Screening,Synthesis And Properties Of Emulsion Demulsifier For Polymer Flooding

In recent years,with the increasing efforts to exploit the ultra-low permeability oilfield in ordos basin,as well as the the use of some new technical measures,chemical surfactants such as flocculants,corrosion inhibitors,fracturing fluids and washing fluids are used widely and extensively.These agents often ultimately enter the downstream oily sludge,which increased the disposal difficulty of sludge oil-water separation process;However,the current demulsifier is not ideal for the dehydration of this emulsion under certain circumstances,the dehydration rate is low and dehydration is slow.Under such a background,this thesis conducted on the certain research in this aspect.The research results are as follows.(1)In this paper,the physicochemical properties of a typical sludge emulsion in an ultra-low permeability oilfield in Ordos was systematically analyzed.According to the test results,the water content and the oil content of the sludge are 33.97%~41.62% and 492.05~510.23mg/L respectively.It is a kind of emulsion of high water content,weak acidity,high solid,colloidal,asphaltene content.(2)For this specific oily sludge,a systematic study of its demulsification process was conducted.15 kinds of demulsifiers(including type of AE polyether,phenolic resin,silicon-containing,etc.)were firstly screened for experiments of comparison and screening demulsification.The results showed that PR02 is an ideal demulsifier for this emulsion.Then on the basis of single factor experiments,the demulsifier was studied about the optimum conditions through orthogonal experiment: demulsification temperature 40℃,dosing amount 130mg/L,centrifugation speed 3000r/min,centrifugation time 18 min,dehydration rate is 94.25%.(3)A kind of silicone polyether demulsifier was developed.The nonylphenol polyether was synthesized by using nonenylphenol and KOH in a mass ratio of 1.0:2.5.Then the nonylphenol polyether was reacted with dodecyl methacrylate and hydrogen silicone oil through hydrosilylation reaction to synthesize comb type modified polysiloxane heavy oil Demulsifier(GPX1).Under the conditions of synthesis temperature 99.20 ℃,reaction time 5.94 h,catalyst dosage 49.35μg/g and solvent content 34.86%,the conversion is 93.82%.The product structure was characterized by FTIR and 1HNMR.The results of demulsification properties test of polymer GPX1 showed that the demulsification rate of GPX1 is 0.3% higher than that of PR02.Microbial degradation performance test proved that the synthetic demulsifier GPX1 is a green and pollution-free demulsifier.(4)According to fast and high dehydration rate of GPX1 and the characteristics of dehydration of cardanol amine resin(CPAE),combined them with cheap,potential neutralization,adsorption bridge and large network surface area of polyaluminum and cationic polyacrylamide to explore the demulsifying effect of the quaternary compound.The results showed that mix proportion of GPX1 and cardanol formaldehyde resin is 3:7,which was named FW1,then the ternary mixture of 100 mg/L FW1,80 mg/L polyaluminum chloride and 3 mg/L CPAM can obtain better emulsion breaking performance.The emulsion breaking rate can reach to 98.46%,the oil content of the water is 18.5mg/L.The experimental results provided a new kind of demulsifier for this particular oil emulsion,which have important application value.