Synthesis And Performance Evaluation Of A Nitric Acid Corrosion Inhibitor

In some special sandstone reservoir(for example Qinghai Gasi oilfield El/3 oil)the acidizing operation,found by conventional acidizing,the effect is not obvious or no effect.Nitrate is a strong oxidizing acid,acid can be used as special reservoirs,improve the acidizing.Acidification in the construction process,we must first consider and solve the problem,is the acid protection of oil well casing corrosion of equipment.The use of corrosion inhibitor is a kind of method of simple operation,less investment,good effect.In this paper through a lot of theoretical research and experimental exploration of aniline,formaldehyde,after the selection of acetophenone,benzyl chloride as the raw material for the synthesis of nitric acid corrosion inhibitor.At the same time to explore the effects of pH value,reaction temperature,reaction time Mannich base and quaternization reaction time on the synthesis of corrosion inhibitor effect.The optimum synthetic conditions:Mannich base with aniline,formaldehyde and acetophenone ratio(molar ratio)is 1:2:2.2,reaction pH value is 2,the reaction temperature was set at 85℃,the reaction time is 6h.Mannich base quaternary ammonium optimum experimental conditions:benzyl chloride and the synthesis of Mannich alkali ratio(molar ratio)is 1:1,the reaction temperature is 90 ℃,reaction.pH value is 7,the reaction time is 4h.The structure of the target products synthesized by infrared spectrum were identified,s-tructural characteristics of all peaks appeared,demonstrates that the synthesis to achieve the desired purpose.The loss of the static properties of corrosion inhibition agent was developed for the determination of static weight loss method and electrochemical polarization curve method.Experimental results show that the static weight loss method at 60℃,corrosion inhibitor added in 1.0%-1.2%,N80 steel sheet in 10%nitric acid corrosion rate can reach 90%;electrochemical polarization curve experiment results show that the corrosion inhibitor synthesis is a mainly suppressed the cathodic corrosion,the compound can also inhibit the anodic corrosion corrosion inhibitor,at20℃,corrosion inhibitor increment in 1.0%,N80 steel sheet in 5%nitric acid corrosion inhibition rate was 89.5%.Synthetic products and a variety of compounds with corrosion inhibition Performance of the compound,the SDBS content in 3～5×10-3mol/L,synthesis inhibitor addition in 1.0%,the inhibition rate reached 92.1%.