This study aims to investigate the propagation characteristics of an optimum wormhole to make an efficient acid treatment in carbonate matrix acidizing based on wormhole visualization using micro X-ray computerized tomography (CT) with high resolution. Five cases comprising 25 core-flood experiments under different experimental conditions using Indiana limestone cores were carried out at various injection rates to obtain the optimum injection rates. From the results, the optimum injection rates tended to increase with permeability but was not related to acid concentrations. The pore volume to breakthrough (PVBT), the amount of acid consumption required to breakthrough, was lower at higher permeability and acid concentration. This means that less amount of acid is consumed to generate the wormholes. Wormhole visualization with X-ray CT imaging showed that the wormhole diameters were gradually reduced along with the wormhole propagation axis in all cases. In addition, the mean of wormhole diameter tended to increase according to the higher permeability and acid concentration. The tortuosity, which is the ratio of actual wormhole length to core length, was exceeded at least 1.35 in each case. This implies that the actual flow length of the optimum wormhole is much longer than the core length. However, previous studies of wormhole propagation regarding the configuration of optimum wormhole are sparse, more intensive research would be required. Therefore, these propagation characteristics of optimum wormholes should be considered to improve the wormhole prediction model, and the wormhole prediction results would be more accurate and realistic than those of the existing models. Further study is needed to develop a new wormhole prediction model considering the propagation characteristics, such as diameter reduction and actual flow length.

这项研究旨在研究最佳虫孔的传播特性，以便在虫孔可视化的基础上使用高分辨率的微型X射线计算机断层扫描（CT）对碳酸盐基质酸化进行有效的酸处理。在不同的注入条件下，以不同的注入速率进行了包括25个岩心驱油实验的5个案例，这些实验是在不同的实验条件下进行的，以获得最佳注入速率。从结果可以看出，最佳注入速率倾向于随渗透率的增加而增加，但与酸浓度无关。在较高的渗透率和酸浓度下，要突破的孔体积（PVBT）（达到突破所需的酸消耗量）较低。这意味着消耗较少的酸以产生虫洞。X射线CT成像的虫孔可视化显示，在所有情况下，虫孔直径均沿虫孔传播轴逐渐减小。另外，随着较高的渗透性和酸浓度，虫孔直径的平均值趋于增加。在每种情况下，曲折度（实际虫孔长度与芯部长度的比）均超过了1.35。这意味着最佳虫孔的实际流动长度比岩心长度要长得多。但是，以前关于虫洞传播的关于最佳虫洞配置的研究很少，需要进行更深入的研究。因此，应考虑最佳虫洞的这些传播特性，以改进虫洞预测模型，虫洞的预测结果将比现有模型更准确，更真实。考虑到传播特性，例如直径减小和实际流长，需要进一步研究以开发新的虫洞预测模型。