Hydraulic fracturing facilitates the development and exploitation of unconventional reservoirs.In this study,the injected hydraulic fracturing fluid(HFF)and flowback and produced water(FPW)in tight oil reservoirs of t...Hydraulic fracturing facilitates the development and exploitation of unconventional reservoirs.In this study,the injected hydraulic fracturing fluid(HFF)and flowback and produced water(FPW)in tight oil reservoirs of the Lucaogou Formation in the Junggar Basin are temporally sampled from day 1 to day 64.Freshwater is used for fracturing,and HFF is obtained.The chemical and isotopic parameters(including the water type,total salinity,total dissolved solids(TDS),pH,concentrations of Na^(+),Cl^(-),Ba^(+),K^(+),Fe^(2+)+Fe^(3+),and CO_(3)^(2-),dD,and δ^(18)O)are experimentally obtained,and their variations with time are systematically analyzed based on the flowback water.The results show that the water type,Na/Cl ratio,total salinity,and TDS of the FPW change periodically primarily due to the HFF mixing with formation water,thus causing δD and δ^(18)O to deviate from the meteoric water line of Xinjiang.Because of watererock interaction(WRI),the concentrations of Fe^(2+)+Fe^(3+)and CO_(3)^(2-)of the FPW increase over time,with the solution pH becoming more alkaline.Furthermore,based on the significant changes observed in the geochemistry of the FPW,three separate time intervals of flowback time are identified:Stage Ⅰ(<10 days),where the FPW is dominated by the HFF and the changes in ions and isotopes are mainly caused by the WRI;Stage Ⅱ(10-37 days),where the FPW is dominated by the addition of formation water to the HFF and the WRI is weakened;and finally,Stage Ⅲ(>37 days),where the FPW is dominated by the chemistry of the formation water.The methodology implemented in this study can provide critical support for the source identification of formation water.展开更多
为实现煤层气井开采过程中压裂返排水的重复利用——配制压裂液,设计合成了含苯环的双子表面活性剂GM,考察了GM质量浓度对体系黏度、耐温耐剪切性能及杀菌性能的影响。试验结果表明:当GM质量分数达到2%时,黏度可达114 m Pa·s,形成...为实现煤层气井开采过程中压裂返排水的重复利用——配制压裂液,设计合成了含苯环的双子表面活性剂GM,考察了GM质量浓度对体系黏度、耐温耐剪切性能及杀菌性能的影响。试验结果表明:当GM质量分数达到2%时,黏度可达114 m Pa·s,形成的交联冻胶在剪切速率49 s-1条件下剪切500 s,黏度维持在80 m Pa·s不变,当GM质量分数为0.05%时,杀菌率达到98%以上。GM与其他添加剂配伍性良好,冻胶破胶彻底,对储层伤害小。展开更多
基金supported by the National Natural Science Foundation of China(No.U2003102).
文摘Hydraulic fracturing facilitates the development and exploitation of unconventional reservoirs.In this study,the injected hydraulic fracturing fluid(HFF)and flowback and produced water(FPW)in tight oil reservoirs of the Lucaogou Formation in the Junggar Basin are temporally sampled from day 1 to day 64.Freshwater is used for fracturing,and HFF is obtained.The chemical and isotopic parameters(including the water type,total salinity,total dissolved solids(TDS),pH,concentrations of Na^(+),Cl^(-),Ba^(+),K^(+),Fe^(2+)+Fe^(3+),and CO_(3)^(2-),dD,and δ^(18)O)are experimentally obtained,and their variations with time are systematically analyzed based on the flowback water.The results show that the water type,Na/Cl ratio,total salinity,and TDS of the FPW change periodically primarily due to the HFF mixing with formation water,thus causing δD and δ^(18)O to deviate from the meteoric water line of Xinjiang.Because of watererock interaction(WRI),the concentrations of Fe^(2+)+Fe^(3+)and CO_(3)^(2-)of the FPW increase over time,with the solution pH becoming more alkaline.Furthermore,based on the significant changes observed in the geochemistry of the FPW,three separate time intervals of flowback time are identified:Stage Ⅰ(<10 days),where the FPW is dominated by the HFF and the changes in ions and isotopes are mainly caused by the WRI;Stage Ⅱ(10-37 days),where the FPW is dominated by the addition of formation water to the HFF and the WRI is weakened;and finally,Stage Ⅲ(>37 days),where the FPW is dominated by the chemistry of the formation water.The methodology implemented in this study can provide critical support for the source identification of formation water.
文摘为实现煤层气井开采过程中压裂返排水的重复利用——配制压裂液,设计合成了含苯环的双子表面活性剂GM,考察了GM质量浓度对体系黏度、耐温耐剪切性能及杀菌性能的影响。试验结果表明:当GM质量分数达到2%时,黏度可达114 m Pa·s,形成的交联冻胶在剪切速率49 s-1条件下剪切500 s,黏度维持在80 m Pa·s不变,当GM质量分数为0.05%时,杀菌率达到98%以上。GM与其他添加剂配伍性良好,冻胶破胶彻底,对储层伤害小。
