Abstract Recently, flowback data analysis enabled us to evaluate important fracture parameters including fracture conductivity and volume in unconventional reservoirs. To perform the analysis, diagnostic plots, straight-line techniques, and history-matching techniques have been used. Immediate water and gas production usually occurs on flowback in shale gas wells. In this paper, a novel workflow is developed for the analysis of water flowback data and the early-time production of shale gas wells. This analysis then helps to define the movable water and the applicability of the soaking process on these wells. Rate transient analysis (RTA) combined with decline curve analysis (DCA) were used to analyze different shale gas wells. Effective fracture volume and geometry were calculated from the RTA analysis. The estimated ultimate water recovery (EURw) was calculated from DCA. The calculated original water-in-place (OWIP) and the EURw were compared to the injected fracturing fluid. The impact of the soaking process on the well performance was studied. Results showed that in high-quality shale wells, with no movable formation water, gas kicked off early. OWIP was equal to the total injected water volume, and boundary dominated flow (BDF) regime was observed with no transient period. The performance of these wells improved with soaking. On the other hand, in low-quality shale wells, initial formation water saturation was higher than the connate water, and water production was from both the frac fluid and formation water. Consequently, gas kicked off later and transient flow regimes were observed. Transient flow regimes were used to estimate the fracture stimulated area. In this case, however, soaking had a negative impact on the performance as the movable water saturation was high. Honoring the flowback data can be used to estimate the fracture geometry and judge the quality of the shale formation and its validity for the soaking process.

中文翻译：

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一种新的水回流 RTA 分析工作流程，用于对页岩质量进行排序并估计裂缝几何形状

摘要 最近，返排数据分析使我们能够评估重要的裂缝参数，包括非常规储层的裂缝导流能力和体积。为了进行分析，使用了诊断图、直线技术和历史匹配技术。页岩气井的返排通常会立即产生水和气。在本文中，开发了一种新的工作流程，用于分析回水数据和页岩气井的早期生产。然后，该分析有助于确定可移动水和浸泡过程对这些井的适用性。采用速率瞬态分析（RTA）结合递减曲线分析（DCA）对不同的页岩气井进行分析。从 RTA 分析计算有效裂缝体积和几何形状。估计的最终水回收率 (EURw) 由 DCA 计算得出。将计算出的原始原位含水量 (OWIP) 和 EURw 与注入的压裂液进行比较。研究了浸泡过程对井性能的影响。结果表明，在没有可动地层水的优质页岩井中，气提早开始。OWIP 等于总注入水量，并且观察到边界主导流 (BDF) 状态，没有过渡期。这些井的性能通过浸泡得到改善。另一方面，在低品质页岩井中，初始地层含水饱和度高于原生水，产水来自压裂液和地层水。因此，气体开始较晚并观察到瞬态流态。瞬态流态用于估计裂缝刺激面积。然而，在这种情况下，由于可动水饱和度很高，浸泡对性能产生了负面影响。尊重返排数据可用于估计裂缝几何形状并判断页岩地层的质量及其对浸泡过程的有效性。