低幅度构造成图技术

在总结塔里木盆地库车坳陷托乎拉—三道桥地区低幅构造研究成果的基础上,提出了一套适于深层低幅度构造成图的技术和方法,利用这项技术和方法能够提高低幅度构造成图的精度,落实局部构造,降低勘探风险,对于类似地区的低幅度构造研究,具有借鉴意义。

Technique for Mapping Low-Amplitude Structure

The study results of low-amplitude structure i n Tuohula-Sandaoqiao area of Kuche depression in Tarim basin are summarized,base d on which this paper presents the technique for mapping deep low-amplitude str uctures.The technique can be used to improve the mapping accuracy of low-ampli tude structures,verify local structures,reduce risk for exploration.The key o f the mapping technique is in un-derstanding of seismic velocity,in which the main procedures are described as following:1)calculation of interval velocity from Dix formula and obtaining the average velocity by using the stack velocity ;2)calculation of pseudo average velocity from drilling geologic zonation dat a and seismic interpreted interval as well as its transversal variation gradient ;3)analysis and correlation of the average velocity and variation(i.e.velo city and gradient matching);4)averaging the difference between steps2)and 3),and making correction by Kriging interpolation tech-nique;5)correlatio n of t 0 interpretation and average velocity change;6)consideration and remove of 3D boundary effect,and7)making time-depth conversion.