乙酸在砂岩酸化中的功能

从缓速性、铁离子稳定性、缓蚀性、抗酸渣性及缓冲性几个方面系统分析了乙酸在砂岩酸化中的功能。结果表明．乙酸不仅仅是一种有机弱酸，更是一种多功能酸用添加剂，具有多方面的用途；乙酸可作为缓蚀增效剂，减小盐酸、氢氟酸对施工设备和管柱的腐蚀；作为抗酸渣荆，减小盐酸及铁离子与沥青质原油作用产生的酸渣量；作为缓冲液，能维持酸岩反应体系的低pH值，减小氟化钙、氢氧化铁、氢氧化铝、氟化铝等砂岩酸化中二次反应伤害沉淀物。现场应用效果进一步证明，乙酸在二连阿南、哈南油田、胜利桩西油田和大庆榆树林油田砂岩储层的酸化过程中实现了油井增产、水井降低井口压力、增加注水量的目的，而且这些酸配方在油田的后续施工中均得到了大面积推广，效果非常明显。

Functions of Acetic Acid in the Acid Treatment of Sand Stones

The functions of acetic acid in the acid treatment of sand stones are systematically analyzed in several aspects such as retardation,stability of ferric ions,corrosion inhibition,acid sludge resistence and buffering property etc.The analyses show that the acetic acid is more than a weak acid;it is multi-functional acid additive.Acetic acid can be used to control the corrosion on the tubular goods caused by hydrochloric acid and hydrofluoric acid.Acetic acid can also be used to reduce the amount of acid sludge generated by the reaction of hydrochloric acid and ferric ions with asphaltic crude.As a buffer fluid,acetic acid can help maintain a low pH in the acid-rock reaction system,reducing the amount of damaging precipitants(such as calcium fluoride,ferric hydroxide,aluminum hydroxide,and aluminum fluoride etc.) generated in the acid treatment of sand.Field practices further show that higher well production rates are obtained using acetic acid in the acid treatment of the reservoir rocks in Erlian(A Nan and Ha Nan),Shengli(Zhuang Xi) and Daqing(Yu Lin).The surface pressures of the injection wells are reduced and the quantity of injected water in increased.Furthermore,the acid formulations are widely applied in the subsequent operations and remarkable benefits are obtained.