叠前道集优化处理技术及其应用

Prestack Gather Optimization Technique and Application

熊晓军 简世凯 李翔 刘阳

XIONG Xiaojun JIAN Shikai LI Xiang LIU Yang

"油气藏地质及开发工程"国家重点实验室 成都理工大学, 四川 成都 610059

State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, Sichuan 610059, China

从提高AVO计算精度的角度出发，提出了一种针对叠前道集“去噪—拉平—切除”组合的优化处理技术。首先，进行目的层段叠前道集的有效波与干扰波的特征分析；然后，采用四阶多项式拟合去噪方法消除目的层段的随机噪声，再采用非地表一致性剩余静校正方法对目的层段的道集同相轴进行拉平处理，最后，优选目的层段的有效入射角度范围对大偏移距拉伸畸变的道集进行切除。在渤海某区实际应用表明，优化后的道集及叠加剖面的信噪比有一定的提高，且目的层段的AVO曲线特征更明显，得到的AVO属性预测结果与实钻情况更符合。

This research presents an optimization technique involving the combination of prestack gather "noise suppression-equalization-reduction" with the improvement of the AVO (Amplitude variation with offset) analysis accuracy as the starting point. First, the characteristics of the effective and interference waves of the target formation of the prestack gather were analyzed; next, random noise from the target formation was removed using a fourth-order polynomial fit; then, the phase-axis target formation gathers were equalized using non-surface-consistent residual static correction. Finally, the effective incidence angle selection range for the target formation was optimized to reduce big-offset, stretched or distorted gathers. The practical application in some areas of the Bohai Sea shows that the signal-to-noise ratio between the optimized gathers and stacked profile improved significantly. Moreover, the AVO-curve characteristics of the target formation became more apparent and the obtained AVO-characteristics prediction results conformed more closely with the actual drilling conditions.

10.11885/j.issn.1674-5086.2016.07.21.02