In order to meet the demand of enhanced oil recovery in medium and low permeability reservoirs,Jiangsu oilfield developed an imbibition system FD1 with small molecular weight multi-head non-ionic surfac-tant as the main raw material.The particle size,interfacial tension,wettability,emulsification and oil-washing efficiency were evaluated in laboratory.The imbibition efficiency was tested by static imbibition experiment.The results showed that the average particle size of FD1 ranged from 7.5 to 15 nm,and the interfacial tension between oil and water could be reduced from 10-2 to 10-1 mN/m with different concentrations of imbibition agent.The imbibition agent FD1 could transform the wetting of oil-wet quartz sheet into a strong hydrophilic one,and form an emulsion with good stability with crude oil,and the oil washing efficiency of oil sand could reach more than 65%.Moreover,the imbibition agent had good temperature and salt resistance,and the static imbibition efficiency could be increased by more than 16%compared with water injection.The huff and puff test results of the two oil wells on site are remarkable,and better economic benefits have been achieved.
关键词
表面活性剂/渗吸效率/吞吐试验/提高采收率/采油用渗吸剂
Key words
surfactant/imbibition efficiency/huff and puff test/enhanced oil recovery/oil recovery imbibi-tion system
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