Synthesis and Performance of Copolymer Silica Scale Inhibitor
1. School of Chemistry and Chemical Engineering, Northeast Petroleum University, Daqing 163318, China；
2. No 2 Oil Production Company of Daqing Oilfield Company Limited, Daqing 163414, China
Abstract The introduction of the alkali component in ASP system results in a severe scaling in the oilfield injection-production system. To solve the problem of intractable silicon in the injection-production equipment scale, the new copolymer scale inhibitor for silicon called ADCA was synthesized by using aconitic acid (AA), diethanolamine (DEA), citric acid (CA), acrylamide (AM) as monomers, isopropanol as chain transfer agent and ammonium persulfate as initiator. The proper synthesis conditions were optimized as polymerization temperature at 75 ℃, polymerization time of 2 h, initiator dosage of 5% . The molar ratio of the monomers of n(AA):n(DEA):n(CA):n(AM) was at 2.0:1.0:1.0:1.2. Under such optimized synthesis conditions, the anti-scaling effect appeared to be satisfactory. At pH 8, 60 ℃ and scale inhibitor at 70 mg/L, the rate of silica scaling prevention was found to be 77.84%. Comparison experiments of anti-scaling rate determination, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) showed that the anti-scaling effect of ADCA was significant, and the main scale inhibition mechanism of copolymer was preliminarily considered as the adsorption and chelation.
