Utah FORGE: Well 16A(78)-32 Stage 1 - Pressure Falloff Analysis

This is an analysis of the pressure falloff in stage 1 fracture stimulation of FORGE well 16A(78)-32. The objective of this research is to understand the information content of the well stimulation data of FORGE Well 16A(78)-32. The Stage 1 step-rate test, a variant of the classic diagnostic fracture injection test (DFIT), contains valuable information about the success of well fracturing and the nature of resulting formation stimulation in the drainage volume of Well 16A(78). The analysis we have provided is based on the classic pressure transient analysis in petroleum reservoirs. The next step in the analysis is to use the information we have discovered in the analysis of tracer flowback data. This set of slides we have provided includes the pressure falloff analysis of the data recorded during stimulation of Stage 1 in injection Well 16A(78)-32 conducted in April of 2022. To honor multiple rate a superposition approach for linear flow regime was applied. The analysis yielded a permeability two orders of magnitude larger than permeability from cores. Our calculated permeability is essentially the effective permeability of micro- and macro-fracture system in the stimulated volume of the Well 16A(78)-32. Another observation is that after using the classic G-function plot, no closure stress was observed. This could suggest that pre-existing natural fractures were reopened during stimulation and yet had no propensity to close in accordance to the poroelastic properties.

本项研究旨在对FORGE 16A(78)-32井第一阶段压裂刺激过程中的压力衰减现象进行深入剖析。研究目标在于揭示FORGE 16A(78)-32井的井刺激数据所蕴含的信息含量。第一阶段步长测试，作为经典诊断性裂缝注入测试（DFIT）的一种变体，提供了关于井压裂成功与否以及16A(78)井排水体积内形成的刺激性质的重要信息。本研究所提供的分析基于石油储层中的经典压力瞬态分析。分析工作的下一阶段将利用我们在追踪剂回流数据分析中获得的发现。我们提供的这一系列幻灯片包含了2022年4月对注入井16A(78)-32第一阶段刺激过程中所记录的压力衰减分析数据。为了符合多速率叠加的线性流动规律，本研究采用了超级叠加方法。分析结果表明，渗透率比岩心渗透率高出两个数量级。我们计算得到的渗透率实质上是16A(78)井刺激体积内微裂缝和宏观裂缝系统的有效渗透率。另一观察结果是，在应用经典的G函数图后，未观察到闭合应力。这或许表明，在刺激过程中，原本存在的自然裂缝被重新打开，但并未表现出按照孔隙弹性特性闭合的倾向。