变阶数有限差分法及逆时偏移有效边界存储最优化策略

发布时间：2018-11-18 21:49

【摘要】：地震资料逆时偏移方法在计算过程中需要保存大量的波场信息,这种巨大的存储需求限制了该方法的实际应用.因此,研究能够显著降低波场存储量的存储策略对于推进逆时偏移方法的实用化具有重要的理论意义和实际价值.本文分别从时间和空间的角度提出了相应的波场存储策略:(1)提出变阶数有限差分算子,在计算波场左、右和下边界处时,将差分阶数由高阶递减至二阶,结合有效边界存储策略,可在不损失波场重建精度的同时大幅降低波场存储量;(2)借鉴checkpoint策略和缓冲区思想,提出了基于拉格朗日乘子法的参数最优化方案,在时间方向上压缩波场存储量.通过对二维盐丘模型进行震源波场重建和逆时偏移存储量测试,结果表明:本文方法可实现对震源波场的高精度重建,与传统方法相比,在不损失成像精度的前提下,新的存储策略可大幅降低逆时偏移方法的波场存储需求.
[Abstract]:The inverse time migration method of seismic data needs to preserve a large amount of wave field information in the calculation process, which limits the practical application of this method. Therefore, it is of great theoretical and practical value to study the storage strategy which can significantly reduce the storage capacity of the wave field for advancing the practical application of the inverse time migration method. In this paper, the corresponding wave field storage strategies are proposed from the point of view of time and space respectively. (1) A variable order finite difference operator is proposed. When calculating the left, right and lower boundary of the wave field, the difference order is reduced from higher order to second order. Combined with the effective boundary storage strategy, the storage capacity of the wave field can be greatly reduced without losing the reconstruction accuracy of the wave field. (2) drawing on checkpoint strategy and buffer thought, a parameter optimization scheme based on Lagrange multiplier method is proposed, which compresses the storage of wave field in time direction. By testing the source wave field reconstruction and inverse time migration storage of 2-D salt dome model, the results show that the proposed method can achieve high accuracy reconstruction of the source wave field. Compared with the traditional method, the proposed method does not lose the imaging accuracy. The new storage strategy can greatly reduce the wave field storage requirements of the inverse time migration method.
【作者单位】：东北石油大学;黑龙江省普通高校科技创新团队"断层变形封闭性及流体运移";大庆钻探工程公司地球物理勘探一公司;
【基金】：国家自然科学基金项目(41574117,41474118) 黑龙江省杰出青年科学基金项目(JC2016006) 黑龙江省博士后科研启动项目(LBH-Q15017) 黑龙江省自然科学基金项目(D2015011) 东北石油大学引导性创新基金项目(2017YDL-02);东北石油大学研究生创新科研项目(YJSCX2016-002NEPU)联合资助
【分类号】：P631.44

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