基于改进BISQ模型的AVA方程

AVA analysis equation based on modified BISQ model

振幅随入射角变化(AVA)技术是油气储层地震预测核心技术。目前,AVA技术建立在单相介质基础上,但实际储层是典型的多相介质,因此研究多相介质AVA分析技术具有重要意义。通过推导基于改进BISQ模型(不含喷射流长度)的AVA方程,建立了双相-双相、双相-单相、单相-双相、单相-单相介质分界面模型,对AVA曲线进行了数值模拟分析。分析结果显示:BISQ-AVA方程在单相介质分界面时退化为传统Zoeppritz方程,在含双相介质界面处,其反射、透射分析结果与Zoeppritz方程分析结果有较大差异,该结果对油气储层地震解释有重要影响。

Amplitude Versus Angle(AVA)is a core seismic prediction technology for hydrocarbon reservoirs.At present,the application of AVA technology is based on single-phase medium,but actual reservoirs are typical multiphase medium.Therefore,it is of great significance to study the AVA analysis technology based on multiphase medium.AVA equation based on modified BISQ model(without squirt-flow length)is derived to establish double phase-double phase,double phase-single phase,single phase-double phase and single phase-single phase medium interface models,and further carry out numerical simulation analysis of AVA curve.The analysis results indicate that BISQ-AVA equation degenerates to the traditional Zoeppritz equation in case of single-phase medium interface.At double-phase medium interface,the reflection and transmission analysis results have great differences from the analysis result of Zoeppritz equation.Such results have important influences on seismic interpretation of hydrocarbon reservoirs.