逆掩推覆构造的地震波照明与观测系统优化

Seismic wave illumination for overthrust nappe structures and optimal seismic survey design.

1. 同济大学，上海200092;2. 中国石油天然气股份有限公司玉门油田分公司，甘肃玉门735200;3. 浙江大学，浙江杭州200092

Tongji University,Shanghai 200092,China

在中国的西部和西南部地区,地表条件复杂,逆掩推覆构造广泛分布。在这些地区进行野外地震资料采集,观测系统设计应该基于 CRP 点而不是 CMP 点。为此,对基于 CRP 点的观测系统设计方法进行了探讨。根据波动方程地震波照明结果,利用照明统计、双程波照明或单程波照明方法,确定针对某勘探目的层的地面最优炮点分布范围；利用射线追踪和波动方程模拟,分析特定目的层各 CRP 点的覆盖次数以及照射能量的分布情况；综合地下各目的层不同炮检距地震道对各 CRP 点的覆盖次数和能量贡献分布曲线,确定这些目的层的最优检波器排列方式和排列长度。以玉门油田 JX01逆掩推覆构造模型为例,对面向目标的地震波照明和观测系统优化设计方法进行了讨论,结果表明,利用该方法可以对勘探目标更好地进行成像。

Overthrust nappe structures spread widely in western and southwestern area of China.It should be performed based on CRPs rather than CMPs in this area.By wave e- quation illumination,the optimal source positions are de- termined through illumination statistical method,two-way equation modeling method or one-way equation modeling method.The combination of ray tracing and seismic wave equation simulation is used to calculate the folds and energy distribution for different offsets along the CRPs of a certain surface.From these distribution curves,the optimal re- ceiver array pattern and receiver array length is deter- mined.Using this target-oriented illumination analysis and design,the objective surface is imaged better.