一种基于叠前数据的综合Q值求取及应用

Integrated Q-value estimation based on prestack seismic data

传统的基于叠后地震资料的地层Q值估算法因受叠加平均效应的影响,Q值估算精度较低、适用性差。叠前地震资料本身包含的地层信息丰富,受环境噪声的影响较小。基于叠前地震资料利用S变换可得到Q值,但其准确性还有待进一步改进。本文提出一种基于叠前地震资料,利用广义S变换求取时频域表层Q值的方法,具体做法为:借助于广义S变换对叠前地震数据做时—频分析,逐道求取频谱比斜率,经炮检距归零处理得到零炮检距处的表层Q值,通过表层Q值与井控深层Q值建立综合Q体。将这套方法应用于西柳地区的实际资料处理,实现了综合Q值补偿,取得了令人满意的效果。

Conventional Q-value estimations based on poststack seismic data suffer low precision and poor applicability.Prestack seismic data is rich in strata information and less affected by environmental noise.However Q-value estimation with Stransform based on prestack seismic data still needs to be improved.In this paper,we propose an integrated Q-value estimation.First we calculate surface Q-value in the time-frequency domain with generalized S-transform based on prestack seismic data.Then we construct a Q-value volume by combining surface Q-value with well-constrained deep-layer Q-value in the time-frequency domain.Application of the propose estimation in Xiliu area obtains satisfactory results.