中东孔隙型低渗灰岩储层酸液体系缓速性

Retarding Property of Acid System for Middle East Porous Type Low Permeability Limestone Reservoir

酸液的缓速性是影响酸液有效作用距离的关键因素,是优选酸压工作液的重要依据。采用旋转岩盘进行了普通盐酸、胶凝酸和乳化酸与伊朗雅达油田Sarvak储层灰岩岩心的酸岩反应实验,构建了反应动力学方程和变温动力学方程。结果表明,普通盐酸的反应速率明显快于胶凝酸和乳化酸,温度对反应速率影响显著,温度越高,反应速率越快。而相同反应温度下,乳化酸的反应速率常数分别比胶凝酸与普通盐酸小1和2个数量级,同时乳化酸的反应级数最大,现场配液时需要考虑酸液浓度对其反应速率的影响;酸液浓度相同时,乳化酸的反应活化能最大,其次为胶凝酸,普通盐酸的最小。乳化酸与胶凝酸的缓速性相对较好,预测其有效作用距离更大。

The retarding property of acids is the key factor that determines the effective distance of acid,and is an important basis for selecting acid fracturing fluid.Experiments about acid-rock reaction between hydrochloric acid,gelled acid,emulsified acid and limestone cores of the Sarvak reservoir in Yadavaran oilfield of Iran were conducted respectively by a rotating rock disk,then reaction kinetic equations and variable temperature kinetic equations were constructed.The results indicate that the reaction rate of hydrochloric acid was significantly faster than that of gelled acid and emulsified acid,and temperature had a significant effect on acid-rock reaction rate,the higher temperature,the faster reaction rate was.At the same reaction temperature,the reaction rate constants of emulsified acid were 1 and 2 orders of magnitude smaller than that of gelled acid and ordinary hydrochloric acid,respectively.Simultaneously,the reaction order of emulsified acid was the largest,and the influence of acid concentration on the reaction rate should be considered when the field liquid was mixed.When the acid concentration was the same,the reaction activation energy of emulsified acid was the largest,followed by that of gelled acid,and that of ordinary hydrochloric acid was the smallest.The retarding property of emulsified acid and gelled acid was relatively good,and the effective action distance was predicted to be larger.