AVO方法与应用

AVO TECHNIQUE AND ITS APPLICATION

振幅随偏移距变化关系的研究,近年来深受勘探地球物理学家的青睐。这项技术称之为AVO(Amplitude Versus Offset)。其方法是把CMP道集转换成CMP—角度道集,然后比较大入射角与小入射角道之间的能量关系,再用简化的Zoeppritz方程在CMP—角度道集内作振幅与Sin^2θ的线性拟合,提取岩性参数。用这些岩性参数作的剖面将为直接寻找油气藏提供解释依据。本文着重讨论AVO的实际应用,且以P波叠加与CMP叠加之间的差异分析为主。

In recent years, the study of 'Amplitude versus Offset' arouses a great interest in exploration geophysicists circle. The technique above mentioned is abbreviated as AVO. In practice, the usual way is to turn the CMP gather into the angular CMP gather and then compare the energy level between the small incident angles and the large ones and followed by making a linear fitting befween the amplitude and the sin2 θ within the CMP-angular gather by means of the simplified Zoeppritz equation. Consequently, the lithological parameters can be extracted. Sections constructed with these parameters will provide basis for interpretation in direct detection of oil and gas. The stress laid in this paper is to expound the application of the AVO technique. And particularly the detailed description given is to examine the difference between the P-wave and the CMP stacking.