化学驱中聚合物水动力学尺寸及最优匹配注入研究

Study on Hydrodynamic Size and Optimal Matching Injection of Polymer in the Chemical Flooding

罗莉涛 廖广志 严文瀚 刘卫东 闫福丽 田 浩

LUO Litao LIAO Guangzhi YAN Wenhan LIU Weidong YAN Fuli TIAN Hao

为了明确化学驱中聚合物的注入性，针对聚合物（P）体系、碱-聚合物（AP）体系、表面活性剂-聚合物（SP）体系及碱-表面活性剂-聚合物（ASP）体系通过多组对比实验分析了各因素对聚合物水动力学直径Dh的影响，并进行了6种渗透率K岩心的P体系注入性实验以确定最优匹配注入界限。结果表明：P体系中，Dh随着聚合物相对分子质量Mr、浓度C的增加而增大。AP体系中，Dh随着碱浓度的增加而减小，且强碱作用效果比弱碱大；SP体系中，Dh随着表面活性剂浓度的增加而略微增大然后减小。ASP体系中，当表面活性剂含量相对聚合物较小时，碱和表面活性剂对Dh起相互制约作用；当表面活性剂含量较大时，碱和表面活性剂对Dh起协同作用。将聚合物溶液注入岩心时，需要遵循以下条件：当53×10-3≤K＜91×10-3μm2时，注入的聚合物溶液应满足C＜1g·L-1、Mr＜1×107；当91×10-3≤K＜146×10-3μm2时，注入的聚合物溶液应满足C＜2 g·L-1、Mr≤1×107；当146×10-3≤K＜199×10-3μm22时，注入的聚合物溶液应满足C≤2 g·L-1、Mr≤1.5×107；而当199×10-3≤K＜252×10-3μm2时，注入的聚合物溶液应满足C≤2.5 g·L-1、Mr≤2.7×107。图12表2参10

In order to confirm the polymer injectivity of the chemical displacing agents, the influence factors of hydrodynamic size of polymer was analyzed for polymer(P), alkali-polymer(AP), surfactant-polymer(SP) and alkali-surfactant-polymer(ASP) flooding, respectively, and the polymer solution injection experiments for the different reservoir with 6 kinds of permeability was carried out to obtain the optimal matching polymer injection. The results showed that, for P system, the hydrodynamic diameter Dh of polymer increased with the increase of polymer molecular weight (Mr) and polymer concentration(C), respectively. For AP system, Dh decreased with the increase of concentration of alkali and the effect of strong base was better than that of weak base. For SP system, surfactant concentration needed for maximum Dh was decided by the relative content of surfactant and polymer. For ASP system, when surfactant content is relatively less than polymer content, alkali and surfactant had mutual restriction effect for Dh; when surfactant content was relatively more than polymer content, alkali and surfactant have mutual synergy effect for Dh. When polymer solution was injected into the cores, the C and Mr of polymer should match with the K of the cores, when 53≤K＜91×10-3μm2，C＜1g?L-1 and Mr＜1×107；when 91≤K＜146×10-3μm2，C＜2 g?L-1 and Mr≤1×107；when 146≤K＜199×10-3μm2，C≤2 g?L-1and Mr≤1.5×107；when 199≤K＜252×10-3μm2，C≤2.5 g?L-1and Mr≤2.7×107.