复杂区深井VSP层析求速度场的方法  

A method for velocity field with deep-well VSP tomography in complex areas

作　　者：侯爱源[1] 李庆忠[1] 张文波 

机构地区：[1]中国海洋大学海洋地球科学学院,山东青岛266100 [2]东方地球物理公司物探技术研究中心,河北涿州072750

出　　处：《石油地球物理勘探》2017年第6期1150-1155,共6页Oil Geophysical Prospecting

摘　　要：针对中国西部山前带地区叠前深度偏移速度场尤其是深层速度场难以确定的难题,提出了一种复杂区深井VSP层析求速度场的方法。该方法以零井源距VSP速度作为相对稳定值填充井径附近速度网格,并通过零井源距VSP速度加权外推建立初始速度模型,同时还给出了一种基于置信度和射线长度的VSP初至旅行时双加权层析反演的算法,通过模型试算验证了方法的有效性。One of the difficulties in piedmont belts of Western China is to obtain prestack depth migration velocity field,especial the deep velocity field.To solve this problem,we propose the deep-well VSP tomography method for velocity field in complex areas.In this method,the velocity of zero-offset VSP is taken as a relative stable value to fill velocity grids near the well,and a weighted velocity of zero-off-set VSP is extrapolated to establish an initial velocity model.Meanwhile,we put forward a VSP first break bi-weighted tomography inversion algorithm based on the confidence level and the raypath length.Tests on a synthetic model demonstrate the effectiveness of the proposed method.

关 键 词：复杂区 VSP 初至旅行时 双加权层析 深层速度场 

分 类 号：P631[天文地球—地质矿产勘探]