适用于碳酸盐岩深穿透的潜在酸试验研究

Experimental study on potential acid suitable for deep penetration of carbonate rock

为了提高碳酸盐岩储层的酸压效果,在增加潜在酸有效距离、增加酸蚀、提高裂缝导流能力等方面研究碳酸盐岩储层酸压效果的影响因素,以减少酸液损失等等。以大量实验为主要研究方法,根据在不同酸系统中测量的反应酸限值计算的活酸有效距离与根据先前标准计算的活酸有效距离大不相同。通过自行研制的小型岩心破裂能力测试仪,分析了岩石埋置强度、闭合应力、酸用量、岩石酸接触时间、酸液损失、酸泵排量等因素对裂缝导流能力的影响。结果表明:裂缝导流能力是影响酸压效果的关键参数之一,由于酸岩反应的强随机性以及各种影响因素,裂缝导流能力难以准确预测。酸化压裂过程中的滤失可以通过增稠液体和固体颗粒很好地控制,但不可避免地会对地层造成损害。

In order to improve the acid fracturing effect of carbonate reservoir,the influencing factors of acid fracturing effect of carbonate reservoir are studied in terms of increasing the effective distance of potential acid,increasing acid etching,improving fracture conductivity,etc.,so as to reduce acid loss,etc.With a large number of experiments as the main research method,the effective distance of active acid calculated according to the limit value of reactive acid measured in different acid systems is quite different from that calculated according to the previous standard.The influence of rock embedment strength,closure stress,acid dosage,rock acid contact time,acid loss,acid pump displacement and other factors on fracture conductivity is analyzed through a self-developed small core fracture capacity tester.The results show that the fracture conductivity is one of the key parameters affecting the acid fracturing effect.Due to the strong randomness of acid rock reaction and various influencing factors,it is difficult to accurately predict the fracture conductivity.The filtration during acid fracturing can be well controlled by thickening liquid and solid particles,but it will inevitably cause damage to the formation.