摘要
研究了压裂返排液变色的机理及影响变色的因素,并提出了去除色度和浊度的措施。实验结果表明,压裂返排液从地层中携带出的Fe^(2+)与高聚物分子发生络合,使返排液变黄;返排液放置过程中会滋生大量的硫酸盐还原菌,它代谢产生的S^(2-)与Fe^(2+)反应产生黑色的FeS胶体沉淀,使返排液变黑。返排液中加入杀菌剂可以抑制返排液变黑。环境温度、光照及密封性都会影响返排液变色时间。将已变黑的返排液在空气中搅拌24 h以上,或加入200 mg/L的H_(2)O_(2)和(NH_(4))_(2)S_(2)O_(8)反应1 h都可以有效去除返排液的黑色;消除返排液的黄色则需加入更高质量浓度的氧化剂。结合500 mg/L H_(2)O_(2)氧化和2 000 mg/L聚合氯化铝+2 mg/L阴离子聚丙烯酰胺絮凝的方式可以彻底脱除返排液的颜色。
Discoloration mechanism of the fracturing flowback fluid and factors affecting discoloration were investigated.It is found that the Fe^(2+) carried by the fracturing fluid from the formation are complexed with polymer molecules during the flowback process,which makes the color of the flowback fluid turn yellow.At the same time,a large number of sulfate reducing bacteria(SRB)will grow during the placement of the flowback fluid.The S^(2+) produced by its metabolism reacts with Fe^(2+) to produce black precipitation FeS,which makes the flowback liquid black.The growth of SRB can be effectively inhibited by adding bactericide to the flowback fluid,thus inhibiting the blackening of the flowback fluid.In addition,environmental temperature,illumination and sealing will affect the discoloration time of the flowback fluid.The black of the flowback liquid can be effectively removed by stirring the blackened liquid in the container for more than 24 h,or adding 200 mg/L H_(2)O_(2),as well as(NH_(4))_(2)S_(2)O_(8) for oxidation 1 h.However,to eliminate the yellow color of the flowback fluid,a higher concentration of oxidant should be added.Combined with 500 mg/L H_(2)O_(2) oxidation and 2000 mg/L polyaluminium chloride+2 mg/L anionic polyacrylamide flocculation,the color of the flowback fluid can be completely removed.
作者
孙妩娟
王文武
姚兰
李还向
柯从玉
张群正
Sun Wujuan;Wang Wenwu;Yao Lan;Li Huanxiang;Ke Congyu;Zhang Qunzheng(College of Chemistry and Chemical Engineering,Xi’an Shiyou University,Xi’an Shaanxi 710065,China;Changqing Downhole Technology Company,CNPC Changqing Drilling Engineering Co.,Ltd.,Xi’an Shaanxi 710021,China)
出处
《石油化工》
CAS
CSCD
北大核心
2021年第8期788-794,共7页
Petrochemical Technology
基金
国家自然科学基金项目(21676215)
陕西省教育厅科研计划项目资助(20JY057)。
关键词
压裂返排液
变色机理
EM50体系压裂液
生物胶
fracturing flowback fluid
discoloration mechanism
EM50 system fracturing fluid
biopolymer
