深水钻井浅水流地层井眼坍塌影响因素分析
|
摘要
为了定量评价和防治浅水流对深水钻井的危害,进行了浅水流地层井眼坍塌影响因素分析。基于流固耦合理论建立了浅水流地层井眼稳定理论模型,并分别根据Mohr-Coulomb准则和最大拉应力准则判断砂体的剪切和拉伸破坏,分析了各因素对井周最大破坏半径及砂体临界超压的影响。计算分析发现:超压将导致浅水流地层发生破坏,随着超压增大,其最大破坏半径随之快速增至大;水平有效地应力与垂直有效地应力的比值(K_0)越大,砂体埋深越大,浅水流地层越不容易发生破坏;砂体内摩擦角越大,砂体越稳定;井周最大破坏半径随着钻井液密度升高呈线性递减;浅水流地层存在临界超压,砂体埋深、强度和K_0越大,临界超压越大。研究结果表明,浅水流地层井眼坍塌的风险较大,井周破坏程度与超压、地应力、砂体埋深、钻井液密度和内摩擦角等因素有关,当砂体中的超压超过临界值时,整个砂体都将处于不稳定状态,而提高钻井液密度有利于浅水流地层的稳定。
In order to quantitatively evaluate and effectively prevent the damage of shallow water flow during deep water drilling, the contributing factors of wellbore collapse in shallow water flow formations during deep water drilling were analyzed. Based on the fluid-solid coupling theory, the theoretical model of wellbore stability in shallow water flow formation was established. Then they determined the shear and tensile damages of the sand body by the MohrCoulomb and maximum tensile stress criteria respectively, as well as analyzed the influence of each factor on maximum damage radius and sand body critical overpressure. The calculation and analysis found that the overpressure would lead to the damage of shallow water flow formation, the maximum damage radius increased rapidly with the increase of overpressure. The greater the ratio of effective horizontal geostress to effective vertical geostress(K_0), and the greater the burial depth of sand body, and the less likely the shallow water flow formation is to be damaged; the larger the internal friction angle in the sand body, the more stable the sand body. Likewise, the smaller the internal friction angle, the more significant impact will be. The maximum damage radius around wellbore linearly decreases with the increase of drilling fluid density. There is a relations between critical overpressure found in the shallow water flow. The larger the burial depth,strength and K_0 of sand body, the larger the critical overpressure. The results showed that the risk of wellbore collapse in shallow water flow formation was high. Further, the damage degree around wellbore was related to such factors as overpressure, geostress, sand body depth, drilling fluid density, internal friction angle, etc. When the critical overpressure is exceeded, the entire sand body will be in an unstable state, and the increase of drilling fluid density will be conducive to the wellbore stability in the shallow water flow formation.
In order to quantitatively evaluate and effectively prevent the damage of shallow water flow during deep water drilling, the contributing factors of wellbore collapse in shallow water flow formations during deep water drilling were analyzed. Based on the fluid-solid coupling theory, the theoretical model of wellbore stability in shallow water flow formation was established. Then they determined the shear and tensile damages of the sand body by the MohrCoulomb and maximum tensile stress criteria respectively, as well as analyzed the influence of each factor on maximum damage radius and sand body critical overpressure. The calculation and analysis found that the overpressure would lead to the damage of shallow water flow formation, the maximum damage radius increased rapidly with the increase of overpressure. The greater the ratio of effective horizontal geostress to effective vertical geostress(K_0), and the greater the burial depth of sand body, and the less likely the shallow water flow formation is to be damaged; the larger the internal friction angle in the sand body, the more stable the sand body. Likewise, the smaller the internal friction angle, the more significant impact will be. The maximum damage radius around wellbore linearly decreases with the increase of drilling fluid density. There is a relations between critical overpressure found in the shallow water flow. The larger the burial depth,strength and K_0 of sand body, the larger the critical overpressure. The results showed that the risk of wellbore collapse in shallow water flow formation was high. Further, the damage degree around wellbore was related to such factors as overpressure, geostress, sand body depth, drilling fluid density, internal friction angle, etc. When the critical overpressure is exceeded, the entire sand body will be in an unstable state, and the increase of drilling fluid density will be conducive to the wellbore stability in the shallow water flow formation.
引文
[1]孙宝江,张振楠.南海深水钻井完井主要挑战与对策[J].石油钻探技术,2015,43(4):1-7.SUN Baojiang,ZHANG Zhennan.Challenges and countermeasures for the drilling and completion of deepwater wells in the South China Sea[J].Petroleum Drilling Techniques,2015,43(4):1-7.
[2]CUNDIFF L W,DAUGHERTY B,MIX K.Case study:statistical risk to a drill center from shallow-water flow[J].Journal of Petroleum Technology,2005,57(3):64-67.
