珠江口盆地中中新世陆架边缘三角洲的类型及控制因素

Types and controlling factors of shelf margin delta of Middle Miocene in Pearl River Mouth Basin

陆架边缘三角洲研究对于区域水动力条件分析及深水油气勘探具有重要意义。运用二维、三维地震数据及测井曲线等,通过地震剖面内部层序划分、平面属性与切片提取分析、测井相解释等手段,在中中新世晚期南海北部珠江口盆地珠二坳陷识别出可容空间驱动的河控、浪控及河流-波浪交互作用3种类型的陆架边缘三角洲。陆架边缘三角洲的发育规模受相对海平面变化的影响,形成位置与高位体系域背景下水道的发育位置相关。珠江口盆地中中新世陆架边缘三角洲物性较好,储盖组合良好,具有一定的油气勘探潜力。

The research of shelf margin delta has important significant for the analysis of hydrodynamic conditions and exploration of deep water hydrocarbon.The high-quality 2D and 3D seismic data and well logs were used to divide the internal sequence in seismic profile,and analyze the plane attribute distribution and well logging interpretation.Three types of shelf margin delta were identified in Middle Miocene in Zhu 2 Depression of Pearl River Mouth Basin,including fluvial-dominated,wave-dominated and mutual-influenced shelf margin delta.The fluvial-dominated shelf margin delta developed in lowstand system tract in Kaiping Sag,the wave-dominated type developed in falling-stage system in Baiyun Sag.The mutual types developed in falling-stage system in Kaiping Sag.The sequence and types of shelf margin deltas are influenced by the change of sea level and hydrodynamic conditions.While the developed location close to channel position in earlier high stand tract and further extended to the shelf margin delta.What more,the main body of shelf margin delta transfers from Baiyun Sag to Kaiping sag gradually,which was affected by the local change of source supply caused by neotectonic movement,including the activities of Dongsha uplift and Yunkai uplift.Finally,the shelf margin deltas show favorable reservoir quality,which can be good oil-gas exploration targets.