超临界CO_2压裂液增黏剂的长管实验评价及增黏机制探讨
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摘要
针对超临界CO_2压裂中CO_2黏度低、携砂困难等问题,开展6种超临界CO_2压裂液增黏剂的性能研究。分析增黏剂聚乙酸乙烯酯、聚苯乙烯、氟化丙烯酸酯、聚甲基倍半硅氧烷、聚甲基倍半硅氧烷-乙酸乙烯酯以及氟化丙烯酸酯-苯乙烯的分子结构,测试其增黏效果及热稳定性,评价温度、压力、增黏剂注入量对超临界CO_2压裂液黏度的影响,测试不同管径中压裂液的阻力系数,并探讨超临界CO_2增黏的机制。实验结果表明,在温度为50℃、压力为12MPa、注入增黏剂质量分数为3%时,氟化丙烯酸酯-苯乙烯对超临界CO_2的增黏效果最好,增黏倍数为316.7倍,黏度值为15.202mPa·s;改善增黏剂在CO_2中的溶解性可以有效提高超临界CO_2压裂液的黏度;具备两亲特性、具有无定形、无规则结构特征以及分子上既存在路易斯酸又有路易斯碱的共聚物能有效提高其在CO_2中的溶解性,并形成大分子相互缠绕的空间网络结构,达到增黏的效果。该研究对超临界CO_2增黏剂的研制以及超临界CO_2压裂施工具有重要的现实意义。
Aiming at the problems of low CO_2 viscosity and difficulty in carrying sand in supercritical CO_2 fracturing, the performance of six supercritical CO_2 fracturing fluid tackifiers was studied. The molecular structure of tackifiers polyvinyl acetate, polystyrene, fluorinated acrylate,polymethylsilsesquioxane, polymethylsilsesquioxane-vinyl acetate, and fluorinated acrylate-styrene is analyzed. The thickening effects and the thermal stability of those tackifiers are tested, the effect of temperature, pressure, and the amount of tackifier injection on the viscosity of the supercritical CO_2 fracturing fluid is evaluate, and the drag coefficient of the fracturing fluid in different pipe diameters is tested, at the same time we explore the mechanism of supercritical CO_2 viscosity increase. The results of experimental show that fluoroacrylate-styrene has the best thickening effect on supercritical CO_2, at a temperature of 50℃, a pressure of 12 MPa, and an injection mass percentage of 3%. And its adhesion increase rate is 316.7 times, viscosity value is 15.202 mPa·s. To improve the solubility of the tackifier in CO_2 can effectively increase the viscosity of the supercritical CO_2 fracturing fluid. The supercritical CO_2 fracturing fluid possesses amphiphilic characteristics and is characterized by amorphous and irregular structures, which has both Lewis acid and Lewis base copolymers on molecules, that can effectively increase their solubility in CO_2 and forms a spatial network structure with large molecules intertwined to achieve the effect of increasing viscosity. This research has important practical significance for the development of supercritical CO_2 tackifiers and the application of supercritical CO_2 fracturing.
Aiming at the problems of low CO_2 viscosity and difficulty in carrying sand in supercritical CO_2 fracturing, the performance of six supercritical CO_2 fracturing fluid tackifiers was studied. The molecular structure of tackifiers polyvinyl acetate, polystyrene, fluorinated acrylate,polymethylsilsesquioxane, polymethylsilsesquioxane-vinyl acetate, and fluorinated acrylate-styrene is analyzed. The thickening effects and the thermal stability of those tackifiers are tested, the effect of temperature, pressure, and the amount of tackifier injection on the viscosity of the supercritical CO_2 fracturing fluid is evaluate, and the drag coefficient of the fracturing fluid in different pipe diameters is tested, at the same time we explore the mechanism of supercritical CO_2 viscosity increase. The results of experimental show that fluoroacrylate-styrene has the best thickening effect on supercritical CO_2, at a temperature of 50℃, a pressure of 12 MPa, and an injection mass percentage of 3%. And its adhesion increase rate is 316.7 times, viscosity value is 15.202 mPa·s. To improve the solubility of the tackifier in CO_2 can effectively increase the viscosity of the supercritical CO_2 fracturing fluid. The supercritical CO_2 fracturing fluid possesses amphiphilic characteristics and is characterized by amorphous and irregular structures, which has both Lewis acid and Lewis base copolymers on molecules, that can effectively increase their solubility in CO_2 and forms a spatial network structure with large molecules intertwined to achieve the effect of increasing viscosity. This research has important practical significance for the development of supercritical CO_2 tackifiers and the application of supercritical CO_2 fracturing.
