南沙曾母盆地地质构造特征与油气资源潜力

TECTONIC CHARACTERISTICS AND HYDROCARBON RESOURCE POTENTIAL OF ZENGMU BASIN IN NANSHA AREA

曾母盆地是南沙海域热点研究区域,为揭示该盆地油气资源潜力,依据曾母盆地地震剖面和钻井等资料,对曾母盆地的构造演化史和烃源岩进行综合分析。曾母盆地主要烃源岩为渐新统和中新统含有机质泥岩,通过排聚系数法对盆地的油气资源量作出估算,得出曾母盆地的油气当量为140.18×10~8 t,其中位于我国传统疆界内的有99.98×10~8 t。进一步根据盆地各亚区的构造特征和石油地质条件,将曾母盆地划分为3个不同等级的油气有利勘探区,其中南康台地和西部斜坡2个次级造单元为最有利勘探区。

The Zengmu Basin has been a hot spot in the Nansha area for research of hydrocarbon gener- ation and exploitation. In order to assess the hydrocarbon resources potential in the basin, this paper made a comprehensively investigation on the tectonics and the characteristics of source rocks based on regional geology, seismic survey and drilling data. The main source rock of the Basin is the Oligocene and Miocene organic-bearing mudstone. It is estimated that the hydrocarbon resources of the basin is about 140.18 × 10-8 t calculated upon the accumulation to discharge coefficient, of which 99.98 ×10-8 t is located within the traditional boundaries of China. According to the tectonic characteristics and hy- drocarbon geologic conditions, the Zengmu Basin could be further divided into three exploration areas on different grade. The Nankang platform and the west slope are both located in the most favorable exploration area.