利用预测有机碳含量探讨鄂尔多斯盆地延长组有机质丰度空间分布及控制因素

发布时间：2018-11-10 17:38

【摘要】：为了快速查明鄂尔多斯盆地延长组有机质丰度的空间分布特征,选取盆地南部不同地区的5口典型钻井,通过基于测井数据定量预测有机碳(TOC)含量的快捷方法,评价了不同钻井区域长9段~长4+5段烃源岩的TOC丰度,并对其差异性分布的控制因素进行了探讨。结果显示,研究区西部和西南部延长组TOC含量以烃源岩评价标准中的"好"和"很好"等级为主,而盆地中部、东部和南部地区以"一般"和"好"等级为主。华池、合水和瑶曲地区有机质富集层主要集中在长7段,达到"很好"烃源岩标准的连续厚度约30m,志丹地区有机质富集层集中在长9段,达到"很好"等级的连续烃源岩厚约20m,它们形成于延长组层序Ⅰ或层序Ⅱ的高位体系域中;而宜川地区不发育有机质富集层段。研究认为,沉积相的展布和演化是导致延长组有机质空间分布差异的主要控制因素,火山活动和沉积速率的变化加剧了有机质丰度的空间差异,而深部热流体活动和古气候条件等可能也是延长组有机质丰度差异分布的影响因素。
[Abstract]:In order to quickly find out the spatial distribution characteristics of organic matter abundance in Yanchang formation of Ordos Basin, five typical drilling wells from different areas in the southern part of the basin were selected, and a quick method for quantitative prediction of (TOC) content of organic carbon based on logging data was presented. The TOC abundance of source rocks in Chang 9 ~ Chang 45 member in different drilling regions is evaluated, and the controlling factors of its differential distribution are discussed. The results show that the TOC content of the Yanchang formation in the west and southwest of the study area is mainly "good" and "very good" grades in the evaluation criteria of source rocks, while in the central, eastern and southern regions of the basin, the "average" and "good" grades are the main ones. The enrichment layer of organic matter in Huachi, Heshui and Yao qu areas is mainly concentrated in Chang7 formation, and the continuous thickness of "very good" source rock is about 30 m, and the enrichment layer of organic matter in Zhidan area is concentrated in Chang9 formation. The continuous source rocks of "very good" grade are about 20m thick, and they are formed in the upper system tracts of Yanchang formation I or II. In Yichuan area, the enrichment layer of organic matter is not developed. It is considered that the distribution and evolution of sedimentary facies are the main controlling factors for the spatial distribution difference of organic matter in Yanchang formation, and the changes of volcanic activity and deposition rate aggravate the spatial difference of organic matter abundance. The deep thermal fluid activity and paleoclimate conditions may also affect the distribution of organic matter abundance in Yanchang formation.
【作者单位】：中国科学院油气资源研究重点实验室/甘肃省油气资源研究重点实验室;中国科学院大学;中国石油东方地球物理公司;中国地质大学;
【基金】：国家重点基础研究发展计划“973”项目(编号:2012CB214704-02) 国家自然科学基金课题(批准号:41172131) 甘肃省重点实验室专项(编号:1309RTSA041)资助成果
【分类号】：P618.13

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