基于CMP直线分布的不规则观测系统设计方法研究

Research on irregular geometry design methods based on linear CMP distribution

(1.西南石油大学资源与环境学院,四川成都610500;2.同济大学海洋地质国家重点实验室,上海200092)

Yin Cheng,School of Resources and Environment Engineering,Southwest Petroleum University,Chengdu 610500,China

我国南方海相碳酸盐岩油气区及西部前陆盆地边缘探区,均面临着地表起伏剧烈和地下构造高陡的双复杂地震勘探问题。为了准确勘查地下构造形态,野外地震采集中应尽可能降低起伏地表的复杂性及优选最佳的激发参数,从而获得高信噪比的地震单炮记录。在保证沟谷平坦区有利激发的前提下,通过最优化反演进行弯曲接收排列的设计,使得最终得到的二维地震剖面具有直线反射面元的特征,通过加入局部宽线的采集措施,使弯线地震采集的每个中心面元的覆盖次数和炮检距能够均匀分布。进行了四川盆地东北部镇巴地区复杂山地不规则观测系统的设计和属性分析,证明了基于CMP直线分布的不规则观测系统设计方法具有很好的实际应用价值。

At the marine carbonate area of Southern China and the foreland basin edge of Western china,severe rugged surface and high-steep subsurface structures are the double-complex area for seismic exploration.In order to obtain accurate subsurface structure configuration,we should try our best to decrease the complexity of rugged surface and select optimal shooting parameters so as to obtain high S/N seismic records.On the premise of beneficial shooting at flatten area in gully,the crooked-line survey was designed by optimal inversion,which made the 2-D seismic sections with linear reflection bins.The application of local wide-line assured the even distribution of fold and offset of every central bin acquired by crooked-line survey.We carried out irregular geometry design and attribute analysis in the complex mountainous area at Zhenba area in the Northeast of Sichuan Basin,and the result proofed that the irregular design based on linear CMP distribution is flexible.