| 摘要: |
| 酸液沿酸蚀蚓孔的滤失是酸液滤失的主要控制因素，酸液滤失严重制约了酸蚀主裂缝的延伸，减小了与远井优势储集体沟通的几率，影响酸压改造的有效率。利用长岩心平板流动实验，模拟酸压改造中酸液在裂缝内的二维流动反应过程。实验发现，酸蚀蚓孔的数量及尺寸主要与酸液注入速率有关，而蚓孔的产生位置具有很强的规律性，主要沿天然裂缝生长发育。通过变裂缝开度酸刻蚀实验研究了酸液不同开度微裂缝中的流动反应过程，实验发现岩面的主要刻蚀形态包括：大于1 mm尺度裂缝对应的全岩板均匀溶蚀；1 mm～0.5 mm尺度裂缝对应岩板大面积非均匀刻蚀；0.1 mm左右尺度裂缝对应的局部较深、较窄圆柱形溶蚀通道。实验测试结果对针对性地采取降滤失措施具有一定的指导意义 |
| 关键词: 酸化压裂 酸蚀蚓孔 天然裂缝 滤失 刻蚀形态 |
| DOI： |
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| Experimental study on wormhole distribution and etching pattern in naturally fractured carbonate formation |
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He Chunming1, Guo Jianchun2, Liu Chao1
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1.Gradute Institute of Southwest Petroleum University，Chengdu 610500, Sichuan, China;2.Petroleum Engineering Institute of Southwest Petroleum University，Chengdu 610500, Sichuan, China
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| Abstract: |
| The main control factor of acid loss during acid fracturing treatment is acid loss through acid wormhole. Acid excessive loss seriously restrained the propagation of hydraulic fracture, which diminished the chance to connect the cave cleft system and the effectiveness of acid fracturing. This thesis utilizes the long core plate flow experiment, which modeling two dimension flowing and reaction of acid in fracture. The experiment indicates that the number and scale of acid wormhole is determined by acid flow rate, while the acid wormhole place is controlled by the distribution of natural fracture. Through the way of changing the aperture of fracture modeling the etching patterns of core with different aperture of fracture find that mainly etching patterns include: 1 mm aperture fracture corresponding to whole rock beam homogeneous etching; and 1 mm～0.5 mm aperture fracture corresponding to heterogeneous etching of most rock beam; and when the aperture of crack is around 0.1 mm the etching pattern is correspond to local deep and narrow dissolution channel. The test outcome has a guiding significance for adapting loss control measures in acid fracturing treatment |
| Key words: acid fracturing, acidizing wormhole, natural fracture, leakoff, etching pattern |
