亚硝酸钠与氯化铵体系的反应特征

Reaction characteristics of sodium nitrite and ammonium chloride system

针对油田常用的亚硝酸钠和氯化铵自生氮气体系,通过常压/高压产气实验探究了不同因素对产气性能的影响。研究结果表明:反应物摩尔浓度比为1∶1时,反应物浓度、氢离子浓度及温度越高,反应速率及产气量越高,反应初始压力对体系产气量影响较小。自生氮气反应的生热能力随着反应物浓度、氢离子浓度和初始反应温度的增加而增加,反应体系的峰值温度也随之升高。NaNO2和NH4Cl体系的反应动力学方程为■;NaNO2和NH4Cl混合反应中存在H2N—NO和HN=NOH两种中间产物,NH3与N2O3经SN2亲核取代历程形成H2N—NO的反应决定了反应速率,H2N—NO转化得到的HN=NOH可自发分解生成最终产物N2和H2O。

On the basis of in-situ nitrogen generation system of sodium nitrite and ammonium chloride commonly used in oil fields,the effects of various factors on gas production performance were investigated by atmospheric pressure/high pressure gas production experiments.The results show that when the molar concentration ratio of reactants is 1∶1,the higher the reactant concentration,hydrogen ion concentration and temperature,the higher the reaction rate and gas production.The initial pressure of the reaction has little effect on gas production of the system.The heat generation capacity of the in-situ nitrogen reaction increases with an increase in the concentration of reactants,the concentration of hydrogen ions,and the initial reaction temperature,and the peak temperature of the reaction system is also increased.The reaction kinetic equation of NaNO2/NH4Cl system is■.There are two intermediate products during the mixing reaction of NaNO2 and NH4Cl,i.e,H2N—NO and HN=NOH.The reaction rate is determined by the reaction forming H2N—NO by NH3 and N2O3 through the nucleophilic substitution process of SN2.The HN=NOH obtained by H2N—NO conversion can be spontaneously decomposed,producing the final products N2 and H2O.