页岩气压裂返排液高效破胶剂的研究  

Research on efficient gel breaker for fracturing flowback fluid of shale gas production

作　　者：张太亮[1] 郭威[2] 

机构地区：[1]西南石油大学化学化工学院,成都610500 [2]中石化西南油气分公司川东北采气厂,阆中637402

出　　处：《环境工程学报》2015年第4期1869-1874,共6页Chinese Journal of Environmental Engineering

摘　　要：针对页岩气开采过程中产生的非常规压裂返排液具有高粘度、高COD及高稳定性的特点,以Fe(NO3)3和Ca(Cl O)2为原料,采用化学湿法中的两步法合成了一种绿色氧化剂K2Fe O4,并对合成出的K2Fe O4进行了定量分析,得到合成的高铁酸钾产率为67.63%,纯度为93.41%。采用X衍射、红外光谱、扫描电镜及X衍射能谱,对合成的K2Fe O4进行了表征。将K2Fe O4作为某气田页岩气压裂返排液的高效破胶剂,并对影响破胶效果的因素进行了分析。确定了K2Fe O4的加量为3 000 mg/L,体系p H为11.0及反应时间为40 min的最优条件,在最优条件下,得到出水的粘度为1.4 m Pa·s,其COD、SS和色度的去除率分别为59.1%、93.3%和88.9%。通过红外光谱和扫描电镜进行了微观观察,对K2Fe O4氧化非常规压裂返排液中主要成分胍胶的过程进行了机理分析。研究还发现,K2Fe O4在还原分解后,具有比单一铁离子更强的混凝效果。因此,K2Fe O4的应用对页岩气压裂返排液的处理有深远的影响。focused on the resulting problem of unconventional fracturing flow-back fluid of shale gas production such as high viscosity,high COD and high stability,a green and efficient gel breaker K2 Fe O4was synthesized by a two-step wet process with Fe( NO3)3and Ca( Cl O)2as initial material. Quantitative analysis shows the productivity of K2 Fe O4is 67. 63% and the corresponding purity is 93. 41%. The molecular composition and molecular structure were examined by XRD,FT-IR and SEM-EDS. The optimal dosage of K2 Fe O4,p H,and reaction time are 3 000 mg / L,11. 0,and 40 min,respectively. With the conditions mentioned above,viscosity of flow-back fluid reduced to 1. 4 m Pa · s,while removal rates of COD,SS and chromaticity were 59. 1%,93. 3%,and88. 9%,respectively. Besides,the mechanism of gel breaking was also studied in this work. After deoxidation and decomposition,coagulation effect of K2 Fe O4is better than single iron ions.

关 键 词：页岩气 压裂返排液 高铁酸钾 破胶剂 

分 类 号：TE377[石油与天然气工程—油气田开发工程]