Particle Image Velocimetry (PIV) is a technique that has been widely employed to study velocity fields in complex fluid flows. In this paper, we describe how PIV methods can be applied to high-resolution X-Ray Computed Tomography (XRCT) of solid samples. Unlike traditional PIV techniques for fluids, the XRCT-PIV method does not rely on introduced tracer particles, but rather uses in-situ sample heterogeneities. As such, the technique provides a non-destructive, non-invasive method for tracking sample deformation. In addition, the use of XRCT allows three dimensional volumes to be compared, rather than the two dimensional images used in traditional PIV. This adds to the robustness of the method, allowing accurate displacements to be obtained despite measurement artifacts or changes in sample mineralogy. In this presentation we demonstrate the use of XRCT-PIV on tomographic images from a study of wellbore-cement integrity in which the cement samples undergo a series of reactions following exposure to carbon-dioxide rich brine. The XRCT-PIV method is used to reveal the deformation that occurs as a result of the mechanical changes in the cement surface. We also verify the precision and robustness of the technique in the presence of noise with tests conducted on numerically-generated virtual samples. The results from both the cement samples and numerical tests reveal that accurate displacement measurements are obtained despite chemical alteration and instrument artifacts. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
|Number of pages||1|
|Publication status||Published - 2012|
|Event||Fall Meeting of the American-Geophysical-Union 2012 - San Francisco, United States of America|
Duration: 3 Dec 2012 → 7 Dec 2012
|Conference||Fall Meeting of the American-Geophysical-Union 2012|
|Country||United States of America|
|Period||3/12/12 → 7/12/12|