Qiao Sanyuan, Liu Qingwang, Zhang Xian, Che Hongchang
Petroleum Engineering, Northeast Petroleum University, Daqing, China.
Wells and Operation Department, PetroChina International Middle East, Beijing, China.
Front Chem. 2021 Nov 5;9:738717. doi: 10.3389/fchem.2021.738717. eCollection 2021.
A hyperbranched carboxylate-type polymer was synthesized through esterification and carboxymethylation, and its performance on enhanced oil recovery was experimentally evaluated. The optimum condition for esterification was 8 h at 120°C, where 3% PTSA as the catalyst and 9:1 mol ratio of the AB intermediate and trimethylolpropane were used. The optimum condition for carboxymethylation was 4 h at 80°C. The critical micelle concentration of the hyperbranched polymer was 433.63 mg/L, the Krafft point was 5°C, and the surface tension was lowered to 28 mN/m. In the range of 400-500 mg/L concentration, the adsorption onto the oil sand surface achieved equilibrium, and micellar solubilization reached 600 ml/mol. The interfacial tension can be lowered to a level of 10mN/m by the single use of the hyperbranched polymer, and the value further decreased to a level of 10mN/m while being formulated with sodium dodecylsulfate or NaOH. Oil recovery of water flooding was further enhanced by the single use of a hyperbranched polymer or the combination of hyperbranched polymer/sodium dodecylsulfate. The latter exhibited more prosperous advantages in low-permeability reservoirs.
通过酯化和羧甲基化反应合成了一种超支化羧酸盐型聚合物，并对其提高采收率的性能进行了实验评估。酯化的最佳条件是在120℃下反应8小时，使用3%的对甲苯磺酸作为催化剂，AB中间体与三羟甲基丙烷的摩尔比为9:1。羧甲基化的最佳条件是在80℃下反应4小时。超支化聚合物的临界胶束浓度为433.63mg/L，克拉夫特点为5℃，表面张力降至28mN/m。在400-500mg/L浓度范围内，在油砂表面的吸附达到平衡，胶束增溶量达到600ml/mol。单独使用超支化聚合物可将界面张力降至10mN/m的水平，与十二烷基硫酸钠或氢氧化钠复配时，该值进一步降至10mN/m的水平。单独使用超支化聚合物或超支化聚合物/十二烷基硫酸钠组合均可进一步提高水驱采收率。后者在低渗透油藏中表现出更显著的优势。
