南海琼东南工区地层吸收衰减模型研究

Stratal absorption attenuation model for southeastern Qiong area in South China Sea.

由于直接从地震记录求取地层吸收特性的精度较低,因此利用层速度与Q值的经验公式来建立大致符合工区实际的吸收衰减模型。对理论公式中的射线参数进行高阶泰勒展开忽略计算机的计算误差就可以精确地计算出反射波在每层的传播距离,从而得到较为准确的不同偏移距在不同频率时的地层吸收量,这在进行地震数据采集时有助于设计合适的观测系统和激发能量。

The quality factor (Q) estimated directly from seismic records suffers from poor precision. Instead of estimating Q directly from seismic records, we determine the Q value from the empirical relation between interval velocity and Q. The relatively accurate quantities of absorption at different offsets are obtained by expanding ray parameter with taylor' s series. This method can also be used to help design proper acquisition layout and exciting energy.