非重复采集时移地震正演模拟及可行性分析

Forward-modeling and feasibility study of non-repeating acquired time-lapse seismic exploration

本文主要研究前期为常规三维地震勘探和后期为高精度三维地震勘探的这种典型非重复采集时移地震的可行性,主要使用正演模拟和匹配处理相结合的方法进行.本文推导了基于PML边界的三维声波波动方程时空域高阶有限差分正演方程,根据岩石物理流体替代分析方法计算得到时移前后储层的弹性参数,建立了时移地震地球物理模型,设计了常规三维和高精度三维观测系统,进行地震正演模拟,获得了非重复采集时移地震理论模拟数据.利用匹配处理法对非重复采集时移地震正演模拟数据和实际资料进行可行性分析,匹配处理过程主要包括初始数据匹配、一致性处理和互均化处理等.理论模拟数据和实际资料的匹配处理结果表明,通过针对性的分析和处理,利用非重复采集的地震资料进行时移地震研究是可行的,能够得到较好的时移地震响应,在一定程度上反映了油藏的变化情况.

With recent high-precision three-dimensional seismic data and earlier conventional three-dimensional data this paper mainly discussed the feasibility of non-repeating acquired time-lapse seismic exploration through forward modeling and match processing. In order to do forward-modeling, we derived stable and effective time-domain higD order finite-difference formula with PML boundary condition for three-dimensional acoustic wave equation, calculated the time-lapse elastic parameters of the reservoir based on rock physical fluid substitution theory, built the timeqapse geophysical models, designed conventional three-dimensional and high-precision three-dimensional recording geometries, then obtained theoretical non-repeating time-lapse seismic data. Next, we applied match processing to theoretical and real non-repeating time-lapse seismic data, including target data matching, consistency processing and cross-equalization processing, most of the unwanted inconsistent responses was removed. The processing results of theoretical and real data showed that it is feasible to use the non-repeating acquired data to study the time-lapse seismic exploration by aimed analysis and match processing, and it is available to obtain a better time-lapse seismic response. It reflects the changes of the reservoir to a certain extent.