| The discovery of oil resources plays an irreplaceable role in the development of human society,and has a profound influence on the economic and political pattern of the world.Nowadays,87%of the world's energy supply still comes from oil,natural gas,coal and other fossil fuels,besides this number will remain at a relatively high level in the short term.As the basis of the current world's energy supply,thus the stable supply of oil resources has risen to the strategic position related to national economic safety and political stability.In the development of oil industry in China,the large fields such as Shengli,Daqing and Dagang have made an indelible contribution to the rapid development of our country.With an increasing demand for oil consumption and the end of primary and secondary oil recovery period for conventional oilfields,it becomes an immediate task to maintain the balance of oil production and consumption and reduce the dependence on imported oil.In this situation,it is one of the effective way to alleviate this dilemma that the exploitation of high temperature and salinity reservoirs.However,polyacrylamide flooding agents have some shortcomings,such as poor high-temperature resistance and high-salt tolerance.Therefore,the development of polymer flooding agents with high temperature and salt resistance has become a hot topic.Based on this research background and trend of development,the suitable functional monomers were selected to synthesize two kinds of ionic hydrophobically associating polymers by exploring the relationship between the aggregation morphology and the properties for polymer aqueous solutions.Besides,the effects of different factors on thickening ability of polymers were investigated and the best synthetic scheme was screened out.The research contents and main conclusions of this paper are derived as follows:1.A new amphoteric hydrophobically associating polymer was synthetized by non-soap emulsion polymerization using acrylamide(AM)as hydrophilic monomer,acrylic acid(AA)as anionic monomer,stearylmethylacrylate(SMA)as hydrophobic monomer,self-made methacryloxyethyl dimethylcetyl ammoniumbromide(DMC 16)as cationic surface active monomer.The characteristics were carried out by 1H NMR,FTIR,TG/DTG and elemental analysis.Besides,the effect of different contents hydrophobic monomers on the thickening ability of polymer,anti-shear properties,temperature resistance and salt tolerance were studied.The results showed that the synthesis of new amphoteric hydrophobically associating polymer(PAADS)was realized successfully.When the hydrophobic monomer content reached 1%of the total mass of monomers,the apparent viscosity of polymer solution reached the maximum and the structure of the intermolecular hydrophobic association could be observed clearly by SEM.Compared with polyacrylamide,the results showed that the polymer had good thickening ability,anti-shear properties,temperature resistance and salt tolerance.2.A new hydrophobically graft modified natural polymer was prepared which had excellent temperature resistance and salt tolerance property,using hydroxypropyl methyl cellulose(HPMC)as the matrix,hydrophilic monomer acrylamide(AM),acrylic acid(AA)and hydrophobic monomer stearylmethylacrylate(SMA).The structure characteristics were carried out by 1H NMR,FTIR,TG/DTG and elemental analysis and the properties of temperature resistance,salt tolerance and anti-shear properties were tested.The results showed that the polymer had better thickening ability and high temperature resistance.In addition,the properties of temperature resistance,salt tolerance,aging test,anti-shear and shear recovery for mixed system with sodium alginate(SA)were tested,which could select the optimal system against the high salinity in reservoir.The results showed that when the concentration of sodium alginate reached 0.3wt%,the mixed system had the advantage of the lowest cost and the best salt resistance. |
PDF Full Text Request