微胶囊固体硝酸酸化液实验研究

固体硝酸酸压是近年来新发展起来的酸化技术，借鉴水力压裂微胶囊延迟破胶技术，先将固体硝酸微胶囊化，再用水基液携带固体酸颗粒带入地层裂缝，在裂缝中释放出H⁺，对地层实现深

EXPERIMENTAL STUDY ON MICRO CAPSULE SOLID NITRIC ACID LIQUID

Acidfracturing technology with solid nitric powder is a new one for acidizing,in recent years,its basic principle is that the liquid nitric acid is transformed into acid powder first,and then the acid powder is injected into the designed fractures that are just made by the fracturing fluid by nonactive liquid.After that,the releasing fluid is injected into the formation and the acid powder will release.The released acid will react with rocks to make the fracture faces etched and realize deep reform with the realized H⁺.With the idea of hydraulic fracturing of microencapsulated gel breaker technique and phase separation method,using ethyl cellulose and paraffin as coating material for solid nitric powder,the ration is 1.5:10.0 and 1.5:6.0respectively,the microencapsulated solid nitric acid can be injected into the formation with water based liquid.Under normal pressure or high pressure,the corrosion rate of microencapsulated solid nitric acid system is lower than hydrochloric acid liquid;its dissolution rate for rocks is different from hydrochloric acid liquid,with the time increasin,dissolution rate increases,the properties is good to realize deep acid,also,it has the same dissolution capacity as hydrochloric acid liquid.By analyzing flow conductivity of fractures after acidizing,it is demonstrated that complex acidizing fluid composed of hydrochloric acid and microencapsulated solid nitric acid is of higher flow conductivity after acidizing.