【摘要】 珠江口盆地白云凹陷叠前深度偏移三维地震资料揭示了6个位于mfs18.5之上约250m处的大型丘状构造,这些丘状地质体最显著的特征为剖面上不对称的丘形和平面上不规则的椭圆形态。丘状体底座直径为826~3 542m,最大高度可达403m,规模最大的丘状体体积可达0.53 km~3。这些丘状地质体与国外报道的丘状砂岩侵入体有着相似的地震反射特征,在符合SEG标准的零相位正常极性地震资料中,其顶面和底面分别响应于连续性较好的中-强振幅正向和负向反射同相轴,其核部以杂乱反射为主要特征,与围岩地层平行-亚平行的席状反射相比具有明显差异;且丘状体内部速度较围岩地层速度高,综合分析判断为砂岩侵入体。该沉积体具有良好的生储盖组合条件,具有巨大的油气勘探潜力。更多还原

【Abstract】 Three-dimensional pre-stack depth migration seismic data reveal that there exist six large-scale mounded structures at approximately 250 m above MFS18.5 in the Baiyun sag in Pearl River Mouth Basin.The mounds are most distinctive for their asymmetric mounded shape in the section and the irregular oval shape in the plan view.The mounds have the base diameter widely ranging from 826 to 3 542 m,with the maximum height of 403 m and the largest volume of approximately 0.53 km3.The mounds in Baiyun sag have similar seismic reflection characteristics as the mounded sand intrusions reported previously in other countries.The seismic data of zero phases with SEG normal polarity indicate that the top and base of the mounds mainly respond to continuous,medium- to high-amplitude,positive and negative reflection events;the core of mounds is dominated by incoherent and chaotic reflections that are greatly different from sheet-like reflections(sub)-parallel to the surrounding rock formations,and velocity of the core is relatively higher than that of the surrounding rock formations.As a result,the mounds are comprehensively interpreted as sand intrusions;these sedimentary bodies are favorable source-reservoir-cap rock assemblages with great potential for oil and gas exploration.更多还原