Method and apparatus for running and retrieving logging instruments in highly deviated well bores

Abstract

The system consists of means for running a logging instrument connected to a long rigid extension on a logging cable through open-ended drill pipe. The extension consists of a number of sections of tubing that are joined together on top of the instrument as the instrument is lowered into the drill pipe prior to the logging cable being connected to the well logging instrument. As soon as the last section of the tubing has been added, the well logging cable, having an electrical probe member attached to its lower end and having weighting means to cause the probe to lower itself through the tubing, is fed down through the tubing and into a circulation and electrical connection sub connected to the well logging instrument itself. After the connection is made, the tubing and well logging instrument are supported by the well logging cable and together they are lowered further through the drill pipe and out through the end of the drill pipe until a cable tension adapter sub reaches a catcher sub at the end of the drill pipe. During logging, the logging cable is hoisted in the upward direction to log the formations surrounding the well bore beneath the lower end of the drill pipe.

Dependencies are inferred from the claim text.