Synthesis and Performance Evaluation of a New Deoiling Agent for Treatment of Waste Oil-Based Drilling Fluids

Table 4

Relationship between recovery rate of SDA and time of passing gas through when the deoiling agent switches from hydrophilicity to hydrophobicity.

Gas injection time (min)	Volume of hydrophobic layer (mL)	Recovery rate (%)
0	0	0
20	1	10
40	2.5	25
60	3.9	39
80	5.1	51
100	6.4	64
120	6.5	65
140	6.5	65

The highest recovery rate is 65%. Therefore, 35% SDA is lost in the process of switching. Such high loss rate may be due to long blowing.