The Preparation And Plugging Performance Of AM/2-EHA-based Copolymer As Profile Control Agent

Daqing oilfield has been exploited for more than fifty years ago.Oil reservoir heterogeneity is an increasingly serious problem,especially since the application of water flooding technology,and the injection water has a declining efficiency.Accordingly,Profile control agents are used to adjust water absorbing profile and so as to enhance oil recovery.AM/2-EHA polymers are studied as new profile control agents aiming at the better performances of anti-hydrolytic property,high temperature resistance,good alkali resistance and salt resistance.In this dissertation,the AM and 2-EHA copolymerization mechanism and the kinetics were studied.The blocking performances of the AM/2-EHA polymers were evaluated through the simulatly calculated by using Aspen Plus software,which can provide the basis for sand/core test.The process of AM/2-EHAcopolymerization wasthe development of the laboratory pilot plant theoretically and experimentally.The main contents of this dissertation are summarized as follows:The reactivity ratios of copolymerizationg of AM and 2-EHA were studied by FT-IR method and Elemental Analysis Method,and the data were analyzed by FR method with positive order,FR method with reverse order,KT method with positive order,KT method with reverse order and YBR method.The result s indicate that the reactivity ratios of AM and 2-EHA are both less than 1 and increase with temperature increasing.The relation between polymer composition and monomer conversion,the chain segment distribution and the monomer unite distribution of copolymer were investigated and analyzed.The best formula of AM/2-EHA copolymer was determined by the above mentioned studies and the performance test results.It shows: AM was 1.46 mol/L,2-EHA was 3.18 mol/L,BPO was 2%wt of the the total mass of monomers,and the volume ratios of ethanol and ethyl acetate was 1:1.AM/2-EHA copolymer,P?AM/2-EHA?/SiO₂ composite and AM/2-EHA /VTEOS copolymer were prepared and evaluated through the sand/core test.The results indicate that AM/2-EHA polymers shows better blocking effect by more than 90%.The profile control agent particles can transport to th e deeper part of the sand filled pipe/core.and form an effective plugging agent.AM/2-EHA polymers showed good alkali resistance,salt resistance and erosion resistance.The mechanical properties of AM/2-EHA polymers had been improved owing to SiO₂.The reaction rate and the apparent activation energy were studied by the dilatometric method,including AM homopolymerization,2-EHA homopolymeri-zation and AM/2-EHA copolymerization.The effects of monomer concentration,initiator concentration and temperature were also discussed.The results indicat that the apparent activation energy of AM/2-EHA copolymerization was lower,so that AM and 2-EHA may tend to copolymerization which was consistent with the result of the monomer reactivity ratios.The steady state simulation model was made for AM/2-EHA copolymerization using Aspen Plus software.The calculation of material balance and energy balance was based on the 50 kg AM/2-EHA copolymers.The feed composition was the best formula of AM/2-EHA copolymer above.?Rbatch? model was selected as reactor type and ?POLYNRTL? was used as property method.Mn,Mw and PDI measured by GPC was used for model validation.Sensitivity was selected as a model analysis method,and the effect of temperature,initiator feeding rate,AM feeding rate,2-EHA feeding rate,the total monomer feeding rate on the Mn,Mw and PDI were disccussed.The process flow was designed,including feed preparation,copolymerization,slurry washing and drying,product pelletization,product drying,product size-grading,product blending and product bagging.The type and structure of reactor were designed according to the high viscosity of AM/2-EHA copolymer.This thesis can provide the basis for the development of the laboratory pilot plant.