Abstract Horizontal wells and hydraulic fracturing technologies are the only way that makes commercial production from the low and ultra-low permeability unconventional plays possible. The development of analytical and semi-analytical tools to analyze transient behavior of multi-fractured horizontal gas wells have been largely biased towards solving the simplified problem of one-dimensional (1D) Cartesian gas flow in matrix domain, which are only applicable to the production from infinite-conductivity fractures. This study presents a novel semi-analytical method for transient behavior analysis of horizontal gas wells producing from finite-conductivity fractures. Unlike the available transient analysis tools for finite-conductivity fractures which are developed based on empirical and approximate solution, the proposed solution is rigorously derived by solving the governing gas diffusivity equations written for gas flow in two contiguous regions of matrix and fracture simultaneously. Nonlinear, pressure-dependent gas properties remaining in pseudopressure-based diffusivity equations—namely viscosity and compressibility—are rigorously and straightforwardly captured in both fracture and matrix systems. The validity of proposed solution is verified against commercial numerical simulator (COMSOL Multiphysics®) for a series of synthetic cases considering constant and variable -rate production constraints. The case studies presented in this paper also showcase the applicability of proposed solution to the analysis of transient behavior of multi-fractured horizontal gas wells in shale plays under the following two state-of-the-art interpretations: 1) production from finite-conductivity hydraulic fractures in a single-porosity matrix; and 2) production from infinite-conductivity hydraulic fractures in a naturally-fractured matrix.

中文翻译：

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具有有限电导率裂缝的非常规气井的瞬态压力行为

摘要 水平井和水力压裂技术是实现低渗透和超低渗透非常规油藏商业化生产的唯一途径。用于分析多裂缝水平气井瞬态行为的分析和半分析工具的开发很大程度上偏向于解决矩阵域中一维（1D）笛卡尔气流的简化问题，这些工具仅适用于生产来自无限电导断裂。本研究提出了一种新的半解析方法，用于对有限电导裂缝生产的水平气井进行瞬态行为分析。与基于经验和近似解开发的有限电导裂缝瞬态分析工具不同，所提出的解决方案是通过求解同时为基质和裂缝的两个连续区域中的气体流动编写的控制气体扩散方程而严格推导出来的。保留在基于伪压力的扩散系数方程中的非线性、与压力相关的气体特性——即粘度和压缩性——在裂缝和基质系统中被严格而直接地捕获。针对考虑恒定和可变速率生产约束的一系列合成案例，针对商业数值模拟器 (COMSOL Multiphysics®) 验证了所提出解决方案的有效性。本文中的案例研究还展示了所提出的解决方案在以下两种最新解释下对页岩区多裂缝水平气井瞬态行为分析的适用性：1) 在单孔基质中从有限电导率水力裂缝中生产；和 2) 在自然压裂基质中从无限电导率水力压裂中生产。