初至层析静校正在复杂山地三维地震勘探中的应用

Application of First Arrival Tomographic Statics in Complicated Mountainous Region 3D Seismic Prospecting

随着地形高差增大、地貌单元多变、近地表模型复杂,目前被广泛应用的初至折射静校正的精度已无法满足精细勘探的要求。初至层析静校正技术,由给定的初始模型进行正演,用射线追踪方法得到初始模型的初至波,利用该初至波和实际拾取的初至波进行比较,计算地表模型的修正量,反复迭代求得准确的地表模型。山西省国阳新能股份有限公司二矿390水平九采扩区地表标高940～1 100m,地貌单元复杂,在对该区资料处理时,利用初至层析折射静校正,经9次迭代计算后,真实地刻划出近地表模型。在二种静校正技术对比中,初至折射静校正不但近地表模型精度低于层析折射静校正,而且其叠加剖面精细程度也远低于层析静校正,如在初至折射静校正叠加剖面同相轴上呈现的凹凸形态,在层析静校正叠加剖面并无显示,且后者剖面的信噪比也比前者明显提高。

On account of relief height difference increasing, variable landforms and complex near-surface model, widely applied first arrival refraction statics at present is unable to meet precision prospecting demand. The first arrival tomographic statics technology from given initial model forward modeling, get initial model first arrival by the use of ray tracing, compare the first arrival to actually picked first arrival, calculate surface model correction, iterate and get exact surface model. The Shanxi Guoyang New Energy Co. Ltd. No.2 coalmine, 390m level winning district surface elevation is 940-1100m with complex landform, during the area＇s data processing, use first arrival tomograhpic statics, after 9 iterates exactly scored surface model. Comparing the two statics, not only the precision of near-surface model of first arrival fraction statics is lower than tomographic statics, but the stacked section precision is also far lower than the tomographic statics If unsmooth configurations appearing on phase axis of first arrival refraction static correction stacked sections, as against, there are no appearing on the tomographic static correction stacked sections, and section S/ N ration of the later obviously higher than the former.