引文
[1]赵万金,李海亮,杨午阳.国内非常规油气地球物理勘探技术现状及进展[J].中国石油勘探, 2012, 17(4):36-40.ZHAO W J, LI H L, YANG W Y. Current status and progress of domestic unconventional oil and gas geophysical exploration technologies[J]. China Petroleum Exploration, 2012, 17(4):36-40.
[2]赵群,王红岩,刘人和,等.世界页岩气发展现状及我国勘探前景[J].天然气技术与经济, 2008(3):11-14.ZHAO Q, WANG H Y, LIU R H, et al. Development status of world shale gas and exploration prospects in China[J]. Natural Gas Technology and Economy, 2008(3):11-14.
[3]赵志恒,李晓,张搏,等.超临界二氧化碳无水压裂新技术实验研究展望[J].天然气勘探与开发, 2016, 39(2):58-63.ZHAO Z H, LI X, ZHANG B, et al. Prospect of experimental research on new technology of supercritical carbon dioxide waterless fracturing[J]. Natural Gas Exploration and Development, 2016, 39(2):58-63.
[4]彭成勇.页岩油气水平井压裂工艺技术展望[J].天然气勘探与开发, 2014, 37(1):68-71.PENG C Y. Prospect of fracturing technology for shale gas horizontal wells[J]. Natural Gas Exploration and Development, 2014, 37(1):68-71.
[5]孙张涛,吴西顺.页岩气开采中的水力压裂与无水压裂技术[J].国土资源情报, 2014(5):51-55.SUN Z T, WU X S. Hydraulic fracturing and waterless fracturing technology in shale gas mining[J]. Land and Resources Information,2014(5):51-55.
[6]肖博,张士诚,张健,等. CO2增黏剂研究述评[J].西安石油大学学报(自然科学版), 2014, 29(4):78-83.XIAO B, ZHANG S C, ZHANG J, et al. Review of CO2tackifier research[J]. Journal of Xi’an Shiyou University(Natural Science),2014, 29(4):78-83.
[7]刘巍.超临界CO2增黏剂研究进展[J].断块油气田,2012, 19(5):658-661.LIU W. Research progress of supercritical CO2tackifiers[J]. Fault Block Oil&Gas Field, 2012, 19(5):658-661.
[8]黄洲.二氧化碳增黏剂的制备及其压裂性能评价[D].成都:西南石油大学, 2017.HUANG Z. Preparation of carbon dioxide thickener and evaluation of its fracturing performance[D]. Chengdu:Southwest Petroleum University,2017.
[9]孙宝江,孙文超.超临界CO2增黏机制研究进展及展望[J].中国石油大学学报(自然科学版), 2015(3):76-83.SUN B J, SUN W C. Research progress and prospects of supercritical CO2viscosification mechanism[J]. Journal of China University of Petroleum(Natural Science). 2015(3):76-83.
[10]崔伟香,舒玉华,崔明月,等.液态CO2增稠压裂液流变性能分析[J].油田化学, 2017, 34(2):250-254.CUI W X, SHU Y H, CUI M Y, et al. Rheological analysis of liquid CO2thickening fracturing fluid[J]. Oil Field Chemistry, 2017, 34(2):250-254.
[11]崔伟香,邱晓惠. 100%液态CO2增稠压裂液流变性能[J].钻井液与完井液, 2016, 33(2):101-105.CUI W X, QIU X H. Rheological of 100%liquid CO2thickening fracturing fluid[J]. Drilling Fluid and Completion Fluid,2016, 33(2):101-105.
[12] KUMAR S K, JOHNSTON K P. Modelling the solubility of solids in supercritical fluids with density as the independent variable[J]. Journal of Supercritical Fluids,2015,1(1):15-22.
[13] LEI H. Identification, design and synthesis of oxygenated hydrocarbonbased carbon dioxide-soluble polymers for chemical and petroleum engineering applications[D]. Pittsburgh:University of Pittsburgh, 2006.
