高分子预交联凝胶颗粒的制备与性能评价

Preparation and Performance Evaluation of Polymer Pre-crosslinked Gel Particle

渤海绥中36-1油田储层非均质性强、大孔道窜流十分普遍,导致注水或常规调剖过程中化学剂沿大孔道窜流指进,驱替效果降低。为了改善这一问题,以钠膨润土、丙烯酰胺、N,N-亚甲基双丙烯酰胺、醋酸铬、过硫酸铵、硫脲为原料制备了复合交联插层高分子预交联凝胶颗粒(XD),评价了XD的吸水膨胀性、增黏性、强度、韧性及调驱效果,分析了XD的调堵机理。结果表明,XD遇水膨胀,在水中的悬浮分散性较好。体系初始黏度较低,注入性较好。XD吸水膨胀性良好,膨胀时间可控,膨胀一定时间后体系黏度增加,在65℃地层水中浸泡20 h的膨胀倍数约为8。具有吸附能力的酰胺基团在水中逐渐伸展,增加了XD表面的黏度,但微球的完整性仍然保持,XD在膨胀前后均具有良好的强度和韧性。XD体系调驱后二次水驱可在一次水驱的基础上提高采收率15.7%,满足渗透率大于3μm2甚至更高渗透储层的深部调堵需求。图6表1参10.

The reservoir heterogeneity of Suizhong 36-1 oilfield in Bohai Sea is strong and the channeling flow in large channel is very common,which leads to the channeling flow of chemical agents along large channels during water flooding or conventional profile control.In order to improve this problem,polymer pre-crosslinked gel XD with composite crosslinked intercalation was prepared by using sodium bentonite,acrylamide,N,N-methylene-bis-acrylamide,chromium acetate,ammonium persulfate and thiourea as raw materials.The water swelling,viscosify capacity,strength,toughness and profile control effect of XD were evaluated,and the profile control mechanism of XD was analyzed.The results showed that XD expanded when it met with water and had good suspension and dispersion in water.The system had low initial viscosity and good injectability.XD had good water swelling property and controllable expansion time.After a certain expansion time,the viscosity of the system increased.The expansion multiple of XD after steeping 20 hours in formation water at 65℃was about 8.The amide group with absorption ability gradually extended in water,which increased the viscosity of XD surface,but the integrity of the microsphere remained.XD had good strength and toughness before and after expansion.After the injection of XD system,the secondary water flooding could enhance the oil recovery by 15.7%on the basis of the primary water flooding,which met the deep profile requirement of reservoir with permeability greater than 3μm2 or even higher.