聚合物段塞交替注入参数优化研究

The Research of Parameter Optimization in Polymer Slug Alternative Injection

通过室内物理模拟实验,研究了注入方式对压力梯度的影响。研究表明,交替注入方式的压力梯度在较宽范围内均高于笼统注入方式。表明交替注入时,由压力梯度产生的,促使残余油受力以及变形的力,在较长的受效时间内大于笼统注入方式;同时研究了段塞交替次数和段塞组合方式对驱油效果的影响。实验结果表明:在聚合物用量相同的情况下,随着段塞交替次数的增加,化学驱采收率呈先增大后减小的趋势,最佳交替次数为4次;先注高浓度高分子量段塞组合驱油效果好于低分子量低浓度段塞组合的驱油效果;在聚合物用量不变的情况下,高分子量聚合物和低分子量聚合物交替注入驱油效果优于单独高分子量聚合物的驱油效果;最终优选最佳驱油体系为:主段塞0.1 PV2 g/L(分子量2 500×104),副段塞0.25PV0.5 g/L(分子量700×104),交替4次。

The influence on the pressure gradient of injection pattern has been researched by the laboratory physical simulation. Results show that, the pressure gradient of alternating injection pattern is higher than the general injection pattern in a wider range. In the period of alternating injection, the force which was generated by the pressure gradient is greater than the general injection pattern in a long period, and this force can make residual oil stressed and distorted. The impact on oil displacement effect of alternating slug frequency and slug combination has also been researched. Results show that, chemical recovery present the trend of first increasing and then decreasing with the increase of alternating slug frequency under the same usage of polymer, and the best alternate number is 4 times. The displacement effect of high concentration and high molecular weight slug combination is better than the low molecular weight and low concentration slug combination. When polymer injection amount is constant, the displacement effect of high molecular weight polymer and low molecular weight polymer alternately injecting is better than the high molecular weight polymer separately. The best displacement system ： main slug 0. 1 PV 2 g/L （25 ×10^6）, deputy slug 0. 25 PV 0. 5 g/L（7 × 10^6）, alternate four times.