[14] BRAY C L, TAN B, WOOD C D, et al. High-throughput solubility measurements of polymer libraries in supercritical carbon dioxide[J].Journal of Materials Chemistry,2005,15(4):456-459.
[15] BAYRAKTAR Z, KIRAN E. Miscibility, phase separation, and volumetric properties in solutions of poly(dimethylsiloxane)in supercritical carbon dioxide[J]. Journal of Applied Polymer Science,2015, 75(11):1397-1403.
[16] KILIC S, MICHALIK S, WANG Y, et al. Effect of grafted Lewis base groups on the phase behavior of model poly(dimethyl siloxanes)in CO2[J]. Industrial&Engineering Chemistry Research, 2003, 42(25):6415-6424.
[17] ROSE A B S, MARCENEIRO S, BRAGA M E M, et al. Solubility of all-trans, retinoic acid in supercritical carbon dioxide[J]. Journal of Supercritical Fluids, 2015, 98:70-78.
[18]曹晓萌.渝东南下寒武统牛蹄塘组黑色页岩储层特征及主控因素[D].北京:中国地质大学(北京), 2014.CAO X M. Reservoir characteristics their controlling factors of the lower cambrian niutitang formation black shales in southeast Chongqing[D]. Beijing:China University of Geosciences(Beijing),2014.
[19] WANG Yang. Molecular modeling applied to CO2-soluble molecules and confined fluids[D]. Commonwealth,Pennsylvania:University of Pittsburgh, 2006.
[20]沈爱国,刘金波,佘跃惠,等. CO2潜在增黏剂苯乙烯乙酸乙烯酯二元共聚物的设计与合成[J].石油天然气学报, 2011, 33(2):131-134.SHEN A G, LIU J B, SHE Y H, et al. Design and synthesis of CO2potential adhesion styrene vinyl acetate binary copolymer[J]. Journal of Oil and Gas Technology, 2011, 33(2):131-134.
[21]孙少俊.亲CO2聚乙酸乙烯基聚合物的设计与合成[D].上海:华东理工大学, 2015.SUN S J. Design and synthesis of pro-CO2polyvinyl acetate polymer[D]. Shanghai:East China University of Science and Technology,2015.
[22]沈爱国,刘金波,佘跃惠,等. CO2增黏剂聚乙酸乙烯酯-甲基倍半硅氧烷的合成[J].高分子材料科学与工程, 2011, 27(11):157-159.SHEN A G, LIU J B, SHE Y H, et al. Synthesis of CO2tackifier polyvinyl acetate-methyl silsesquioxane[J]. Polymer Materials Science&Engineering, 2011, 27(11):157-159.
[23] HEIDARYAN E, HATAMI T, RAHIMI M, et al. Viscosity of pure carbon dioxide at supercritical region:measurement and correlation approach[J]. Journal of Supercritical Fluids, 2011, 56(2):144-151.
[24] TERRY R E,ZAID A,ANGELOS C,et al. Polymerization in supercritical CO2to improve CO2/oil mobility ratios[R].SPE 16270,1987.
[25] GULLAPALLI P, TSAU J S, HELLER J P. Gelling behavior of 12-hydroxystearic acid in organic fluids and dense CO2[C]//International Symposium on Oilfield Chemistry. Society of Petroleum Engineers,1995:349-361.
[26]黄洲,周明,王刚,等.液态CO2增稠剂的研究现状[J].现代化工,2016, 36(10):25-28.HUANG Z, ZHOU M, WANG G, et al. Research status of liquid CO2thickeners[J]. Modern Chemical Industry, 2016, 36(10):25-28.
[27] KIKIC I, VECCHIONE F, ALESSI P, et al. Polymer plasticization using supercritical carbon dioxide:experiment and modeling[J].Industrial&Engineering Chemistry Research, 2003, 42(13):3022-3029.
[28]王鉴,张楠,武芹,等.超临界CO2溶解性能的研究进展[J].炼油与化工, 2011, 22(5):1-5.WANG J, ZHANG N, WU Q, et al. Research progress of supercritical CO2solubility[J]. Refinery and Chemical Industry, 2011, 22(5):1-5.
[29] FRANKEN H H, KNOETZE J H, SCHWARZ C E. High-pressure binary phase equilibria, density and dynamic viscosity of 100&200cSt polydimethylsiloxane(PDMS)with supercritical CO2[J]. Journal of Supercritical Fluids, 2018,139:1-7.
