碳酸盐岩气藏不同酸液体系对裂缝导流能力影响的实验研究

Influence of Reservior on Acid Etched Fracture Conductivity Experiment of Different Acid System for Carbonnate Gas Reservoirs

模拟酸压过程中大部分酸液沿裂缝流动、小部分滤失的流动方式,开展实验室酸蚀导流能力测试实验。岩样选用鄂尔多斯盆地碳酸盐岩储层白云岩,温度控制在100℃,测试不同闭合压力下酸液类型、接触时间及注入流速对导流能力的影响,得到以下结论:1稠化酸、交联酸、转向酸三种酸液体系所测试的导流能力有很大的区别,结果表明转向酸酸化后产生的裂缝导流能力最高;2对于一些酸液体系,所产生的裂缝导流能力并不总是随酸岩反应时间的延长而增强,在更长的酸岩反应时间下,裂缝导流能力反而下降,这表明在酸压过程存在最佳的酸化时间;3酸液流速为500 m L/min、800 m L/min、1 000m L/min时,随着酸液流速的增大,酸蚀裂缝导流能力增大;注酸速度1 000 m L/min时,酸蚀导流能力最大。通过开展酸导实验理论研究,为更加准确进行酸压设计提供重要指导。

Most of the acid flow along the fissures on the acid fracturing process, a small number of filtration, the experimental of acid conductivity is test in the lab, the rock sample selection of ordos basin carbonate reservoir dolostone, the experimental test the conductivity influence on acid type, contact time and injection velocity under different closure pressure, the experimental control the temperature of 100℃ , draw a conclusions： ①Gelled acid, crosslinking acid, diversion acid three acid system, it is difference in the test by conductivity experimental study, the results showed that the capacity of diversion acid is strongest. ②For some acid system, the acid-etching fracture capacity does not always increase with acid rock reaction time, the acid-etching fracture capacity is declined in the longer acid rock reaction time, it shows that there is the best time to acidification in acid fracturing process. ③The experimental study showed that the capacity increase with the increase of acid flow velocity under flowing rate of acid 500 mL/min, 800 mL/min, when acid injection rate is 1 000 mL/min, it is the higer that acid-etching fracture capacity. Based on the experimental theory study, the important guidance has been got in acid fracturing design for more accurate provide important.