Reamer-stabilizer

Abstract

A roller reamer-stabilizer tool includes a tubular body having threaded pin and box connectors at each end adapted to be connected in a drill string and providing a fluid passage connecting the upper part of the drill string with the lower part. Rollers having integral pins at their ends are mounted in pockets in the sides of the body. The pins are journaled in holes in arcuate cross section bearing blocks received in correlative sockets in the body at the ends of the pockets. The blocks make an interference fit with the body. Release bar access passages allow a release bar to be inserted behind each block to drive, wedge or pry it out. The holes in the blocks extend only part way through the blocks, the hole in the block at one end of each roller being blind, and the wall at the end of the hole in the block at the other end of each roller being ported. Each bearing is sealed by an O ring at the mouth or open end of the hole in the block. An additional O ring is provided adjacent the end wall of the ported block. Grease is stored in a bore extending axially in each roller through the pins at each end. Radial ports in the pins communicate the bore with the bearings. A flexible elastomeric boot closes the bore at the end of each roller received in the respective ported block, the port subjecting the interior of the boot to drilling fluid pressure.