Acrylamide am

Tetraethyl orthosilicate (TEOS, 28.5%, Modern Oriental Fine Chemicals Co., Ltd., Beijing, China), acrylamide (AM, Sinopharm Chemical Reagent Co., Ltd., Beijing, China), N, N-methylene-bis-acrylamide (MBAA, Sinopharm Chemical Reagent Co., Ltd., Beijing, China), azodiisobutyronitrile (AIBN, Sinopharm Chemical Reagent Co., Ltd., Beijing, China), acetonitrile (Sinopharm Chemical Reagent Co., Ltd., Beijing, China), ethyl alcohol (Beihua Fine Chemicals Co., Ltd., Beijing, China), and ammonia (25%, Beihua Fine Chemicals Co., Ltd., Beijing, China) were purchased from a local supplier and were reagents of analytical grade. All the solutions were freshly prepared using deionized water. In addition, a crude oil sample with a density of 0.895 g/cm³ and a viscosity of 15.2 mPa·s (45 °C), and eight cores with lengths of 5.0 cm and diameters of 2.5 cm were obtained from a Daqing oil reservoir for the displacement experiments. The synthetic formation water used for the displacement experiments was a brine with a total dissolved solids (TDS) value of 5380 mg/L.

AMPS with effective weight over 98%, N,N-dimethylacrylamide (NNDMA) with effective weight over 98%, acrylamide (AM) with effective weight over 98%, IA with effective weight over 99%, MA with effective weight over 99.5%, AA with effective weight over 98%, sodium hydroxide (NaOH) with effective weight over 96%, ammonium persulfate (APS) with effective weight over 98%, sodium bisulfite (SOB) with effective weight over 99% and potassium persulfate with effective weight over 99.5% were obtained from Sinopharm Chemical Reagent Co. (Shanghai, China). API class ‘G’ cement was obtained from Sichuan Jiahua Enterprise (Leshan, China), and the phase composition and physical properties of class ‘G’ cement are presented in table 1.
Table 1.

Phase composition and physical properties of class G oil well cement.

C3S (wt%)	C2S (wt%)	C3AC (wt%)	C3AF (wt%)	specific density (kg l−1)	specific surface area (m2 kg−1)
53.7	30.46	2.8	8.0	3.17	332