珠江口盆地南部隆起中新统碳酸盐岩分布的地震预测

Seismic Predication of Miocene Carbonate Rock in the South Uplift,Zhujiangkou Basin

珠江口盆地中新统碳酸盐岩台地发育,并在东沙隆起发现了生物礁油田。借鉴区域岩相古地理研究,依据典型的特强振幅低频地震反射特征,推断在南部隆起下中新统发育有碳酸盐岩。针对钻井空白的情况,通过正演模型,分析不同厚度碳酸盐岩对应的地震响应特征,据此在南部隆起的二维地震剖面上识别出了碳酸盐岩的尖灭点、调谐厚度、1/2波长厚度和大于1/2波长厚度等重要厚度控制点,编制了碳酸盐岩厚度图。根据碳酸盐岩相模式、厚度和地震反射特征,初步分析了碳酸盐岩孤立台地的沉积相,这可为南部隆起碳酸盐岩油气勘探提供参考。

It is inferred that Miocene carbonate reservoirs probably develop in the South Uplift in Zhujiangkou Basin according to regional paleogeography and typical seismic responses with high-amplitude and low-frequency features. In the case of no drilled well, a forward modeling is used to analyze seismic responsibility to different thickness of Miocene carbonate rock. Consequently, some key thickness points, including pinchout points, tuning points,1/2 wavelength points and more than 1/2 wavelength points, are recognized in seismic profiles. Then a thickness map of Miocene carbonate rock is compiled. On integrated analysis of the Guan′s carbonate facies model, the thickness map and the seismic reflection features, the Miocene sedimentary facies isolated carbonate platform is described. It is expected that this result will be useful to future oil exploration in the carbonate rock in this uplift.