Patent ID: 7921730

Claim:
A tool for identifying the relative strength of subsurface intervals of formations through which a borehole has been drilled, comprising: a tool body configured to be moved through a borehole; a plurality of movable arms mounted on the tool body, wherein each of the plurality of movable arms is configured to apply a lateral force independently; a scratcher mounted on each movable arm, wherein each scratcher is configured to perform a scratch test of a section of a wall of the borehole when applying the lateral force corresponding to one of the plurality of movable arms; a plurality of tandem powered calipers mounted on the tool body and configured to measure a depth of the scratch test; and a borehole imager mounted on the tool body and configured to measure a width of the scratch test, wherein the depth and the width of the scratch test are used to determine a relative strength of the section of the wall of the borehole.