Abstract We analyze flowback and post-flowback production data from six multi-fractured horizontal wells completed in Eagle Ford shale formation. Petrophysical analysis of samples from an offset well shows that the target shale is in oil window with type II kerogen. We analyze two groups of wells with different well-completion and operational parameters. Wells fractured with slickwater, with higher total injected volume (TIV) and larger choke size show higher initial oil rate, but faster pressure depletion compared with the wells fractured with cross-linked gel, with lower TIV and smaller choke size. Both groups show supercharged fractures when flowback starts and reservoir pressure remains above bubble point during post-flowback period. Interestingly, rate-normalized pressure plots of oil and water from both groups during post-flowback period show pronounced unit slope indicating boundary dominated flow (BDF), while this trend is not observed during flowback period. Analysis of rate-normalized pressure and rate-decline data suggests that both oil and water are produced from a closed tank under BDF conditions. We propose a multiphase flowing material balance (FMB) model to describe water and oil production from an effective stimulated reservoir volume (ESRV) during post-flowback period. The proposed FMB model assumes negligible oil and water influx into ESRV. The driving forces considered are closure of fractures and expansion of oil and water in ESRV. Applying the proposed model on post-flowback data confirms that after fracture depletion, oil is produced from highly stimulated matrix around hydraulic fractures while water is mainly produced from fractures.

中文翻译：

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对回流后生产数据的分析表明，从有限的增产储层容积中抽油：鹰福特页岩油案例

摘要 我们分析了在 Eagle Ford 页岩地层完成的 6 口多级压裂水平井的返排和返排后生产数据。对邻井样品的岩石物理分析表明，目标页岩处于油窗内，具有Ⅱ型干酪根。我们分析了具有不同完井和操作参数的两组井。与使用交联凝胶压裂、具有较低 TIV 和较小节流管尺寸的井相比，采用滑溜水压裂、具有更高总注入量 (TIV) 和较大节流管尺寸的井显示出更高的初始产油率，但压力消耗更快。当返排开始时，两组都显示增压裂缝，并且在返排后时期储层压力保持在泡点以上。有趣的是，回流后两组油和水的速率归一化压力图显示出明显的单位斜率，表明边界主导流（BDF），而在回流期间未观察到这种趋势。对速率归一化压力和速率下降数据的分析表明，在 BDF 条件下，油和水都是从封闭罐中生产的。我们提出了一个多相流动物质平衡 (FMB) 模型来描述回流后有效增产储层体积 (ESRV) 的水和油产量。提议的 FMB 模型假设流入 ESRV 的油和水可以忽略不计。考虑的驱动力是 ESRV 中裂缝的闭合和油和水的膨胀。将所提出的模型应用于返排后数据证实，在裂缝耗竭后，