【摘要】 地震走时层析成像在油气田勘探和开发中的应用日益广泛。主要用于速度分析,为其它的地震资料处理方法提供精确的速度模型。逆垂直地震剖面RVSP(Reversed Vertical Seismic Profile)层析成像的关键是求解一个大型稀疏的线性方程组。求解方程组常用的迭代法,需要一个比较合理的初始猜测解,也即是初始速度模型。初始模型关系到反演的效率甚至成像的正确性。提出了一种自动求取层析成像初始速度模型的方法。该方法假定激发点到接收点间的射线是直射线,并利用最小路径法射线追踪得到初至走时来求取初始速度模型。通过建立数学模型验证了自动生成速度初始模型的可行性及可靠性,并对出现的问题进行探讨。更多还原

【Abstract】 The seismic wave tomography is more and more widely used in the exploration and development of oil and gas fields.This method is mainly used in velocity analysis to provide accurate velocity model for other seismic data processing.The key of RVSP tomography is to solve one large-scale and sparse linear equation.The rational initial solution and speed model are commonly used in the iterative method of linear equation.The initial model concerns the exactness and efficiency in the inversion.This paper puts forward a method to produce the initial velocity model of tomography automatically.We assume the line from source to receiving is straight and we gain the initial velocity model by using minimum path-way method to trace initial travel-time.The feasibility and reliability of the automatically produced initial velocity model is verified by mathematical model and the problems have been discussed.更多还原