天环坳陷南段延安组低幅度构造预测技术及应用效果

Prediction on low amplitude structures of the Yanan Formation in the southern Tianhuan Depression and its application

天环坳陷南段侏罗系延安组发育低幅度构造。受临近西南缘复杂构造演化影响,导致低幅度构造成藏规律认识不清,勘探部署难度大。为提高研究区二维地震资料覆盖区低幅度构造预测效果,优选层析静校正技术解决研究区长波长和短波长的成像问题,提高低幅度构造成图精度之后,利用基于数据重构的反向线性噪音压制技术对研究区存在的干扰重和信噪比低等问题进行精细处理,然后,利用精细速度场及变速成图和小网格大比例尺成图技术对低幅度构造进行精细落实。最后,运用二维趋势面技术突出构造局部高点。综合运用以上处理解释一体化精细构造成图技术落实低幅度构造19个。经钻井证实,该低幅度构造预测技术对二维地震资料覆盖区低幅度构造预测具有较好应用效果。

Low amplitude structure developed in Jurassic Yanan Formation in the southern section of Tianhuan Depression.Due to the influence of complex tectonic evolution of the conterminous southwest margin,it is difficult to reveal the regularity of hydrocarbon accumulation in the low amplitude structure. So exploration deployment is difficult. In order to improve the prediction effect of low amplitude structure of the Yanan Formation in the southern Tianhuan Depression that is covered by 2 D seismic data,tomographic static correction technology was optimized to solve the problems of long and short wavelength imaging,and therefore the precision of low amplitude structure mapping can be improved. After that,reverse linear noise suppression technique based on data reconstruction was used to reprocess the data which have problems of strong interference and low signal-to-noise ratio in loess tableland area. On the basis of fine processing,by using subtle velocity field,variable-velocity and small grid of large-scale mapping,the'fasle-high'caused by high-speed conglomerate-interlayer was removed and the structure can be mapped correctly. Finally,the trend surface analysis was utilized to highlight the local structure heights. Nineteen low amplitude structures were determined based on comprehensive use of the integration of data process and interpretation mentioned above. It has been proved by drilling that the low amplitude structure prediction technique has a good effect on low amplitude structure prediction in area that is covered by 2 D seismic data.