塔里木盆地和田河气田奥陶系裂缝应力敏感性研究
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摘要
为研究碳酸盐岩储层应力敏感性及其对气藏产能和气井见水的影响,选取塔里木盆地和田河气田奥陶系钻井岩心,开展了应力敏感性研究,结合实验结果及数学推导建立了裂缝开度和有效应力之间的力学关系模型,最终借助有限元方法,对持续开发过程中碳酸盐岩储层裂缝开度的空间变化规律进行了模拟分析。结果表明:裂缝开度的变化随围压或有效应力变化呈非线性关系;随着围压或有效应力的升高,裂缝开度不断减小,0～0.8 MPa之间减小速度快,岩样应力敏感性强,到2.6 MPa或5.4 MPa后变化趋于稳定,说明高应力环境下,岩样的应力敏感性减弱,塑性变形特征明显;随着围压的逐渐降低,裂缝开度不断增大,但不能恢复至初始情况;未来若干年内随着快速开采,和田河气田有效应力增大,裂缝闭合,产能下降;随着生产井关闭或开采速度放缓,气水界面之上有效应力仍然降低,裂缝闭合,界面之下有效应力增大,裂缝开启,底水上升,破坏气藏生产。建议在裂缝性碳酸盐岩气藏开发政策的制定过程中,一方面要开展裂缝分布精细研究,分析裂缝应力敏感性主控因素,同时要制定合理的开发方式和开采速度,确保气藏稳产、高产。
To investigate the stress sensitivity of carbonate reservoir as well as its effect on oil and water productivities, seven rock samples from the Upper Ordovician Lianglitage Formation of the southwestern Tarim Basin were selected for sensitive experiment.Based on the experimental results and mathematical derivation, the relationship between stress-strain and fracture aperture of rock was established. Spatial distribution of fracture aperture under various confining pressure and pore pressure was simulated through finite element method. Results show that effective stress and fracture aperture change rate have a good inverse nonlinear proportional relationship. Along with the increase of confining pressure, the fracture aperture decreases continuously, with a fast decreasing rate at the initial stage(0-0.8 MPa). This indicates that the stress sensitivity of rocks is strong. To a high pressure(2.6 MPa or 5.4 MPa), the aperture changes only a little, implying that the stress sensitivity is weakened under high stress and the plastic deformation is obvious.With the decrease of confining pressure, the fracture aperture tends to be opened till to a zero pressure, but the aperture cannot be restored to the initial state. This is indicative of certain plastic deformation. In the next few years, with continuous and rapid exploitation in the Hetianhe Gas Field, the effective stress will increase, the fractures will tend to be closed and the productivity will decline.However, along with discontinuous mining or manual well shutdown, the effective stress above the gas-water interface will still decrease and the fractures tend to be closed. In contrast, the effective stress below the interface will increase, fractures tend to be opened and bottom water rises to destroy the gas reservoir production. As such, we suggest that a fine study on the fracture distribution and the main controls for fracture stress sensitivity must be carried out when shaping development plan for fractured carbonate gas reservoir.Meanwhile, reasonable development model and producing rate should be developed and taken.
To investigate the stress sensitivity of carbonate reservoir as well as its effect on oil and water productivities, seven rock samples from the Upper Ordovician Lianglitage Formation of the southwestern Tarim Basin were selected for sensitive experiment.Based on the experimental results and mathematical derivation, the relationship between stress-strain and fracture aperture of rock was established. Spatial distribution of fracture aperture under various confining pressure and pore pressure was simulated through finite element method. Results show that effective stress and fracture aperture change rate have a good inverse nonlinear proportional relationship. Along with the increase of confining pressure, the fracture aperture decreases continuously, with a fast decreasing rate at the initial stage(0-0.8 MPa). This indicates that the stress sensitivity of rocks is strong. To a high pressure(2.6 MPa or 5.4 MPa), the aperture changes only a little, implying that the stress sensitivity is weakened under high stress and the plastic deformation is obvious.With the decrease of confining pressure, the fracture aperture tends to be opened till to a zero pressure, but the aperture cannot be restored to the initial state. This is indicative of certain plastic deformation. In the next few years, with continuous and rapid exploitation in the Hetianhe Gas Field, the effective stress will increase, the fractures will tend to be closed and the productivity will decline.However, along with discontinuous mining or manual well shutdown, the effective stress above the gas-water interface will still decrease and the fractures tend to be closed. In contrast, the effective stress below the interface will increase, fractures tend to be opened and bottom water rises to destroy the gas reservoir production. As such, we suggest that a fine study on the fracture distribution and the main controls for fracture stress sensitivity must be carried out when shaping development plan for fractured carbonate gas reservoir.Meanwhile, reasonable development model and producing rate should be developed and taken.
