Abstract Due to formation damage and fracture closure, the effective fracture half-length is usually much shorter than the designed half-length. However, available pressure transient analysis (PTA) models of multi-fractured horizontal wells (MFHWs) hardly consider the effect of non-uniform fracture closure of double-segment fractures (DSF) on transient pressure characteristics, which could bring about incorrect results since conductivity and flux density of fracture segment near wellbore are much larger than those of fracture segment far from wellbore. To fill this gap, this paper aims at presenting a novel approach to evaluate effective fracture properties through PTA more accurately. This new model allows each hydraulic fracture of MFHW consists of two individual segments with their own properties (e.g. length, conductivity and flux density, etc). Pressure and its derivative curves are developed for flow-regime analysis. The solution is validated with numerical results in Saphir. Sensitivity analysis further seek the feasible application on interpretation of effective fracture properties. The field application demonstrates the practical use of the proposed model in estimating fracture half-length with different conductivity during production stage to identify the extent of fracture closure using pressure data.

中文翻译：

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基于井底压力的致密气藏多裂缝水平井裂缝闭合评价创新模型

摘要 由于地层破坏和裂缝闭合，有效裂缝半长通常远小于设计半长。然而，现有的多裂缝水平井（MFHWs）压力瞬态分析（PTA）模型几乎没有考虑双段裂缝（DSF）不均匀裂缝闭合对瞬态压力特性的影响，这可能会导致不正确的结果，因为导流能力近井眼的裂缝段的通量密度远大于远离井眼的裂缝段。为了填补这一空白，本文旨在提出一种通过 PTA 更准确地评估有效断裂特性的新方法。这种新模型允许 MFHW 的每个水力压裂由两个单独的段组成，它们具有自己的属性（例如长度、电导率和通量密度，等等）。压力及其衍生曲线是为流动状态分析而开发的。该解决方案已通过 Saphir 中的数值结果进行验证。敏感性分析进一步寻求在解释有效裂缝特性方面的可行应用。现场应用证明了所提出的模型在估计生产阶段具有不同导流能力的裂缝半长方面的实际用途，以使用压力数据确定裂缝闭合程度。