Young's Elastic Modulus:Comparing the Dynamic and Static approaches

This is a work that presents the correlation results of static and dynamic Young's moduli based on standard and simplified defect model approaches for some rock intervals at two different locations. Elastic properties of rocks can be determined in two ways; either by in-situ seismic velocity measurements accomplished by borehole logging, or by laboratory compressive tests on sample cores drawn from such borehole. The first method defines the dynamic Young's modulus determination. And the later defines the static method. However, these two measurement methods do not give the same results or values. Studies have shown that the difference in values stems from their differential strain amplitude.The simplified defect model therefore tend to compensate or rather improve the in-situ static (Young's modulus) estimates with respect to the contributions of defects (fractures, micro-cracks,inter-granular boundaries) which tend to close up in laboratory measurements, giving higher laboratory values. Hence, this work not only compares standard correlations of the elastic properties but also discusses the application of the aforementioned model in correlations for available log data.