特种油气藏 ›› 2021, Vol. 28 ›› Issue (3): 139-143.DOI: 10.3969/j.issn.1006-6535.2021.03.021

• 钻采工程 • 上一篇    下一篇

页岩膨胀应变及固井质量对套管变形的影响研究

李皋1, 李泽1, 简旭2, 李红涛1, 于浩1, 王涛3   

  1. 1.西南石油大学油气藏地质及开发工程国家重点实验室,四川 成都 610500;
    2.中国石油川庆钻探工程有限公司,重庆 401147;
    3.西南石油大学,四川 成都 610500
  • 收稿日期:2020-08-13 修回日期:2021-03-25 出版日期:2021-06-25 发布日期:2022-02-16
  • 作者简介:李皋(1976—),男,研究员,博士生导师,1999年毕业于西南石油学院地质学专业,2005年毕业于西南石油大学油气井工程专业,获博士学位,现从事气体钻井、欠平衡钻井、控压钻井、储层保护技术与理论以及岩石力学研究工作。
  • 基金资助:
    国家自然科学基金“井下碳酸盐岩裂缝多物理场耦合变形与渗流机理研究”(51674217);国家自然科学基金青年基金“深井超深井井筒多相瞬态流动模型及压力演变规律研究”(51904264);中国博士后科学基金“超深层碳酸盐岩钻井复杂工况井筒多相瞬态流动规律研究”(2018M643792XB)

Study on the Effect of Shale Expansion Strain and Cementing Quality on Casing Deformation

Li Gao1, Li Ze1, Jian Xu2, Li Hongtao1, Yu Hao1, Wang Tao3   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploration, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    2. CNPC Chuanqing Drilling Engineering Co., Ltd., Chongqing 401147, China;
    3. Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2020-08-13 Revised:2021-03-25 Online:2021-06-25 Published:2022-02-16

摘要: 威荣地区页岩气井套管变形问题突出,但目前引发该区域套管变形的机理尚不明确。该文基于页岩理化性质,分析了页岩膨胀应变对套管应力的影响,研究了考虑页岩膨胀应变条件下的固井质量与套管变形的关系。研究表明:威荣地区页岩呈硬脆性,力学强度高,水化后强度变化不明显;页岩膨胀应变及固井质量的综合作用对套管应力有明显影响,当水泥环缺失及存在微环隙时,能为膨胀应力提供足够的释放空间,降低套管应力,当膨胀应力不能被充分释放时,需尽量保证井筒组合体结构的完整性。高密度射孔对膨胀应力的释放具有积极效果,在合理的射孔参数条件下开展高密度射孔作业是预防套管变形的有效措施之一。该研究为同类页岩气藏套管变形机理研究提供了参考。

关键词: 页岩气藏, 页岩膨胀, 套管变形, 固井质量, 应力释放, 高密度射孔

Abstract: The casing deformation in shale gas wells in Weirong area is a prominent problem, but the mechanism that causes casing deformation in this area is still unclear. In this paper, based on the physical and chemical properties of shale, the effect of shale expansion strain on casing stress was analyzed, and the relationship between cementing quality and casing deformation under the consideration of shale expansion strain was studied. It was found in the study that the shale in the Weirong area was hard and brittle, with high mechanical strength and insignificant strength changes after hydration and the combined action of shale expansion strain and cementing quality exerted a significant effect on the casing stress. When cement sheath was missing and micro-annulus existed, there was sufficient space for releasing expansion strain to reduce casing stress. When the expansion stress could not be released completely, it was necessary to ensure the structural integrity of wellbore assembly. High-density perforation had a positive effect on the release of expansion strain. High-density perforation based on reasonable perforation parameters was one of the effective measures to prevent casing deformation. This study provides a reference for the study of casing deformation mechanism in similar shale gas reservoir.

Key words: shale gas reservoir, shale expansion, casing deformation, cementing quality, stress release, high-density perforation

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