我们非常感谢来自卡塔尔碳酸盐和碳封存研究中心（QCCSRC）资助，由卡塔尔石油，壳牌和卡塔尔科技园联合提供。我们也承认，从国子监联盟孔隙尺度建模资金。

1.成像策略设计<ol><li>以预测不同溶质的选择对盐水的成像性能，计算入射的X射线29-31的x射线谱。包括芯 - 保持器，芯组件上的X射线光谱的影响，并限制流体。使用的87微安80千伏和电子电流的加速电压，例如，入射的X射线光谱示于图1中 。 </li><li>这个频谱比较含不同孔隙流体样品的透射因子。模拟由于改变使用比尔-朗伯定律的孔隙流体的变化在透射系数，假定一个有效的光学长度的样品内的物种，以及计算出的X射线衰减系数（ 图3）32。确定通过集成在所有入射的X射线的能量的总的传输因子。所得有效传输因子岩石马特里的一例x和孔隙空间的材料，并且改变相对于当孔隙空间填充有真空的情况下传输的因素可以看出，在表1中 。 </li><li>选择一个盐水溶质和浓度，使得在用盐水相关的传输因子的变化是大约一半与固体相关的传输因子的变化。这将最大限度地在重构图像三相对比度。称量出所需的盐的量（7％（W / W）KI用于从该代表结果所采取的实验）并用去离子水剧烈混合。 <ol><li>可替代地，如果特定盐水洗涤组合物是期望的，改变X射线源的加速电压来改变入射的X射线的光谱。 </li></ol></li></ol> 2.装配设备和细胞<ol><li>组装如图2所示的设备。使用的PEEK油管，以减少对流动池侧向样品负载。仔细测试每个连接任何液体泄漏。 <ol><li>放置盐水洗涤，的过程中的步骤1.1-1.3组合物决定，在反应器的底部。包裹流动池周围的柔性加热器。 </li></ol></li><li>构建金属接头。从1/8"减速机配件的1/8"的1/16结束"删除线程。然后切成小凹槽入的嵌合的1/8"端面部分发注入的CO 2在芯的整个表面。 </li><li>通过使用¼"套圈和螺母微流动池和密封的金属端部通过高压热电偶，故热电偶的热接点位于邻近所述芯的入口面，电池的限制环形内。 </li><li>钻所需的样品放入一个芯直径6.5毫米30毫米至50毫米的长度。磨掉芯扁平的端部，以确保与金属端件连接良好。包装这个核心铝箔然后将withi呐flouro聚合物弹性套。 <ol><li>弹性体套筒的端部连接到金属端部配件。放置旁边单元的围环形热电偶的热接点和添加的铝箔的最终卷绕之前添加铝箔的弹性体套筒的外部的另一缠绕。这形成了芯组件（ 图4）。 </li></ol></li><li>装配有在其内密封所述芯组件的微流小区和小区连接到阶段的显微CT外壳内（ 图5），使用的夹具安装在旋转CT阶段的顶部。 </li></ol> 3.系统加压<ol><li>关闭所有的阀门除了阀1，2和3中， 如图3，负载CO 2的定义从缸体进入泵1和反应器中，然后关闭阀1，在反应器内的温度和压力下慢慢地提高到所期望的在实验过程中孔隙流体。 </li><lI&gt;大力混合反应器中，至少12小时，以确保所有阶段都在注射前的化学平衡。 </li><li>打开阀14并加载限制流体流入泵3关闭阀14打开阀12和13加压的小区的围环形比所提出的孔隙流体压力高至少10％。 </li><li>开阀11.加载到盐水泵2.关闭阀11，开阀9,8和6。 <ol><li>慢慢加压岩石的孔隙空间，直到它在所需的孔隙流体压力，填充用盐水样品尚未平衡的SCCO 2的孔隙空间。 </li></ol></li><li>开阀4冲洗通过芯平衡盐水超过1000孔体积由再填充泵2以恒定的流速。孔体积是由芯体积通过使用氦孔度计发现孔隙率乘以找到。 注意:这将miscibly取代非平衡盐水，保证100％的初始盐水饱和度和CREA婷条件在芯如同对地下条件在含水层的点处稍微超前一SCCO 2羽流的前面。 </li></ol> 4.流体流动和图像采集<ol><li>通过SCCO 2的10孔体积（约1ml）中通过铁氧体磁芯在非常低的流率（1.67×10 -9米3 /秒），确保了约10 -6的低毛细管数。不断采取二维投影，以便精确地测量通过观察点时SCCO 2置换盐水在孔隙空间中的总注射体积。 </li><li>通过平衡盐水的10孔体积（约1毫升）穿过芯以相同的低流率，导致SCCO 2成为被困在孔隙空间中的残留相位。 </li><li>之后的步骤4.1或4.2，取样品图像引流或吸的扫描分别。使用一个体素尺寸，使得所述芯的整个直径争夺的视野内配合瓦特</li><li>重建使用断层重建方案扫描。扫描所述芯的整个长度，同时保持一个小的体素尺寸，通过缝合在一起的多个重叠的部分中，顺次获取重构复合卷。 注:要求每节大约400预测，以15-20分钟获得，因此整个复合卷的扫描花了大约90分钟。 </li></ol> 5.图像处理和分割<ol><li>申请非本地手段边缘保持滤波器33,34的数据集和纠正图像的任何束硬化或通过模拟这些文物为径向对称高斯函数35软化图像重建过程中创建的文物。 </li><li>段中的数据（将灰度信息转换成CO 2的图像内的二进制表示）通过使用分水岭算法的使用二维直方图36中产生的种子，处理该CO <sub&gt; 2作为1相和盐水洗涤和岩一起作为其它相。 </li><li>分析这种分割后的图像，以找到的CO 2的体素两者的总数和残余的 CO 2的各连接簇也大小。 </li></ol>

The authors have nothing to disclose.

