珠江口盆地惠州26-6泛潜山油气田地震资料处理关键技术及应用

Application of Seismic Data Processing Key Technology in Huizhou 26-6 Pan-buried Hill Oil and Gas Field in Pearl River Mouth Basin

惠州26-6构造位于惠州凹陷惠州26洼西南陡坡带,是近NWW向北倾控洼断裂下降盘的断块构造,经多年勘探已实现二次三维采集覆盖。早期单方位处理的地震资料已不能满足在中生届及古近系寻找大中型油气田的需求,特别是在主力目标层析地震成像信噪比低、多次波干扰严重、内幕反射结构不清晰、基底与断层不清、局部受断层阴影带影响的情况下,落实中深层构造界面形态,还原古近系地层内幕结构反射特征,沉积体系分析面临了很大困难。因此,为了有效利用不同年度和方位采集三维地震数据,本次研究在分析不同方位采集差异的基础上,通过应用宽频处理技术、三维并联多次波衰减技术、双方位TTI高精度速度建模技术、TTI叠前深度偏移成像技术及基于目标优化的双方位融合技术等处理技术,得到的中深层构造界面形态清楚,断点清晰,提高了目的层分辨率和信噪比,还原了古近系地层内幕结构反射特征,深层成像效果明显得到改善,为目标评价提供了可靠的基础资料。

Huizhou 26-6 structure is located in the southwest steep slope zone of Huizhou 26 sag in Huizhou depression.It is a fault block structure near the descending wall of NWW northward-dipping depression fault,which has been covered by the secondary 3D acquisition coverage.The early seismic data from single azimuth can not meet the needs of searching for large and medium-sized oil and gas fields in Mesozoic and Paleogene,especially for the main target tomographic seismic imaging with low signal-to-noise ratio,severe multiple interference,poor internal reflection structure,unclear basement and faults,and partially affected by fault shadow zones,have brought great difficulties to the identification of the morphology of the middle-deep structural interface,the restoration of the reflection characteristics of the inner structure of the Paleogene strata,and the analysis of the sedimentary system.Therefore,in order to effectively use the 3D seismic data acquired in different years and azimuths,this paper first analyzes the differences in acquisitions in different azimuths,then adopts wide-band processing technology,3D parallel multiple attenuation technology,dual azimuth TTI high-precision velocity modeling technology,TTI prestack depth migration imaging technology and dual azimuth fusion technology based on target optimization.It is found that the interface morphology of the middle and deep layer is clear and the breakpoint is distinct,which improves the resolution and signal-to-noise ratio of the target layer,restores the reflection characteristics of the inner structure of the Paleogene strata,improves the deep-seated imaging obviously,and provides reliable basic data for the target evaluation.