可溶性硅磷酸盐复合体系驱油效果研究

Studies on Oil Displacement Efficiency of Soluble Silicophosphate Combinational Flooding Fluids

报道了用可溶性硅磷酸盐替代NaOH构成的可用于大庆油田的三元及二元复合体系驱油效能的室内研究结果，实验温度45℃。一般性地介绍了该可溶盐的化学结构及作用原理。该可溶盐商品有缓蚀阻垢作用。由4～12g／L该可溶盐、1～4g／L烷基苯磺酸盐、1．2g／L聚合物组成的三元复合体系与原油之间产生超低（10-3mN／m）界面张力。分别与12／3／1．2（g／L）NaOH/表／聚三元体系及1．2（g／L）聚合物溶液相比，12／3／1．2可溶盐／表／聚三元体系和8／1．2可溶盐／聚二元体系，在0．2时人造均质岩心中的流动压差相近，流度控制能力较强，根据岩心分流率测定结果，高、中、低渗（1．2、0．6、0．2μm^2）并联岩心中调剖能力相当但耐水冲刷能力较强。在高、中、低渗并联岩心上，水驱后注入0．5PV8／3／1．2可溶盐像／聚体系的采收率增值（37％）与12／3／1．2强碱像／聚体系相当，如将可溶盐浓度提高至12g／L，则采收率增值可达40．7％。表4参6。

The results of laboratory studies at 450C on oil displacement by tri- and bieomponent combinational flooding fluids eontaining a soluble silieophosphate （SSP） instead of alkaline NaOH used in Daqing are presented. The chemical structure and functions of SSP are dipicted in general terms. Trieomponent fluids eomposed of 4-12 g/L SSP, 1-4 g/L surfactant, alkylbenzene sulfonates, and 1.2 g/L polymer create ultralow interracial tension with crude oil. In comparison with 12/3/1.2 g/L NaOH/surfactant/polymer fluid or 1.2 g/L polymer solution, 12/3/1.2 g/L SSP/surfatant/polymer fluid and 8/1.2 SSP/polymer fluid produce similar flow pressures but have stronger fluidity eontrolling capability in artificial homogeneous eore of 0.2 tan2 and indicate similar profiling capability and stronger resistance to water flush in parallel cores of higher, medium, and lower permeability, 1.2,0.6, and 0.2 μm^2, as shown by partial core flow rate determinations. On these parallel eores of higher, medium, and lower permeability after water flood finished, injecting 0.5 PV of 8/3/1.2 g/L SSP/surfactant/polymer fluid has led to an enhancement in oil recovery （EiOR） similar to that by 12/3/1.2 g/L NaOH/surfactant/polymer fluid, 37%, and the EiOR is increased to 40.7% when the dosage of SSP in the former fluid is raised to 12 g/L.