酸压过程中多尺度酸岩反应特征实验研究

EXPERIMENTAL STUDY OF MULTI-SCALE REACTION BETWEEN ACID AND ROCK IN ACID FRACTURING

李小刚 杨兆中 苏建政 杨宇航

Li Xiaogang Yang Zhaozhong Su Jianzheng Yang Yuhang

西南石油大学, 成都, 610500 2. 中国石油化工股份有限公司, 石油勘探开发研究院, 北京, 100083 3. 海洋石油工程股份有限公司, 设计分公司, 天津, 300451

Southwest Petroleum University, Chengdu, Sichuan 610500, China 2. SINOPEC Exploration & Production Research Institute, Beijing 100083, China 3. Engineering Company of Offshore Oil Engineering CO., LTD, Tianjin, 300451, China

前人有关碳酸盐岩与酸液反应的研究多局限于单一尺度,尚缺乏对酸岩反应特征的多尺度探索。该文采用正交实验方法,进行了9次四川二叠系长兴组灰岩颗粒的酸液溶蚀实验,探索了主体酸浓度、温度、反应时间和酸型等4种因素影响下的宏观反应速率和介观反应机理。在所分析的因素中,酸型对宏观反应速率影响最强,其次是主体酸浓度。酸蚀前后的岩样在扫描电镜下的孔、缝、面的变化表现出多样性,表明碳酸盐岩酸蚀存在多种介观机理,前人所述的酸液对碳酸盐岩"通缝扩喉"的反应机理,只是其中的一种情况。对比不同尺度的反应特征,发现宏观反应速率与介观反应机理之间的相关性不明显。

Most of previous researches about acid/rock reaction are single scale and lack of multi-scale investigations.With orthogonal experiment method,nine acid erosion experiments of limestone particles,obtained from Changxing Formation of Permian in Sichuan Province,were designed and carried out.From the experiments result,it is discussed that the macroscopical reaction rate and mesoscopic reaction mechanism,which are influenced by four factors such as main acid concentration,temperature,reaction duration and acid type.The macroscopical reaction rate is most greatly affected by acid type,which is followed by main acid concentration.The rock mesoscopic structures observed by scanning electron microscope,such as pores,fractures and surfaces patterns,may be variously changed by acid erosion.In other words,there are various mesoscopic erosion mechanisms of carbonate rock."communicating fractures and expanding pore throat",summarized by previous researchers,is only a special case of mesoscopic erosion mechanism of limestone.When it comes to the relationship of different scale reaction properties,there is no obvious correlation between macroscopical reaction rate and mesoscopic reaction mechanism.

国家科技重大专项(2008ZX05005—006—08HZ);教育部高等学校博士学科点专项科研基金(20095121110001);四川省青年科技基金前期资助项目(06ZQ026—045)联合资助

https://doi.org/10.11781/sysydz201005504