引文
卞德智,赵伦,陈烨菲,等.2011.异常高压碳酸盐岩储集层裂缝特征及形成机制:以哈萨克斯坦肯基亚克油田为例[J].石油勘探与开发,38(4):394-399.
戴俊生,冯建伟,李明.2011.砂泥岩间互地层裂缝延伸规律探讨[J].地学前缘,18(2):277-283.
邓玉珍.2010.低渗透储层应力敏刚性评价影响因素分析[J].油气地质与采收率,17(4):80-83.
冯建伟,戴俊生,马占荣,等.2011.低渗透砂岩裂缝参数与应力场关系理论模型[J].石油学报,32(4):664-671.
丁文龙,王兴华,胡秋嘉,等.2015.致密砂岩储层裂缝研究进展[J].地球科学进展,30(7):737-750.
傅春梅,唐海,吕栋梁,等.2009.不同含水饱和度下应力敏感性对致密低渗气井产能影响分析[J].天然气勘探与开发,32(1):32-34.
鞠玮,侯贵廷,黄少英,等.2014.断层相关褶皱对砂岩构造裂缝发育的控制约束[J].高校地质学报,20(1):105-113.
郭平,张俊,杜建芬,等.2007.采用两种实验方法进行气藏岩心应力敏感研究[J].西南石油大学学报,121(2):7-9.
李孟涛,姚尚林,单文文,等.2006.低渗透气藏应力敏感性实验研究[J].大庆石油地质与开发,25(6):69-72.
刘宏,谭秀成,李凌,等.2011.孔隙型碳酸盐岩储集层特征及主控因素:以川西南嘉陵江组嘉5段为例[J].石油勘探与开发,38(3):275-281.
刘晓旭,胡勇,朱斌,等.2006.储层应力敏感性影响因素研究[J].特种油气藏,13(3):18-21.
游利军,康毅力,陈一健,等.2004.含水饱和度和有效应力对致密砂岩有效渗透率的影响[J].天然气工业,24(12):105-107.
康毅力,张浩,陈一健,等.2006.鄂尔多斯盆地大牛地气田致密砂岩气层应力敏感性综合研究[J].天然气地球科学,17(3):335-344.
秦积舜.2002.变围压条件下低渗砂岩储层渗透率变化规律研究[J].西安石油学院学报,17(4):28-35.
邬光辉,朱海燕,张立平,等.2011.和田河气田奥陶系碳酸盐岩气藏类型再认识及其意义[J].天然气工业,31(7):5-10.
新丽.2015.含微裂缝低渗储层应力敏感性及其对产能影响[J].特种油气藏,22(1):127-130.
曾联波,漆家福,王成刚,等.2008.构造应力对裂缝形成与流体流动的影响[J].地学前缘,15(3):292-298.
赵文智,沈安江,胡素云,等.2012.中国碳酸盐岩储集层大型化发育的地质条件与分布特征[J].石油勘探与开发,39(1):1-12.
赵伦,陈烨菲,宁正福,等.2013.异常高压碳酸盐岩油藏应力敏感实验评价--以滨里海盆地肯基亚克裂缝-孔隙型低渗透碳酸盐岩油藏为例[J].石油勘探与开发,40(2):194-199.
钟高润,张小莉,杜江民,等.2016.致密砂岩储层应力敏感性实验研究[J].地球物理学进展,31(3):1300-1306.
朱维耀,马东旭,朱华银,等.2016.页岩储层应力敏感性及其对产能影响[J].天然气地球科学,27(5):892-896.
张鹏,侯贵廷,潘文庆,等.2013.塔里木盆地北缘碳酸盐岩野外构造裂缝发育规律研究[J].高校地质学报,19(4):580-587.
Dou H G,Zhang H J,Yao S L,et al.2016.Measurement and evaluation of the stress sensitivity in tight reservoirs[J].Petrol.Explor.Develop.,43(6):1116-1123.
Durham W B and Bonner B P.1994.Self-propping and fluid flow in slightly offset joints at high effective pressures[J].Journal of Geophysical Research,99(B5):9391-9399.
Fatt I and Davis D H.1952.Reduction in permeability with overburden pressure[J].Trans AIME,195:329-334.
Gai S H,Liu H Q and He S L.2015.An improved particles model for stress sensitivity in low-permeability sandstones[J].Geosystem Engineering,19(2):89-95,DOI:10.1080/12269328.2015.1110059.
Guo X,Zou G F,Wang Y H,et al.2017.Investigation of the temperature effect on rock permeability sensitivity[J].Journal of Petroleum Science and Engineering,156:616-622.
