疏水缔合聚合物传输运移特性及其改进方法

Transmission Migration Features of Hydrophobic Associated Polymer and Its Improving Method

三次采油技术中使用的部分水解聚丙烯酰胺(HPAM)在高温高盐条件下会发生明显的水解和降解反应,抗温抗盐性能较差。疏水缔合聚合物凭借聚合物分子间缔合作用形成的大分子网状结构使其抗盐性有所改善,从而弥补了HPAM抗盐性差的缺陷。然而,疏水缔合聚合物存在其分子线团尺寸与油藏多孔介质孔隙尺寸间适应性差的问题,导致疏水缔合聚合物注入困难。针对疏水缔合聚合物与油藏适应性较差的问题,采用β-环糊精(β-CD)为疏水缔合聚合物缔合程度调节剂,通过室内岩心驱替实验方法,开展了β-CD对疏水缔合聚合物传输运移特性影响的研究。结果表明,β-CD可以改变AP-P4的缔合作用及在多孔介质中的行为。在浓度为1 g/L的疏水缔合聚合物AP-P4溶液中加入β-CD后,溶液黏度随β-CD加量的增加而减小,当β-CD加量达到0.07%时,AP-P4溶液黏度最低(26.2 m Pa·s),为本体黏度,难以发生缔合作用。同时,随着β-CD加量的增大,AP-P4分子链间缔合作用减弱,聚合物分子线团尺寸减小。随着β-CD加量的增大,在岩心渗透率相同(相近)条件下,AP-P4溶液的阻力系数和残余阻力系数减小,疏水缔合聚合物溶液在岩心内的传输运移能力增强。

Due to the apparent phenomena of hydrolysis and degradation reaction of HPAM in the condition of high temperature, the property of temperature resistance and salt resistance of HPAM is worse. Depending on the macromolecule net structure formed through the association among molecules, the property of salt-resistance of hydrophobic associated polymer is improved, which compensated the defect of the poor salt-resistance of HPAM. However, there exists a problem that the compatibility between the molecular thread size of hydrophobic associated polymer and pore size of porous medium of the reservoir is poor, which result in the difficulty of injection of hydrophobic associated polymer. Aiming at the problem of worse compatibility between hydrophobic associated polymer and reservoir, β-cyclodextrin （β-CD）was used as association-degree adjustment agent of hydrophobic associated polymer, by means of indoor core displacement experiment, the influence of a β-CD on the transmission migration of hydrophobic associated polymer AP-P4 was probed. Results showed that, β-CD could change the association action of AP-P4 and the behaviors of AP-P4 in the porous media. After adding β-CD into the AP-P4 solution with the concentration of 1 g/L, the viscosity of AP-P4 solution reduced with the increase of β-CD content, and when the β-CD content was 0.07%, the viscosity of the AP-P4 solution reduced to the lowest （26.2 mPa. s, which was of bulk viscosity）, at this time, the aggregation hardly happened. As the aggregation among molecular chains of hydrophobic associated polymer became weaker, the molecule thread size also reduced. With the increase of the concentration of β-CD, on the condition of the same core permeability, the resistance coefficient and residual resistance coefficient of hydrophobic associated polymer solution decreased, and its transmission migration capacity in the core pores was enhanced.