逆时深度偏移处理技术在塔里木盆地塔北牙哈地区三维地震资料处理中的应用

Application of RTM(Reverse Time Migration)Depth Migration Technology in 3D Seismic Data Processing in Yaha Area of Northern Tarim Basin

逆时深度偏移有别于单程波方程的波场延拓,是双程波波动方程的波场延拓,避免了上、下行波的分离处理,是较为准确的成像算法,且不受偏移倾角的限制,并能实现回转波和多次波成像。逆时深度偏移处理技术的关键是正演子波选取、偏移速度场的建立及偏移孔径的确定等。通过在塔里木盆地塔北牙哈地区三维地震资料中采用逆时深度偏移处理技术,提高了资料信噪比及断层和构造偏移精度,为该区断裂展布和构造圈闭落实奠定了良好的地震资料基础。

RTM depth migration was a method different from the wave field continuation of one way wave equation(1WWE).It was the wave field continuation of two-way wave equation(2WWE),which avoided the separate processing of up wave and down wave,so it could be the most accurate algorithm of imaging and was not limited by the dip angle,and also it could realize the imaging of returning wave and the multiples.Selection of Forward modeling wavelet,building-up of migration velocity field,choice of migration aperture and etc.were the key parameters of RTM depth migration.The RTM depth migration technology is used for 3Dseismic processing in Yaha Area of Northern Tarim Basin,which achieved the predicted effects,such as enhancing the signal-to-noise ratio(SNR)and the improving accuracy of fault and structure migration,it provides a good basis for fault interpretation and delineating structural traps.