Abstract Multi-linear analytical models are of high computational convenience to simulate the fluid production out of low-permeability unconventional (tight and shale) reservoirs stimulated with multifractured horizontal wells (MFHWs). But multi-linear models cannot accurately describe the flow behavior in such reservoirs since the fluid flow around hydraulic fracture tips is not linear flow. This creates barriers for the multi-linear models to consider pressure/stress-dependent fracture and reservoir characteristics. In addition, multi-linear models in the literature cannot consider or fully consider heterogeneity conditions including the reservoir heterogeneity and well completion heterogeneity. In this study, a composite model is developed to model the fluid flow in unconventional reservoirs with MFHWs under various heterogeneity conditions. In the composite model, the reservoir is divided into sub-systems and each sub-system is further divided into flow regions. The fluid flow in one flow region can be simply linear, radial or source/sink flow. The composite model considers the pressure/rate distribution characteristics beyond fracture tips with fast calculations. The composite model is applicable to one or combinations of the following three heterogeneous conditions-fractured horizontal wells with heterogeneous completions, reservoir heterogeneity around the horizontal well and reservoir heterogeneity around a hydraulic fracture. The model’s applicability in heterogeneous reservoirs is demonstrated by the comparison with the trilinear-flow model, five-region model and numerical solutions. In this study solutions of the composite model are utilized to analyze two sets of production data from fractured horizontal wells in heterogeneous conditions.

中文翻译：

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复合模型多压裂水平井生产分析：复杂非均质性的影响

摘要 多线性分析模型具有很高的计算便利性，可用于模拟多压裂水平井（MFHW）增产的低渗透非常规（致密和页岩）储层的产液。但是多线性模型无法准确描述此类储层中的流动行为，因为水力压裂尖端周围的流体流动不是线性流动。这为多线性模型考虑压力/应力相关的裂缝和储层特征造成了障碍。此外，文献中的多线性模型无法考虑或充分考虑储层非均质性和完井非均质性等非均质性条件。在这项研究中，开发了一个复合模型来模拟各种非均质条件下具有 MFHW 的非常规储层中的流体流动。在复合模型中，储层被划分为子系统，每个子系统又进一步划分为流动区域。一个流动区域中的流体流动可以是简单的线性、径向或源/汇流。复合模型通过快速计算考虑了裂缝尖端以外的压力/速率分布特征。该复合模型适用于非均质完井压裂水平井、水平井周围储层非均质性和水力裂缝周围储层非均质性三种非均质条件中的一种或组合。通过与三线流模型、五区域模型和数值解的比较，证明了该模型在非均质油藏中的适用性。