西南石油大学学报(自然科学版) ›› 2019, Vol. 41 ›› Issue (6): 60-67.DOI: 10.11885/j.issn.1674-5086.2019.09.17.10

• 页岩气开发专刊 • 上一篇    下一篇

川西硬脆性页岩力学特征及井壁稳定性研究

刘厚彬1, 崔帅1, 孟英峰1, 吴双2, 吴坷3   

  1. 1. 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;
    2. 中国石油川渝页岩气前线指挥部, 四川 成都 610000;
    3. 中国石油西南油气田分公司勘探事业部, 四川 成都 610041
  • 收稿日期:2019-09-17 出版日期:2019-12-10 发布日期:2019-12-10
  • 通讯作者: 孟英峰,E-mail:mengyf523@sina.com
  • 作者简介:刘厚彬,1980年生,男,汉族,山东东平人,副教授,博士,主要从事岩石力学与井壁稳定、钻井提速等方面的研究工作。E-mail:liuhoubin523@sina.com;崔帅,1990年生,男,汉族,山东日照人,博士研究生,主要从事岩石力学与井壁稳定方面的研究。E-mail:1046785621@qq.com;孟英峰,1954年生,男,汉族,河北保定人,教授,博士生导师,主要从事储层保护与欠平衡钻井系列技术的教学与研究工作。E-mail:mengyf523@sina.com;吴双,1988年生,男,汉族,四川南充人,工程师,主要从事页岩气生产运行方面的管理工作。E-mail:wushuang123@petrochina.com.cn;吴坷,1988年生,男,汉族,四川成都人,工程师,主要从事钻井工程方面的管理工作。E-mail:wuke0829@petrochina.com.cn
  • 基金资助:
    国家自然科学基金(51134004)

Study on Mechanical Characteristics and Wellbore Stability of Hard Brittle Shale in Western Sichuan

LIU Houbin1, CUI Shuai1, MENG Yingfeng1, WU Shuang2, WU Ke3   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    2. Sichuan and Chongqing Shale Gas Front Headquarters, PetroChina, Chengdu, Sichuan 610000, China;
    3. Exploration Department, Southwest Oil and Gas Field Company, PetroChina, Chengdu, Sichuan 610041, China
  • Received:2019-09-17 Online:2019-12-10 Published:2019-12-10

摘要: 在硬脆性页岩地层钻井过程中井壁失稳现象频发,严重阻碍了现场钻井作业的进程。针对小塘子组页岩钻进过程中发生的井下垮塌现象,通过开展系统室内实验测试,并结合实验数据建立的理论模型,评价分析小塘子组页岩地层的井壁稳定情况。结果显示,小塘子组页岩属于典型的硬脆性页岩,层理缝发育,在外力或高应力环境下可以产生张性裂缝;钻井液浸泡效应可降低小塘子组页岩地层力学强度,层理走向及力学弱面效应对小塘子组页岩力学性能影响明显;裂缝走向、井眼轨迹及井壁渗流场影响小塘子组页岩地层井壁稳定性,当裂缝面与井眼轴线之间夹角满足一定关系,井壁岩石容易沿裂缝面发生滑移垮塌。

关键词: 硬脆性页岩, 裂缝, 层理, 井壁稳定, 弱面效应

Abstract: In the drilling process of hard brittle shale formation, the phenomenon of wellbore instability occurs frequently, which seriously hinders the process of field drilling. In view of the phenomenon of downhole collapse in the process of shale drilling in Xiaotangzi Formation, we carryied out systematic laboratory tests of the shale cores of Xiaotangzi Formation established the theoretical model with experimental data, and evaluated and analyzed the wellbore stability of Xiaotangzi Formation. The results showed that Xiaotangzi Formation is the typical hard brittle shale with developed bedding cracks, which can produce tensile fracture under external force or high stress. Drilling fluid immersion effect can reduce the mechanical strength of shale formation in Xiaotangzi Formation. The influence of bedding strike and weak plane effect on the mechanical properties of shale in Xiaotangzi Formation is obvious. Fracture strike, wellbore trajectory and wellbore seepage field affect wellbore stability of shale in Xiaotangzi Formation. When the angle between fracture surface and borehole axis satisfies a certain relationship, the borehole wall rock is prone to slip and collapse along the fracture surface.

Key words: hard brittle shale, fracture, bedding plane, wellbore stability, weak plane effect

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