stirring was stopped temperature recorded and the viscosity measured using the brookfield viscometer at rpm 39 s revolutions per minute of 6 12 30 and 60 and then back down 30 12 and 6 rpm viscosity was calculated by using a multiplication factor of 200 100 40 and 20 for the respective speeds times the dial reading on the viscometer it may be well to mention that the final result at 6 rpm is an indication of the stability of the solution being tested the test was repeated using 300 ml crude oil plus 300 ml of the goodwin synthetic water containing varying amounts of the described surfactants and combinations of the described surfactants an additional procedure was used on the crude oil water surfactant composition this procedure consisted of stirring the emulsions a second time allowing them to set for two minutes upon completion of stirring then making the viscosity determination as previously this procedure is a more severe test of long term stability for emulsions the results for the crude alone are not being stated here these results were in the range of 1500 9500 cp at 6 rpm only the initial and final 6 rpm values are being given for the two procedures ______________________________________concentration first procedure second proceduresurfactant ppm initial final initial final______________________________________b 250 20 20 120 180c 250 40 80 500 360a 500 40 400 400 320b 500 400 140 140 80c 500 20 60 60 60d 500 700 400 300 200a d 250 250 80.