摘要：The marine crude oil in Tarim Basin is considered to be mainly originated from two sets of source rocks, i.e., Cambrian-Lower Ordovician and Middle-Upper Ordovician, but which is a dominant contributor has been in dispute for a long term. Based on previous research works, through a comprehensive study based on the comparison of biomarkers, fraction carbon isotopes, n-alkane carbon isotopes and the mass balance simulation of carbon isotope, the marine crude oil in Tabei area is confirmed to be mainly contributed by the Middle-Upper Ordovician source rocks (up to 88%), and different regions make different contributions. However, confirmed by current drillings, the high-abundance Middle-Upper Ordovician source rocks show limited distribution, based on which it is difficult to explain the scale of hydrocarbon resource from the giant marine oil field widely distributed in Tabei area. Based on the geological and geochemical evidences including the kerogen elements changing with burial depth, the variation of hydrocarbon generation potential and the paleo-TOC recovery, it is validated that a large scale of hydrocarbon generation and expulsion have occurred in the deep present-day low-TOC source rocks of the platform area, Tarim Basin. In addition, the effective present-day low-TOC source rocks are comprehensively identified according to the hydrocarbon expulsion threshold, source rock geochemistry and logging features. On this basis, the hydrocarbon-generation potential method is adopted to evaluate the hydrocarbon expulsion quantity in the Middle-Upper Ordovician high-abundance and effective low-abundance source rocks of various accumulation systems in the platform area, Tarim Basin. The hydrocarbon expulsion quantity of Middle-Upper Ordovician low-abundance source rocks in the platform area is 494.4×10⁸t, and that from the high-abundance source rocks is 1 353×10⁸t. The relative contribution ratios of high-abundance and low-abundance source rocks are 73.2% and 26.8% respectively. Among them, the hydrocarbon expulsion quantity of Middle-Upper Ordovician source rocks in Lunnan-Yingmaili accumulation system, Tabei uplift is 327.7×10⁸t, and the relative contribution ratios of high-abundance and low-abundance source rocks are 59.8% and 40.2% respectively, indicating that the low-TOC source rocks make an important contribution to the formation of giant marine oilfield discovered in Tarim Basin.
© 2018, Editorial Office of ACTA PETROLEI SINICA. All right reserved.

ISSN号：0253-2697

卷、期、页：v 39,n 1,p23-41 and 91

发表日期：2018-01-01

期刊分区（SCI为中科院分区）：无

收录情况：EI（工程索引）

发表期刊名称：Shiyou Xuebao/Acta Petrolei Sinica

通讯作者：赵正福

第一作者：庞雄奇,陈君青,李素梅,庞宏,陈践发

论文类型：期刊论文

论文概要：庞雄奇,陈君青,李素梅,庞宏,陈践发,赵正福，Crude oil sources of giant marine oilfield in Tarim Basin: evidences and relative contribution evaluation of deep present-day low-TOC source rocks，Shiyou Xuebao/Acta Petrolei Sinica，2018，v 39,n 1,p23-41 and 91

论文题目：Crude oil sources of giant marine oilfield in Tarim Basin: evidences and relative contribution evaluation of deep present-day low-TOC source rocks