西南石油大学学报(自然科学版) ›› 2019, Vol. 41 ›› Issue (5): 134-141.DOI: 10.11885/j.issn.1674-5086.2019.03.27.05

• 石油与天然气工程 • 上一篇    下一篇

页岩自支撑裂缝导流能力预测方法研究

曹海涛1,2,3, 关小旭4, 李晓平5, 赵勇3, 余小群3   

  1. 1. 中国石化西南油气分公司博士后科研工作站, 四川 成都 610041;
    2. 西南石油大学博士后科研流动站, 四川 成都 610500;
    3. 中国石化西南油气分公司勘探开发研究院, 四川 成都 610041;
    4. 西南石油大学国家大学科技园, 四川 成都 610500;
    5. “油气藏地质及开发工程”国家重点实验室·西南石油大学, 四川 成都 610500
  • 收稿日期:2019-03-27 出版日期:2019-10-10 发布日期:2019-10-10
  • 通讯作者: 赵勇,E-mail:zhaoyong.xnyq@sinopec.com
  • 作者简介:曹海涛,1987年生,男,汉族,山西晋中人,博士,主要从事页岩气开发方面的研究工作。E-mail:cht198702@126.com;关小旭,1980年生,男,满族,吉林东丰人,博士研究生,主要从事页岩气开发、油气增产改造方面的研究。E-mail:guanxiaoxu@tom.com;李晓平,1963年生,男,汉族,四川西充人,教授,博士生导师,主要从事油气渗流力学及油气田开发工程的研究工作。E-mail:lixiaoping@swpu.edu.cn;赵勇,1981年生,男,汉族,四川南充人,高级工程师,主要从事页岩气开发方面的研究工作。E-mail:zhaoyong.xnyq@sinopec.com;余小群,1966年生,女,汉族,广东茂名人,高级工程师,主要从事页岩气开发方面的研究。E-mail:yuxiaoqun.xnyq@sinopec.com
  • 基金资助:
    国家科技重大专项(2017ZX05036003-006);中国石化科技攻关项目(P18058-1)

Method to Predict the Self-supporting Fracture Conductivity of Shale

CAO Haitao1,2,3, GUAN Xiaoxu4, LI Xiaoping5, ZHAO Yong3, YU Xiaoqun3   

  1. 1. Postdoctoral Research Station, Southwest Oil and Gas Branch, SINOPEC, Chengdu, Sichuan 610041, China;
    2. Postdoctoral Research Station, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    3. Exploration and Production Research Institute, Southwest Oil & Gas Company, SINOPEC, Chengdu, Sichuan 610041, China;
    4. National Science Park, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    5. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2019-03-27 Online:2019-10-10 Published:2019-10-10

摘要: 页岩气井的产能主要取决于支撑剂充填层裂缝和储层剪切滑移形成的自支撑裂缝提供的导流能力,目前对页岩自支撑裂缝导流能力变化规律和影响机理的认识仍不够充分,采用分形理论方法,引入裂缝开度分形维数和迂曲度分形维数对裂缝空间进行定量表征,建立了考虑闭合应力作用的自支撑裂缝导流能力数学模型。开展自支撑裂缝导流能力实验,结果显示初期裂缝导流能力可达30~50 D·cm,在40 MPa的闭合压力下仍可保持在1 D·cm以上;理论模型预测的结果与实验测试结果基本吻合;模型敏感性分析表明,裂缝开度分形维数与导流能力呈正相关关系;迂曲度分形维数与导流能力呈负相关关系。利用此方法可实现自支撑裂缝导流能力的快速、准确预测,为合理预测气井产能提供支撑。

关键词: 分形, 导流能力, 闭合应力, 页岩气, 自支撑裂缝

Abstract: The production capacity of shale gas wells primarily depends on the conductivity of the proppant filling layer fracture and the self-supporting fracture formed by the shear slip of the reservoir. Currently, our understanding of the variation law and mechanism that influences the self-supporting fracture conductivity of shale is insufficient. The fractal theory method was used to introduce the fractal dimensions of fracture aperture and tortuosity to characterize the fracture space quantitatively, and a mathematical model of self-supporting fracture conductivity was established that considers the effect of closure stress. An experiment of self-supporting fracture conductivity was conducted. The results show that the initial fracture conductivity reached 30~50 D·cm and could be maintained above 1 D·cm under a closure pressure of 40 MPa. The theoretical model prediction results agree well with the experimental test results. The sensitivity analysis shows that the fractal dimension of fracture aperture is positively correlated with the conductivity, while the fractal dimension of tortuosity is negatively correlated with the conductivity. The proposed method can quickly and accurately predict the self-supporting fracture conductivity of shale and provide support for rational prediction of gas well productivity.

Key words: fractal, conductivity, closure stress, shale gas, self-supporting fracture

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