时移地震叠前差异数据表征油藏参数变化方法研究

Time-lapse seismic characterize the reservoir parameter changes using the two seismic data, is the important means of development seismic. At present the poststack and AVO data is used to characterize the changes of reservoir parameter. Because of the stack and other processing, the accuracy of these data is very low and this greatly limits the application of time-lapse seismic. The project plans to study the characterization problem of reservoir parameter changes based on prestack difference shot gather data. Based on the Viscoelastic wave theory, the equation between prestack time-lapse seismic difference data and reservoir elastic parameter changes will be constructed, and then the full waveform inversion method of reservoir elastic parameter changes will be studied. Aiming at the the stability problem, wavelet problem and computing cost problem in the full waveform inversion of difference data, the compressed sensing constrained inversion method, source-independent inversion method and local parameter inversion method will be studied. Based on the reservoir rock physics theory, the relationship that reservoir elastic parameter varies with reservoir parameters will be studied. Mainly study the relations that elastic parameters varies with the reservoir fluid saturation and pressure change. On this basis, characterization method of reservoir parameters change using prestack time-lapse seismic difference data will be studied. The theory of time-lapse seismic reservoir monitoring using wave equation full waveform inversion will be improved, and the capacity of time-lapse seismic monitoring of reservoir will be effectively improved.

时移地震利用两次观测的地震数据差异表征油藏参数的变化，是开发地震的重要手段，目前主要利用叠后时移地震数据或AVO数据表征油藏参数的变化。由于叠加等处理，精度降低，限制了时移地震在复杂地区的应用。本项目拟基于叠前炮集差异数据研究油藏参数变化的表征问题。首先基于粘弹性波动理论，建立储层弹性参数变化的时移地震叠前差异响应，进而研究储层弹性参数变化的全波形反演方法，针对差异数据全波形反演的不稳定、子波未知和计算量大的问题，探索压缩感知约束反演、不依赖子波反演和局部参数反演方法。基于油藏岩石物理理论，研究弹性参数差异表征储层流体饱和度和压力等油藏参数变化的关系。在此基础上，研究时移地震叠前差异数据表征油藏参数变化的方法，完善时移地震波动方程全波形反演进行油藏监测的理论，有效提高时移地震监测油藏参数变化的能力和水平。

时移地震是开发地震的重要手段，如何利用两次观测的地震数据来表征油藏参数的变化是时移地震关键问题之一，目前都是利用叠后地震数据或AVO数据表征油藏参数的变化，在复杂油气藏地区，这些数据的精度很低，限制了时移地震在复杂地区的应用。本项目研究了基于叠前炮集差异数据表征油藏参数变化的问题。主要进行了如下几个方面的研究：①对时移地震叠前差异数据与储层弹性参数变化之间的关系式进行了研究；②开展了时移地震差异数据全波形反演方法研究；③对储层弹性参数变化与油藏参数变化关系进行了研究；④开展了时移地震差异数据表征油藏参数变化的方法。通过项目研究形成了粘弹性波动方程模拟方法、基于对数谱面积差的Q值反演方法、不依赖子波的全波形反演方法、时移地震全波形反演方法、时移地震储层参数反演方法等。这些方法的综合应用初步形成了时移地震叠前差异数据表征油藏参数变化的方法，完善时移地震差异数据表征油藏参数变化的理论。该套方法对于改善时移地震监测油藏变化的能力具有重要的理论意义和实际应用价值。项目共完成论文24篇，其中SCI检索论文11篇，其中9篇论文是国外SCI论文。