【摘要】 AVO技术是利用振幅随炮检距(或入射角)变化的规律,求取地下地层的岩性信息.鄂尔多斯盆地是典型克拉通盆地,构造平缓(倾角不到1°),断层不发育,非常适用AVO理论假设反射层为水平层这一基本条件.根据工区的地震地质特征,在AVO分析的基础上,对用钻井地质、测井资料设计的模型进行AVO正演研究,总结了一套在现有地震分辨率条件下的鄂尔多斯盆地上古生界致密砂岩储层AVO响应特征,即:无论砂岩储层是否含气,其底部反射振幅随入射角增加,均会出现从强到弱一极性反转一从弱到强的现象,只是反转的角度有所差异;在梯度剖面上,含气砂岩与不含气砂岩的亮点特征差异小于较大,据此响应特征预测了有利的储集区.更多还原

【Abstract】 The AVO technology uses the relationship between amplitude and shot-receiver distance (or incidence angle) to acquire lithology information of subsurface strata.The Ordos basin is a craton with gentle structure (dip less than 1°) and little faults, where the assumption that the reflective layer is horizontal for AVO theory id applicable.Based on geology of the work area, we have made an forward modeling of AVO on the model constructed using drill geology and logging data.We have setup a series of AVO response features of the compact sandstone reservoirs of Paleozoic in the Ordos basin under the current seismic resolution.The result shows that whether the sandstone reservoir contains gas or not, the reflective amplitude at its bottom would experience changes from strong to weak, polarity reverse, and from weak to strong with increasing incidence angle, though the reverse angles differ some what.On the gradient profile, the bright spot characters are different between the gas-bearing sandstone and the sandstone without gas.In terms of these response features, we have predicted the favorable accumulation areas.更多还原