新疆石油地质 ›› 2025, Vol. 46 ›› Issue (6): 723-733.doi: 10.7657/XJPG20250608

• 油藏工程 • 上一篇    下一篇

吉木萨尔凹陷芦草沟组页岩油储层体积改造主控地质力学因素

刘向君1(), 甘仁忠2a, 熊健1, 汤诗棋2b, 万有维1, 周鑫1, 梁利喜1, 张淼1   

  1. 1.西南石油大学 油气藏地质及开发工程全国重点实验室,成都 610500
    2.中国石油 新疆油田分公司 a.勘探事业部;b.勘探开发研究院,新疆 克拉玛依 834000
  • 收稿日期:2025-11-18 修回日期:2025-11-19 出版日期:2025-12-01 发布日期:2025-12-05
  • 作者简介:刘向君(1969-),女,四川资中人,教授,博士,非常规油气地质工程一体化和油气工程测井,(Email)liuxj@swpu.edu.cn
  • 基金资助:
    中国石油科技创新基金(2023DQ02-0101)

Dominant Geomechanical Factors Controlling the Volumetric Stimulation Effectiveness in the Shale Oil Reservoirs of the Lucaogou Formation, Jimsar Sag

LIU Xiangjun1(), GAN Renzhong2a, XIONG Jian1, TANG Shiqi2b, WAN Youwei1, ZHOU Xin1, LIANG Lixi1, ZHANG Miao1   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
    2. PetroChina Xinjiang Oilfield Company, a.Exploration Department; b.Research Institute of Exploration and Development, Karamay, Xinjiang 834000, China
  • Received:2025-11-18 Revised:2025-11-19 Online:2025-12-01 Published:2025-12-05

摘要: 针对准噶尔盆地吉木萨尔凹陷芦草沟组页岩油储层体积改造效果存在难题开展系统研究。基于研究区岩性组合特征与地质力学参数,采用数值模拟方法,分析不同岩性组合下压裂缝扩展规律,重点研究储/隔层层间强度参数和地应力参数、层间界面强度系数、排量与水平井位置对裂缝扩展行为的控制作用,并探讨压裂段差异化优选方法。结果表明:储/隔层弹性模量增大与抗张强度降低均利于裂缝纵向扩展,而水平应力差大则明显抑制裂缝纵向扩展;层间界面强度系数存在临界阈值,直接控制裂缝扩展行为,其中临界条件下高排量促进裂缝穿透隔层,而低排量则导致裂缝沿界面转向;布井位置对裂缝扩展形态影响有限,水平井无论置于储层或隔层中均能实现有效纵向扩展;基于地质工程双甜点的非均匀分段方案可有效提升改造效率、减少无效作业。研究成果可为研究区页岩油水平井轨迹优化、压裂段优化与施工参数设计提供理论支撑与工程指导。

关键词: 准噶尔盆地, 吉木萨尔凹陷, 页岩油, 岩性组合, 裂缝扩展, 储/隔层地质力学特性

Abstract:

In response to the challenges in enhancing volumetric stimulation effectiveness in the shale oil reservoirs of the Lucaogou formation in the Jimsar sag of the Junggar Basin, a systematic study was conducted. Based on the lithological assemblage characteristics and geomechanical parameters of the study area, numerical simulation was employed to analyze the propagation patterns of hydraulic fractures under different lithological assemblages. The research focused on the controlling effects of interlayer strength, in-situ stress, interface strength coefficient, displacement, and horizontal well placement on fracture propagation, and explored a differentiated optimization method for fracturing stages. The results indicate that an increase in the elastic modulus of the reservoir/barrier layers and a decrease in tensile strength both facilitate vertical fracture propagation, whereas a high horizontal stress difference significantly inhibits vertical fracture extension. A critical threshold exists for the interlayer interface strength coefficient, which directly governs fracture propagation behavior. Under this critical condition, high displacement promotes fracture penetration through barriers, while low displacement lead to fracture diversion along interfaces. Well placement exhibits a limited impact on fracture geometry, as effective vertical propagation can be achieved regardless of whether the horizontal well is placed within the reservoir or barrier layers. A nonuniform staging scheme based on geological-engineering sweet spot evaluation effectively enhances stimulation efficiency and reduces ineffective operations. This research results provide theoretical support and practical guidance for optimizing horizontal well trajectory, fracturing stage design, and treatment parameters in the shale oil development of the study area.

Key words: Junggar Basin, Jimsar sag, shale oil, lithological assemblage, fracture propagation, reservoir/barrier geomechanical property

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