胶凝酸反应动力学试验研究

Experimental study on gelling acid reaction kinetics.

胶凝酸是目前酸化压裂技术中广泛应用的一种酸液体系,具有良好的缓速、降滤失、造缝、携砂与减阻性能,并能减轻二次伤害,在低渗透油气藏改造中,可有效提高酸的穿透距离和酸蚀裂缝的导流能力.介绍了胶凝酸反应动力学的试验方法及基本原理,开展了普通酸和胶凝酸与灰岩的反应动力学试验,得出不同条件下的酸岩反应动力学参数及反应动力学方程.从试验结果可以看出,在相同温度和酸液浓度条件下,普通酸的反应速度大于胶凝酸反应速度,普通酸的反应速度为胶凝酸的2～3倍;温度对酸岩反应速度的影响较大,在相同酸液浓度下,温度升高,酸岩反应速度增加,其中普通酸反应速度增加明显,胶凝酸增加缓慢.

Gelling acid is a sort of acid fluid system widely applied in acid fracturing technology,which not only has better retarding,filtration reducing,fracture generating,sand-carrying and resistance reducing effect but also reduces secondary damage.In stimulation of low permeable oil-gas reservoir,it can effectively increase the penetrating length of acid and flowing capability of acid etching fracture.In this paper,the testing method and basic theory on gelling acid reaction kinetics were presented,and the reaction kinetics parameters and equations on reaction of acid with limestone in various conditions were deduced on the basis of experiment on reaction of common acid and gelling acid with limestone.The results from tests indicated that the reaction speed of common acid was as 2~3 times as that gelling acid when the reacting temperature and concentration of acid fluids are same;temperature is the main factor affecting the reaction speed of acid with rock;the reaction speed of acid with rock enhanced when the temperature increased,but the reaction speed of common increases much faster than that of gelling acid.