论文详情
密度是地震勘探中最重要的信息之一,在岩性解释、储层流体预测等多个方面起到不可替代的作用。但在全波形反演(FWI)中,由于密度和速度串扰的影响,很难反演出理想的密度信息。针对该问题,采取分步多参数全波形反演的策略,将反演的高精度速度结果作为初始速度模型,联合初始密度模型进行下一步多参数同时反演,通过提高初始速度模型的精度,得到更为准确的密度结果。同时,为了进一步平衡梯度能量,减小地震波传播过程中几何扩散的影响,采用照明预处理L-BFGS法提高反演精度。模型测试结果表明,分步多参数全波形反演及照明预处理L-BFGS法能很好地提高反演精度。
Density can predict fluid saturation of reservoir and plays an important role in reservoir interpretation and hydrocarbon prediction.Due to the cross-talk effects of velocity and density,density is difficult to reconstruct in multi-parameter full waveform inversion.To solve this problem,the strategy of stepped multi-parameter FWI is chosen which takes more accurate velocity inversion result as the initial velocity model and combines with the initial density model for next step simultaneous multi-parameter inversion.The more accurate the initial velocity model is,the more accuracy the density result is.In the meantime,to further balance the energy of gradient and reduce the influence of geometric diffusion in seismic wave propagation,the preprocessing L-BFGS method is carried out based on the illumination analysis.The numerical examples testify the feasibility of the stepped multi-parameter FWI and the pretreatment L-BFGS method that they can improve accuracy of result.
国家自然科学基金(41674130)、国家科技重大专项(2016ZX05027004-001,2016ZX05002-005-009)、国家重点基础研究发展计划(973计划)项目(2014CB239201-7HZ)、中央高校基本科研业务费专项资金(15CX08002A)联合资助。