[3]BRUCE R,MCKEOWN J,SARGENT T,et al.Mitigating the shallow water flow risk at Mississippi canyon 849:a team approach[R].OTC 15249,2003.
[4]OSTERMEIER R M,PELLETIER J H,WINKER C D,et al.Dealing with shallow-water flow in the deepwater Gulf of Mexico[R].OTC 11972,2000.
[5]PUTANS V,MERKLIN L R,LEVCHENKO O V.Sediment waves and other forms as evidence of geohazards in Caspian Sea[J].International Journal of Offshore&Polar Engineering,2010,20(4):241-246.
[6]ALBERTY M W,HAFLE M E,MINGE J C,et al.Mechanisms of shallow water flows and drilling practices for intervention[J].SPEDrilling&Completion,1999,14(2):123-129.
[7]FULLER G A,BOLADO D L,HARDY F.A Gulf of Mexico case history:benefits of foamed cementing to combat a SWF[R].SPE128160,2010.
[8]叶志,樊洪海,张国斌,等.深水钻井地质灾害浅层水流问题研究[J].石油钻探技术,2010,38(6):48-52.YE Zhi,FAN Honghai,ZHANG Guobin,et al.Investigation of shallow water flow in deepwater drilling[J].Petroleum Drilling Techniques,2010,38(6):48-52.
[9]MALLICK S,DUTTA N C.Shallow water flow prediction using prestack waveform inversion of conventional 3D seismic data and rock modeling[J].The Leading Edge,2002,21(7):675-680.
[10]DENNEY D.Shallow-water-flow prediction from multicomponent seismic data[J].Journal of Petroleum Technology,2000,52(7):34-36.
[11]MUKERJI T,DUTTA N,PRASAD M,et al.Seismic detection and estimation of overpressure:partⅠ:the rock physics basis[J].CSEGRecorder,2002,27(7):34-57.
[12]ZIMMER M,PRASAD M,MAVKO G.Pressure and porosity influences on Vp-Vs ratio in unconsolidated sands[J].The Leading Edge,2002,21(2):178-183.
[13]吴时国,孙运宝,王秀娟,等.南海北部深水盆地浅水流的地球物理特性及识别[J].地球物理学报,2010,53(7):1681-1690.WU Shiguo,SUN Yunbao,WANG Xiujuan,et al.Geophysical signature and detection of shallow water flow in the deepwater basin of the Northern South China Sea[J].Chinese Journal of Geophysics,2010,53(7):1681-1690.
[14]任韶然,宫智武,张亮,等.南海北部陆坡浅水流评估及深水钴井防治措施[J].中国石油大学学报(自然科学版),2017,41(4):99-106.REN Shaoran,GONG Zhiwu,ZHANG Liang,et al.Shallow water flow hazard assessment in the northern slope of the South China Sea and control measures during deepwater drilling[J].Journal of China University of Petroleum(Edition of Natural Science),2017,41(4):99-106.
[15]李广信,周晓杰.土的渗透破坏及其工程问题[J].工程勘察,2004(5):10-13,52.LI Guangxin,ZHOU Xiaojie.Seepage failure of soil and related engineering problems[J].Geotechnical Investigation&Surveying,2004(5):10-13,52.
[16]SUN Jin,DENG Jingen,YU Baohua,et al.Model for fracture initiation and propagation pressure calculation in poorly consolidated sandstone during waterflooding[J].Journal of Natural Gas Science and Engineering,2015,22:279-291.
[17]BENMEBAREK N,BENMEBAREK S,KASTNER R.Numerical studies of seepage failure of sand within a cofferdam[J].Computers and Geotechnics,2005,32(4):264-273.
[18]孙运宝,赵铁虎,秦柯.南海北部白云凹陷沉积压实作用对浅水流超压演化影响数值模拟[J].地球科学进展,2014,29(9):1055-1064.SUN Yunbao,ZHAO Tiehu,QIN Ke.Numerical simulation of overpressure of shallow water flow in Baiyun Sag of the Northern South China Sea[J].Advances in Earth Science,2014,29(9):1055-1064.
[19]OSTERMEIER R M,PELLETIER J H,WINKER C D,et al.Trends in shallow sediment pore pressures:deepwater Gulf of Mexico[R].SPE 67772,2001.
[20]陈仲颐,周景星,王洪瑾.土力学[M].北京:清华大学出版社,1994:46-47.CHEN Zhongyi,ZHOU Jingxing,WANG Hongjin.Soil mechanics[M].Beijing:Tsinghua University Press,1994:46-47.
