疏水缔合聚合物与储层适应性对采收率的影响

Influence of Adaptability between Hydrophobic Associated Polymer and Reservoir on Oil Recovery

王荣健 薛宝庆 卢祥国 康晓东 李建冰

WANG Rongjian XUE Baoqing LU Xiangguo KANG Xiaodong LI Jianbing

以疏水缔合聚合物为代表的抗盐型聚合物在油田提高采收率实践中获得良好增油降水效果。但是矿场实践中往往只重视聚合物溶液视黏度，而忽视聚合物溶液中聚合物分子聚集体与储层孔隙和非均质性间的匹配关系。以SZ36-1油田储层地质特征和流体为研究对象，开展了疏水缔合聚合物缔合程度及其调节方法研究，在此基础上进行了储层非均质性与疏水缔合聚合物缔合程度适应性评价。结果表明，在浓度为1750 mg/L的 AP-P4溶液中加入β-环糊精（β-CD），β-CD加量由0增至0.08%时，β-CD/AP-P4体系中的黏度由172.1 mPa?s降至7.7 mPa?s，聚合物分子线团尺寸由1078.2 nm减至500.1 nm，与之相适应的岩心渗透率极限由1500?10-3 μm2降至150?10-3 μm2。由此可见，加入β-CD可以调节疏水缔合聚合物溶液中超分子聚集体尺寸及其大小分布，进而改善其与储层岩石孔喉间匹配关系。岩心非均质性不同，与之相适应疏水缔合聚合物缔合程度也不同。当驱油剂体系与岩心孔喉相匹配时，采收率增幅才能达到最大。图4表4参14

Salt-resistangt polymer, in particular the hydrophobic associated polymer get good effect during the practice of EOR in oilfield, however, technical staff just concentrated on viscosity of polymer solution and neglected the adaptability between polymer molecular aggregates and rock pore and heterogeneity of reservoir in the past. Experiment that the degree association of hydrophobic associated polymer AP-P4 and the adjustment method was carried out based on reservoir and liquid in Bohai SZ36-1 oilfield, and the evaluation of adaptation between heterogeneity of core and the degree of hydrophobic associated polymer molecule association was conducted. The results showed that, When β- CD was added into the AP-P4 solution with concentration of 1750 mg/L, the amount of β-CD increased from 0 to 0.08%, the viscosity of β-CD/AP-P4 system reduced from 172.1 mPa?s to 7.7 mPa?s and the molecular clew dimension Dh of β-CD/AP-P4 system decreased from 1078.2 nm to 500.1 nm, while the suitable core permeability varied from 1500?10-3 μm2 to 150?10-3 μm2, respectively. β-CD could adjust the size and size distribution of polymer aggregates and improve the adaptability of the polymer with rock pore of reservoir. The hydrophobic associated polymer with different association degree was suitable for special heterogeneity of reservoir. When the adaptability between flooding agent and pore throat of core was well, the oil recovery could reach to the maximum.