Synthesis And Property Research Of New Polymer Retarder

With gradually reducing of oil and gas reserves,exploration and development of oil and gas field have been faced to deep well,and ultra-deep well.However,there are some problems in deep petroleum wells,including long cementing interval,a large temperature difference between the top and bottom of cement slurry column,and the super-retardation of column top.During well cementing,additive especially retarder are added into cement slurry to solve these above problems.Nowadays,traditional retarders still have some defects,such as the narrowly applicable temperature range,postpone the rapid compressive strength development in low temperature and so on,which would affect the cementing quality.In this paper,aiming at the above-mentioned problems of well cementing and oil well cement retarder,a kind of hydrophobically associating water-soluble copolymer as retarder was synthesized by introducing the monomers with hydrophobic chains.This polymer comprising of 2-acrylamido-2-methyl-propane sulfonate(AMPS),itaconic acid(IA),acrylic acid(AA),N,N-dimethylacrylamide(DMAA)and quaternary ammonium salt(DMAPMA-1-BD)was synthesized by free radical aqueous solution polymerization.By studied the effect of reaction conditions,the optimum reaction conditions of copolymerization can be obtained.The molecular structure was characterized by FT-IR and 1H NMR and the results of IR spectra and 1H NMR spectra indicate that all of the monomers are involved in the copolymerization reaction.The heat resistance was measured by thermogravimetric analysis and the result of TG spectrum show that the polymer is stable and has good heat resistance.In this paper,the comprehensive performance of cement slurry with retarder PAIADD was evaluated.And this material can remarkably improve the performance of cement slurry,e.g.the excellent retarding ability in high temperature,the rapid compressive strength development in low temperature and nearly same setting time as temperature rose with same dosage.Thus its performance was thermo-responsive and it was able to eliminate the phenomenon of super-retarded on the top of cement slurry in deep petroleum wells with large temperature difference.The proposed method could have a wide application,especially for long cementing interval of deep well.Moreover,the retarding mechanism of PAIADD was studied by SEM and XRD and it can be found that the delayed coagulation of the cement slurry is attributed to precipitation,chelation and nucleation effects of the PAIADD molecules on the surface of hydrated particles or ions.This paper also studied the thermo-responsive behavior of PAIADD.The hydrophobic association structure was tested via rheological test,hydrodynamic diameter test and fluorescence probing test.The hydrophobic association structure would change as temperature increasing and these change could affect the complexing ability of PAIADD which test by potentiometric titration and ultraviolet spectrum test.