Potential for significantly improving comprehensive performance of oil-well cement by a new type of latex

Abstract

In this study, a new type of soap-free inorganic/organic composite latex(SBML-II) was prepared by soap-free emulsion polymerization method using sodium p-styrenesulfonate(SSS) and modified SiO2 as copolymer emulsifiers, which were characterized by fourier transform infrared spectrometer(FT-IR), transmission electron microscope(TEM), thermo gravimetric analysis(TGA) and other means. Then the latex were employed to prepare polymer latex modified oil well cement and evaluate the influence of the latex on the basic properties of cement slurry,mechanical properties and microstructure of cement matrix. The characterization of SBML-II showed that the synthesized latex present typical core-shell structure and possess better dispersibility, stability and excellent thermal stability than the conventional latex(SBML-I). At same time, the SBML-II latex is easier to form membranous morphology than SBML-I at the same temperature and has better compatibility with additives and resistance to ions. Performance evaluation in cement slurry and cement matrix evidenced that the SBML-II has good dilution effect on cement slurry and excellent potential to improve the mechanical properties of cement matrix. Meanwhile, the addition of SBML-II is helpful to improve microstructure due to the film formation in cement matrix.