Deformation bands and their impact on fluid flow in sandstone reservoirs: the role of natural thickness variations
Deformation bands and their impact on fluid flow in sandstone reservoirs: the role of natural thickness variations
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DOI：
10.1111/gfl.12030
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发表时间：
2013-08
期刊：
影响因子：
1.7
通讯作者：
A. Rotevatn;T. H. Sandve;E. Keilegavlen;D. Kolyukhin;H. Fossen
中科院分区：
文献类型：
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作者：
A. Rotevatn;T. H. Sandve;E. Keilegavlen;D. Kolyukhin;H. Fossen
碎裂变形带在砂岩储层中很常见，可能对流体流动产生负面影响，通常与显著的厚度变化有关。先前已经提出，这种厚度变化代表了对变形带如何影响流体流动的重要控制。这种厚度变化的影响进行了测试，在这项研究中，通过统计分析和流体流动模拟的一系列碎裂变形带在白垩纪砂岩在盆地的苏德-埃斯特在法国普罗旺斯。对空间露头数据进行统计分析，以纳入流动模拟模型，并使用数值模拟来研究显着的厚度变化对变形带如何影响有效渗透率和流动动力学的影响。使用细尺度和粗尺度网格的组合进行一套模拟，揭示了模拟储层的有效渗透率降低了15-25倍。更有趣的是，模拟进一步表明，与变形带阵列对流体流动的整体影响相比，沿带的厚度变化沿着被证明仅具有可忽略的影响。因此，我们的模拟表明，变形带的配置和连通性，以及带和围岩之间的渗透率对比度和平均带厚度，是最重要的控制有效渗透率。我们的研究结果代表了新的洞察变形带对地下含水层和水库中的流体流动的影响，表明个别变形带的厚度变化比以前认为的意义不大。
Cataclastic deformation bands, which are common in sandstone reservoirs and which may negatively affect fluid flow, are generally associated with notable thickness variations. It has been suggested previously that such thickness variations represent an important control on how deformation bands affect fluid flow. The effects of such thickness variations are tested in this study though statistical analysis and fluid flow simulation of an array of cataclastic deformation bands in Cretaceous sandstones in in the Bassin de Sud-Est in Provence, France. Spatial outcrop data are statistically analyzed for incorporation in flow simulation models, and numerical simulations are used to investigate the effects of notable thickness variations on how the deformation bands influence effective permeability and flow dynamics. A suite of simulations is performed using a combination of fine-scale and coarse-scale grids, revealing that the effective permeability of the simulated reservoir is reduced by a factor of 15–25. More interestingly, the simulations further demonstrated that, as compared to the overall effect of the deformation band array on fluid flow, thickness variations along the bands proved to have negligible effects only. Thus, our simulations indicate that the configuration and connectivity of the deformation bands, together with the permeability contrast between the bands and the host rock and the mean band thickness, are the most important controls on the effective permeability. Our findings represent new insight into the influence of deformation bands on fluid flow in subsurface aquifers and reservoirs, indicating that thickness variations of individual deformation bands are of less significance than previously thought.