利用VSP资料提取地层参数

Extracting earth parameters from VSP data

长庆石油勘探局物探处研究所, 吴忠751104

Reseach Institute of Geophysical Exploration Division, Changqin Petrolcum Administration, Wuzhong

速度参数是地震勘探中的重要参数,尤其横波速度是常规二维地震资料无法确定的。本文根据VSP资料波场丰富的特点,把VSP记录看成少量的平面波场之和。以少量地震道组,分别从零井源距和非零井源距资料中提取纵横波速度,进而估算出与油气相关的泊松比参数。经过实际资料的处理,反演效果较好,质量可靠,认为该方法切实可行。

It is well known that velocity is a very important parameter in seismic prospecting. Especially the shear velocity can’t be gotten from 2D coventional seismic data. Based on the characteristics of VSP data, the paper presents a parameter inversion method for getting earth parameters. By recognizing VSP records as the sum of a small number of plane-waves and using a few of VSP traces in a small spatial aperture, both compressional velocity and shear velocity can be found from zero-offset VSP data and offset VSP data respectively, then Possion’s ratio can be got which is affinity with oil and gas. Having finished the real data processing, the good result was obtained.These parameters of the earth will give a lot of help to oil and gas prediction.