Synthesis and mechanism study of an environmentally friendly filtrate reducing agent from humic acid and organic silicon

In this study, organic silicon was introduced to humic acid for the first time, and set the novel polymer NaHm/AMPS/AM/TSP-L12 (HASSi) as an environmentally friendly filtrate reducing agent, which was developed by using silica modified material (TSP-L12), sodium humic acid (NaHm), 2-acrylamido-2-methylpropanesulfonic acid sodium (AMPS), and acrylamide (AM) as raw materials. The molecular structure, chemical composition of HASSi has been investigated and results show that HASSi shows the chemical structure was conformed to the molecular design. Differential scanning calorimetry–thermogravimetric analysis results illustrate that thermal decomposition temperature of HASSi under nitrogen was 250°C. Though temperature resistance evaluations, HASSi could withstand temperature up to 230°C. Salt and calcium resistance evaluations confirmed its resistance of NaCl could reach up to 5% and CaCl 2 to 0.5%. The filtrate reduce mechanism of HASSi was investigated through various methods, including scanning electron microscope analysis of HASSi aqueous solution, microstructure of filter cake, measurements of zeta potential, and particle size distribution, results showed that HASSi participation in the formation of mud cakes and illustrated an excellent filtration reduction effect. In addition, HASSi was identified as an environmentally friendly filter loss reducing agent through environmental performance evaluation, which shows a great application prospect in oilfield.