Effective and optimal hydrocarbon production from heterogeneous and anisotropic reservoirs is a developing challenge in the hydrocarbon industry. While experience leads us to intuitive decisions for the production of these heterogeneous and anisotropic reservoirs, there is a lack of information concerning how hydrocarbon and water production rate and cumulative production as well as water cut and water breakthrough time depend on quantitative measures of heterogeneity and anisotropy. In this work, we have used Generic Advanced Fractal Reservoir Models (GAFRMs) to model reservoirs with controlled heterogeneity and vertical and/or horizontal anisotropy, following the approach of Al-Zainaldin et al. (Transp Porous Media 116 (1):181–212, 2017). This Generic approach uses fractal mathematics which captures the spatial variability of real reservoirs at all scales. The results clearly show that some anisotropy in hydrocarbon production and water cut can occur in an isotropic heterogeneous reservoir and is caused by the chance placing of wells in high-quality reservoir rock or vice versa. However, when horizontal anisotropy is introduced into the porosity, cementation exponent and grain size (and hence also into the permeability, capillary pressure, water saturation) in the reservoir model, all measures of early stage and middle stage hydrocarbon and water production become anisotropic, with isotropic flow returning towards the end of the reservoir’s lifetime. Specifically, hydrocarbon production rate and cumulative production are increased in the direction of anisotropy, as is water cut, while the time to water breakthrough is reduced. We found no such relationship when varying vertical anisotropy because we were using vertical wells but expect there to be an effect if horizontal wells were used.

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模拟各向异性对非均质储层中油气生产的影响

从非均质和各向异性储层中有效和优化地生产碳氢化合物是碳氢化合物行业发展中的挑战。虽然经验引导我们对这些非均质和各向异性储层的生产做出直观的决定，但缺乏关于碳氢化合物和水的生产速率和累积产量以及含水率和见水时间如何取决于非均质性和各向异性的定量测量的信息. 在这项工作中，我们遵循 Al-Zainaldin 等人的方法，使用通用高级分形储层模型 (GAFRM) 来模拟具有受控非均质性和垂直和/或水平各向异性的储层。(Transp 多孔介质 116 (1):181–212, 2017)。这种通用方法使用分形数学来捕捉所有尺度的真实储层的空间变异性。结果清楚地表明，在各向同性非均质储层中，油气产量和含水率可能会出现一些各向异性，这是由于在优质储层岩石中井位的机会造成的，反之亦然。然而，当将水平各向异性引入到储层模型中的孔隙度、胶结指数和粒度（因此也引入渗透率、毛管压力、含水饱和度）中时，早期和中期产烃和产水的所有措施都变得各向异性，随着各向同性流动在油藏寿命结束时返回。具体而言，油气产量和累积产量向各向异性方向增加，含水量也增加，同时减少了水突破的时间。我们在改变垂直各向异性时没有发现这种关系，因为我们使用的是垂直井，但预计如果使用水平井会产生影响。