基于碳酸盐岩酸化溶蚀形态的酸液最优注入速度界限

发布时间：2018-04-06 05:36

本文选题：蚓孔　切入点：碳酸盐岩　出处：《中国石油大学学报(自然科学版)》2017年05期

【摘要】：成功的碳酸盐岩基质酸化是在储层中形成几条主要的酸蚀孔道(蚓孔),穿过井筒附近污染带形成油气渗流的优势通道。储层中蚓孔的分布形态决定酸液的穿透距离及其酸化效果,而酸液的注入速度又会直接影响到酸蚀蚓孔的扩展。选取碳酸盐岩岩心,采用岩心驱替试验研究不同注入速度对蚓孔扩展的影响,通过计算突破体积比寻找碳酸盐岩酸化时酸液的最优注入速度,并通过压降曲线分析酸蚀蚓孔的生长过程。同时采用核磁共振成像技术分析酸化前后岩心端面及内部结构特征,用于判断酸液溶蚀类型,寻找到不同溶蚀形态所对应的酸液注入速度界限。结果表明,盐酸质量分数为20%时,开始形成酸蚀蚓孔时的注入速度为2 m L/min,注入速度为3~4 m L/min时酸化效果最佳。
[Abstract]:Successful carbonate matrix acidification is the dominant channel for formation of several major acid-etching pores (wormhole) through the polluted zone near the wellbore to form oil and gas percolation in the reservoir.The distribution of the wormhole in the reservoir determines the penetration distance and acidizing effect of the acid solution, and the injection rate of the acid solution will directly affect the expansion of the acid wormhole.The influence of different injection rates on the wormhole expansion was studied by using the core displacement test, and the optimum injection rate of acid solution was obtained by calculating the breakthrough volume ratio when the carbonate rock was acidified.The growth process of acid wormhole was analyzed by pressure drop curve.At the same time, nuclear magnetic resonance imaging (NMR) was used to analyze the core end face and internal structure before and after acidizing, to judge the corrosion type of acid solution and to find out the injection velocity limit of acid solution corresponding to different dissolution forms.The results show that when the mass fraction of hydrochloric acid is 20, the acidizing effect is the best when the acid wormhole is formed at the rate of 2 mL / min and the injection rate is 3 ~ 4 m / L/min.
【作者单位】：中国石油大学石油工程学院;中国石油勘探开发研究院廊坊分院;
【基金】：“十三五”国家科技重大专项(2017ZX005030005) 山东省自然科学基金项目(ZR201702180073) 中央高校基本科研业务费专项(14CX05019A)
【分类号】：TE357.2

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