一种用于水力压裂水平井的全局敏感性分析与降阶模型
A global sensitivity analysis and reduced order models for hydraulically-fractured horizontal wells
AI总结：
本文通过Sobol方法进行全局敏感性分析，以确定影响水力压裂水平井中孔隙压力耗尽和应力变化的变量重要性，同时提出降阶模型以降低计算成本。
摘要：
我们提出了一种系统性的全局敏感性分析方法，利用Sobol方法来确定影响水力压裂水平井中孔隙压力耗尽和应力变化的变量的重要性，这些变量包括岩石属性和压裂设计变量。为了考虑生产导致的孔隙压力和应力变化，我们使用了完全耦合的渗流弹性水力压裂模型。为了降低模拟器的计算成本，我们还提供了降阶模型（ROMs），可以将复杂的数值模型替换为相对简单的解析模型，以计算不同位置处的孔隙压力和应力。本研究的主要发现是：（i）流动性、生产压力和裂缝半长是影响感兴趣量变化的主要因素，每个参数的贡献百分比取决于其相对于现有水力裂缝的位置和感兴趣量。 （ii）随着时间的推移，流动性的效应降低，而生产压力的效应增加。 （iii）这两个变量在远离水力裂缝的大距离处对水平应力也有主导作用。 （iv）在靠近水力裂缝尖端或在间距区域内的区域，其他参数如裂缝间距和半长是影响最小水平应力的主要因素。本研究的结果将为遗留井的压裂设计和二次操作如再压裂和填充分钻提供有用的指导。
英文摘要：
We present a systematic global sensitivity analysis using the Sobol method which can be utilized to rank the variables that affect two quantity of interests -- pore pressure depletion and stress change -- around a hydraulically-fractured horizontal well based on their degree of importance. These variables include rock properties and stimulation design variables. A fully-coupled poroelastic hydraulic fracture model is used to account for pore pressure and stress changes due to production. To ease the computational cost of a simulator, we also provide reduced order models (ROMs), which can be used to replace the complex numerical model with a rather simple analytical model, for calculating the pore pressure and stresses at different locations around hydraulic fractures. The main findings of this research are: (i) mobility, production pressure, and fracture half-length are the main contributors to the changes in the quantities of interest. The percentage of the contribution of each parameter depends on the location with respect to pre-existing hydraulic fractures and the quantity of interest. (ii) As the time progresses, the effect of mobility decreases and the effect of production pressure increases. (iii) These two variables are also dominant for horizontal stresses at large distances from hydraulic fractures. (iv) At zones close to hydraulic fracture tips or inside the spacing area, other parameters such as fracture spacing and half-length are the dominant factors that affect the minimum horizontal stress. The results of this study will provide useful guidelines for the stimulation design of legacy wells and secondary operations such as refracturing and infill drilling.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
