VSP转换波成像技术及实例分析

VSP converted-wave imaging technique and its application

1. 中国石化石油勘探开发研究院南京石油物探研究,江苏南京210014;2. 中国石化新星石油公司西北局规划院,新疆乌鲁木齐830011

1. Institute of Geophysical Prospecting, SINOPEC Research Institute of Petroleum Exploration and Development, Nanjing 210014, China;2. The Planning Institute of Northwest Petroleum Bureau, SINOPEC New Star Petroleum and Production Company, Urumchi 830011, China

VSP三分量测井记录含有丰富的地震波场信息, 除纵波外还有转换横波资料。由于横波具有不在液体或气体中传播的特点, 因此可以联合利用横波和纵波信息进行井旁储层分析。根据PSV波的特征, 导出了PSV波动校正公式, 实现了PSV波水平叠加归位。通过数值计算及井旁成像剖面的实例分析, 表明转换波的VSPCDP方法原理是可靠的, 这就为井旁构造分析和岩性分析提供了可靠资料。

3-C VSP logging data contains plenty of information about seismic waves such as P waves and converted S waves. Because shear waves do not travel in liquid and gas, we can use P waves and S waves jointly to study the reservoirs around a borehole. A NMO equation of P SV waves was derived and used to horizontal stacking for P SV data. Numerical calculation and analysis of real sections around boreholes showed the validity of VSP CDP method for converted waves. The converted waves from Tahe Oilfield are of strong reflectivity at Triassic and Carboniferous formations, indicating potentials of VSP converted S waves in exploration and reservoir characterization for Triassic and Carboniferous reservoirs.