不同周期的地形起伏分量对叠加速度的影响

The effect of topographic relief on velocity analysis

中国石化石油勘探开发研究院南京石油物探研究所,江苏南京 210014

Institute of Geophysical Prospecting, SINOPEC Research Institute of Petroleum Exploration and Development, Nanjing 210014, China

起伏的地形可被分解成一系列不同周期的分量。从地形起伏周期和地震排列长度关系的角度分析了地形起伏对速度分析结果的影响。在地形起伏不同周期的分量中,当周期与地震排列长度相近的起伏分量比较大时,常规静校正产生的偏差对速度分析结果的影响会大到无法忽略的程度,这是常规静校正方法所固有的。速度分析时,为了得到可靠的叠加速度,应包含周期与排列长度相近的地形起伏分量的高点和低点位置。用模型数据分析了不同地形起伏分量对速度分析结果的影响,并用实例进行了说明。

Topographic relief is treated approximately as a wave consisted of harmonic waves of different cycles in this paper, and the effect of topographic relief on velocity analysis is discussed. The effect of the biases resulted from conventional static correction on velocity analysis is not neglectable when the period of harmonic wave that has a matched length as spread length are larger compared to other ones. In order to get reliable stacking velocity, the high and low points of relief harmonic component must be included in the set of velocity analysis locations. The effect of different relief harmonic components on velocity analysis is illustrated with theoretical and real data.