Study And Preparation On New Sandstone Type Latent Acid

The object of this study was to develop the latent acid which is of low release propriety. A kind of acid solution was prepared by blending chemical reagent method; Solid-acid microcapsule and acid solution microcapsule was prepared by spary cooling method and separation method.It was obtained by blending Chemical reagent method of testing Formaldehyde - ammonium chloride system, citric acid - citrate system, the low pH acid system, the potential acid system. The research shows that NH₄C1-HCHO system has slow release property and high pH value. The compound of the formula with EDTA is poorly, the volume of corrosion is also not to meet the requirement. Citric acid - citrate system had a better slow release. But its corrosion effect is not ideal. The property of slow release can be enhanced by joining the chelating agent and surfactant, and fluoride and chloride salt can be added to improve the volume of corrosion. The low pH value latent acid system has a good corrosion effect, but the ph value is too low.It was obtained that solution acid microencapsulation prepared by spary cooling method. The coating material was separately 60#, 70#, 75# and 85# paraffin. The research shows that the optimum process conditions were that: span-80 and tween-80 emulsifying agent, the emulsifying agent of 1:7 to 1:9, emulsifying stirring speed of 1500 r/min.It was obtained that solid acid microcapsule prepared by phase separation method using follow process conditions: 2.0wt% enthylcellulose, 0.4wt% polyethylene paraffin with the molecular weight of 2000, the wall-core ratio of 1:5, stirring speed of 50 r/min, phase separation time of 180 min. The product prepared by this method was of better release property.