论文详情
基于常规模拟退火算法的零偏VSP全波形反演面临着计算量大和耗时长的问题。为此提出了一种不同阶段对应不同扰动模型和退火方式的分段快速模拟退火(segmented fast simulated annealing,SFSA)反演策略,以提高零偏VSP资料全波形反演的效率。在反演前期采用大模型扰动空间和较慢温度衰减速度,充分发挥全局搜索能力,而在后期引入限制因子产生扰动模型,在迭代不断增加的时候逐渐减小模型的扰动空间,同时采用较快的温度衰减速度,有效提高反演的速度,使反演快速收敛到最优解。基于相同的初始温度和马尔可夫链长度,分别利用基于SFSA和非常快速模拟退火(very fast simulated annealing,VFSA)方法进行零偏VSP纵波速度全波形反演测试。结果表明,基于SFSA的反演方法的反演效率提高约50%,在迭代次数更少的条件下能获得更好的反演效果。基于SFSA的零偏VSP全波形反演具有高效和高精度的特点,其反演结果为地震地质层位标定、成果解释及油气预测奠定了基础。
The application of the full-waveform inversion technique based on the conventional simulated annealing algorithm to zero-offset VSP data is time consuming and complex.This paper therefore proposes an efficient segmented fast simulated annealing (SFSA) strategy,which uses different disturbance models and annealing methods at different stages to improve the waveform inversion efficiency of zero-offset VSP data.In the early stage of inversion,large model perturbation space and slow decay rate of temperature were adopted to fully perform global search;in late stage,the perturbation model with restriction factor was adopted;the model perturbation space was gradually reduced as the iteration increased,with a faster decay rate of temperature,to improve the efficiency of the inversion and help the algorithm converge to the optimal solution quickly.Finally,SFSA and conventional very fast simulated annealing (VFSA) algorithms were compared for P-wave velocity inversion of zero-offset VSP.The test results showed that the SFSA algorithm can improve the inversion efficiency by 50%,while a better inversion effect could be obtained using less iteration.The proposed method could lay the foundation for the calibration of seismic geological horizons,seismic interpretation,and reservoir prediction.
国家自然科学基金 (U1562215,41604101)和国家油气重大专项(2016ZX05024004,2017ZX05009001,2017ZX05036005,2017ZX05032003)共同资助。