石油与天然气地质 ›› 2021, Vol. 42 ›› Issue (5): 1030-1042.doi: 10.11743/ogg20210502

• 油气地质 • 上一篇    下一篇

鄂尔多斯盆地热动力演化史及其对油气成藏与富集的控制作用

任战利1,2(), 祁凯1, 李进步3, 霍小菊4, 崔军平1, 杨鹏1, 王琨1, 陈占军2,5, 杨桂林1   

  1. 1. 西北大学 地质学系 大陆动力学国家重点实验室, 陕西 西安 710069
    2. 陕西省陆相页岩气成藏与开发重点实验室, 陕西 西安 710075
    3. 中国石油 长庆油田公司 勘探开发研究院, 陕西 西安 710018
    4. 中国石油 长庆油田公司 第二采油厂, 甘肃 庆阳 745100
    5. 陇东学院, 甘肃 西峰 745000
  • 收稿日期:2021-02-03 出版日期:2021-10-28 发布日期:2021-10-26
  • 第一作者简介:任战利(1961-), 男, 博士、研究员、博士生导师, 盆地热演化史与油气、地热资源评价及勘探开发。E-mail: renzhanl@nwu.edu.cn
  • 基金项目:
    国家自然科学基金重点项目(41630312);国家重点研发计划项目(2017YFC0603106);长庆油田分公司科技重大专项;陕西省陆相页岩气成藏与开发重点实验室开放课题项目

Thermodynamic evolution and hydrocarbon accumulation in the Ordos Basin

Zhanli Ren1,2(), Kai Qi1, Jinbu Li3, Xiaoju Huo4, Junping Cui1, Peng Yang1, Kun Wang1, Zhanjun Chen2,5, Guilin Yang1   

  1. 1. State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an, Shaanxi 710069, China
    2. Shaanxi Key Laboratory of Lacustrine Shale Gas Accumulation and Exploitation, Xi'an, Shaanxi 710075, China
    3. Institute of Petroleum Exploration and Development, Changqing Oilfield Company, PetroChina, Xi'an, Shaanxi 710018, China
    4. The second oil Production Plant of Changqing Oilfield Company, PetroChina, Qingyang, Gansu, 745100, China
    5. Longdong University, Xifeng, Gansu 745000, China
  • Received:2021-02-03 Online:2021-10-28 Published:2021-10-26

摘要:

鄂尔多斯盆地热演化史及热岩石圈厚度恢复表明,中生代晚期早白垩世存在构造热事件及深部热岩石圈减薄的动力学过程,盆地南部岩石圈厚度薄,热流值及地温梯度高。不同层位烃源岩在盆地南部热演化程度高,热异常明显。烃源岩热模拟实验以及盆地深部热动力演化史研究表明,早白垩世热事件及形成的热异常使烃源岩生烃量明显增加,是盆地油气富集的重要原因之一。不同层位烃源岩在早白垩世大规模生油、生气及成藏,主要受早白垩世岩石圈减薄的深部热动力学过程及构造热事件控制。古生界和中生界不同层位的油气田分布主要受烃源岩、热演化程度及储层控制。从烃源岩发育层系及热演化程度来看,盆地南部延长组7段致密油、页岩油热演化程度高,分布面积广,勘探潜力巨大;石炭系-二叠系煤系烃源岩全盆地大面积分布,天然气勘探前景广阔;深层下古生界奥陶系碳酸盐岩层系具有形成大气田的条件,需要进一步明确烃源岩生烃潜力;深层中-新元古界值得进一步勘探,关键是明确规模断陷分布及烃源岩的生烃规模。

关键词: 生烃量, 热异常, 构造热事件, 岩石圈厚度, 热动力, 成藏期, 油气富集, 鄂尔多斯盆地

Abstract:

The thermal history and thermal lithospheric thickness restoration for the Ordos Basin indicate that tectonic thermal events and dynamic processes of deep thermal lithosphere thinning in the Early Cretaceous result in thin lithosphere, high heat flow values and geothermal gradient at the southern part of the basin.Source rocks at different horizons there also show high maturity and obvious thermal anomalies.Thermal simulation for the source rocks and thermodynamic history of the basin indicate strong influence of the thermal events and thermal anomalies in the Early Cretaceous on the significantly increasing amount of hydrocarbon generation, which is also interpreted to be one of the important reasons behind the high oil and gas enrichment in the basin.The large-scale hydrocarbon generation and accumulation from these source rocks in the Early Cretaceous are mainly controlled by the deep thermodynamic process of lithosphere thinning and tectonic thermal events during the period.The distribution of oil and gas fields in different Paleozoic and Mesozoic layers is mainly controlled by the distribution of source rocks and their thermal maturity as well as reservoirs.From the perspective of source rock development and thermal maturity, tight oil and shale oil in the Chang 7 member (Yanchang Formation) of southern basin have high thermal maturity, and are widely distributed, making the member a quite promising exploration target.The Carboniferous-Permian with its basin-wide occurring coal-measure source rocks has high exploration potential for natural gas.The deep Lower Paleozoic Ordovician carbonate sequences have the conditions favorable for large gas fields to form but further study is needed to clarify the hydrocarbon generation potential of source rocks.The deep Proterozoic is also worthy of an exploratory gaze with the distribution of fault depressions and the hydrocarbon generation capacity of source rocks being recommended as the focuses.

Key words: hydrocarbon generation amount, thermal anomaly, tectonic thermal event, lithospheric thickness, thermodynamics, accumulation period, hydrocarbon enrichment, Ordos Basin

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