This study continues the work of presenting a novel approach for making petrophysical assessments of tight core samples. This method, the full-immersion pressure-pulse decay (Hannon 2019), involves applying a rapid increase in pressure in a chamber surrounding the entire outer surface area of a cylindrical sample, shutting the system in, and monitoring the pressure decay in the chamber as it reaches a new equilibrium. A precursor article covered the numerical simulator designed to model flow through the sample, demonstrating its performance and accuracy in addition to providing a first-order comparison between the speed and shape of the pressure-decay responses of the full-immersion method with those of other similar transient methods. This study covers the parameter-estimation procedure and experimental verification through a proof-of-concept laboratory investigation. The investigations provided here demonstrate that under appropriate, achievable experimental conditions, the pressure data can be analyzed in such a way that returns an estimate of the porosity and apparent permeabilities both parallel and perpendicular to bedding from a single test performed on a single cylindrical sample. After determining these experimental conditions (the uniqueness window), this report outlines a data-inversion strategy to estimate the petrophysical properties (porosity, horizontal permeability, and vertical permeability) from each test. This strategy is put to the test through comparisons with measurements performed by a commercial core laboratory. A common set of samples recovered from an outcrop of a tight-gas sandstone formation were investigated using the full-immersion method, and their results are compared with those from conventional steady-state measurement procedures performed by the commercial laboratory. Comparisons between petrophysical characterizations of these samples, which had permeabilities between 25 nd and 2.3 μd, demonstrated close agreement in most cases. However, whereas steady-state measurements performed at the professional laboratory required 4 to 5 hours of testing time per measurement of a single permeability, similar assessments using the full-immersion technique, requiring approximately 5 to 10 minutes to complete, returned estimates of the horizontal and vertical permeability simultaneously. Additional analyses are provided to determine principal reasons of discrepancies in instances where agreement was not as strong. Based on lessons learned from these experiences, the report closes with suggestions on areas of improvement in the experimental approach. Once complete, these developments should propel this technology to fill a critical need to determine petrophysical properties (porosity and permeability) of tight rocks in a time-efficient manner and in a way that does not compromise their accuracy.

这项研究继续了提出一种新方法的工作，该方法用于对致密岩心样品进行岩石物理评估。这种方法是全浸入式压力脉冲衰减（Hannon 2019），涉及在围绕圆柱样品整个外表面的腔室中施加压力的快速增加，将系统关闭，并监控腔室中的压力衰减随着达到新的平衡。前体文章涵盖了设计用于对样品流动进行建模的数值模拟器，除了提供了全浸没法与其他方法的压力衰减响应的速度和形状之间的一阶比较之外，还展示了其性能和准确性。类似的瞬态方法。这项研究涵盖了概念验证实验室研究的参数估计程序和实验验证。此处提供的研究表明，在适当的，可实现的实验条件下，可以对压力数据进行分析，以使对单个圆柱样品进行的单个测试返回的孔隙率和表观渗透率的估算值平行于和垂直于床层。在确定了这些实验条件（唯一性窗口）之后，本报告概述了一种数据反演策略，以估算每个测试的岩石物理特性（孔隙度，水平渗透率和垂直渗透率）。通过与商业核心实验室执行的测量结果进行比较，将该策略进行了测试。使用全浸没法研究了从致密气砂岩地层露头中回收的一组普通样品，并将其结果与商业实验室的常规稳态测量程序进行了比较。这些样品的岩石物理特征之间的比较（渗透率在25 nd和2.3μd之间）在大多数情况下显示出密切的一致性。但是，虽然在专业实验室进行的稳态测量每次测量一次渗透率需要4到5个小时的测试时间，但是使用全浸入技术进行的类似评估需要大约5到10分钟才能完成，返回的水平估算值和垂直渗透率同时。提供了更多分析来确定出现不一致的情况下出现差异的主要原因。根据从这些经验中学到的经验教训，该报告以实验方法的改进领域结尾给出建议。一旦完成，这些发展将推动该技术满足以紧迫的方式，并且不影响其准确性的方式确定致密岩石的岩石物性（孔隙度和渗透性）的关键需求。