页岩储层自发渗吸实验及润湿性研究
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摘要
页岩储层一般需要水力压裂技术进行开发,压裂液在储层中的自发渗吸是页岩气藏开发的重要机理。文中利用页岩粉末装置分别在页岩油气系统和气水系统开展自发渗吸实验研究,对页岩储层的渗吸特征取得了进一步的认知。实验结果表明:页岩粉末渗吸油量高于渗吸水量,但渗吸水的速率高于渗吸油的速率。其结论与常规渗吸实验相反,主要是由于页岩中有机质纳米孔数量较多,粉末化后疏水网络能有效连接,比表面积增大,引起页岩粉末渗吸油量大于渗吸水量;同时由于有机纳米孔孔径较小,摩擦阻力较大,引起渗吸油速率降低,平衡时间延长。通过应用液-液萃取(LLE)润湿性实验和润湿性指数法进一步表明,实验页岩粉末的润湿性为弱油湿。
To increase the shale gas productivity, hydraulic fracturing is a common technique. The spontaneous imbibition of fracturing fluids in reservoirs is an important mechanism for the development of shale gas reservoirs. In this paper, the experiment is conducted by using a shale powder device under the air-oil and the air-water system, and the imbibition characteristics of shale reservoirs are further recognized. The experimental results show that the oil uptake is higher than the water uptake, but the rate of water imbibition is higher than the rate of oil imbibition. The conclusion is inconsistent with conventional imbibitions. Due to the high content of organic nanopores in the shale, the hydrophobic network can be effectively connected after powdering, and the specific surface area increases, causing the oil uptake higher than the water uptake. At the same time, the organic nanopore pore size is smaller, which enhanced greater frictional resistance, resulting in lower oil imbibition rate and longer equilibration times. The LLE method and wettability index were used to further demonstrate that the experimental shale powders are oil-wet.
To increase the shale gas productivity, hydraulic fracturing is a common technique. The spontaneous imbibition of fracturing fluids in reservoirs is an important mechanism for the development of shale gas reservoirs. In this paper, the experiment is conducted by using a shale powder device under the air-oil and the air-water system, and the imbibition characteristics of shale reservoirs are further recognized. The experimental results show that the oil uptake is higher than the water uptake, but the rate of water imbibition is higher than the rate of oil imbibition. The conclusion is inconsistent with conventional imbibitions. Due to the high content of organic nanopores in the shale, the hydrophobic network can be effectively connected after powdering, and the specific surface area increases, causing the oil uptake higher than the water uptake. At the same time, the organic nanopore pore size is smaller, which enhanced greater frictional resistance, resulting in lower oil imbibition rate and longer equilibration times. The LLE method and wettability index were used to further demonstrate that the experimental shale powders are oil-wet.
引文
[1]ZOU C N,DONG D Z,WANG S J,et al.Geological characteristics and resource potential of shale gas in China[J].Petroleum Exploration and Development Online,2010,37(6):641-653.
[2]姜生玲,张金川,李博,等.中国现阶段页岩气资源评价方法分析[J].断块油气田,2017,24(5):642-646.
[3]HORN A D.Breakthrough Mobile water treatment converts 75%of fracturing flowback fluid to fresh water and lowers CO2emissions[R].SPE 121104,2009.
[4]杨发荣,左罗,胡志明,等.页岩储层渗吸特性的实验研究[J].科学技术与工程,2016,16(25):63-66.
[5]孟庆帮,刘慧卿,王敬.天然裂缝性油藏渗吸规律[J].断块油气田,2014,21(3):330-334.
[6]LAI F P,LI Z P,WEI Q,et al.Experimental nvestigation of sontaneous imbibition in tight reservoir with nuclear magnetic resonance testing[J].Energy&Fuels,2016,30(11):9097-9105.
[7]CHENG Z L,WANG Q,NING Z F,et al.Experimental investigation of countercurrent spontaneous imbibition in tight sandstone using nuclear magnetic resonance[J].Energy&Fuels,2018,32(6):6507-6517.
[8]黄睿哲,姜振学,高之业,等.页岩储层组构特征对自发渗吸的影响[J].油气地质与采收率,2017,24(1):111-115.
[9]ZHOU X M,MORROW N R,MA S X.Interrelationship o f wettability,initial water saturation,aging time,and oil recovery by spontaneous imbibition and waterflooding[J].SPE Journal,2000,5(2):199-207.
[10]DEHGHANPOUR H,LAN Q,SAEED Y,et al.Spontaneous imbibition of brine and oil in gas shales:effect of water adsorption and resulting microfractures[J].Energy&Fuels,2013,27(6):3039-3049.
