油气藏评价与开发 ›› 2021, Vol. 11 ›› Issue (2): 223-229.doi: 10.13809/j.cnki.cn32-1825/te.2021.02.012

• 页岩气开发 • 上一篇    下一篇

威荣深层页岩气水平井压裂套变原因分析

乔智国(),叶翠莲   

  1. 中国石化西南油气分公司石油工程技术研究院,四川 德阳 618000
  • 收稿日期:2020-10-27 出版日期:2021-04-26 发布日期:2021-04-30
  • 作者简介:乔智国(1979 —),男,硕士,高级工程师,主要从事气井完井测试及井下作业的设计、科研工作。地址:四川省德阳市龙泉山北路298号,邮政编码:618000。E-mail: 120408391@qq.com
  • 基金资助:
    中国石化科技部项目“深层页岩气高效钻完井技术”(P18058-2)

Cause analysis of casing deformation in fracturing of horizontal wells in Weirong deep shale gas field

QIAO Zhiguo(),YE Cuilian   

  1. Research Institute of Engineering Technology, Sinopec Southwest China Oil and Gas Company, Deyang, Sichuan 618000, China
  • Received:2020-10-27 Online:2021-04-26 Published:2021-04-30

摘要:

针对四川盆地威荣页岩气开发过程中出现的套管变形问题,统计分析了套管变形特征,利用有限元分析方法对3种套变形态进行载荷和变形量分析,探讨了威荣页岩气套管变形类型;采用理论分析、有限元模拟、等效试验评价等方法,对钻完井工程涉及的井身全角变化率、固井质量、井筒温压变化、瞬时停泵等工程参数开展了量化分析,得到了不同工程因素对套管强度减弱的影响,表明工程因素不是套管变形的主要因素;通过开展改造过程中地层各向异性、井筒温度压力耦合、储层岩性界面影响等综合因素分析,认为工程条件下套管强度减弱,压裂改造过程中地层薄弱面滑移或储层对套管产生非均布挤压载荷导致套管应力集中而变形,其相关认识为制定威荣页岩气套变防控措施提供了借鉴。

关键词: 页岩气, 套管变形, 固井质量, 体积压裂, 剪切变形, 挤压变形

Abstract:

Casing deformation occurs frequently during the development of the Weirong Shale Gas Field in the Sichuan Basin. In order to solve this problem, analysis on load and deformation degree of three casing deformation has been carried out by finite element method to discuss the deformation type. Meanwhile, by means of theoretical analysis, finite element simulation and equivalent test evaluation, the quantitative analysis is carried out on the parameters such as the overall angle change rate, cementing quality, wellbore temperature-pressure change and instantaneous stop pump. The influence of different engineering factors on casing strength weakening shows that the engineering factors are not the main factors of casing deformation. According to the analysis of comprehensive factors in the transformation process such as formation anisotropy, wellbore temperature-pressure coupling and reservoir lithologic interface, it is considered that the casing strength decreases under engineering conditions, while in the process of fracturing, the slip of weak strata or the non-uniform compression load of reservoir on casing leads to casing stress concentration and deformation. The relevant understanding provides a reference for the formulation of casing deformation prevention and control measures of Weirong Shale Gas Field.

Key words: shale gas, casing deformation, cementing quality, volume fracturing, shear deformation, extrusion deformation

中图分类号: 

  • TE37