黄土塬地区双井微测井近地表Q模型的求取及应用  

The calculation and application of a near-surface Q-value model based on dual-well micrologs for a loess tableland area

作　　者：夏常亮 戴海涛 李国强 古发明 吴德明 韩利 XIA Chang-Liang;DAI Hai-Tao;LI Guo-Qiang;GU Fa-Ming;WU De-Ming;HAN Li(BGP INC.,China National Petroleum Corporation,Xi’an 710021,China)

机构地区：[1]中国石油东方地球物理勘探有限责任公司研究院,陕西西安710021

出　　处：《物探与化探》2024年第3期698-704,共7页Geophysical and Geochemical Exploration

基　　金：中石油集团公司“十四五”科技项目(2021DJ3705)。

摘　　要：针对鄂尔多斯盆地黄土塬地区地震资料分辨率低、子波一致性差的问题,提出一种近地表Q模型求取方法,进而开展地震数据近地表Q吸收补偿处理。以往通常采用微测井资料求取Q值进而插值获得全工区Q场,本文在前人基础上采用双井微测井资料计算井点位置的Q值和近地表速度值,通过最小二乘法拟合近地表速度与Q的区域关系函数,利用基础静校正初至波层析反演的近地表速度场,通过区域关系函数得到本区近地表的Q场,从而实现以微测井位置的Q值求得全工区近地表Q场的目的,进而开展叠前道集近地表Q吸收补偿处理。鄂尔多斯盆地黄土塬“双复杂”地震资料应用结果表明,利用本方法反演Q场开展近地表Q吸收补偿处理,能够有效提高地震资料的子波一致性,拓宽频带,改善井震匹配关系,消除近地表对地震子波的影响。Given the low resolution and poor wavelet coherence of seismic data for the loess tableland area of the Ordos Basin,this study proposed a method for calculating the near-surface Q-value model for near-surface Q-absorption compensation of seismic data.Investigations reveal that micrologs have been used to obtain the Q field of a whole survey area by calculating the Q value and subsequent interpolation.Based on previous research results,this study calculated the Q values of well sites and near-surface velocity values using dual-well micrologs.Then,the regional relationship function between near-surface velocity and Q was determined through fitting using the least squares method.Furthermore,the near-surface Q field of the study area was obtained using the near-surface velocity field derived from the tomographic inversion of the first arrival wave post basic static correction.Consequently,the near-surface Q field of the whole survey area were calculated from the Q values of microlog positions,and the near-surface Q absorption compensation of prestack gathers was achieved.As indicated by the application of the study area’s seismic data,which are characterized by complex surface and subsurface conditions,the inversion of the Q field for near-surface Q absorption compensation using the method proposed in this study can effectively enhance the wavelet coherence of seismic data,broaden the frequency band,improve the log-seismic matching relationship,and eliminate the influence of near surface on seismic wavelets.

关 键 词：黄土塬 双井微测井 Q吸收补偿 子波一致性 

分 类 号：P631.4[天文地球—地质矿产勘探]