四川盆地元坝气田低压地层井漏引发套管变形的瞬态动力学研究
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摘要
四川盆地元坝气田某新钻超深井完井过程中,因封隔三叠系石灰岩井段的厚壁套管段和镍基合金套管段出现长井段、大尺度变形的现象而被迫侧钻新井眼,因而有必要对超深井常规钻完井工艺的适应性进行重新认识。为此,依据该井井筒条件和现场施工数据,从动力学角度分析了低压地层井漏引发的井筒压力场变化,进而描绘了不同时间井筒内外压差的变化规律,从理论上揭示出发生该复杂情况的根本原因:低压地层瞬时漏失产生的压力波,将导致井下封闭空间内的压力重新分布,进而导致局部低压区附近的套管被压溃。据此对避免此类工程复杂提出了具体建议:①对裸眼完井、衬管完井或已射孔井采取井下封闭套管作业时,应考虑井漏对套管的潜在损害;②慎重选择井下封闭点与封闭方式,封闭点宜选择在固井质量较好的井段,或尽量选择靠近套管鞋的位置;③封闭方式除采用水泥塞外,也可以考虑使用机械桥塞封闭。结论指出,良好的固井质量对于预防该类套管变形有着重要的作用。
In the course of completion of an ultra-deep well newly drilled in the Yuanba Gasfield,Sichuan Basin,long-section and large-scale deformation occurred in the heavy casing section and nickel base alloy casing section of the sealing Triassic limestone interval,so a new hole had to be sidetracked,which impels us to rediscover the applicability of conventional drilling and completion technology in ultra-deep wells.In this paper,based on the borehole condition and field operation data of this well,the borehole pressure field variation initiated by lost circulation in the low-pressure formation was analyzed from the perspective of dynamics,then,the variation pattern of differential pressure inside and outside the well bore at different time intervals was depicted,and the primary cause of such complication was theoretically revealed,i.e.,the pressure wave generated by instant lost circulation in low-pressure formation would result in redistribution of pressure inside the downhole confined space,and then the crush of casing in the vicinity of local low-pressure areas.Pertinent proposals for avoiding this kind of engineering complexities were put forward:① when downhole sealing casing operation is conducted in open hole completion,liner completion or perforated hole,the potential damage of lost circulation to casing should be considered;②the downhole sealing point and sealing mode should be selected cautiously:the sealing point had better be selected in the section with good cementing quality or as close to the casing shoe as possible,and the sealing mode can be either cement plug or mechanical bridge plug.This paper finally points out that good cementing quality plays an important role in preventing this type of casing deformation.
In the course of completion of an ultra-deep well newly drilled in the Yuanba Gasfield,Sichuan Basin,long-section and large-scale deformation occurred in the heavy casing section and nickel base alloy casing section of the sealing Triassic limestone interval,so a new hole had to be sidetracked,which impels us to rediscover the applicability of conventional drilling and completion technology in ultra-deep wells.In this paper,based on the borehole condition and field operation data of this well,the borehole pressure field variation initiated by lost circulation in the low-pressure formation was analyzed from the perspective of dynamics,then,the variation pattern of differential pressure inside and outside the well bore at different time intervals was depicted,and the primary cause of such complication was theoretically revealed,i.e.,the pressure wave generated by instant lost circulation in low-pressure formation would result in redistribution of pressure inside the downhole confined space,and then the crush of casing in the vicinity of local low-pressure areas.Pertinent proposals for avoiding this kind of engineering complexities were put forward:① when downhole sealing casing operation is conducted in open hole completion,liner completion or perforated hole,the potential damage of lost circulation to casing should be considered;②the downhole sealing point and sealing mode should be selected cautiously:the sealing point had better be selected in the section with good cementing quality or as close to the casing shoe as possible,and the sealing mode can be either cement plug or mechanical bridge plug.This paper finally points out that good cementing quality plays an important role in preventing this type of casing deformation.
引文
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[3]薛彩军,邱清盈,武建伟.地应力和温度载荷耦合作用下注汽井射孔套管损坏的数值模拟[J].岩石力学与工程学报,2005,24(增刊2):5716-5720.Xue Caijun,Qiu Qingying,Wu Jianwei.Numerical simulation of a perforated casing damage in steam injection wells under geostress and temperature load[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(S2):5716-5720.
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[6]于桂杰.长效地应力机制下套管应力与抗挤强度理论研究[D].东营:中国石油大学,2009.Yu Guijie.Theoretical study of casing stress and strength under long-term In-situ stresses[D].Dongying-China University of Petroleum,2009.
