Determining correct drill pipe length and formation depth using measurements from repeater subs of a wired drill pipe system

Abstract

A method includes accepting as input to a processor measurements of a characteristic of a subsurface formation made at a plurality of spaced apart positions along a pipe string moved along a wellbore. Measurements are made of pipe string depth in the wellbore from the Earth's surface. The measurements of pipe string depth include measurements of apparent depth of each of the spaced apart locations. The subsurface formation is identified from the measurements of the characteristic. A true depth of the subsurface formation is made using the measurements of pipe string depth and apparent depth of the formation from each of the spaced apart positions. A record of measurements of the characteristic with respect to depth corrected for changes in length of the pipe string caused by axial forces along the pipe string is generated.