Study on the Preparation and System of Desulfonated Anti-High Temperature Fluid Loss Agent

In this study, a desulfonated hybrid organic/inorganic fluid loss agent resistant to high temperatures is synthesized by using free-radical copolymerization. The fluid loss agent consists of the organic monomer acrylamide (AM), N-vinylpyrrolidone (NVP), dimethyl diallyl ammonium chloride (DMDAAC), and the inorganic monomer KH570 modified by nano-silica (M-SiO2). A field emission transmission electron microscope, an infrared spectrometer, and a thermogravimetric analyzer are used to examine the morphology and structure of the fluid loss agent. The results show that the inorganic nanoparticles and organic polymers are successfully grafted, and the resulting “core-shell” structure is connected by molecular chains. When 2% wt of the synthetic fluid loss additive E(AND-SiO2) is added to the base slurry, the normal-pressure fluid loss (FLAPI) and high-temperature, high-pressure fluid loss (FLHTHP) of the slurry are determined by the aging tests at 150, 160, 170, 180, 190, and 200°C for 16 hours. The results show that when the temperature is 180°C, FLAPI is 6.4 mL, FLHTHP is 28 mL, and temperature resistance is good. The biological toxicity and biodegradability tests show that the fluid loss control agent does not only effectively reduce the fluid loss, but also easily degrades, making it an environmentally-friendly treatment agent.