地质构造约束层速度模型在时深转换中的应用

Geologic structure constrained interval velocity modeland its application in time-depth conversion

钻井资料与海量的地震数据相比总是显得太少 ,大区域速度场的建立必须借助数学插值方式 ,把井点速度外推至全区。以纯数学的距离内插方式生成速度场而不考虑实际地质结构变化 ,生成的速度场与实际速度规律是有差距的 ,在复杂构造区 ,这种差异非常大。以地层反射界面和断层面为约束条件 ,建立起沿反射层变化的、更为精确的层速度场 ,从而实现三维资料的精确时深转换。该方法应用灵活 ,建场方式直观 ,适合于各种复杂构造的时深转换。

The amount of drilling data available for building velocity models in a large area appears always too small to extend the velocities in well locations to the whole survey area. Therefore, mathematical interpolation methods are widely used in velocity model building. However, the resulted velocity models are somewhat different from the true velocity ones, especially in complex zones, due to without taking the geology into account. In this paper, an interval velocity model was built under the constraints of reflection interfaces and fault planes. The proposed method is flexible, and can be used for time-depth conversion of any complex structures.