多孔介质中聚合物弹性微球的运移规律与调驱性能

为了促进聚合物弹性微球深部调驱技术的大规模应用,通过岩心驱替实验,研究了多孔介质中聚合物弹性微球的运移规律与调驱性能。结果表明:聚合物弹性微球能够在多孔介质中不断地运移、封堵、变形、再运移、再封堵,注入压力呈现出波动式变化特征,后续注水阶段仍保持较高的注入压力水平;聚合物弹性微球的滞留量随距入口端距离的增加而减少,在出口端也有少量的聚合物弹性微球滞留;聚合物弹性微球能够选择性进入和封堵高渗大孔道,在后续注水过程中,高、低渗管的分流率仍保持在50%左右;岩心渗透率、注入浓度、注入速率和矿化度均影响聚合物弹性微球的调驱效果,在实际应用时需要选择合理的参数范围。可见聚合物弹性微球具有良好的注入性和运移性,可以依靠自身弹性运移至储层深部区域,且对低渗层具有保护作用,聚合物弹性微球封堵后具有较强的耐冲刷能力,从而达到较好的深部调驱效果。

Migration Law, Profile Control and Oil Displacement Performance of Polymer Elastic Microspheres in Porous Medium

In order to promote large-scale application of polymer elastic microspheres in-depth profile control and oil displacement technology, a series of core flooding experiments was used to investigate the migration law, profile control and oil displacement performance of polymer elastic microspheres in porous medium. The results show that polymer elastic microspheres can constantly transport, plug, deform, transport and plug again in porous medium, the injection pressure presents the characteristics of fluctuating variation, and still remains at a relatively high level in the subsequent water injection phase; the retention of polymer elastic microspheres decreases with the increase of distance to inlet end, and a small amount of polymer elastic microspheres are also retained at the outlet end; polymer elastic microspheres can selectively enter and plug large pore channels with high permeability, and the fraction flow ratios of high-permeability and low-permeability tubes still remain at about 50% during the subsequent water injection process; core permeability, injection concentration, injection rate and salinity all affect the profile control and oil displacement performance of polymer elastic microspheres, and a reasonable range of these parameters should be selected in practical application. It is concluded that polymer elastic microspheres have good injection and migration properties, and can transport into the deep area of reservoirs depending on their own elasticity. In addition, polymer elastic microspheres have a protective effect on the low permeability layer. After the porous medium are plugged, these polymer elastic microspheres have a strong resistance to washing, so as to achieve a better in-depth profile control and oil displacement effect.