弹性波阻抗反演技术在辽东湾隐蔽油气藏勘探中的应用

An application of the elastic impedance inversion technique to exploration of subtle reservoirs in Liaodong gulf

A目标位于辽中凹陷中段中央底辟断裂带西侧,钻井资料证实其所在区域储层岩石物理特征复杂,东营组砂岩和泥岩波阻抗分布范围交错,即使砂岩含油气其波阻抗与围岩的差别也很小,因此应用常规波阻抗反演技术无法解决该区域岩性识别和含油气性检测等问题。根据A目标所在区域的横波速度反演、岩石物理分析以及AVO模型分析结果,利用弹性波阻抗反演技术对该目标进行储层岩性识别和含油气性检测,取得了良好的应用效果,预测结果得到了钻井的证实。

Target A is located west of the central diaper-fracture belt in the middle part of Liaozhong sag. In this area, the well data has proved that the reservoir rocks are complex in petrophysical properties, and that the impedances of sand and shale in Dongying Formation interlace each other, with the impedance difference between a sandstone saturat-ed with oil or gas and its surrounding rocks, very small. Therefore the conventional methods of im- pedance inversion can not identify lithology and detect hydrocarbon in the area. Based on shear velocity inversion, petrophysical analysis and AVO model analysis, the technique of elastic impedance inversion has been used to recognize reservoir lithology and detect hydrocarbon for target A, with the results confirmed by drilling.