乳化酸在低渗油层中选择性酸化的实验研究

Experimental Research on Selective Acidization of Emulsified Acid in Low- permeability Reservoivs

In order to solve the problem that conventional acidization may make water- bearing pore passage increase but make oil- bearing pore passage be unchanged in heterogeneous low- permeability reser- voir,a new emulsified acid formula system is developed,which can be prior into oil- bearing pore passage and remove deep blockage.The selection standard for the system is putforward.The characteristic of the system in viscosity and its acidization effectare studied with experiments.A large number of experimental results show that the viscosity will increase when the system meets with water and it will decrease when the system meets with oil.And itis also shown thatthe interfacial tension between the emulsified acid and oil is less than that between itand water.In static behavior,the acidization corrosion speed of the emulsi- fied acid is also less than that of conventional acids.The acidization corrosion percent of oil- bearing pore passage is over60 % ,and that of oil- bearing pore passage is below1 5 % .