聚合物微球与储层岩石孔喉的匹配关系

The matching relationship between polymer microsphere and pore throat of reservoir rock

渤海Q油田储层非均质强,注水开发又加剧了其非均质性。为满足该油田深部液流转向技术的需求,文中利用激光粒度仪、生物显微镜、扫描电镜分析以及人造岩心驱替实验,研究了3种聚合物微球(简称微球)水化膨胀性能、微球与人造岩心孔喉的匹配关系及微球液流转向效果。结果表明:在磨口瓶中缓膨8 d后,微球A粒径中值从0.59μm增大至2.21μm,微球B粒径中值从3.80μm增大至28.02μm,微球C粒径中值从9.18μm增大至31.40μm,均表现出良好的缓膨效果;扫描电镜分析显示,提纯后的3种微球均呈球形堆积结构;微球A适用储层渗透率范围为100×10^(-3)~1000×10^(-3)μm^(2),微球B为200×10^(-3)~1500×10^(-3)μm^(2),微球C为500×10^(-3)~1800×10^(-3)μm^(2);与微球B,C相比,微球A粒径较小,界面能较高,容易在注入过程中发生聚并现象,微球A的岩心孔喉直径/微球粒径值较高,这与“架桥”理论确定的值相差较大。

Reservoirs of Bohai Q oilfield has strong heterogeneity,which is aggravated during water injection development.In order to meet the technical requirements of deep fluid diversion in Q oilfield,this paper studies the expansibility of three kinds of polymer microsphere(microspheres for short),the compatibility between microsphere and artificial core pore throat and the effect of fluid diversion by means of laser particle size analyzer,biomicroscope,scanning electron microscope and artificial core displacement experiment.The results show that the median particle size of microsphere A in the flasks increases from 0.59μm to 2.21μm after eight days of slow swelling,that of microsphere B from 3.80μm to 28.02μm,and that of microspheres C from 9.18μm to 31.40μm,all of which shows good effect of slow swelling.After purification,the scanning electron microscope images of microsphere A,B and C show spherical stacking structure.Microsphere A is suitable for reservoir permeability ranging from 100×10^(-3)to 1,000×10^(-3)μm^(2),microsphere B is from 200×10^(-3)to 1,500×10^(-3)μm^(2),and microsphere C is from 500×10^(-3)to 1,800×10^(-3)μm^(2).Compared with microspheres B and C,microsphere A has smaller particle size and higher interface energy,and is easy to coalesce during injection.The ratio of throat diameter/microsphere particle size of microsphere A is higher,which is quite different from that determined by"bridging"theory.