西沙海域中新世碳酸盐台地的时空分布及其油气成藏模式

发布时间：2018-07-05 15:23

本文选题：西沙海域 + 碳酸盐台地　；参考：《地质学报》2017年06期

【摘要】：本文基于南海北部西沙海域地震数据及钻井资料,结合碳酸盐台地的边缘特征及其地震反射特征,首次建立了研究区中新世碳酸盐台地边界的三个识别标志:岩性突变界面、断层界面和潮汐水道。在对地震数据系统的解释和钻井资料分析基础之上,厘定了该区生物礁及碳酸盐台地的时空分布,总结其分布规律,西沙海域中新世碳酸盐台地可以分为六期,进一步划分三个演化阶段,分别为中中新世早期的繁盛阶段、中中新世晚期的衰退阶段、晚中新世以来的淹没阶段,各阶段碳酸盐台地的沉积相带发育完整,其中生物礁主要分布台地的西-西南缘。统计结果显示,生物礁及碳酸盐台地全面发育时期的面积达到了80000km~2,后期随着台地的衰退而规模有所减小。西沙海域中新世碳酸盐岩分布广泛、规模巨大,而且在发育过程中经历了多期暴露而遭受淋滤,进一步增大了其孔隙度,具备形成优质储层的前提。结合区域油气地质条件分析与探讨,建立生物礁及碳酸盐台地的成藏模式,提出西沙海域碳酸盐台地具有典型"下生上储上盖"的成藏过程,指出西沙海域邻近华光凹陷和中建南盆地北部的碳酸盐台地是油气勘探的两大有利区带。
[Abstract]:Based on the seismic data and drilling data of Xisha sea area in the northern part of the South China Sea, combined with the marginal characteristics of carbonate platform and its seismic reflection characteristics, three identification markers of Miocene carbonate platform boundary in the study area are established for the first time: the lithologic abrupt interface. Fault interfaces and tidal channels. Based on the interpretation of seismic data system and the analysis of drilling data, the temporal and spatial distribution of reef and carbonate platform in this area is determined, and the distribution law is summarized. The Mesocene carbonate platform in Xisha Sea area can be divided into six periods. It is further divided into three stages: the prosperous stage in the early Miocene, the declining stage in the late Miocene, the submerged stage since the late Miocene, and the complete development of sedimentary facies in each stage. Among them the reef mainly distributes the west-southwest margin of platform. The statistical results show that the area of the reef and carbonate platform reaches 800 km / m ~ 2 during the full development period, and the scale decreases with the decline of the platform in the later stage. The Carbonate rocks of the Miocene in Xisha Sea area are widely distributed and have a large scale, and have experienced multiple periods of exposure and been leached during the development process, which further increases the porosity of the carbonate rocks and has the premise of forming high quality reservoirs. Based on the analysis and discussion of regional oil and gas geological conditions, the reservoir forming model of reef and carbonate platform is established, and it is proposed that the carbonate platform in Xisha sea area has the typical process of "upper reservoir cap". It is pointed out that the carbonate platform near Huaguang Sag in Xisha Sea area and the carbonate platform in the northern part of Zhongjiannan Basin are two favorable zones for oil and gas exploration.
【作者单位】：国土资源部海底矿产资源重点实验室广州海洋地质调查局;中国科学院深海科学与工程研究所;中国科学院资源地层学与古地理学重点实验室南京地质古生物研究所;
【基金】：中国地质调查局项目:南海南部油气资源调查(编号:DD20160155) 国家自然科学基金面上项目(编号:41272014)的联合资助成果
【分类号】：P588.245;P618.13

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