用于多相流体在升高的压力和温度下的成功的成像的最重要的步骤是:1）从周围围流体孔隙流体的成功分离; 2）在注射前的流体和岩石的有效平衡; 3）在整个实验有效的温度控制;和4）所产生的图像的有效分割。 穿过套筒迅速，并且内芯的饱和不保持恒定的扫描的持续时间使用的铝涡卷的是对于孔隙流体从周围围流体的成功分离在其不存在扩散交换的关键。这个问题也可能是显而易见的，当流体保持在PEEK油管的时间过长（&gt; 2小时）之前，注入到芯中的步骤4.1和4.2。再次，CO 2穿过塑料漫射交流，使盐水饱和度。如果德饱和食盐水注入该芯，在芯的饱和将减小残留群集由注入盐水溶解。 其它方法用于流体和岩石，包括液体再循环50的平衡，已经提出了在文献中。这些方法增加了的实验装置，这反过来会增加的时间量为每个实验中，这将在转弯的复杂性增加的可能性，在流动管线中的盐水会漫去饱和。 有效的温度控制是必要的，并且流动池的围环形内的热电偶的存在对于这个关键。温度仅测量在单个点，这意味着有可能是整个样本的一些梯度，导致溶解度不平衡和溶解或出溶。这可以通过定位热电偶的热接点尽可能接近到t最小化他入口面岩石核心。 所产生的图像的有效分割可以与这些系统一个真正的挑战，因为含有多种流体的局部饱和的图像的分割是显著更具挑战是干的图像的分割，所以使用简单的灰度阈值的通用的是不足51。使用分水岭分割，不仅给出了最可靠的结果，相对于在文献中其它算法，但也是在处理环和部分体积伪影35的最有效的。 一个该技术的最显著局限性在于，它只能访问一个岩石的宏观孔隙空间。的微孔（上鳞比图像分辨率小）仍然无法访问，并且可以是用于多相流重要。更高的分辨率揭示的孔隙空间这些部分的比例更大，而且还对应于在第一个下降看E场。该技术对一个特定的岩石类型的适用性可以通过扫描来使用独立的方法得到的孔喉尺寸分布的分辨率进行比较，如汞注入毛细管压力来解决。 此方法是一种用于多种流体在现实的系统储层条件的细孔级成像的领先技术，与现有的应用程序，包括毛细管捕集24的横比较研究和接触角26的测量，并且该方法很容易应用于大范围的多孔系统。今后的工作中可以研究，在孔隙规模，各种单相和多相流在多孔介质问题的条件有代表性的地下含水层，油气田和其他深部地质系统。

碳捕获和储存在这里的 CO 2是从大型点源捕获并存储在多孔岩石，取代居民盐水，使之保持在地下的数百万年1成千上万的过程。在CO 2驻留在地下作为致密超临界相（SCCO 2），具有性质完全不同的对CO 2在环境条件下。有四种主要的机制，其中SCCO 2可能在地下被固定:地层，溶解度，矿物和残余捕集。地层圈闭就是CO 2保持密封不透水的岩石下方;溶解度俘获是其中的CO 2溶解到注入的CO 2月2日 至4日围绕驻地盐水;矿物俘获就是碳酸盐矿物相沉淀成石5;和残余的或毛细管捕集是其中的 CO 2是由表面力保持作为微小液滴（神经节）在岩石6的孔隙空间。可能出现这种情况是天然，通过CO 2羽7-9的迁移，或可诱导的注射追逐的盐水10。为了了解管的流动和捕集此CO 2在地下的新的实验套件必须进行的，在技术利用新的进步，以更好地理解与多相流相关联的基本物理过程。 X射线显微断层已经开发作为一种技术在过去的25年，由早期的尝试来可视化两个干地质样品11和多个流体相12为岩芯的非侵入性成像的主要方法，既用于建模和实验实施13-15。因为微断层是非侵入性的，它具有学习系统在代表性条件的能力，这是特别attractive表示在CO 2 -brine岩系统，如SCCO 2的多相流动行为是高度依赖于热物理特性，如表面张力和接触角，这是在转弯的系统条件，如温度的强函数，压力和盐度16-18。