[7]王陶,杨胜来,朱卫红,卞万江,刘敏,雷雨,等.塔里木油田油水井套损规律及对策[J].石油勘探与开发,201l,38(3):352-361.Wang Tao,Yang Shenglai,Zhu Weihong,Bian Wanjiang,Liu Min,Lei Yu,et al.Law and countermeasures for the casing damage of oil production wells and water injection wells in Tarim Oilfield[J].Petroleum Exploration and Development,2011,38(3):352-361.
[8]艾池.套管损坏机理及理论模型与模拟计算[D].大庆:大庆石油学院,2003.Ai Chi.Mechanism and theoretical model and simulation calculation of casing damage[D].Daqing:Daqing Petroleum Institute,2003.
[9]艾池,王臣.葡北油田套管损坏规律统计分析[J].大庆石油学院学报,2003,27(2):19-21.Ai Chi,Wang Chen.Statistical analysis of factors of casing failure in Pubei Oilfield[J].Journal of Daqing Petroleum Institute,2003,27(2):19-21.
[10]曾义金,杨春和,陈锋,丁秀丽.深井石油套管盐膏岩层蠕变挤压应力计算研究[J].岩石力学与工程学报,2002,21(4):595-598.Zeng Yijin,Yang Chunhe,Chen Feng,Ding Xiuli.Numerical analysis of creep pressing stress of casing in deep salt rock stratum[J].Chinese Journal of Rock Mechanics and Engineering,2002,21(4):595-598.
[11]张金成.盐岩地层套管蠕变荷载试验及其数值分析[J].中国石油大学学报:自然科学版,2009,33(1):115-119.Zhang Jincheng.Casing load creep test under gypsum formation and its numerical simulation analysis[J].Journal of China University of Petroleum:Edition of Natural Science,2009,33(1):11l5-119.
[12]宋胜利,王海涛,马海涛,宋明,蒋晓明.中原油田盐岩蠕变规律研究及套管损坏预防措施[J].石油学报,2005,26(2):119-121.Song Shengli,Wang Haitao,Ma Haitao,Song Ming,Jiang Xiaoming.Creeping regularity of salt bed and measures for avoiding casing damage in Zhongyuan Oilfield[J].Acta Petrolei Sinica,2005,26(2):119-121.
[13]张广清,陈勉,王群立.泥页岩地层水井套管载荷、临界注水时间确定[J].哈尔滨工业大学学报,2006,38(8):1273-1277.Zhang Guangqing,Chen Mian,Wang Qunli.Study on casing load in injections wells of shale formation and the critical injection time[J].Journal of Harbin Institute of Technology,2006,38(8):1273-1277.
[14]韩建增.套管抗挤强度研究[D].南充:西南石油学院,2001.Han Jianzeng.Research on casing collapse resistance[D].Nanchong:Southwest Petroleum Institute,2001.
[15]邓金根,田红,王治中,周建良.非均匀外载作用下油井套管强度特性的实验研究[J].岩土力学,2005,26(6):855-858.Deng Jingen,Tian Hong,Wang Zhizhong,Zhou Jianliang.Laboratory study of casing strength under nonuniform load[J].Rock and Soil Mechanics,2005,26(6):855-858.
[16]Wylie EB,Streeter VL.Fluid transients[M].New York:McGraw-Hill International Book Company,1978.
[17]Zhao Guanghui,Liang Zheng,Zhao Hongrui,Deng Xiong,Jiang Faguang.Failure analysis of high-drop pipeline in the process of dewatering[J].Engineering Failure Analysis,2013,33(4):139-150.
[2]闫相祯,刘复元,王同涛,杨秀娟,王建军.基于能量平衡方法的套管抗挤规律分析[J].中国石油大学学报:自然科学版,2011,35(1):106-109,114.Yan Xiangzhen,Liu Fuyuan,Wang Tongtao,Yang Xiujuan,Wang Jianjun.Analysis of casing collapse pressure based on energy balance method[J].Journal of China University of Petroleum:Edition of Natural Science,2011,35(1):106-109,114.
[3]薛彩军,邱清盈,武建伟.地应力和温度载荷耦合作用下注汽井射孔套管损坏的数值模拟[J].岩石力学与工程学报,2005,24(增刊2):5716-5720.Xue Caijun,Qiu Qingying,Wu Jianwei.Numerical simulation of a perforated casing damage in steam injection wells under geostress and temperature load[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(S2):5716-5720.
