弱碱三元复合体系传输运移和深部液流转向能力——以大庆萨北油田储层为例

Research on transmission and migration capacity and deep fluid diversion ability of weak-base ternary compound system-Taking reservoirs in northern Saertu of Daqing oilfield as an example

近年来,大庆油区采用弱碱三元复合体系替代强碱三元复合体系,不仅克服了采油系统结垢问题,而且采收率增幅有所提高。与强碱三元复合体系相比,弱碱三元复合体系研究起步较晚,存在许多有待进一步攻关的技术难题。为此,以物理化学、高分子材料学和油藏工程理论为指导,以仪器检测、化学分析和物理模拟技术为手段,以大庆萨北油田油藏储层和流体为实验对象,以渗流阻力、分流率和采收率等作为评价指标,开展弱碱三元复合体系传输运移和深部液流转向能力及其对增油降水效果影响实验研究。结果表明:聚合物质量分数和碳酸盐颗粒数量是影响弱碱三元复合体系传输运移能力的主要因素;在粘度相同的条件下,随着界面张力的降低,弱碱三元复合体系深部液流转向能力降低;在界面张力相同的条件下,随着粘度的增加,弱碱三元复合体系深部液流转向能力增强;传输运移和深部液流转向能力可从不同方面评价弱碱三元复合体系性能,当二者与储层性质实现合理匹配时,弱碱三元复合驱才能取得最佳技术经济效果。

recent years,weak-base ternary compound system has been adopted by Daqing oilfield to replace strong-baseternary compound system,which not only overcomes the scaling problem at the production end,but also enhances oil recov?ery. Compared with the strong-base ternary compound system,the research of weak-base ternary compound system startslate,and some chemical flooding mechanism needs to be further explored. Taking the reservoir and fluid in northern Saertuof Daqing oilfield as experimental object,the transmission and migration capacity and deep fluid diversion ability of weakbaseternary compound system and its impact on increasing oil production and decreasing water cut were researched bymeans of instrument detection,chemical analysis and physical simulation guided by physical chemistry,polymer materialsand reservoir engineering. Seepage resistance,shunt rate and oil recovery were the evaluation indexes. Results show thatpolymer concentration and carbonate micro particle number are the main factors which have influence on the transmissionand migration capacity of the weak-base ternary compound system. Under the condition of the same viscosity,the deep fluid diversion ability of weak-base ternary compound system is reduced with the decrease of interfacial tension. However,under the condition of the same interfacial tension,it is enhanced with the increase of viscosity. The performance characteristics of weak-base ternary compound system can be evaluated by the transmission and migration capacity and deep fluid diversion ability from different aspects. Only when the two properties and reservoir properties achieve a reasonable match,theweak-base ternary compound system can obtain the best technical and economic results.