地震伪井速度点宏观校正方法与应用——以珠江口盆地M气田为例

地震勘探开发中速度研究方法的选取是时深转换的关键。鉴于珠江口盆地M气田断裂系统复杂，构造主体部位受断层影响导致横向速度变化明显，而以往时深转换方法诸如变速成图法或井时深关系拟合法得到的深度构造图误差偏大，很难满足开发阶段高精度构造研究的需求。由此在传统变速成图方法的基础上进行了改进，优化后的地震伪井速度点宏观校正方法是利用伪井速度时间函数与测井速度时间函数的差值对地震速度进行校正，将井纵向分辨率高和地震横向分辨率高的优势更好地结合在一起，从而提高了工作效率，同时也降低了构造的不确定性。新提出的地震伪井速度点宏观校正方法有效提高了该区时深转换的精度。

Macro-correction method and application of seismic pseudo-well velocity point:a case study from M gas field in Pearl River Mouth Basin

In seismic exploration and development,the selection of velocity research method is the key to timedepth conversion.In view of the complexity of fault system in M gas field of Pearl River Mouth Basin,the transverse velocity variation is obvious due to the influence of faults on the main part of structure,while the error of depth structure map obtained by previous time-depth conversion methods,such as variable velocity mapping or well-time-depth relationship fitting,is obvious.It is too large to meet the needs of high-precision structural research in the development stage.The traditional variable speed mapping method was improved.The optimized pseudo-well velocity point macro-correction method is to use the difference between pseudo-well velocity time function and logging velocity time function to correct the seismic velocity,which combines the advantages of high vertical resolution of wells and high lateral resolution of earthquakes better.It can improve work efficiency and reduce structural uncertainty at the same time.The actual drilling results show that the macro-correction method of pseudo-well velocity points effectively improves the accuracy of time-depth conversion in this area.