热引发聚合方法制备抗240℃水泥浆降失水剂OACSTPCD

A terpolymer cement slurry filter loss reducer HTFLA-A is developed to deal with the poor thermal stability of the cement slurry filter loss reducers presently in use.HTFLA-A is designed and synthesized through high temperature thermally induced polymerization instead of the conventional water solution initiation polymerization.HTFLA-A works normally at temperatures up to 240℃.The optimal synthesis condition of HTFLA-A is:mass ratio of water to the monomers is 1:1,reaction temperature is 150℃,pH of the reaction system is 9,and the reaction time is 32 h.The molecular structure of HTFLA-A is characterized with FT-IR,DSC/TGA and NMR.The results of the study show that the final synthesis product HTFLA-A is the expected product.Weight loss on heating of HTFLA-A at 439℃is only 23.80%.The reason for this low weight loss on heating is because in the high temperature synthesis,the unstable structures in the monomer molecules and the by-products of the synthesis process are all removed from the final product,thus improving the high temperature stability of the target product.Performance evaluation of HTFLA-A shows that at a concentration of 1.2%,HTFLA-A can control the API filtration rate of a cement slurry to below 50 mL at test condition of 180-240℃and 6.9 MPa.