Abstract：The paper summed up and summarized calculating method for elastic modulus of dry core sample and gave brief analysis for feature and practicelity of different methods.Comprehensively using the results in petrophysical laboratory of Daqing Oil field (1996) and Phillips et al (1989) and a part of logging data in Daqing Oil field on that basis,the effects of porosity,clay content,effective pressure and temperature in sandstone on elastic modulus of dry core sample has been studied and two optimal fitting formulas have been obtained.These two formulas overcome the limits in former empiric formulas and made it possible that uses Gassmann equation to analyze changing rule of sandstone velocity in a condition of reservoir in a area where results in petrophysical laboratory are absent.There is of great significance especially to model and analyze feasibility of time-lapse seismic monitoring for enhancing oil recovery of reservoir.
