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。
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.
[1] LIU Kui,TALEGHANI Arash Dahi,GAO Deli.Calculation of hydraulic fracture induced stress and corresponding fault slippage in shale formation[J].Fuel,2019, 254:115525.
[2] LIAN Zhanghua, YU Hao, LIN Tiejun, et al.A study on casing deformation failure during multi-stage hydraulic fracturing for the stimulated reservoir volume of horizontal shale wells[J].Journal of Natural Gas Science and Engineering,2015,23:538-546.
[3] 席岩,柳贡慧,李军,等.力-热耦合作用下套管应力瞬态变化研究[J].石油机械,2017,45(6): 8-12.
XI Yan,LIU Gonghui,LI Jun,et al.Study on casing transient stress under thermo-mechanical coupling effect[J].China Petroleum Machinery,2017,45(6):8-12.
[4] 窦益华,韦堃,罗敬兵,等.水泥环缺失对水平井套管强度安全性影响分析[J].石油机械, 2019, 47(9): 17-22.
DOU Yihua,WEI Kun,LUO Jingbing,et al.Analysis of the influence of cement sheath absence on casing strength safety in horizontal well[J].China Petroleum Machinery,2019,47(9):17-22.
[5] 麦洋,莫丽,傅栋,等.固井质量对页岩气井水平井段套管失效的影响[J].石油机械,2019, 47(12):123-130.
MAI Yang,MO Li,FU Dong,et al.Effect of cementing quality on casing failure in horizontal section of shale gas well[J].China Petroleum Machinery,2019,47(12):123-130.
[6] 陈占锋,朱卫平,狄勤丰,等.非均匀地应力下套管偏心对抗挤强度的影响[J].上海大学学报(自然科学版),2012, 18(1):83-86.
CHEN Zhanfeng,ZHU Weiping,DI Qinfeng,et al.Effects of eccentricity of casing on collapse resistance in non-uniform in-situ stresses[J].Journal of Shanghai University (Natural Science Edition),2012,18(1):83-86.
[7] 郭雪利,李军,柳贡慧,等.温-压作用下水泥环缺陷对套管应力的影响[J].石油机械,2018, 46(4):112-118.
GUO Xueli,LI Jun,LIU Gonghui,et al.Influence of cement sheath defect on casing stress under temperature-pressure effect[J].China Petroleum Machinery,2018,46(4):112-118.
[8] 席岩,李军,柳贡慧,等.瞬态力-热耦合作用下水泥环形态对套管应力的影响[J].断块油气田,2017,24(5):700-704.
XI Yan,LI Jun, LIU Gonghui,et al.Impact analysis of cement sheath shape on casing stress under transient mechanical-thermal coupling effect[J].Fault-Block Oil & Gas Field,2017,24(5):700-704.
[9] 曾义金.深层页岩气开发工程技术进展[J].石油科学通报,2019,4(3): 233-241.
ZENG Yijin.Progress in engineering technologies for the development of deep shale gas[J].Petroleum Science Bulletin,2019,4(3):233-241.
[10] 朱宝龙,李晓宁,巫锡勇,等.黑色页岩遇水膨胀微观特征试验研究[J].岩石力学与工程学报,2015,34(增刊2):3896-3905.
ZHU Baolong,LI Xiaoning,WU Xiyong,et al.Experimental study of micro-characteristics of swelling for black shale under influence of water[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(S2):3896-3905.
[11] XI Yan,LI Jun,LIU Gonghui,et al.Numerical investigation for different casing deformation reasons in Weiyuan-Changning shale gas field during multistage hydraulic fracturing[J].Journal of Petroleum Science and Engineering,2018,163:691-702.
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