Study On The Novel Diesel Microemulasified Acid Systems

In this paper, the diesel microemulsified hydrochloric acid systems were preparded by using cetyltrimethylammonium chloride (CTAC), n-octadecylglycidylammonium chloride(Gemini), aliphatic ethoxylate alcohol (AEO9, AEO15), Docosanylamidopropyl trimethyl ammonium chloride (S-22), Sodium salicylate, hydrochloric solution (volume ratio is 1:1) and diesel. The systems were optimized through phase behavior and orthogonal tests. The effects of types and amount of the main surfactants and cosurfactants on the formation of microemulsified acid systems were investigated. The stability, salt tolerance, corrosion inhibition and control-released delay reactivity of microemulsified acid systems were also investigated. The main conclusions were made as follows:1) The diesel microemulsified acid systems can be obtained by using CTAC and AEO15 as main surfactants, n-butnaol and n-octanol as cosurfactants.Under the volum ratio of 3:7 for diesel and hydrochloric acid, the optimal formula of emulsifier is the mass ratio of 4:1 for CTAC/AEO15,1:1.5 for cosurfactants/main surfactants,1:2.5 for n-butanol/n-octanol. The microemulsified acid system kept good thermal stability at 70℃, the tolerance to CaCl2 reached 90000mg/L, and possessed good corrosion inhibition and remarkable delayed reaction. The transparent thickening and gelling acid systems with S-22/AEO15/Sodium salicylate was obtained firstly.2) The diesel microemulsified acid systems can be obtained by using Gemini and AEO9 as main surfactants, n-butnaol and n-octanol as cosurfactants. Under the volum ratio of 3:7 for diesel and hydrochloric acid, the proper formulation of emulsifier was determined:the mass ratio of 1:1 for Gemini/AEO9,1:1.3 for cosurfactants/main surfactants,1:2.5 for n-butanol/n-octanol. The microemulsified acid system showed good stability at 90℃, the tolerance to CaCl2 reached 100000mg/L, and the corrosion inhibition and delayed reaction property were significant.3) The diesel microemulsified acid systems can be obtained by using Gemini and AEO15 as main surfactants, n-butnaol and n-octanol as cosurfactants. Under the volume ratio of 3:7 for diesel and hydrochloric acid, the optimal formula of emulsifier was:the mass ratio of 8:2 for Gemini/AEO9,1:1.3 for cosurfactants/main surfactants,1:2.5 for n-butanol/n-octanol. The microemulsified acid system could keep stability at 70℃, the tolerance to reached 70000mg/L, and the corrosion inhibition and delayed reaction were remarkable. The study in this paper was expected to provid basis for the application of new microemulsified acid system in the field of deeply acidification for low penetrability diesel and gas fields.