疏水缔合聚合物/表面活性剂二元体系性能研究

Performance of Hydrophobic Associating Water-solute Polymer/Surfactant System

曹伟佳 卢祥国 苏鑫 杨怀军 张杰

CAOWeijia LU Xiangguo SU Xin YANG Huaijun ZHANG Jie

针对大港油田孔南地区油藏具有高凝、高黏和高矿化度等特点及水驱开发效果较差的问题，进行了疏水缔合聚合物/表面活性剂二元复合体系应用的可行性研究。分别考察了疏水缔合聚合物AP-P7 溶液及由聚合物AP-P7 和非离子表面活性剂官109PS985 组成的聚/表复合二元体的系黏度、分子线团尺寸、界面张力及其影响因 素，采用β-环糊精作为调节剂改善疏水缔合聚合物油藏适应性，分析了高凝高黏油藏聚合物和聚/表二元复合驱提高采收率机制。结果表明，β-环糊精可改变疏水缔合聚合物分子形态结构，使其与岩心孔喉匹配性变强，减少堵塞。由注入水和软化水配制的浓度2000 mg/L 的聚合物溶液黏度分别为223.4 mPa·s 和302.5 mPa·s，而加入0.07%的β-环糊精后的黏度分别为26.5 mPa·s 和35.3 mPa·s，加入β-环糊精后聚合物AP-P7 溶液的黏度明显降低。调节剂β-环糊精加量由0.001%增加至0.07%时，聚合物的分子线团尺寸由235 nm降至155 nm。此外，β-环糊精加量由0.001%增至0.07%或溶剂水中钙镁离子浓度由508 mg/L降低至0 时，聚/表二元体系与原油间界面张力降低，洗油效率提高。将含有β-环糊精的由注入水配制的浓度2000 mg/L的AP-P7 溶液注入气测渗透率3500×10-3μm2的岩心，β-环糊精加量由0.001%增至0.07%时，阻力系数和参数阻力系数分别由35.6 和15.9 分别降至25.7 和11.0。在聚/表二元复合体系（Cp=2000 mg/L，Cs=2000 mg/L）中加入0.02%的β-环糊精，软化水配制的聚/表二元复合体系的黏度（81.5 mPa·s）高于未除去加药后注入水中沉淀的含垢水所配制的聚/表二元复合体系的黏度（69.5 mPa·s），但后者的阻力系数和残余阻力系数高于前者的，后者的注入压力也高于前者的。图5表8参16

Aimed at the characteristics of hypercoagulable，high viscosity and high salinity in Kongnan block of Dagang oilfield and the poor development effect of water flooding，the feasibility of the application of hydrophobic associating polymer/surfactant displacement system was probed. The dimension of polymer molecular coil Dh，interfacial tension between the crude oil and the hydrophobic associating polymer AP-P7 solution or“polymer/surfactant”displacement system，compounded of AP-P7 and nonionic surfactant Guan 109PS985，and their influential factors were studied under the experimental conditions，and β-cyclodextrin（β-cd） was used as the regulator to improve the suitability of polymer with oil reservoir，also the EOR mechanism of polymer flooding and “polymer/surfactant”displacement system in high viscosity and high condensate reservoirs was analyzed. The results showed that， β-cd could change the molecular morphological structure of the hydrophobic associating polymer，and make the matching of the polymer structure and core pore throat stronger，resulting in the reduction of the blockage. The viscosity hydrophobic associating polymer solution and“polymer/surfactant”system prepared with soft water，increased by 35.2% and 20.2% compared to that of the inject water，the viscosity of the polymer solution at the concentration of 2000 mg/L prepared with injected water and soft water， respectively，were 223.4 mPa.s and 302.5 mPa·s，When adding 700 mg/L of β-cd，the viscosity decreased to be of 26.5 mPa·s and 35.3 mPa·s，respectively，which indicated that the addition of the β-cd made the viscosity of AP-P7 solutions decrease obviously. When the concentration of β-cd increased from 10 mg/L to 700 mg/L，the Dh of AP-P7 decreased from 235 nm to 155 nm. In addition，when the concentration of β-cd increased from 10 mg/L to 700 mg/L or the concentration of Ca2+ and Mg2+ decreased from 508 mg/L to 0，the interfacial tension between the polymer system and the simulated reduced to some degree. The 2000 mg/L polymer solution containing β-cd was injected into the core with permeability of 3500×10-3 μm2，and the residual factor and residual resistance factor of polymer solution reduced from 35.6 and 15.9 to 25.7 and 11.0，respectively，when the β-cd dosage increased from 0.001% to 0.07%. After adding 0.02% β-cd，The viscosity of the“polymer/surfactant”system（Cp=2000 mg/L，Cs=2000 mg/L）prepared with soft water was of 81.5 mPa·s，which was higher that prepared with the soft water containing stains，while，the residual factor and residual resistance factor of the latter was higher than that of the former，and the injection pressure of the latter was higher than that of the former.

10.19346/j.cnki.1000-4092.2016.06.024