复杂断层快速三维体解释方法

Fast interpretation of complex faults on 3-D seismic volume

1. 中国地质大学,北京100083;2. 兰德马克公司北京代表处,北京100004

1. China University of Geosciences, Beijing 100083, China;2. Beijing Office, Landmark Graphics International Inc, Beijing 100004, China

三维地震构造解释中最主要的难点是断层解释。尽管地震相干分析方法可以突出断层特征, 但断层解释方法多数采用二维解释模式。这种模式不仅降低数据体的利用率, 无法充分发挥相干数据体的优势, 而且还影响断层解释精度, 增加断层解释难度。尤其是对复杂地区而言, 断层的空间组合、断点闭合这些常常困扰解释人员的难题, 在二维解释模式下就更加复杂。针对这个问题, 提出了复杂断层快速三维体解释的新方法。该方法利用叠后处理及可视化等技术手段, 对相干数据体作进一步的分析处理, 用突出断层为特点的选择性滤波及断层数据体分离等方法, 把断层数据从相干体中剥离出来, 最后把分离得到的断层数据与原始数据合成新的三维数据体。这种新数据体用常规的层位自动追踪方法可实现复杂断层的快速自动解释, 也可沿解释层面自动生成断层多边形。

One of the most challenging tasks for seismic interpreters is locating subtle faults within a 3-D seismic volume. A major step forward in the interpretation of 3-D seismic data was the introduction of coherency cube, which replaces the original seismic data by a volume of coherency estimates, ideally gives an interpreter a clearer visual indication of subtle faults. Unfortunately, the method for fault interpretation is mainly 2-D mode, which fails to fully utilize the advantages of the coherency cube, and is hard to locate subtle faults correctly, especially in a complicated structural environment. A new method for auto fault interpretation in complicated structural environment was proposed in this paper. A selective filter was applied to the coherency cube, and the result was then put into 3-D visualization tool. The resulting fault features were normalized and added back to the original seismic data. Auto fault interpretation and fault polygon generation can be easily performed on the new data set.