Study On The Systhesis And Properties Of Hydrophobically Associating Hydroxyl Ethyl Cellulose

Compared with polyacrylamide, hydrophobic associating polymer had good efficienttackifying property, thermal-resistance and salt-tolerance property, shear resistance propertyand viscoelasticity, and so on, which would have broad application prospect in enhanced oilrecovery field. Hydrophobic groups were introduced to modify hydroxyl ethyl cellulose andsynthesize hydrophobically associating hydroxyl ethyl cellulose(BHEC) in this paper.Reaction temperature, concentrations of oxidizer, concentrations of hydroxyl ethyl cellulose,amout of hydrophobic monomer, and reaction time were investigated through single factorexperiment, optimum experimental conditions were found, structure of the product wascharacterized by IR spectra and differential scanning calorimetry, synthetic product wasconsisitent with the target product. Tackifying property of BHEC was investigated, when theconcentration was about 4000mg/L, the apparent viscosity of BHEC was 2040mPa·s, and theapparent viscosity of HEC was 93mPa·s, viscosified property of BHEC is nearly 22 times ofthat of HEC, what's more, BHEC had low critical associating concentration, good shearresistance property, acid and alkali resistance property, thermal-resistance and salt-toleranceproperty had certain improvement; the influence of active agent and alcohol on aqueoussolution viscosity of BHEC, alcohol had promotion to aqueous solution of BHEC intackifying property, and with the increase of carbon atom of alcohol, alcohol was added tomake aqueous solution of BHEC have more obvious tackifying property, surfactant was addedto form mixed micelle to increase apparent viscosity of BHEC solution; BHEC had a certainsurface activity, alcohol had influence to surface activity of BHEC, monohydric alcoholsdecreased surface activity of BHEC, diol increased surface activity of BHEC, and with theincrease of carbon atom of alcohol, alcohol had more obvious influence to surface activity ofBHEC; BHEC had good viscoelasticity, when the concentration of BHEC got to 4000mg/L, ithad viscoelastic property, the storage modulus G' and the lose modulus G" increased withincreasing the concentration and the viscoelasticity showed increasing property. the higher theconcentration of polymer, the lower SF point, the more obvious viscoelasticity of BHEC inaqueous solution; in the artificial core displacement experiment showed that BHEC hadgreater drag coefficient and residual resistance factor than HEC at the same conditions, the influence of different concentration of polymer, slug and injection rate to oil displacementefficiency of BHEC solution were studied, compared with HPAM, the oil recovery factor ofBHEC was improved 7%～8%, BHEC had good oil displacement property; visualizationexperiment was used to discuss oil displacement mechanism of BHEC solution.BHEC wouldapply in chemical flooding through further study.