非均质油藏深部调驱用聚合物微球的制备及性能评价

Preparation and Performance Evaluation of Polymer Microspheres for Deep Profile Control and Flooding in Heterogeneous Reservoirs

为解决常规丙烯酰胺类聚合物微球在高温高盐非均质油藏中应用效果较差的问题,以丙烯酰胺(AM)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)和改性环状单体(NW-1)为合成原料,以N,N-亚甲基双丙烯酰胺和有机锆作为交联剂,制备了一种具有双重交联结构的聚合物微球SAM-2,室内评价其长期热稳定性能、黏弹性能、深部运移能力、剖面改善效果以及驱油效果,分析了调驱机理,并成功进行了现场应用。结果表明,聚合物微球SAM-2在储层温度(110℃)和矿化度(10.2×10^(4) mg/L)条件下老化180 d后仍能够具备较高的黏度和良好的膨胀性能,具有良好的耐温抗盐性能和长期热稳定性能。聚合物微球SAM-2的黏弹性能较好,且具有较强的深部运移能力。注入长岩心后能够在深部区域产生有效的封堵,并能有效地改善非均质岩心的吸水剖面,注入聚合物微球后高、低渗透岩心的剖面改善率可以达到98.7%。三层非均质岩心水驱结束后注入0.5 PV聚合物微球SAM-2,可使采收率继续提高25.34百分点,调剖驱油效果较好。现场应用结果表明,M-101井采取聚合物微球SAM-2深部调驱措施后,平均日产油量提升56.8%,平均含水率降低10.1%,达到了良好的降水增油效果。

In order to solve the problem of poor application effect of conventional acrylamide polymer microspheres in high temperature and high salinity heterogeneous reservoirs,a polymer microspheres SAM-2 with double crosslinking structure was prepared with acrylamide(AM),2-acrylamide-2-methylpropanesulfonic acid(AMPS)and modified cyclic monomer(NW-1)as raw materials,N,N-methylenebisacrylamide and organic zirconium as crosslinking agents.The long-term thermal stability performance,viscoelastic performance,deep migration ability,profile improvement effect,and oil displacement effect of SAM-2 was evaluated,the mechanism of profile control and flooding was analyzed,and SAM-2 had applied successfully on-site.The results showed that the polymer microspheres SAM-2 could still have high viscosity and good expansion performance,good temperature and salt resistance and long-term thermal stability after aging for 180 d at the formation temperature of 110℃ and mineralization of 10.2×10^(4) mg/L.SAM-2 had good viscoelastic properties,resulting in strong deep migration ability.After injected into long cores,SAM-2 could produce effective plugging in deep areas and effectively improve the water absorption profile of heterogeneous cores.The profile improvement rate of high and low permeability cores could reach up to 98.7%.Injection of 0.5 PV polymer microsphere SAM-2 into three-layer heterogeneous core after water flooding could continue to enhance oil recovery by 25.34%,exhibiting good profile control and oil displacement effect.The field application results showed that the average daily oil production of M-101 well was increased by 56.8% and the average water cut was reduced by 10.1%after the polymer microsphere SAM-2 deep profile control and flooding measures were taken,achieving a good effect of water production decline and oil production increase.