Preparation Of Sulfonate Hyperbranched Polymer Surfactants And Its Application In Flooding

With the development and disseminate of enhanced oil recovery（EOR）technology, under the influence of oil geological conditionsthat the deeper formation the higher salinity and temperature offormation water, resulting in surfactants occurred in chromatographicseparation so that displacement agent can not effectively improve therecovery efficiency. Due to the requirment of surfactant concentration ishigher and dosage is bigger, cost is considerable. Therefore looking forhigh efficiency surfactants with heat resistance and salt resistanceproperyies, and according to the specific situation put forward the rightformula in recent years become the urgent work to be studied.Combining the current oil displacement surfactant’s requirementswith the characteristics of hyperbranched polymer, two new kinds ofhyperbranched polymer surfactants were preparated through modified tothe end hydroxy of hyperbranched polymer （HPAE）. One is alkylsulfonate of hyperbranched polymer surfactant （SHBP） and the other isalkyl aryl sulfonic acid salt of hyperbranched polymer surfactant（AAS-HBP）. Using to SHBP synthesis conditions were optimized bysingle factor experiments, the structures of the products werecharacterized by Infrared spectrum （FTIR）, Nuclear magnetic resonance（¹H-NMR）, Gel permeation chromatography （GPC） and Scanningelectron microscopy （SEM） spectroscopy. The surface activity andcritical micelle concention（CMC） of product solution weredeterminated by surface tension meter methord, and emulsificationpower of SHBP and AAS-HBP was investigated by the "cylindermethod" and compared with dodecyl benzene sulfonate （SDBS）. Thetolerance of SHBP and AAS-HBP to NaCl, MgCl₂, CaCl₂was alsostudied compatively. SHBP and AAS-HBP were lastly applied in crude oil, through the indoor evaluation experiment of products, oil/waterinterfacial tension, wettability, adhesion work, wash oil efficiency wasinvestigated, and compound, compared with petroleum sulfonate.Results of SHBP synthetic single factor experiment showed thatthe better conditions for SHBP synthetic as follow: esterificationreaction temperature was105℃, reaction time was3h； sulfonationreaction temperature was95℃, the dosage of HBPE was0.01mol, n（Na2SO3）: n （NaHSO₃）=1:2, dosage of NaNO3was2%of the totalweight of HBPE and NaHSO₃, n （HBPE）: n （NaHSO₃）=1:9, thereaction time for7h. The results of FTIR,¹H-NMR, SEM spectroscopywhich characterized the structure of the product showed that thesynthesis according to the expected synthetic route to got the expectedproducts; GPC results demonstrated that relative molecular massdistribution of SHBP is uniform.SHBP and AAS-HBP performance study experiment results showedthat with the increase of the sulfonation degree, SHBP surface activityincreased, while the CMC decreased, and when SHBP sulfonationdegree was5.19mmol·g^-1, with CMC was0.63mmol·L^-1, γCMCwas28.1mN·m^-1; AAS-HBP CMC was0.40mmol·L^-1, γCMCwas25.55mN·m^-1;SHBP and AAS-HBP have lower CMC and stronger ability to reduce thewater surface tension than traditional alkyl aryl sulfonate surfactantSDBS; The emulsion force of AAS-HBP, SHBP were no dfferent fromdodecyl benzene sulfonate （SDBS）, while SHBP and AAS-HBP’sparaffin emulsion stability was better than that of the formation ofSDBS; The greater degree of sulfonation of SHBP product the highersurface activity is; The lower sulfonation degree is, the higher toleranceto NaCl, changing SHBP’s sulfonation degree can adjust tolerance toNaCl; At25℃, SHBP （5mmol/L） tolerance to NaCl, MgCl₂, CaCl₂was150g/L,65g/L and40g/L respectively; AAS-HBP （5mmol/L） toleranceto NaCl, MgCl₂, CaCl₂was110g/L,85g/L,80g/L respectively.Application experiment results showed that SHBP or AAS-HBPused alone cannot make oil/water interfacial tension to the low that justlike the varieties of any single surfactant, however, compounding with the other surfactants, adding suitable amount（2%） of weak base such assodium carbonate, at50℃, surfactant concentration0.15%conditions,can make the oil/water interfacial tension to ultra-low interfacialtension, that is10^-3mN/m order of magnitude; SHBP and AAS-HBP canmake the core surface wettability changed to hydrophilic direction;Complex dispensing system which composed of SHBP, AAS-HBP andpetroleum sulfonate can reduce the adhesion work four orders ofmagnitude; Using thermal analysis instrument and chemical method tostudy the SHBP and AAS-HBP thermal stability, the results show thatSHBP and AAS-HBP have good thermal stability which is greater than95%; Displacement efficiency of the SHBP and AAS-HBP on simulationof oil-sand were investigated through the static deoiling experiment, theresults showed that washing oil at50℃for2hours,0.15%of the SHBPand0.15%AAS-HBP displacement efficiency is86.3%and84.9%respectively, while washing oil displacement efficiency of combinedsystem can up to93.1%.