[30] FERNANDO J G, VEQUIZO R M, ODARVE M K G, et al. Effect of supercritical carbon dioxide treatment on the polarons of HCl-doped polyaniline films[J]. Physica Status Solidi, 2015, 12(6):576-579.
[2]赵群,王红岩,刘人和,等.世界页岩气发展现状及我国勘探前景[J].天然气技术与经济, 2008(3):11-14.ZHAO Q, WANG H Y, LIU R H, et al. Development status of world shale gas and exploration prospects in China[J]. Natural Gas Technology and Economy, 2008(3):11-14.
[3]赵志恒,李晓,张搏,等.超临界二氧化碳无水压裂新技术实验研究展望[J].天然气勘探与开发, 2016, 39(2):58-63.ZHAO Z H, LI X, ZHANG B, et al. Prospect of experimental research on new technology of supercritical carbon dioxide waterless fracturing[J]. Natural Gas Exploration and Development, 2016, 39(2):58-63.
[4]彭成勇.页岩油气水平井压裂工艺技术展望[J].天然气勘探与开发, 2014, 37(1):68-71.PENG C Y. Prospect of fracturing technology for shale gas horizontal wells[J]. Natural Gas Exploration and Development, 2014, 37(1):68-71.
[5]孙张涛,吴西顺.页岩气开采中的水力压裂与无水压裂技术[J].国土资源情报, 2014(5):51-55.SUN Z T, WU X S. Hydraulic fracturing and waterless fracturing technology in shale gas mining[J]. Land and Resources Information,2014(5):51-55.
[6]肖博,张士诚,张健,等. CO2增黏剂研究述评[J].西安石油大学学报(自然科学版), 2014, 29(4):78-83.XIAO B, ZHANG S C, ZHANG J, et al. Review of CO2tackifier research[J]. Journal of Xi’an Shiyou University(Natural Science),2014, 29(4):78-83.
[7]刘巍.超临界CO2增黏剂研究进展[J].断块油气田,2012, 19(5):658-661.LIU W. Research progress of supercritical CO2tackifiers[J]. Fault Block Oil&Gas Field, 2012, 19(5):658-661.
[8]黄洲.二氧化碳增黏剂的制备及其压裂性能评价[D].成都:西南石油大学, 2017.HUANG Z. Preparation of carbon dioxide thickener and evaluation of its fracturing performance[D]. Chengdu:Southwest Petroleum University,2017.
[9]孙宝江,孙文超.超临界CO2增黏机制研究进展及展望[J].中国石油大学学报(自然科学版), 2015(3):76-83.SUN B J, SUN W C. Research progress and prospects of supercritical CO2viscosification mechanism[J]. Journal of China University of Petroleum(Natural Science). 2015(3):76-83.
[10]崔伟香,舒玉华,崔明月,等.液态CO2增稠压裂液流变性能分析[J].油田化学, 2017, 34(2):250-254.CUI W X, SHU Y H, CUI M Y, et al. Rheological analysis of liquid CO2thickening fracturing fluid[J]. Oil Field Chemistry, 2017, 34(2):250-254.
[11]崔伟香,邱晓惠. 100%液态CO2增稠压裂液流变性能[J].钻井液与完井液, 2016, 33(2):101-105.CUI W X, QIU X H. Rheological of 100%liquid CO2thickening fracturing fluid[J]. Drilling Fluid and Completion Fluid,2016, 33(2):101-105.
[12] KUMAR S K, JOHNSTON K P. Modelling the solubility of solids in supercritical fluids with density as the independent variable[J]. Journal of Supercritical Fluids,2015,1(1):15-22.
[13] LEI H. Identification, design and synthesis of oxygenated hydrocarbonbased carbon dioxide-soluble polymers for chemical and petroleum engineering applications[D]. Pittsburgh:University of Pittsburgh, 2006.
[14] BRAY C L, TAN B, WOOD C D, et al. High-throughput solubility measurements of polymer libraries in supercritical carbon dioxide[J].Journal of Materials Chemistry,2005,15(4):456-459.
[15] BAYRAKTAR Z, KIRAN E. Miscibility, phase separation, and volumetric properties in solutions of poly(dimethylsiloxane)in supercritical carbon dioxide[J]. Journal of Applied Polymer Science,2015, 75(11):1397-1403.