[2]CUNDIFF L W,DAUGHERTY B,MIX K.Case study:statistical risk to a drill center from shallow-water flow[J].Journal of Petroleum Technology,2005,57(3):64-67.
[3]BRUCE R,MCKEOWN J,SARGENT T,et al.Mitigating the shallow water flow risk at Mississippi canyon 849:a team approach[R].OTC 15249,2003.
[4]OSTERMEIER R M,PELLETIER J H,WINKER C D,et al.Dealing with shallow-water flow in the deepwater Gulf of Mexico[R].OTC 11972,2000.
[5]PUTANS V,MERKLIN L R,LEVCHENKO O V.Sediment waves and other forms as evidence of geohazards in Caspian Sea[J].International Journal of Offshore&Polar Engineering,2010,20(4):241-246.
[6]ALBERTY M W,HAFLE M E,MINGE J C,et al.Mechanisms of shallow water flows and drilling practices for intervention[J].SPEDrilling&Completion,1999,14(2):123-129.
[7]FULLER G A,BOLADO D L,HARDY F.A Gulf of Mexico case history:benefits of foamed cementing to combat a SWF[R].SPE128160,2010.
[8]叶志,樊洪海,张国斌,等.深水钻井地质灾害浅层水流问题研究[J].石油钻探技术,2010,38(6):48-52.YE Zhi,FAN Honghai,ZHANG Guobin,et al.Investigation of shallow water flow in deepwater drilling[J].Petroleum Drilling Techniques,2010,38(6):48-52.
[9]MALLICK S,DUTTA N C.Shallow water flow prediction using prestack waveform inversion of conventional 3D seismic data and rock modeling[J].The Leading Edge,2002,21(7):675-680.
[10]DENNEY D.Shallow-water-flow prediction from multicomponent seismic data[J].Journal of Petroleum Technology,2000,52(7):34-36.
[11]MUKERJI T,DUTTA N,PRASAD M,et al.Seismic detection and estimation of overpressure:partⅠ:the rock physics basis[J].CSEGRecorder,2002,27(7):34-57.
[12]ZIMMER M,PRASAD M,MAVKO G.Pressure and porosity influences on Vp-Vs ratio in unconsolidated sands[J].The Leading Edge,2002,21(2):178-183.
[13]吴时国,孙运宝,王秀娟,等.南海北部深水盆地浅水流的地球物理特性及识别[J].地球物理学报,2010,53(7):1681-1690.WU Shiguo,SUN Yunbao,WANG Xiujuan,et al.Geophysical signature and detection of shallow water flow in the deepwater basin of the Northern South China Sea[J].Chinese Journal of Geophysics,2010,53(7):1681-1690.
[14]任韶然,宫智武,张亮,等.南海北部陆坡浅水流评估及深水钴井防治措施[J].中国石油大学学报(自然科学版),2017,41(4):99-106.REN Shaoran,GONG Zhiwu,ZHANG Liang,et al.Shallow water flow hazard assessment in the northern slope of the South China Sea and control measures during deepwater drilling[J].Journal of China University of Petroleum(Edition of Natural Science),2017,41(4):99-106.
[15]李广信,周晓杰.土的渗透破坏及其工程问题[J].工程勘察,2004(5):10-13,52.LI Guangxin,ZHOU Xiaojie.Seepage failure of soil and related engineering problems[J].Geotechnical Investigation&Surveying,2004(5):10-13,52.
[16]SUN Jin,DENG Jingen,YU Baohua,et al.Model for fracture initiation and propagation pressure calculation in poorly consolidated sandstone during waterflooding[J].Journal of Natural Gas Science and Engineering,2015,22:279-291.
[17]BENMEBAREK N,BENMEBAREK S,KASTNER R.Numerical studies of seepage failure of sand within a cofferdam[J].Computers and Geotechnics,2005,32(4):264-273.
[18]孙运宝,赵铁虎,秦柯.南海北部白云凹陷沉积压实作用对浅水流超压演化影响数值模拟[J].地球科学进展,2014,29(9):1055-1064.SUN Yunbao,ZHAO Tiehu,QIN Ke.Numerical simulation of overpressure of shallow water flow in Baiyun Sag of the Northern South China Sea[J].Advances in Earth Science,2014,29(9):1055-1064.
[19]OSTERMEIER R M,PELLETIER J H,WINKER C D,et al.Trends in shallow sediment pore pressures:deepwater Gulf of Mexico[R].SPE 67772,2001.
[20]陈仲颐,周景星,王洪瑾.土力学[M].北京:清华大学出版社,1994:46-47.CHEN Zhongyi,ZHOU Jingxing,WANG Hongjin.Soil mechanics[M].Beijing:Tsinghua University Press,1994:46-47.