北部湾盆地主要凹陷流沙港组二段主力烃源岩再评价

发布时间：2018-04-24 12:24

本文选题：北部湾盆地 + 流沙港组二段　；参考：《中国海上油气》2017年05期

【摘要】：运用"湖相烃源岩非均质性"的思维方式,对北部湾盆地主要凹陷古近系流沙港组流二段湖相烃源岩进行了对比研究和再评价。基于大量地球化学和沉积地质资料的统计和分析,将烃源岩的有机碳含量、生烃潜量、氢指数和4-甲基C_(30)甾烷指数等作为评价和识别本区湖相烃源岩质量的有效指标,首次建立了北部湾盆地湖相烃源岩评价新标准,据此将流二段湖相烃源岩划分出优质、好、一般和差4类烃源岩。在此基础上,开展了优质烃源岩的形成条件和油源对比研究,认为受烃源岩形成条件不同的影响,北部湾盆地各凹陷流二段湖相主力烃源岩的质量存在较大的差异,其中涠西南凹陷最优,其主力烃源岩为流二段底部厚约50~100 m的湖相优质烃源岩,乌石凹陷其次,优质湖相主力烃源岩仅分布在乌石凹陷的东北洼,且优质烃源岩对这两个凹陷主力油田的形成和分布有明显的控制作用;而海中凹陷和迈陈凹陷主力烃源岩为流二段湖相一般烃源岩,可能不发育较大面积优质湖相烃源岩。本文研究成果对北部湾盆地,特别是对尚未突破的海中凹陷和迈陈凹陷的勘探方向选择有重要启示。
[Abstract]:Using the "heterogeneity of the lacustrine source rock", a comparative study and reassessment of the two lacustrine source rocks in the Paleogene stream sand port of the Paleogene in the Beibuwan Basin were carried out. Based on the statistics and analysis of a large number of geochemical and sedimentary geological data, the organic carbon content, hydrocarbon potential, hydrogen index and 4- methyl C_ (30) steroids of the source rocks were analyzed. As an effective index for evaluating and identifying the quality of the source rocks of the lake facies in this area, the number of alkane indices is the first to establish a new standard for evaluating the source rocks of the lacustrine source rocks in the Beibu Gulf Basin. According to this, the two source rocks of the lacustrine facies are divided into 4 types of source rocks of high quality, good, general and poor. On this basis, the formation conditions of the source rocks and the comparison of the source rocks are carried out. Influenced by the formation conditions of hydrocarbon source rocks, the quality of the main source rocks of the two main lacustrine facies in the depression flow of the Beibu Bay basin is very different. Among them, the southwest depression is the best, and its main source rock is the lacustrine high quality source rock with a thickness of 50~100 M at the bottom of the stream, followed by the Wushi Sag, and the main source rock of the high quality lacustrine facies is only distributed in the Wushi sag. The Northeast Depression and the high quality source rock have obvious control effect on the formation and distribution of the main two depression main oil fields, while the main source rocks of the middle sag and the Mai Chen depression are the general source rocks of the two lacustrine facies, which may not develop the large area of the high quality lacustrine source rocks. The selection of exploration directions in Zhong depression and Mai Chen sag has important implications.

【作者单位】：中海油研究总院;
【基金】：“十三五”国家科技重大专项“中国近海潜在富烃凹陷比较性研究与有利勘探方向预测(编号:2016ZX05024-002)”部分研究成果
【分类号】：P618.13

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