[11]XU M,DEHGHANPOUR H.Advances in understanding wettability of gas shales[J].Energy&Fuels,2014,28(7):4362-4375.
[12]胡宗全,杜伟,彭勇民,等.页岩微观孔隙特征及源储关系:以川东南地区五峰组-龙马溪组为例[J].石油与天然气地质,2015,36(6):1001-1008.
[13]赵迪斐,郭英海,白万备,等.渝东南五峰组-龙马溪组页岩纳米级孔隙的发育特征与影响因素[J].河南理工大学学报(自然科学版),2016,35(4):497-506.
[14]白志强,刘树根,孙玮,等.四川盆地西南雷波地区五峰组-龙马溪组页岩储层特征[J].成都理工大学学报(自然科学版),2013,40(5):521-531.
[15]冉波,刘树根,孙玮,等.四川盆地南缘骑龙村剖面五峰-龙马溪组黑色页岩孔隙大小特征的重新厘定[J].成都理工大学学报(自然科学版),2013,40(5):532-542.
[16]AKBARABADI M,PIRI M.Nano-sscale experimental investigation of in-situ wettability and spontaneous imbibition in ultra-tight reservoir rocks[J].Advances in Water Resources,2017,107:160-179.
[17]YANG S,DEHGHANPOUR H,BINAZAADEH M,et al.A molecular dynamics explanation for fast imbibition of oil in organic tight rocks[J].Fuel,2016,90:409-419.
[2]姜生玲,张金川,李博,等.中国现阶段页岩气资源评价方法分析[J].断块油气田,2017,24(5):642-646.
[3]HORN A D.Breakthrough Mobile water treatment converts 75%of fracturing flowback fluid to fresh water and lowers CO2emissions[R].SPE 121104,2009.
[4]杨发荣,左罗,胡志明,等.页岩储层渗吸特性的实验研究[J].科学技术与工程,2016,16(25):63-66.
[5]孟庆帮,刘慧卿,王敬.天然裂缝性油藏渗吸规律[J].断块油气田,2014,21(3):330-334.
[6]LAI F P,LI Z P,WEI Q,et al.Experimental nvestigation of sontaneous imbibition in tight reservoir with nuclear magnetic resonance testing[J].Energy&Fuels,2016,30(11):9097-9105.
[7]CHENG Z L,WANG Q,NING Z F,et al.Experimental investigation of countercurrent spontaneous imbibition in tight sandstone using nuclear magnetic resonance[J].Energy&Fuels,2018,32(6):6507-6517.
[8]黄睿哲,姜振学,高之业,等.页岩储层组构特征对自发渗吸的影响[J].油气地质与采收率,2017,24(1):111-115.
[9]ZHOU X M,MORROW N R,MA S X.Interrelationship o f wettability,initial water saturation,aging time,and oil recovery by spontaneous imbibition and waterflooding[J].SPE Journal,2000,5(2):199-207.
[10]DEHGHANPOUR H,LAN Q,SAEED Y,et al.Spontaneous imbibition of brine and oil in gas shales:effect of water adsorption and resulting microfractures[J].Energy&Fuels,2013,27(6):3039-3049.
[11]XU M,DEHGHANPOUR H.Advances in understanding wettability of gas shales[J].Energy&Fuels,2014,28(7):4362-4375.
[12]胡宗全,杜伟,彭勇民,等.页岩微观孔隙特征及源储关系:以川东南地区五峰组-龙马溪组为例[J].石油与天然气地质,2015,36(6):1001-1008.
[13]赵迪斐,郭英海,白万备,等.渝东南五峰组-龙马溪组页岩纳米级孔隙的发育特征与影响因素[J].河南理工大学学报(自然科学版),2016,35(4):497-506.
[14]白志强,刘树根,孙玮,等.四川盆地西南雷波地区五峰组-龙马溪组页岩储层特征[J].成都理工大学学报(自然科学版),2013,40(5):521-531.
[15]冉波,刘树根,孙玮,等.四川盆地南缘骑龙村剖面五峰-龙马溪组黑色页岩孔隙大小特征的重新厘定[J].成都理工大学学报(自然科学版),2013,40(5):532-542.
[16]AKBARABADI M,PIRI M.Nano-sscale experimental investigation of in-situ wettability and spontaneous imbibition in ultra-tight reservoir rocks[J].Advances in Water Resources,2017,107:160-179.
[17]YANG S,DEHGHANPOUR H,BINAZAADEH M,et al.A molecular dynamics explanation for fast imbibition of oil in organic tight rocks[J].Fuel,2016,90:409-419.