none 10.1190/1.2542437 Society of Exploration Geophysicists Society of Exploration Geophysicists 186 25811699 5980 2025120813524711800 10.1190 2025-12-08T18:52:54Z 2007-02-12T18:03:48Z 3 The Leading Edge 1070-485X 02 2007 02 01 2007 26 2 Killian C. Ikwuakor IEC 1 , Arvada, Colorado, USA The primary interest set forth in the referenced article (“Resistivity-velocity transforms revisited” by Hacikoylu et al., published in TLE, August 2006) was to improve reconstruction of missing log data (e.g., velocity) from other reliable log measurements (e.g., resistivity). The authors considered an attempt to reconstruct a sonic curve from resistivity by Faust (1953). Faust's empirical equation related P-wave velocity, formation resistivity factor, and depth. The authors saw limitation in the use of Faust's equation and suggested improvements that would eliminate the deficiencies. In reading the article, one notices inconsistent definitions, improper use of equations relating rock property measurements, erroneous crossplots, and inconclusive analysis of data. Consequently, the authors fail to achieve the refinement of Faust's equation that they intended through their publication. In my conclusions, I have provided simpler equations relating resistivity with reciprocal velocity that account for geology and reservoir conditions. 02 2007 02 01 2007 134 137 10.1190/1.2542437 https://pubs.geoscienceworld.org/tle/article/26/2/134/135390/Comments-on-Resistivity-velocity-transforms https://pubs.geoscienceworld.org/seg/tle/article-pdf/26/2/134/7421650/1.2542437.pdf https://pubs.geoscienceworld.org/seg/tle/article-pdf/26/2/134/7421650/1.2542437.pdf https://pubs.geoscienceworld.org/tle/article/26/2/134/135390/comments-on-resistivity-velocity-transforms http://tle.geoscienceworld.org/cgi/doi/10.1190/1.2542437