【摘要】 AVO截距与梯度(P-G)交会图分析是AVO碳氢检测技术的一种重要分析手段.以AVO技术为基础,应用完全形式的Zoeppritz方程合成AVO理论模型,并根据Shuey简化公式拟合P,G值,通过改变砂岩层的纵波速度及泊松比参数,研究它们对P-G交会直线的影响.结果表明:P-G交会直线的斜率随着地层泊松比差异的增大而增加;P-G交会直线的长度随着纵波速度差异的增加而增长.对实际地震资料进行P-G交会图分析进一步证实,根据P-G交会直线的特征可预测泊松比异常地层,即含油气层.更多还原

【Abstract】 AVO intercept and gradient crossplot analysis is an important analysis tool of hydrocarbon detection.In this paper,based on AVO technique,AVO theoretical models are computed by using Zoeppritz equation,P and G values are fitted according to Shuey’s simplified equation.The effect of longitudinal wave velocities and Poisson’s ratios on P-G Cross lines is dealt with by changing velocities and Poisson’s ratios of layers.By analysis,we find that the slope of the P-G cross line increases along with the Poisson’s ratio difference and that the length of the P-G cross line increases along with longitudinal wave velocity difference.By analyzing P-G crossplot of real seismic data,we approve that Poisson’s ratio anomaly layers i.e.oil and gas bearing layers can be predicted according to the characteristics of the P-G cross line.更多还原