Measuring wellbore cross-sections using downhole caliper tools

Abstract

Tools and methods are described to measure dimensions of wellbores. Downhole caliper tools include: a downhole collar; an uphole collar; and a caliper sensor assembly disposed between the downhole collar and the uphole collar. The caliper sensor assembly include: an annular sensor module defining a plurality of radially extending tracks; and a caliper including: a plurality of linear slide arms, each linear slide arm at least partially disposed in the annular sensor module in one of the plurality of radially extending tracks and radially moveable relative to the annular sensor module, each linear slide arm extending from a first end within the annular sensor module to a second end outside the annular sensor module, and a cover extending from the downhole collar to the uphole collar. The annular sensor module can measure the radial position of the plurality of linear slide arms relative to the annular sensor module.