石油与天然气地质 ›› 2016, Vol. 37 ›› Issue (6): 874-881.doi: 10.11743/ogg20160609

• 油气地质 • 上一篇    下一篇

鄂尔多斯盆地华庆地区长7油层组致密油成藏条件与成藏模式

吴伟涛1,2, 邓静3, 赵靖舟1,2, 孙勃3, 郭汉卿4, 邓秀芹3, 耳闯1,2, 白玉彬1,2   

  1. 1. 西安石油大学 地球科学与工程学院, 陕西 西安 710065;
    2. 西安石油大学 陕西省油气成藏地质学重点实验室, 陕西 西安 710065;
    3. 中国石油 长庆油田公司 勘探开发研究院, 陕西 西安 710029;
    4. 中国石油 长庆油田公司 第一采油厂, 陕西 延安 716000
  • 收稿日期:2015-11-12 修回日期:2016-10-12 出版日期:2016-12-08 发布日期:2017-01-02
  • 第一作者简介:吴伟涛(1983-),男,博士、讲师,油气成藏与非常规油气地质。E-mail:wuweitaohao1013@163.com。
  • 基金项目:
    陕西省教育厅重点科研计划项目（2015JS094）；西安石油大学博士启动基金项目（134010179）。

Accumulation conditions and models of tight oil reservoirs in Chang-7 of Huaqing area,the Ordos Basin

Wu Weitao1,2, Deng Jing3, Zhao Jingzhou1,2, Sun Bo3, Guo Hanqin4, Deng Xiuqin3, Er Chuang1,2, Bai Yubin1,2   

  1. 1. School of Earth Sciences and Engineering, Xi'an Shiyou University, Xi'an, Shaanxi 710065, China;
    2. Key Laboratory of Hydrocarbon Accumulation of Shaanxi Province, Xi'an Shiyou University, Xi'an, Shaanxi 710065, China;
    3. Research Institute of Petroleum Exploration, PetroChina Changqing Oilfield Company, Xi'an, Shaanxi 710029, China;
    4. No. 1 Oil Plant, PetroChina Changqing Oilfield Company, Yan'an, Shaanxi 716000, China
  • Received:2015-11-12 Revised:2016-10-12 Online:2016-12-08 Published:2017-01-02

PDF (PC)

1006

被引次数

11

摘要： 利用钻井、测井、录井、试油资料、薄片观察以及分析化验等资料，研究鄂尔多斯盆地华庆地区长7油层组致密油的储层条件、烃源岩条件和运移聚集条件，建立致密油成藏模式。结果表明，长7油层组储层岩性主要为长石岩屑砂岩，平均孔隙度为7.4%，平均渗透率为0.134×10-3 μm2，储集空间以次生溶蚀孔隙为主，占到总面孔率的70.6%，孔隙半径分布范围多数小于1 μm，属于纳米级孔隙。长7油层组烃源岩以长73最好，有机碳含量平均为8.99%，明显高于长72和长71，后两者的有机碳含量分别为2.17%和1.12%，均属于好-最好烃源岩。长73烃源岩厚度分布在28～36 m，长71+2厚度为35～55 m，主要为I型干酪根，镜质体反射率介于1.02%～1.2%，处于生烃高峰期，生油强度可达到600×104 t/km2。运移通道为水平裂缝、斜交裂缝和砂体构成的三维网状输导体系，尤其是源储界面的斜交裂缝为初次排烃的重要通道。运移动力为生烃作用产生的超压，其分布范围在15～22 MPa。长7油层组致密油藏发育岩性尖灭油藏、透镜体油藏和成岩圈闭型油藏，数量多，横向连片、纵向叠置，呈现出准连续分布特征。长73烃源岩与长71和长72储层形成下生上储型成藏组合，长71和长72烃源岩与自身储层形成源内间互型成藏组合，构成“下生上储-源内间互双源供烃准连续型”成藏模式。

关键词: 长7油层组, 成藏条件, 成藏模式, 致密油, 鄂尔多斯盆地

Abstract: Based on drilling,mud logging,wireline logging,production test results,thin section observation and laboratory data,this paper focuses on a study on accumulation conditions,source rock qualities,migration-accumulation conditions of the Chang-7 tight oil reservoirs in Huaqing area,Erdos Basin.A tight oil pooling model is also established.The result shows that the reservoirs are mainly feldspar lithic sandstones with an average porosity of 7.4%,and an average permeability of 0.134×10-3 μm2.The reservoirs are also found to contain largely secondary dissolved nanopores (accounting for 70.6% of the total surface porosity) with radius mostly less than 1 μm.The best source rock of Chang-7 occurs in the third interval of Chang-7.It has an average TOC of 8.99%,obviously greater than that of its second (2.17%) and the first (1.12%) intervals.Its thickness ranges between 28 m and 36 m,while the total thickness of the first and the second intervals is between 35 m and 55 m.It has Ro values between 1.02% and 1.2%,clearly a type I kerogen and within the peak stage of hydrocarbon generation (the hydrocarbon generation capacity is up to 600×104 t/km2).The migration pathway in Chang-7 is a three dimensional network carrier system consisting of horizontal fractures,oblique crossing fractures and sandbodies.The oblique crossing fractures on the source-reservoir interface are considered to be the primary pathways for the initially expulsed hydrocarbons.The migration is driven by an overpressure in the range from 15 MPa to 22 MPa caused by hydrocarbon generation.The tight oil reservoirs in Chang-7 include lithologic thinning-out type,lenticular type and diagenetic trap type and they are large in number and are laterally connected and vertically superposed,thus being quasi-continuous reservoirs.The source rock in the third interval of Chang-7 and the reservoirs in its first and second intervals constitute a lower-generation and upper-storage assemblage,and the source rocks and reservoirs within the first and second intervals of the Chang-7 form inner-source alternating assemblages.The two types of assemblages constitute a quasi-continuous type of reservoir-forming model with two-source hydrocarbon supply.

Key words: Chang-7 oil-bearing layer, hydrocarbon accumulation condition, hydrocarbon accumulation model, tight oil, Ordos Basin

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