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  

Application of Predicted TOC to the Discussion of Spatial Distribution of Organic Matter Abundance of Yanchang Formation in Southern Ordos Basin and Its Controlling Factors

作　　者：贺聪[1,2] 吉利明[1] 苏奥[3,4] 张明震[1] 吴远东[1,2] HE Cong JI Liming SU Ao ZHANG Mingzhen WU Yuandong(Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences Key Laboratory of Petroleum Resources, Gansu Province, Lanzhou 730000 University of Chinese Academy of Sciences, Beijing 100049 Geophysical Research Institute, Bureau of Geophysical Prospecting, CNPC, Zhuozhou, 072750 China University of Geosciences , Wuhan , 430074)

机构地区：[1]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,兰州730000 [2]中国科学院大学,北京100049 [3]中国石油东方地球物理公司,河北涿州072750 [4]中国地质大学,武汉430074

出　　处：《地质学报》2017年第8期1836-1847,共12页Acta Geologica Sinica

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

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。In order to find out the distribution regularities of organic matter abundance of Yanchang Formation in Ordos Basin, five typical drilling wells of Huachi, Heshui, Zhidan, Yaoqu and Yichuan in the southern basin were chosen, the spatial distribution of TOC contents of Chang 9 to Chang 4＋5 sections of the wells and their controlling factors have been studied through the quantitative recovery method based on logging data. Results show that the TOC contents of well Li 94 and well Ning 36 mainly are “good” and “very good” in hydrocarbon source rock evaluation standard, while the TOC contents are “fair” and “good” in well Dan 48, well Wang 22 and well YK1. In the areas of well Li 94, well Ning 36 and well YK1, the organic matter enrichment layer is mainly concentrated in Chang 7 section, the continuous thickness of “very good” hydrocarbon source rock is up to 30 m. And in the area of well Dan 48, the organic matter enrichment layer is concentrated in Chang 9 section, the continuous thickness of “very good” hydrocarbon source rock is about 20 m, which deposited in the highstand systems tract of the stratigraphic sequence I or II in Yanchang Formation, whereas there is no significant organic matter enrichment section in well Wang 22. Studies suggest that the distribution and evolution of sedimentary facies was the main controlling factor of the different spatial distribution of organic matter abundance, volcanic activities and sedimentation rate aggravated the spatial difference of organic matter abundance, and the bottom thermal fluid activities and ancient climate conditions likely had a certain influence on the organic matter abundance differences of Yanchang Formation.

关 键 词：有机质丰度 烃源岩 测井定量模型应用 延长组 鄂尔多斯盆地 

分 类 号：P618.13[天文地球—矿床学]