Acta Petrolei Sinica ›› 2024, Vol. 45 ›› Issue (2): 358-373.DOI: 10.7623/syxb202402003

• PETROLEUM EXPLORATION • Previous Articles     Next Articles

Classification and characteristics of source-reservoir interlayer and its controlling effect on oil-gas enrichment in continental tight reservoir

Zhang Chunyu1,2,3, Chen Shijia1,2, Zhu Xingcheng1,2, Li Yong1,2, Liu Guanglin4, Li Yaoting1,2, Zhang Yangyang1,2, Gu Tianfu1,2   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Engineering, Sichuan Chengdu 610500, China;
    2. School of Geoscience and Technology, Southwest Petroleum University, Sichuan Chengdu 610500, China;
    3. PetroChina Oil & Gas and New Energy Company, Beijing 100007, China;
    4. Research Institute of Exploration and Development, PetroChina Changqing Oilfield Company, Shaanxi Xi'an 710018, China
  • Received:2022-10-10 Revised:2023-04-04 Online:2024-02-25 Published:2024-03-07

源-储间隔夹层的分类、特征及其对陆相致密储层油气富集的控制作用

张春雨1,2,3, 陈世加1,2, 朱星丞1,2, 李勇1,2, 刘广林4, 李耀庭1,2, 张洋洋1,2, 顾天甫1,2   

  1. 1. 油气藏地质及开发工程国家重点实验室 四川成都 610500;
    2. 西南石油大学地球科学与技术学院 四川成都 610500;
    3. 中国石油天然气股份有限公司油气和新能源分公司 北京 100007;
    4. 中国石油长庆油田公司勘探开发研究院 陕西西安 710018
  • 通讯作者: 陈世加,男,1964年8月生,1998年获中国石油勘探开发研究院博士学位,现为西南石油大学地球科学与技术学院教授,主要从事油气地质和地球化学研究及教学工作。Email:chensj1964@swpu.edu.cn
  • 作者简介:张春雨,男,1984年3月生,2016年获西安石油大学硕士学位,现为中国石油油气和新能源公司高级工程师,主要从事天然气开发及管理工作。Email:zcy1_cq@petrochina.com.cn
  • 基金资助:
    国家自然科学基金项目(No.41872165,No.41572137,No.42002176)资助。

Abstract: At present, it is considered that the accumulation of tight oil is characterized by source-reservoir integration or large-scale near-source distribution. However, the exploration practice indicates that the sweet spots near high-quality source rocks in continental tight oil areas in China generally contain no oil or even produce a large amount of water. Therefore, it is necessary to re-recognize the sweet spots where tight oil is enriched. Based on systematically summarizing the classification scheme and geneses of the existing source-reservoir interlayer, as well as a large amount of core observations, the source-reservoir interlayer is divided into three types, i.e., argillaceous interlayer, tight sandstone with argillaceous laminae, and sand-shale transition section, of which the physical properties, distribution and logging response characteristics are described separately. The study suggests that the tight oil accumulation is mainly driven by the expansive force generated as a result of the hydrocarbon generation pressurization of source rock. When the charging resistance is greater than the expansive force, it is not conducive to oil-gas accumulation. Quantitative characterization shows that the thickness, transverse continuity and fracture development of source-reservoir interlayer jointly control the charging resistance and affect the barrier capacity of source-reservoir interlayer. Based on this, four pool-controlling modes for tight oil enrichment in the source-reservoir interlayer are established as follows. (1)When the thickness of the source-reservoir interlayer is smaller than the effective barrier thickness, the oil and gas will break through the barrier and continue to migrate. (2)When the extension radius of the source-reservoir interlayer is smaller than the radius of the affected area, the oil and gas can break through from the edge area and form a radial oil-gas accumulation zone. (3)When the thickness of the source-reservoir interval is greater than the effective barrier thickness and the extension radius is greater than the radius of the affected area, oil and gas migration can be effectively blocked, resulting in the phenomenon of "sand without oil" in local areas. (4)When cracks are developed in the source-reservoir interlayer, the barrier capacity will be reduced, making it easier for oil and gas to break through. In conclusion, these research results and understandings are expected to improve the theoretical basis of continental tight oil in China and provide theoretical guidance for the exploration and development of continental tight oil in China.

Key words: tight oil, heterogeneity, enrichment regularity, source-reservoir interlayer, sweet spot

摘要: 目前认为致密油具有源-储一体或近源大面积分布的成藏特征,但勘探实践表明,中国陆相致密油区普遍存在紧邻优质烃源岩的"甜点区"不含油甚至有大量出水的现象,因此需对其富集"甜点区"进行重新认识。基于对已有源-储间隔夹层的分类方案与成因进行系统梳理,在大量岩心观察资料的基础上,将源-储间隔夹层划分为泥质隔夹层、含泥质纹层致密砂岩和砂泥岩渐变段3类,并分别对其物性、展布以及测井响应特征进行了描述。研究认为,致密油成藏的主要动力为烃源岩生烃增压所产生的膨胀力,当充注阻力大于膨胀力时,不利于油气成藏。定量表征显示,源-储间隔夹层的厚度、横向连续性以及裂缝的发育情况共同控制着充注阻力的大小,影响着源-储间隔夹层阻隔能力的强弱。基于此,建立了源-储间隔夹层对致密油富集的4种控藏模式:①当源-储间夹层厚度小于有效阻隔厚度时,油气将突破隔挡继续运移;②当源-储间夹层延伸半径小于波及区域半径时,油气可从边缘地区突破,形成辐射状油气聚集带;③当源-储间隔层厚度大于有效阻隔厚度且延伸半径大于波及区域半径时,能够有效阻隔油气运移,导致局部出现"有砂无油"的现象;④当源-储间隔夹层发育裂缝时,将会削减其隔挡能力,使油气能够较容易地突破。研究成果与认识以期完善中国陆相致密油的理论基础,为中国陆相致密油的勘探开发提供理论指导。

关键词: 致密油, 非均质性, 富集规律, 源-储间隔夹层, 甜点区

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