Abstract A problem with the conventional diagnostic fracture injection test (DFIT) design, which involves analysis of the pressure falloff after the pump is shut-off, is the long test times required to achieve closure pressure ( p c ), a proxy for minimum in-situ stress, and after-closure flow regimes that can be analyzed for reservoir pressure in ( p r ) and transmissibility. An alternative approach to DFIT implementation is to flowback the injected fluid immediately after the pump is shutdown. Historically this approach has been to accelerate closure only, but recently the authors have demonstrated that careful design of the flowback procedure can yield accelerated p c estimates and possibly reservoir information. The new DFIT is referred to as ‘DFIT-FBA’, where FBA refers to the flowback analysis component to the test. p c is estimated using a Cartesian plot of flowing pressure versus flowback time. p r is determined through flowback data flow regime identification. The well productivity index for the studied reservoir interval is derived using the flowing material balance method. With constraints applied on created fracture properties, reservoir permeability may be determined. The practical application of the DFIT-FBA method is demonstrated with a field trial performed in a western Canadian tight oil reservoir. The resulting DFIT-FBA data quality is excellent yielding both closure and reservoir pressures due to accurate flow rate measurement. Both pressure estimates are in excellent agreement with a conventional DFIT performed on the same zone in the same area, but were obtained in a fraction of the time. In addition, application of the flowing material balance equation to after-closure data yielded an estimate of well productivity index for the tested interval. The DFIT-FBA demonstrated herein allows estimation of properties of interest to completions and reservoir engineers in a fraction of the time of the conventional DFIT.

中文翻译：

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改进的 DFIT（泵入/回流）的现场试验旨在加速估计关闭压力、储层压力和井生产力指数

摘要 传统诊断性裂缝注入测试 (DFIT) 设计的一个问题是泵关闭后压力下降的分析，是达到关闭压力 (pc) 所需的长时间测试，这是最小输入压力的代表。地应力和闭合后流态，可以分析 (pr) 中的储层压力和传输率。DFIT 实施的另一种方法是在泵关闭后立即回流注入的流体。从历史上看，这种方法仅用于加速关闭，但最近作者已经证明，仔细设计回流程序可以产生加速的 pc 估计和可能的储层信息。新的 DFIT 被称为“DFIT-FBA”，其中 FBA 是指测试的回流分析组件。pc 是使用流动压力与回流时间的笛卡尔图估算的。pr 是通过回流数据流态识别确定的。所研究的储层区间的井产能指数是使用流动物质平衡方法推导出来的。通过对创建的裂缝特性施加约束，可以确定储层渗透率。DFIT-FBA 方法的实际应用通过在加拿大西部致密油油藏进行的现场试验得到证明。由于准确的流速测量，由此产生的 DFIT-FBA 数据质量非常好，可以产生闭合压力和储层压力。两种压力估计都与在同一区域的同一区域执行的传统 DFIT 非常一致，但获得的时间很短。此外，将流动物质平衡方程应用于关闭后数据，可以估算出测试层段的井产能指数。此处展示的 DFIT-FBA 允许在传统 DFIT 的一小部分时间内估计完井和油藏工程师感兴趣的属性。