酸碱类型对pH值控制的可逆乳状液的影响

摘要

可逆乳状液可以通过改变外界条件,在水包油和油包水型乳状液之间实现逆转,以发挥更好的作用.对其制备以及稳定性、不同酸碱类型对其影响进行了研究.结果表明,通过所选用的可逆转乳化剂,按照选定的工艺制备出的可逆乳状液具有良好的可逆转性能,并且在可逆转前后不同的乳状液类型下均可保持较好的稳定性,是性能较好的可逆转乳状液;在乳状液的转相过程中,酸、碱的类型对可逆乳状液转相特性有较大影响,特别是酸液携带的阴离子,尤其是高价阴离子对其影响较大;盐酸和醋酸可以使乳状液实现转相,加入硫酸后乳状液既不转相也不破乳,而在加入柠檬酸后乳状液出现破乳;加NaOH、Na2CO3、NaHCO3和氨水均可使可逆转乳状液实现转相,在转相过程中存在一个电导率的极大值,但该极大值不是出现在转相完全时,而是出现在转相过程中.基于可逆乳状液制备的可逆乳化钻井液产生的滤饼,可以轻易地通过酸液处理的方式处理,效果良好.%By changing external conditions,reversible emulsion can vary between oil-in-water emulsion and water-in-oil emulsion to play a better role that is expected.Studies have been conducted on the preparation and stability of reversible emulsions and the effects of acid and base types on them.The studies demonstrated that,a reversible emulsion with good reversibility can be prepared with selected emulsifiers through a predetermined process,and the emulsion can retain good stability before and after reversion.The types of acid and base,especially the anions of high valence in acids,play an important role in the reversion of reversible emulsion.Hydrochloric acid and acetic acid can reverse the phase of emulsion.Sulfuric acid does not change the phase of emulsion,nor does it demulsify the emulsion.Citric acid demulsifies emulsion.In phase changing of reversible emulsion caused by NaOH,Na2CO3,NaHCO3 and ammonia,a maximal electric conductivity appeared;it appeared just during the process of phase change,not after the completion of phase change.These studies can be applied in the treatment of mud cakes produced by reversible emulsion drilling fluids formulated with reversible emulsions;using acid solution,the mud cakes can be easily disposed of with good results.