[4]杨恒林,陈勉,金衍,张广清.蠕变地层套管等效破坏载荷分析[J].中国石油大学学报:自然科学版,2006,30(4):94-97.Yang Henglin,Chen Mian,Jin Yan,Zhang Guangqing.Analysis of casing equivalent collapse resistance in creep formations[J].Journal of China University of Petroleum:Edition of Natural Science,2006,30(4):94-97.
[5]赵振峰,张广清,陈勉,陈雷.松软地层套管损坏机理分析[J].辽宁工程技术大学学报:自然科学版,2005,24(6):844-846.Zhao Zhenfeng,Zhang Guangqing,Chen Mian,Chen Lei.Casing damage mechanism analysis in soft formations[J].Journal of Liaoning Technical University:Natural Science Edition,2005,24(6):844-846.
[6]于桂杰.长效地应力机制下套管应力与抗挤强度理论研究[D].东营:中国石油大学,2009.Yu Guijie.Theoretical study of casing stress and strength under long-term In-situ stresses[D].Dongying-China University of Petroleum,2009.
[7]王陶,杨胜来,朱卫红,卞万江,刘敏,雷雨,等.塔里木油田油水井套损规律及对策[J].石油勘探与开发,201l,38(3):352-361.Wang Tao,Yang Shenglai,Zhu Weihong,Bian Wanjiang,Liu Min,Lei Yu,et al.Law and countermeasures for the casing damage of oil production wells and water injection wells in Tarim Oilfield[J].Petroleum Exploration and Development,2011,38(3):352-361.
[8]艾池.套管损坏机理及理论模型与模拟计算[D].大庆:大庆石油学院,2003.Ai Chi.Mechanism and theoretical model and simulation calculation of casing damage[D].Daqing:Daqing Petroleum Institute,2003.
[9]艾池,王臣.葡北油田套管损坏规律统计分析[J].大庆石油学院学报,2003,27(2):19-21.Ai Chi,Wang Chen.Statistical analysis of factors of casing failure in Pubei Oilfield[J].Journal of Daqing Petroleum Institute,2003,27(2):19-21.
[10]曾义金,杨春和,陈锋,丁秀丽.深井石油套管盐膏岩层蠕变挤压应力计算研究[J].岩石力学与工程学报,2002,21(4):595-598.Zeng Yijin,Yang Chunhe,Chen Feng,Ding Xiuli.Numerical analysis of creep pressing stress of casing in deep salt rock stratum[J].Chinese Journal of Rock Mechanics and Engineering,2002,21(4):595-598.
[11]张金成.盐岩地层套管蠕变荷载试验及其数值分析[J].中国石油大学学报:自然科学版,2009,33(1):115-119.Zhang Jincheng.Casing load creep test under gypsum formation and its numerical simulation analysis[J].Journal of China University of Petroleum:Edition of Natural Science,2009,33(1):11l5-119.
[12]宋胜利,王海涛,马海涛,宋明,蒋晓明.中原油田盐岩蠕变规律研究及套管损坏预防措施[J].石油学报,2005,26(2):119-121.Song Shengli,Wang Haitao,Ma Haitao,Song Ming,Jiang Xiaoming.Creeping regularity of salt bed and measures for avoiding casing damage in Zhongyuan Oilfield[J].Acta Petrolei Sinica,2005,26(2):119-121.
[13]张广清,陈勉,王群立.泥页岩地层水井套管载荷、临界注水时间确定[J].哈尔滨工业大学学报,2006,38(8):1273-1277.Zhang Guangqing,Chen Mian,Wang Qunli.Study on casing load in injections wells of shale formation and the critical injection time[J].Journal of Harbin Institute of Technology,2006,38(8):1273-1277.
[14]韩建增.套管抗挤强度研究[D].南充:西南石油学院,2001.Han Jianzeng.Research on casing collapse resistance[D].Nanchong:Southwest Petroleum Institute,2001.
[15]邓金根,田红,王治中,周建良.非均匀外载作用下油井套管强度特性的实验研究[J].岩土力学,2005,26(6):855-858.Deng Jingen,Tian Hong,Wang Zhizhong,Zhou Jianliang.Laboratory study of casing strength under nonuniform load[J].Rock and Soil Mechanics,2005,26(6):855-858.
[16]Wylie EB,Streeter VL.Fluid transients[M].New York:McGraw-Hill International Book Company,1978.
[17]Zhao Guanghui,Liang Zheng,Zhao Hongrui,Deng Xiong,Jiang Faguang.Failure analysis of high-drop pipeline in the process of dewatering[J].Engineering Failure Analysis,2013,33(4):139-150.