Hicks T W,Pine R J,Willis Richards J,et al.1996.A hydro-thermomechanical numerical model for HDR geothermal reservoir evaluation[J].Int.J.Rock Mech.Min.Sci.and Geomech.Abstr.,33(5):499-511.
Javadpour F,Fisher D and Unsworth M.2007.Nanoscale gas flow in shale gassediment[J].JournalofCandianPetroleumTechnology,46(10):53-61.
Jing Z,Wills-Richards J,Watanabe K and Hashida T.1998.A new 3-Dstochastic model for HDR geothermal reservoir in fractured crystalline rock[A]//Fourth International HDR Forum,Strasbourg,France,September,28-30.
Laubach S E,Fall A,Copley L K,et al.2016,Fracture porosity creation and persistence in a basement-involved Laramide fold,Upper Cretaceous Frontier Formation,Green River Basin,U.S.A.[J].Geological Magazine,153(5/6):887-910.
Shovkun I and Espinoza D N.2017.Coupled fluid flow-geomechanics simulation in stress-sensitive coal and shale reservoirs:Impact of desorption-induced stresses,shear failure,and fines migration[J].Fuel,260-272.
Wang R,Yue X A,Zhao R B,et al.2009.Effect of stress sensitivity on displacement efficiency in CO2flooding for fractured low permeability reservoirs[J].Pet.Sci.,6:277-283
Warpinski N R and Teufel I W.1992.Determination o1 the effective stress law for permeability and determination in low-permeability rock[J].SPEFormation Evaluation,7(2):123-131.
Wills-Richards J,Watanabe K and Takahashi H.1996.Progress toward a stochastic rock mechanics model of engineered geothermal systems[J].JGeophys Res.,101(B8):17,481-17,496.
Xiao W L,Li T,Li M,et al.2016.Evaluation of the stress sensitivity in tight reservoirs[J].Petrol.Explor.Develop.,43(1):115-123.
Yin S,Lv D W,Ding W L,et al.2018.New Method for Assessing Microfracture Stress Sensitivity in Tight Sandstone Reservoirs Based on Acoustic Experiments[J].Int.J.Geomech.,18(4):04018008,DOI:10.1061/(ASCE)GM.1943-5622.0001100.
Zhang L Q,Zhou J,Brauna A,et al.2018.Sensitivity analysis on the interaction between hydraulic and natural fractures based on an explicitly coupled hydro-geomechanical model in PFC2D[J].Journal of Petroleum Science and Engineering,167:638-653.
戴俊生,冯建伟,李明.2011.砂泥岩间互地层裂缝延伸规律探讨[J].地学前缘,18(2):277-283.
邓玉珍.2010.低渗透储层应力敏刚性评价影响因素分析[J].油气地质与采收率,17(4):80-83.
冯建伟,戴俊生,马占荣,等.2011.低渗透砂岩裂缝参数与应力场关系理论模型[J].石油学报,32(4):664-671.
丁文龙,王兴华,胡秋嘉,等.2015.致密砂岩储层裂缝研究进展[J].地球科学进展,30(7):737-750.
傅春梅,唐海,吕栋梁,等.2009.不同含水饱和度下应力敏感性对致密低渗气井产能影响分析[J].天然气勘探与开发,32(1):32-34.
鞠玮,侯贵廷,黄少英,等.2014.断层相关褶皱对砂岩构造裂缝发育的控制约束[J].高校地质学报,20(1):105-113.
郭平,张俊,杜建芬,等.2007.采用两种实验方法进行气藏岩心应力敏感研究[J].西南石油大学学报,121(2):7-9.
李孟涛,姚尚林,单文文,等.2006.低渗透气藏应力敏感性实验研究[J].大庆石油地质与开发,25(6):69-72.
刘宏,谭秀成,李凌,等.2011.孔隙型碳酸盐岩储集层特征及主控因素:以川西南嘉陵江组嘉5段为例[J].石油勘探与开发,38(3):275-281.
刘晓旭,胡勇,朱斌,等.2006.储层应力敏感性影响因素研究[J].特种油气藏,13(3):18-21.
游利军,康毅力,陈一健,等.2004.含水饱和度和有效应力对致密砂岩有效渗透率的影响[J].天然气工业,24(12):105-107.
康毅力,张浩,陈一健,等.2006.鄂尔多斯盆地大牛地气田致密砂岩气层应力敏感性综合研究[J].天然气地球科学,17(3):335-344.
秦积舜.2002.变围压条件下低渗砂岩储层渗透率变化规律研究[J].西安石油学院学报,17(4):28-35.
邬光辉,朱海燕,张立平,等.2011.和田河气田奥陶系碳酸盐岩气藏类型再认识及其意义[J].天然气工业,31(7):5-10.
