低频采集反射地震数据约束全波形反演关键问题研究

项目名称： 低频采集反射地震数据约束全波形反演关键问题研究

项目编号： No.41304109

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 卞爱飞

作者单位： 中国地质大学（武汉）

项目金额： 24万元

中文摘要： 本项研究通过叠前偏移数据体标志层位解释与块状构造建模、宏观构造约束下地震属性提取与分选优化，实现基于多属性加权的模型局部光滑度估算；通过有限差分法离散化格式频散分析与优化、大型稀疏矩阵LU分解直接解法实现频率域多炮快速模拟；设计基于模型局部光滑度的约束反演目标函数，建立多尺度约束波形反演流程；提取实际低频地震资料信号与噪声特征，设计两组正演模型建立逼近实际低频采集情况的合成地震记录，在合成记录偏移剖面提取模型局部光滑度约束关系，在此基础上逐一改变多组反演参数进行约束波形反演测试，进而分析不同情况下模型局部光滑度约束关系对多尺度波形反演影响规律。本项研究可以建立约束全波形反演与叠前偏移方法之间双向良性反馈机制，进一步提高多源地学信息利用率和波形反演结果地质合理性，为我国海洋深水油气藏、陆地中深层油气藏以及非常规油气勘探开发进程中的高精度速度建模与储层评价方案优化提供技术支持。

中文关键词： 低频；全波形反演；多尺度反演；约束；反演策略

英文摘要： Full waveform inversion (FWI) is a highly non-linear geophysical inverse problem. Using multi-scale and layer-stripping inversion strategies, as well as imposing reasonable model constrains may effectively stabilize the FWI optimization process. Key horizons on prestack migrated images are used to build the block geological structure model. Multi-attributes extraction and classification are used to calibrate the local smoothness of velocity model under the block structure model constrains. Through dispersion analysis and optimization, and direct methods for large-scale sparse matrix LU decomposition, a fast, multi-shot, frequency domain finite difference forward modeling algorithm is developed. A local smoothness based objective function is designed for constrained full waveform inversion. The corresponding constrained inversion workflow incorporates several optimized inversion strategies, including multi-scale, layer-stripping, and gradient preconditioning. Through analysis of real low frequency seismic data, the characteristics of seismic signal and typical noise are extracted. Two kind of Synthetic models are built to mimic the situation of real low frequency seismic acquisition work. After synthetic data processing and prestack migration, attribute analysis is used to extract local model smoothness constrain

英文关键词： low frequency；full waveform inversion；multi-scale inversion；constrains；inversion strategy