CAJ | 학술논문

与其他偏移方法相比,逆时偏移基于精确的波动方程而不是对其近似,用时间外推来代替深度外推.因此,它具有良好的精度,不受地下构造倾角和介质横向速度变化的限制.采用的三角网格差分法最大限度地保持了差分法的简单性,同时兼有有限元法的精确性,可直接用于起伏地表模型的正演模拟和偏移计算而无需对模型做特殊处理.本文首次尝试将三角网格差分法应用于逆时偏移中,模型试算表明了这两种方法的结合具有较好的应用效果.
여기타편이방법상비,역시편이기우정학적파동방정이불시대기근사,용시간외추래대체심도외추.인차,타구유량호적정도,불수지하구조경각화개질횡향속도변화적한제.채용적삼각망격차분법최대한도지보지료차분법적간단성,동시겸유유한원법적정학성,가직접용우기복지표모형적정연모의화편이계산이무수대모형주특수처리.본문수차상시장삼각망격차분법응용우역시편이중,모형시산표명료저량충방법적결합구유교호적응용효과.
Compared with other migration methods, reverse-time migration is based on a precise wave equation, not an approximation, and performs extrapolation in the depth domain rather than the time domain. It is highly accurate and not affected by strong subsurface structure complexity and horizontal velocity variations. The difference method based on triangular grids maintains the simplicity of the difference method and the precision of the finite element method. It can be used directly for forward modeling on models with complex top surfaces and migration without statics preprocessing. We apply a finite difference method based on triangular grids for post-stack reverse-time migration for the first time. Tests on model data verify that the combination of the two methods can achieve near-perfect results in application.