表面活性剂对特低渗油藏渗吸驱油的影响

为了促进延长油田化学渗吸驱油提高采收率的目的,以延长HZP区块长6油藏为研究对象,针对水驱波及范围小,水驱动用程度低的问题,运用室内实验测试及分析的方法,分析不同润湿性和界面张力渗吸体系的渗吸驱油效率和规律。结果表明,润湿性不同的岩心渗吸驱油速度和效率由强到弱依次为亲水性、中性、亲油性,注入水体系中,原油在亲水岩心中的粘附功最小,仅有2.464 5×10^-3 J/m²,在亲油岩心中的粘附功达到16.743 7×10^-3 J/m²,是亲水岩心的6.8倍,不同表面活性剂均可以使粘附功不同程度的降低。十六烷基磺酸钠溶液渗吸效率最高,亲水岩心中渗吸效率达到25.2%,中性润湿岩心中渗吸效率为20%,均高于注入水渗吸驱油效率。矿场应用后油井综合含水下降20个百分点。对低渗油藏化学渗吸提高采收率具有重要意义。

Effect of surfactant on imbibition and displacement in ultra-low permeability reservoir

In order to promote the chemical permeation flooding in Yanchang Oilfield to improve oil recovery,the Chang6 reservoir in Yanchang HZP block is the research object.In view of the small water flooding area and low water drive,indoor experimental testing and analysis are used.Analyze the imbibition oil displacement efficiency and law of different wettability and interfacial tension imbibition systems.The results show that the oil imbibition and displacement speed and efficiency of cores with different wettability are hydrophilic,neutral,and lipophilic in order from strong to weak.In the injected water system,the adhesion work of crude oil in hydrophilic cores is the smallest,only it has 2.4645×10^-3 J/m²,and the adhesion work in the lipophilic core reaches 16.7437×10^-3 J/m²,which is 6.8 times that of the hydrophilic core.Different surfactants can reduce the adhesion work to varying degrees.Sodium hexadecyl sulfonate solution has the highest imbibition efficiency.The imbibition efficiency in the hydrophilic core is 25.2%,and the imbibition efficiency in the neutral-wet core is 20%,both of which are higher than the imbibition and oil displacement efficiency of the injected water.The comprehensive water cut of oil wells decreased by 20%after the application of the mine.It is of great significance for chemical imbibition to improve oil recovery in low-permeability reservoirs.