A commonly used rock stimulation technique in subsurface geoenergy technologies is matrix acidisation. During this process, an acidic solution is injected into the hydrocarbon or geothermal reservoirs to dissolve certain minerals and enhance the injectivity and productivity of the hydrocarbon or heat recovery operation. This study aims to investigate the influence of three-dimensional (3D) lithological heterogeneity of the rock on reactive transport of acid in the porous domain. Through a development and application of a reactive transport model with restricting assumptions (linear calcite dissolution kinetics with hydrochloric acid (HCl)) and simplifications (mineralogical homogeneity) on the geochemistry embedded into the model, we present the results of a series of 3D simulation of carbonate acidisation in presence of varying spatial correlation lengths of petrophysical properties of the domain. The results are compared with the case where petrophysical properties are distributed randomly throughout the domain. The study provides new insights into the impact of increasing correlation lengths that lack in the existing literature. Under the conditions of case studies, the pore volume of the acid injected reduces 10·5 and 12·2% for Damköhler number of 100, when correlation lengths of only 0·0667 and 0·1667 cm are considered in core of length 5 cm.

中文翻译：

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空间相关异质性对酸化虫洞发育的影响

地下地能技术中常用的岩石增产技术是基质酸化。在此过程中，将酸性溶液注入碳氢化合物或地热储层中，以溶解某些矿物质并提高碳氢化合物或热回收作业的注入能力和生产率。这项研究旨在研究岩石的三维（3D）岩性非均质性对多孔区域中酸的反应性输运的影响。通过开发和应用具有限制性假设（使用盐酸（HCl）的线性方解石溶解动力学）和简化模型（矿物均质性）的反应性运输模型，我们介绍了在该域的岩石物理属性的空间相关长度变化的情况下进行碳酸盐酸化的一系列3D模拟结果。将结果与岩石物理特性在整个域中随机分布的情况进行比较。该研究为现有文献中缺少的相关长度增加带来的影响提供了新的见解。在案例研究的条件下，当长度为5 cm的岩心仅考虑到相关长度为0·0667和0·1667 cm时，对于100的Damköhler数，注入的酸的孔体积减小10·5和12·2％。 。该研究为现有文献中缺少的相关长度增加带来的影响提供了新的见解。在案例研究的条件下，当在长度为5 cm的岩心中仅考虑相关长度为0·0667和0·1667 cm时，对于100的Damköhler数，注入的酸的孔体积减小10·5和12·2％。 。该研究为现有文献中缺少的相关长度增加带来的影响提供了新的见解。在案例研究的条件下，当在长度为5 cm的岩心中仅考虑相关长度为0·0667和0·1667 cm时，对于100的Damköhler数，注入的酸的孔体积减小10·5和12·2％。 。