P-P波及P-SV波叠前深度偏移速度模型建立方法

针对多波叠前深度偏移速度模型的建立问题，提出在CDP道集上利用互换原理组成伪地集作为叠前偏移速度分析的数据道集，先用叠前时间偏移方法求取层间互不影响的等效偏移速度模型，再用餐前深度偏移方法逐层求取层速度模型．对各层的速度质量、整个速度模型层位结构及速度横向变化，采用人机交互方式进行监控，并在速度叠代中引入全局寻优的遗传算法，使整个速度模型建立过程具有稳定、可靠和可视化的优点．经理论和实际资料处理结果证明，本方法是行之有效的．

A METHOD OF CREATING P-P AND P-SV WAVE PRESTACK DEPTH MIGRATION VELOCITY MODEL

A method of creating P-P wave and P-SV wave prestack depth ingration velocity model is given in this paper. This is can be done by equivalent shot gather which is formed from CDP gathers according to exchange principle. Firstly, the equivalent migration velocity model can be obtained with prestack time migration method. Then by using prestack depth migration method, we can create interval velocity model layer by layer. The interactive operation is used tO control the quality of interval velocity of each layer, the whole layer structure of velocity model and lateral valuation of velocity, and the global optedzation genetic algorithm is introduced in velocity interative. The procedure of creating velocity model is of the characteristics such as stability, reliability and visualization. It is proved by theoretital and real data processing that this method is very feasible.