Research on frequency variation law of reflection coefficient of gas reservoir based on forward modeling with reflectivity method
Amplitude variation with offset/incident angle(AVO/AVA)has been widely used in oil and gas exploration,and its variation characteristics with frequency play an important indicative role in the study of lithology,reservoir prediction and gas and oil detection.The frequency variation characteristics are not only related to the velocity dispersion caused by the absorption and attenuation of the gas reservoir itself,but also related to the multiple reflections of seismic waves between the top and bottom of the reservoir.In this study,the recurrence formula of frequency-varying reflection coefficient of layered media was established based on the reflectivity method.By using Chapman model,the dispersion velocity was introduced and an AVO fine simulation method that fully considering the absorption and attenuation and layered structure of gas reservoir itself was formed.Finally,the relationship between the thickness,gas saturation,porosity,permeability of the gas reservoir and the frequency-varying reflection coefficient was deeply analyzed.This study provides a basis for using frequency variation law to identify gas reservoir.
gas reservoirvelocity dispersionmultiple reflectionsreflectivity methodfrequency-varying reflection coefficientChapman model
NETL
NSTL
万方数据