新丽.2015.含微裂缝低渗储层应力敏感性及其对产能影响[J].特种油气藏,22(1):127-130.
曾联波,漆家福,王成刚,等.2008.构造应力对裂缝形成与流体流动的影响[J].地学前缘,15(3):292-298.
赵文智,沈安江,胡素云,等.2012.中国碳酸盐岩储集层大型化发育的地质条件与分布特征[J].石油勘探与开发,39(1):1-12.
赵伦,陈烨菲,宁正福,等.2013.异常高压碳酸盐岩油藏应力敏感实验评价--以滨里海盆地肯基亚克裂缝-孔隙型低渗透碳酸盐岩油藏为例[J].石油勘探与开发,40(2):194-199.
钟高润,张小莉,杜江民,等.2016.致密砂岩储层应力敏感性实验研究[J].地球物理学进展,31(3):1300-1306.
朱维耀,马东旭,朱华银,等.2016.页岩储层应力敏感性及其对产能影响[J].天然气地球科学,27(5):892-896.
张鹏,侯贵廷,潘文庆,等.2013.塔里木盆地北缘碳酸盐岩野外构造裂缝发育规律研究[J].高校地质学报,19(4):580-587.
Dou H G,Zhang H J,Yao S L,et al.2016.Measurement and evaluation of the stress sensitivity in tight reservoirs[J].Petrol.Explor.Develop.,43(6):1116-1123.
Durham W B and Bonner B P.1994.Self-propping and fluid flow in slightly offset joints at high effective pressures[J].Journal of Geophysical Research,99(B5):9391-9399.
Fatt I and Davis D H.1952.Reduction in permeability with overburden pressure[J].Trans AIME,195:329-334.
Gai S H,Liu H Q and He S L.2015.An improved particles model for stress sensitivity in low-permeability sandstones[J].Geosystem Engineering,19(2):89-95,DOI:10.1080/12269328.2015.1110059.
Guo X,Zou G F,Wang Y H,et al.2017.Investigation of the temperature effect on rock permeability sensitivity[J].Journal of Petroleum Science and Engineering,156:616-622.
Hicks T W,Pine R J,Willis Richards J,et al.1996.A hydro-thermomechanical numerical model for HDR geothermal reservoir evaluation[J].Int.J.Rock Mech.Min.Sci.and Geomech.Abstr.,33(5):499-511.
Javadpour F,Fisher D and Unsworth M.2007.Nanoscale gas flow in shale gassediment[J].JournalofCandianPetroleumTechnology,46(10):53-61.
Jing Z,Wills-Richards J,Watanabe K and Hashida T.1998.A new 3-Dstochastic model for HDR geothermal reservoir in fractured crystalline rock[A]//Fourth International HDR Forum,Strasbourg,France,September,28-30.
Laubach S E,Fall A,Copley L K,et al.2016,Fracture porosity creation and persistence in a basement-involved Laramide fold,Upper Cretaceous Frontier Formation,Green River Basin,U.S.A.[J].Geological Magazine,153(5/6):887-910.
Shovkun I and Espinoza D N.2017.Coupled fluid flow-geomechanics simulation in stress-sensitive coal and shale reservoirs:Impact of desorption-induced stresses,shear failure,and fines migration[J].Fuel,260-272.
Wang R,Yue X A,Zhao R B,et al.2009.Effect of stress sensitivity on displacement efficiency in CO2flooding for fractured low permeability reservoirs[J].Pet.Sci.,6:277-283
Warpinski N R and Teufel I W.1992.Determination o1 the effective stress law for permeability and determination in low-permeability rock[J].SPEFormation Evaluation,7(2):123-131.
Wills-Richards J,Watanabe K and Takahashi H.1996.Progress toward a stochastic rock mechanics model of engineered geothermal systems[J].JGeophys Res.,101(B8):17,481-17,496.
Xiao W L,Li T,Li M,et al.2016.Evaluation of the stress sensitivity in tight reservoirs[J].Petrol.Explor.Develop.,43(1):115-123.
Yin S,Lv D W,Ding W L,et al.2018.New Method for Assessing Microfracture Stress Sensitivity in Tight Sandstone Reservoirs Based on Acoustic Experiments[J].Int.J.Geomech.,18(4):04018008,DOI:10.1061/(ASCE)GM.1943-5622.0001100.
Zhang L Q,Zhou J,Brauna A,et al.2018.Sensitivity analysis on the interaction between hydraulic and natural fractures based on an explicitly coupled hydro-geomechanical model in PFC2D[J].Journal of Petroleum Science and Engineering,167:638-653.