The permanent magnets and receiving and transmitting antennas are located on a non-rotating sleeve that is clamped against the borehole wall to decouple the permanent magnets and receiving and transmitting antennas from drilling vibrations.