In May 2017, The University of Texas Hydrate Pressure Coring Expedition Gulf of Mexico 2-1 (UT-GOM2-1) drilled two adjacent holes in Green Canyon Block 955 in the deep-water Gulf of Mexico as part of The University of Texas at Austin and US Department of Energy Deepwater Methane Hydrate Characterization and Scientific Assessment. Expedition operations included testing two configurations of a rotary pressure-coring tool in a gas hydrate–bearing formation. In the first hole, an extended core barrel (cutting shoe) configuration of the Pressure Coring Tool with Ball Valve (PCTB-CS) was deployed, and in the second hole, the PCTB face bit configuration (PCTB-FB) was deployed. The PCTB-CS successfully recovered and maintained pressure for only one core out of eight deployments. A series of incremental modifications were made during and after the PCTB-CS deployment period that impacted the operations of the subsequent PCTB-FB deployments. Thus, in the second hole, the PCTB-FB successfully recovered and maintained pressure within the hydrate stability zone for 11 cores out of 13 deployments. The PCTB cored gas hydrate–bearing sandy silt interbedded with non–hydrate-bearing clayey silt within the main reservoir. The PCTB also recovered long intervals of unbroken, high-quality core with preserved sedimentary structures. We recovered one pressure core 130 m (437 ft) above the main hydrate reservoir in the silty clay. Pressure coring is the only available technology for recovering intact cores from sediment that is normally disturbed by gas expansion, dissolution, or dissociation; this allows a wide range of scientific measurements to be obtained with minimal disturbance to the core sediment fabric. Analysis of pressure cores has the potential to illuminate the in situ properties, gas saturation, and gas composition of a wide range of reservoirs including unconventional shale systems.

中文翻译：

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德克萨斯大学墨西哥湾 2-1 (UT-GOM2-1) 墨西哥湾北部格林峡谷区块 955 水合物压力取芯探险期间的压力取芯作业

2017 年 5 月，德克萨斯大学水合物压力取心勘探墨西哥湾 2-1 (UT-GOM2-1) 在墨西哥湾深水区 Green Canyon Block 955 钻探两个相邻的孔，作为德克萨斯大学的一部分奥斯汀和美国能源部深水甲烷水合物表征和科学评估。勘探作业包括在含天然气水合物地层中测试两种配置的旋转压力取心工具。在第一个孔中，部署了带球阀的压力取芯工具 (PCTB-CS) 的扩展取芯筒（切割靴）配置，在第二个孔中，部署了 PCTB 工作面钻头配置（PCTB-FB）。在八次部署中，PCTB-CS 仅成功恢复并维持了一个核心的压力。在 PCTB-CS 部署期间和之后进行了一系列增量修改，这些修改影响了后续 PCTB-FB 部署的操作。因此，在第二个孔中，PCTB-FB 在 13 次部署中的 11 个岩心中成功恢复并维持了水合物稳定区内的压力。主储层内含PCTB 岩心天然气水合物砂质粉砂与不含水合物的粘土质粉砂互层。PCTB 还回收了长间隔的、具有保存沉积结构的高质量岩心。我们在粉质粘土中主要水合物储层上方 130 m (437 ft) 处回收了一个压力岩心。压力取心是从沉积物中恢复完整岩心的唯一可用技术，这些沉积物通常会受到气体膨胀、溶解或分解的干扰；这允许在对核心沉积物结构干扰最小的情况下获得广泛的科学测量。压力岩心分析有可能阐明包括非常规页岩系统在内的各种储层的原位特性、气体饱和度和气体成分。