石油与天然气地质 ›› 2025, Vol. 46 ›› Issue (5): 1597-1613.doi: 10.11743/ogg20250513

• 油气地质 • 上一篇    下一篇

成岩流体系统演化阶段与深层超压致密储层成因——以准噶尔盆地腹部地区为例

李军1(), 袁成灼1, 尚晓庆1, 吴涛2, 吾尔妮萨罕·麦麦提敏3, 许晨航1, 徐泽阳1, 徐会永4()   

  1. 1.西安石油大学 地球科学与工程学院 陕西省油气成藏地质学重点实验室,陕西 西安 710065
    2.中国石油 新疆油田分公司 勘探开发研究院,新疆 克拉玛依 834000
    3.中国石油 新疆油田公司 准东采油厂,新疆 阜康 831511
    4.中国石油大学(华东)期刊社,山东 青岛 266580
  • 收稿日期:2025-07-28 修回日期:2025-08-15 出版日期:2025-10-30 发布日期:2025-10-30
  • 通讯作者: 徐会永 E-mail:lijun@xsyu.edu.cn;xhy7714@upc.edu.cn
  • 第一作者简介:李军(1982—),男,副教授,油气成藏地质学、非常规油气地质与勘探。E-mail: lijun@xsyu.edu.cn
  • 基金项目:
    新疆维吾尔自治区“天山英才”科技创新领军人才支持项目(2023TSYCLJ0001);西安石油大学青年科研创新团队项目(2019QNKYCXTD06)

Diagenetic fluid system evolution and genesis of deep overpressured tight reservoirs: A case study of the hinterland of the Junggar Basin

Jun LI1(), Chengzhuo YUAN1, Xiaoqing SHANG1, Tao WU2, Maimaitimin WUERNISAHAN3, Chenhang XU1, Zeyang XU1, Huiyong XU4()   

  1. 1.School of Earth Sciences and Engineering,Xi’an Shiyou University
    Shaanxi Key Lab of Petroleum Accumulation Geology,Shaanxi Xi’an 710065,China
    2.Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay 834000,China
    3.Xinjiang Oilfield Zhundong Oil Production Plant,PetroChina,Fukang,Xinjiang 831511,China
    4.Periodical Office,China University of Petroleum(East China),Qingdao 266580,China
  • Received:2025-07-28 Revised:2025-08-15 Online:2025-10-30 Published:2025-10-30
  • Contact: Huiyong XU E-mail:lijun@xsyu.edu.cn;xhy7714@upc.edu.cn

摘要:

深层超压致密油气是准噶尔盆地增储上产的重要资源类型之一。以盆地腹部地区为例,针对储层成因及主控因素不明等问题,基于储层分析化验、钻/测井及试油气资料,结合盆地模拟结果与地质综合解析,明确了储层机械压实与化学压实作用的特征及超压发育时序,探讨了半封闭-封闭成岩体系的形成机制,进而揭示了深层超压致密储层成因机制及其主控因素。研究结果表明:在埋深0 ~ 2 400 m阶段,储层以机械压实为主,压实作用导致的减孔率达70% ~ 90%,并形成半封闭-封闭成岩体系;在埋深2 400 m以深阶段,化学压实作用占主导,溶蚀产物迁移显著受阻,多以原地或就近沉淀胶结为主,若无其他建设性成岩作用参与,溶蚀作用增孔效应有限。不同成因超压对储层质量的改善效果存在差异,化学压实成因超压对原生孔隙的保护及次生孔隙形成的强化作用均较弱,而生烃及传导成因超压则可增强溶蚀作用,从而改善储层物性。总体而言,早期机械压实作用所决定的成岩体系开放程度,对晚期深埋阶段成岩演化路径、孔隙演化模式及优质储层(“甜点”)的形成具有重要控制作用。

关键词: 成岩流体系统, 压实作用, 成因机制, 超压, 致密储层, 准噶尔盆地

Abstract:

Deep overpressured tight hydrocarbons represent a significant resource type for additions to reserves from reserve growth in the Junggar Basin. This study aims to determine the origin and primary controlling factors of tight reservoirs in the hinterland of the basin. Based on data from laboratory tests of reservoirs, drilling and logging, and well tests, combined with basin simulation results and integrated geological interpretation, we characterize mechanical and chemical compaction processes in the reservoirs and determine the temporal evolution of overpressure development. By examining the formation mechanisms of the semi-closed to closed diagenetic fluid system, we further reveal the genetic mechanisms and primary controlling factors of deep overpressured tight reservoirs in the hinterland of the Junggar Basin. The results indicate that at burial depths ranging from 0 to 2 400 m, the reservoirs are predominantly subjected to mechanical compaction, which induces porosity reduction rates of up to 70% ~ 90% and the formation of a semi-closed to closed diagenetic fluid system. At burial depths of greater than 2 400 m, chemical compaction predominates, with dissolution products mostly precipitating in situ or nearby as cements since their migration is significantly hindered. This results in limited dissolution-induced porosity enhancement in the absence of other constructive diagenetic processes. Overpressure originating from different mechanisms enhances reservoir quality to varying degrees. Specifically, overpressure induced by chemical compaction plays a minor role in preserving primary pores and forming secondary pores. In contrast, overpressure formed by hydrocarbon generation and pressure transmission can intensify dissolution, thereby improving reservoir physical properties. Overall, the degree of openness of the diagenetic fluid system, determined by early-stage mechanical compaction, plays a significant role in controlling the diagenetic evolutionary pathway, the evolutionary pattern of pores, and the formation of high-quality reservoirs (sweet spots) during late-stage deep burial stage.

Key words: diagenetic fluid system, compaction, genetic mechanism, overpressure, tight sandstone reservoir, Junggar Basin

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