Investigation of non-Darcy flow in tight-gas reservoirs with fractured wells
Investigation of non-Darcy flow in tight-gas reservoirs with fractured wells
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DOI：
10.1016/j.petrol.2006.07.002
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发表时间：
2006-12
影响因子：
--
通讯作者：
T. Friedel;H. Voigt
中科院分区：
文献类型：
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作者：
T. Friedel;H. Voigt
惯性非达西流效应会显着降低压裂气井的产能。考虑到裂缝和储层中的惯性流，对这种影响进行了数值研究。模拟是通过完全隐式的内部模拟器来执行的。非达西流实现基于放松非达西控制参数的隐式处理。与传统方法相反，本方法有利于考虑高惯性流，并且还考虑了非达西流动系数的渗透性（应力）依赖性。该模拟工具适用于典型致密气井的合成生产场景，以获得恒定且与应力相关的参数。结果表明，尽管气体速率相对较低，但非达西流动效应仍会影响生产率。就现实情况而言，天然气总产量将减少 21% 至 40%。提出了裂缝和储层非达西流的新类型曲线，以识别储层非达西流的影响并促进压裂井性能的预测。本文的技术贡献包括 (i) 说明在完全隐式储层模拟工具中实现稳定且稳健的非达西流，(ii) 揭示惯性流效应对致密气井的影响，以及 (iii) 开发解释储层和裂缝中非达西流的新型曲线。
Inertial non-Darcy flow effects can significantly lower the productivity of fractured gas wells. The effects were investigated numerically, taking into account inertial flow in the fracture and the reservoir. Simulations are performed by means of a fully-implicit in-house simulator. The non-Darcy flow implementation is based on an implicit treatment with relaxation of the non-Darcy control parameter. Contrary to the conventional method, the present approach facilitates the consideration of highly inertial flow and accounts also for permeability (stress) dependency of non-Darcy flow coefficients. The simulation tool is applied to a synthetic production scenario in typical tight-gas wells for constant and stress-dependent parameters. Results suggest that non-Darcy flow effects will influence the productivity despite the relatively low gas rates. Regarding a realistic scenario, the total gas production is reduced by 21% to 40%. New type-curves are presented for fracture and reservoir non-Darcy flow to identify the impact of reservoir non-Darcy flow and to facilitate the prediction of the performance of a fractured well. Technical contributions in this paper include (i) the illustration of stable and robust non-Darcy flow implementation in a fully-implicit reservoir simulation tool, (ii) unfolding the impact of inertial flow effects on a tight-gas well, and (iii) developing new type-curves accounting for non-Darcy flow in the reservoir and the fracture.