[16] KILIC S, MICHALIK S, WANG Y, et al. Effect of grafted Lewis base groups on the phase behavior of model poly(dimethyl siloxanes)in CO2[J]. Industrial&Engineering Chemistry Research, 2003, 42(25):6415-6424.
[17] ROSE A B S, MARCENEIRO S, BRAGA M E M, et al. Solubility of all-trans, retinoic acid in supercritical carbon dioxide[J]. Journal of Supercritical Fluids, 2015, 98:70-78.
[18]曹晓萌.渝东南下寒武统牛蹄塘组黑色页岩储层特征及主控因素[D].北京:中国地质大学(北京), 2014.CAO X M. Reservoir characteristics their controlling factors of the lower cambrian niutitang formation black shales in southeast Chongqing[D]. Beijing:China University of Geosciences(Beijing),2014.
[19] WANG Yang. Molecular modeling applied to CO2-soluble molecules and confined fluids[D]. Commonwealth,Pennsylvania:University of Pittsburgh, 2006.
[20]沈爱国,刘金波,佘跃惠,等. CO2潜在增黏剂苯乙烯乙酸乙烯酯二元共聚物的设计与合成[J].石油天然气学报, 2011, 33(2):131-134.SHEN A G, LIU J B, SHE Y H, et al. Design and synthesis of CO2potential adhesion styrene vinyl acetate binary copolymer[J]. Journal of Oil and Gas Technology, 2011, 33(2):131-134.
[21]孙少俊.亲CO2聚乙酸乙烯基聚合物的设计与合成[D].上海:华东理工大学, 2015.SUN S J. Design and synthesis of pro-CO2polyvinyl acetate polymer[D]. Shanghai:East China University of Science and Technology,2015.
[22]沈爱国,刘金波,佘跃惠,等. CO2增黏剂聚乙酸乙烯酯-甲基倍半硅氧烷的合成[J].高分子材料科学与工程, 2011, 27(11):157-159.SHEN A G, LIU J B, SHE Y H, et al. Synthesis of CO2tackifier polyvinyl acetate-methyl silsesquioxane[J]. Polymer Materials Science&Engineering, 2011, 27(11):157-159.
[23] HEIDARYAN E, HATAMI T, RAHIMI M, et al. Viscosity of pure carbon dioxide at supercritical region:measurement and correlation approach[J]. Journal of Supercritical Fluids, 2011, 56(2):144-151.
[24] TERRY R E,ZAID A,ANGELOS C,et al. Polymerization in supercritical CO2to improve CO2/oil mobility ratios[R].SPE 16270,1987.
[25] GULLAPALLI P, TSAU J S, HELLER J P. Gelling behavior of 12-hydroxystearic acid in organic fluids and dense CO2[C]//International Symposium on Oilfield Chemistry. Society of Petroleum Engineers,1995:349-361.
[26]黄洲,周明,王刚,等.液态CO2增稠剂的研究现状[J].现代化工,2016, 36(10):25-28.HUANG Z, ZHOU M, WANG G, et al. Research status of liquid CO2thickeners[J]. Modern Chemical Industry, 2016, 36(10):25-28.
[27] KIKIC I, VECCHIONE F, ALESSI P, et al. Polymer plasticization using supercritical carbon dioxide:experiment and modeling[J].Industrial&Engineering Chemistry Research, 2003, 42(13):3022-3029.
[28]王鉴,张楠,武芹,等.超临界CO2溶解性能的研究进展[J].炼油与化工, 2011, 22(5):1-5.WANG J, ZHANG N, WU Q, et al. Research progress of supercritical CO2solubility[J]. Refinery and Chemical Industry, 2011, 22(5):1-5.
[29] FRANKEN H H, KNOETZE J H, SCHWARZ C E. High-pressure binary phase equilibria, density and dynamic viscosity of 100&200cSt polydimethylsiloxane(PDMS)with supercritical CO2[J]. Journal of Supercritical Fluids, 2018,139:1-7.
[30] FERNANDO J G, VEQUIZO R M, ODARVE M K G, et al. Effect of supercritical carbon dioxide treatment on the polarons of HCl-doped polyaniline films[J]. Physica Status Solidi, 2015, 12(6):576-579.