多边形断层在深水盆地广泛发育，具有断层规模小、断距小、密集、受层序边界控制、平面呈不规则多边形展布等特征，对深水盆地流体超压系统、油气和水合物成藏具有重要的意义。南海北部深水盆地发育了大规模的多边形断层，表现出不同的发育特征。本项目拟以珠江口盆地南部和琼东南盆地东部深水区为对比研究靶区，利用高分辨率3D地震数据精细刻画多边形断层的地震几何特征；基于2D/3D地震数据和测井数据计算多边形断层发育地层的岩性、密度、孔隙度、饱和度等岩石物理性质。通过对南海扩张过程中珠江口盆地和琼东南盆地的构造和沉积成岩过程的分析，建立多边形断层发育地层的2D地质模型计算构造应力作用下地层内部的应力场分布，并应用3DMove技术研究多边形断层的开启和生长过程；计算分析沉积成岩过程中的砂泥岩含量和分布、沉积速率、孔隙压力变化等因素对多边形断层发育的影响。最终揭示南海北部深水盆地多边形断层差异性发育的主控因素，为深水油气运移研究提供依据。

Polygonal faults, usaully arranging in a polygonal structure developing in deepwater sequence, are a network of layer-bound, mesoscale extensional faults with short lengths, small throws and separations. Polygonal faults are found widely developed in sequences of more than 75, 000 square kilometers in deepwater basins and having different developmental charateristics in different basins in South China Sea.In this study, we will compare the devlopments of polygonal faults in southern Pearl River Mouth basin and eastern Qiongdongnnan basin. Using high resolution three dimention (3D) seismic data, seismic geometries of polygonal faults will be studied, and rock physical properties of the sequences where polygonal faults develop will be calculate based on 2D/3D seismic data and wireline log data between the two basins. The tectonic evolution and the process of deposition and diagenesis are inferred to impact diversities of the development of polygonal faults. As a result, 2D and 3D geological models are going to be built in order to analyze ditributions of interior field of stress in sequences hosting polygonal faults　and the development of the faults. The deposition and diagenesis factors such as the content and distribution of sand and mudstone, the deposition rate and the variation of pore pressure are also calculated and studied. Based on the works above, fators controlling the diverse development of polygonal faults are considered to present. The reserches on polygonal faults will help understanding the fluid flow process during the deepwater exploration.