基于Xu-White模型的横波速度预测

Prediction of S-Wave Velocity Based on Xu-White Model

在叠前地震属性分析和叠前地震反演中,若缺失横波信息,将会降低解释精度,对油气勘探造成不利影响。因此,预测横波速度就显得十分重要。与各种预测横波速度的方法相比,Xu-White模型综合考虑孔隙度、密度、泥质含量等因素的影响,符合砂、泥岩地层的实际情况,具有较高的预测精度。但由于砂、泥岩孔隙纵横比难以在实验室测得,使Xu-White模型的应用受到限制。在对Xu-White模型研究的基础上,通过引入模拟退火算法和粒子群算法寻求最优解,避免了搜索过程陷入局部极小解,提高了横波速度预测的精度。该方法在大港油田的实际资料处理中取得了较好的效果。

In the prestack inversion and prestack seismic attributes analysis, the lack of S-wave information usually leads to a bad influ- ence on petroleum exploration by decreasing accuracy of seismic data interpretation. Hence, Prediction of S-wave velocity by using other methods is more significant. Xu-White model, compared with other methods, comprehensively takes account of the influences of porosity, density and clay content, which is suitable for real sand-mudstone formation characterization with higher predictive accuracy. But the application of Xu-White model has been limited because the aspect ratio of the inclusion can not be measured in the laboratory. This paper studies the Xu-White model, introduces simulated annealing algorithm and particle swarm optimization （PSO） to seek optimal solution, by which the local minimum solution is avoided during searching process, and the accuracy of S-wave velocity is obviously improved. The case study from real seismic data processing in an area of Dagang shows good results in application by using this method.