石油学报 ›› 2024, Vol. 45 ›› Issue (12): 1728-1742.DOI: 10.7623/syxb202412003

• 地质勘探 • 上一篇    下一篇

准噶尔盆地腹部地区超压低饱和度油气成因机制与勘探意义

吴涛1, 李军2,3, 闫文琦1, 董桂彤1, 赵靖舟2,3, 曾德龙1, 尚晓庆2,3, 徐泽阳2,3, 吾尔妮萨罕·麦麦提敏2,3, 平赵勇2,3, 孔德诚2,3   

  1. 1. 中国石油新疆油田公司勘探开发研究院 新疆克拉玛依 834000;
    2. 西安石油大学地球科学与工程学院 陕西西安 710065;
    3. 陕西省油气成藏地质学重点实验室 陕西西安 710065
  • 收稿日期:2024-08-19 修回日期:2024-11-13 出版日期:2024-11-25 发布日期:2025-01-03
  • 通讯作者: 李军,男,1982年12月生,2012年获中国石油大学(北京)博士学位,现为西安石油大学地球科学与工程学院副教授,主要从事油气成藏地质学、非常规油气地质与勘探方面的教学与科研工作。Email:lijun@xsyu.edu.cn
  • 作者简介:吴涛,男,1981年6月生,2014年获中国科学院博士学位,现为中国石油新疆油田公司勘探开发研究院正高级工程师,主要从事石油地质综合研究与油气勘探评价工作。Email:wutao33@petrochina.com.cn
  • 基金资助:
    新疆维吾尔自治区"天山英才"科技创新领军人才支持项目"准噶尔盆地深层砾岩高产富集规律与勘探关键技术研究"(2023TSYCLJ0001)和西安石油大学青年科研创新团队项目"致密油气成藏理论及评价方法"(2019QNKYCXTD06)资助。

Genetic mechanism and exploration significance of overpressure and low-saturation oil and gas in the hinterland of Junggar Basin

Wu Tao1, Li Jun2,3, Yan Wenqi1, Dong Guitong1, Zhao Jingzhou2,3, Zeng Delong1, Shang Xiaoqing2,3, Xu Zeyang2,3, Wuernisahan Maimaitimin2,3, Ping Zhaoyong2,3, Kong Decheng2,3   

  1. 1. Research Institute of Exploration and Development, PetroChina Xinjiang Oilfield Company, Xinjiang Karamay 834000, China;
    2. School of Earth Sciences and Engineering, Xi'an Shiyou University, Shaanxi Xi'an 710065, China;
    3. Shaanxi Key Laboratory of Petroleum Accumulation Geology, Shaanxi Xi'an 710065, China
  • Received:2024-08-19 Revised:2024-11-13 Online:2024-11-25 Published:2025-01-03

摘要: 超压、低饱和度是准噶尔盆地腹部地区油气藏的典型特征之一,基于分析化验、钻井/测井及试产资料,结合盆地模拟结果和地质综合分析的认识,明确了腹部地区储层成岩、油气充注和超压发育之间的耦合关系,探讨了压力-应力耦合效应及其成藏作用,揭示了超压低饱和度油气藏的成因及主控因素。研究结果表明,油气充注期滞后于化学压实成因超压的形成期和储层致密期。四要素耦合作用导致了超压低饱和度油气藏的形成:化学压实成因超压降低了油气充注储层的有效空间及烃柱高度,其与致密储层共同作用提升了油气充注的启动压力,压力-应力耦合效应造成断层相关圈闭失效,晚期的掀斜抬升运动导致油气散失。准噶尔盆地腹部地区深层超压层系的油气勘探应避开强化学压实超压区,以岩性圈闭、背斜圈闭以及岩性-构造圈闭为主要目标,断层相关圈闭为次要目标;对于同一类型的圈闭及勘探目标,埋深相对较大者可优先部署钻探。研究认识在准噶尔盆地腹部地区近期的油气勘探中已得到证实,对未来该地区及地质条件类似地区的超压低饱和度油气勘探具有重要指导与借鉴意义。

关键词: 超压, 低饱和度, 成岩-成压-成藏耦合, 压力-应力耦合效应, 准噶尔盆地腹部地区

Abstract: Overpressure and low-saturation are typical characteristics of reservoirs in the hinterland of Junggar Basin. Based on analytical testing, drilling/logging, production test data, basin simulation results, as well as comprehensive geological analysis, this study clarifies the coupling relationship among reservoir diagenesis, hydrocarbon charging, and overpressure development, explores the pressure-stress coupling effect and its role in hydrocarbon accumulation, and reveals the genesis of overpressure and low-saturation oil and gas reservoirs and their main controlling factors. The results indicate that hydrocarbon charging stage lags behind the formation of overpressure caused by chemical compaction and reservoir densification. The formation of overpressure and low-saturation reservoirs is controlled by the coupling of four key factors. Specifically, overpressure caused by chemical compaction reduces the effective pore space in the reservoir available for hydrocarbon charging and decreases the height of hydrocarbon column. Then the overpressure, coupled with tight reservoir, increases the threshold pressure required for hydrocarbon migration and charging. The coupling effect of overpressure and stress leads to the failure of fault-related traps, while late-stage tilting and uplifting movements result in hydrocarbon loss. The hydrocarbon exploration in deep overpressure reservoirs in the hinterland of Junggar Basin should avoid the areas with intense chemical compaction-induced overpressure. The study primarily targets at lithological traps, anticlinal traps, and lithological-tectonic traps, followed by fault-related traps. For the same type of traps and exploration targets, those with relatively greater depth should be prioritized for drilling. This understanding has been confirmed in recent oil and gas exploration in the hinterland of Junggar Basin and provides significant guidance for the exploration of overpressure and low-saturation oil and gas in this area and regions with similar geological conditions.

Key words: overpressure, low-saturation, diagenesis-pressure-accumulation coupling, pressure-stress coupling effect, hinterland of Junggar Basin

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