论文部分内容阅读
本文构造了一个按比例缩小的物理模型,模型的上部是一层倾斜的速度各向异性覆盖层.用来研究由于采用各向同性的处理方法进行处理所引起的成像位置的误差。这个模型是由一块横向各向同性(T1)的苯酚材料组成,TI对称轴的倾角是45°,它的垂向厚度是1500m,用来模拟许多褶皱地区的倾斜碎屑岩系列。在横向各向同性材料苯酚的下面加上一块各向同性的有机玻璃,它是台阶形状,用来模拟礁的边缘或断层。苯酚材料的各向异性参数是δ=0.1,ε=0.24。 在零偏移距记录中,目的层的成像位置往覆盖层的上倾方向横向偏离了320m,而在时间或深度偏移的多道记录中,成像位置偏离了300m。横向偏离量依赖于偏移距的大小.在共中心点道集中,偏离量从小偏移距的320m减到大偏移距的280m。为了取得共偏移距道集的深度成像所做的深度偏移速度分析是引起各向异性介质深度成像位置增加了50m(大约3％)的主要原因。
In this paper, a scaled-down physical model is constructed, and the upper part of the model is a tilted, anisotropic layer of velocity that is used to study the errors in imaging position caused by processing with an isotropic approach. The model is composed of a transverse isotropic (T1) phenolic material with an inclination of 45 ° on the TI symmetry axis and a 1500 m vertical thickness to simulate a series of tilted clastic rocks in many fold areas. An isotropic plexiglass is added under the transversely isotropic material phenol, which is a stepped shape that simulates reef edges or faults. The anisotropy parameters of the phenol material are δ = 0.1, ε = 0.24. In the zero-offset recording, the imaging position of the target layer deviates horizontally to 320 m toward the upwelling direction of the cover layer, while the imaging position deviates from 300 m in the multi-track recording with time or depth offset. The amount of lateral offset depends on the size of the offset In the case of a common-center dot-gathers, the amount of offset decreases from 320 m at a small offset to 280 m at a large offset. Depth migration velocity analysis for depth imaging of common offset gathers is a major cause of an increase of 50 m (about 3%) in the depth imaging position of anisotropic media.