疏水缔合聚合物在孔隙介质上的静态吸附特征

Static adsorption features of hydrophobic association polymer on porous media

模拟大庆油田的油藏条件，测定了缔合聚合物在高岭土、膨润土、石英砂以及油层岩心砂4种吸附剂上的等温吸附曲线。结果表明，缔合聚合物在高岭土、膨润土上的吸附量大于在石英砂、油层岩心砂上的吸附量；同时缔合聚合物在以上各种吸附剂上的吸附规律不符合Langmuir等温吸附，其曲线形状为开口向下的抛物线，即随着缔合聚合物浓度的增加，吸附量逐渐增大并达到一个最大值，之后，随着聚合物浓度的增加，吸附量逐渐降低。此外，缔合聚合物的最大吸附量出现在缔合聚合物的临界缔合浓度400—450mg／L范围。该实验结果的重要意义在于：大庆油田缔合聚合物的使用浓度为1000mg／L，远高于发生最大吸附的临界缔舍浓度，而在使用浓度条件下，缔合聚合物的吸附量非常低，因而注入的缔合聚合物溶液在油层中运移时的吸附损失量较小，从而增加了运移、驱油的有效作用距离，能够大幅度提高缔合聚合物的驱油效果。

Simulating reservoir conditions of Daqing Oilfield, isothermal adsorption curves of association polymer on four adsorbents including kaolinite, bentonite, quartz sand, and oil layer rock core sand are measured. The results show that the adsorption capacity of association polymer on kaolinite and bentonite is higher than on quartz sand and oil layer rock core sand. At the same time, the adsorption law of association polymer on those adsorbents does not accord with Langmuir isothermal adsorption law. Its curve shape is a parabola with mouth down. That is, with the increase of association polymer concentration, adsorption capacity gradually increases and reaches a maximum value. After that, with the increase of polymer concentration, adsorption capacity gradually decreases. Besides, the maximum adsorption capacity of association polymer occurs when the critical association concentration of association polymer is at range of 400-450mg/L. The significance of the experiment result lies in: utilization concentration of association polymer in Daqing Oilfield is 1,000mg/L, which is much higher than the critical association concentration of maximum adsorption. While under the utilization concentration condition, the adsorption capacity of association polymer is very low, so the adsorption loss rate of injected association polymer solution is very low during migration in oil layer, thus the useful effect distance of migration and oil displacement is enhanced and the oil displacement effect of association polymer is greatly improved.