在这样一个复杂的系统，具有如此广泛和知之甚少组相互依赖的变量，使用理想化的孔隙结构19或类似物的流体20,21的实验可能并不适用于在地下流动过程。在条件代表未来的二氧化碳注入地层的成像多种流体已，然而，仍然是一个挑战22。在这项研究中，我们概括为在油藏条件下多流体行为检查的方法，侧重于毛细管俘获23,24的检查。这将包括成像策略的设计，流体单元的组件，所述注入STrategy和随后的图像处理。 在真正的摇滚系统的实验检查孔隙规模多相流的行为集中在部分饱和岩心均非润湿相注射液（排水）和润湿阶段注入（吸）后的成像。这些液体是通过使用灵活的流线连接核心流体喷射泵注入，同时采用了哈斯勒型片芯轴设计25围的核心。为了成功图像SCCO 2和盐水洗涤，一种新的和高度敏感的实验装置的原位安排使用，主要集中在使用高分辨率X射线显微镜23,24,26的。用于进行在升高的温度和压力下的实验的要求是非常严格的，而且需要的最新进展在材料技术和微CT设备。即，必须满足的主要要求是，任何核/样品保持器需要从头勒承受高压高温（HPHT）条件下同时保持足够的X射线透明的以允许进行有效的摄像。基于实验室仪器施加一个额外的约束，如芯 - 保持器必须足够小，使得所述X射线源可以放在靠近样品和足够大的几何X射线倍率可以实现，使得孔隙空间是有效解决。虽然这方面的限​​制已经放宽稍微与在较新的基于实验室的微CT机引进二次光学，它并没有被完全除去，特别是当快速采集时间所需，因为更高的光学倍率趋于增加以获得所需要的时间图像。 实验用可溶性流体使用时冗长的采集时间，以CO 2会扩散通过实验组件的聚合部，减少了原位流体饱和度提供了额外的挑战。一LL这些问题意味着，扫描时间比大约为2小时再是不切实际的。为了保持低于这一要求的扫描时间，对实验室基源特别严格，芯保持器必须在直径约1厘米较大的片芯轴尺寸将需要检测到更远是从源来达到同样的几何放大倍数，减少的x射线通量入射到检测器上，并因此增加了所需的投影曝光时间。在这些实验中所用的流动池是基于传统的哈斯勒单元设计，围绕一个碳纤维套筒创建的，具有类似于用来通过Iglauer 等人的套筒设计27，但有两个显著改变:1）的碳纤维复合在套筒用于制造从T700纤维改变，以230京帕的硬度，以M55纤维，具有550京帕的硬度。这不仅断层扫描采集过程中降低了的采样移动量，而且也增加了最大をrking电池的压力从20兆帕至50兆帕。 2）套筒已伸长是212毫米到262毫米以允许源和检测器，以尽量靠近样品成为可能。 一个主要的缺点，实验在第一项研究中使用的微型CT检查CO 2在油藏条件下是使用金属线来控制流量，并从核心持有人27。作为样品旋转相对于所述泵的流线也需要被旋转。僵硬流线会导致样品移动，降低有效图像分辨率或作出一些数据集不可用的部分或全部。为了防止这种情况，我们全部换成流线靠近与柔性聚醚醚酮（PEEK）管的转动的阶段。这些流线是柔性的，在采集过程中提供了非常小的横向力（负荷）到芯保持器。我们还附着在流线到连接到样品台阀门，而不是流线附着到片芯轴。这意味着，任何现有的流线的负载被直接传递给阶段，而不是到样品，从而降低样品的运动的可能性。采用PEEK管的主要缺点是， 二氧化碳能够通过它慢慢扩散，在约24小时的时间尺度。这意味着CO 2的饱和盐水洗涤残留在流线会逐渐饱和度。 以前的研究的另一个主要实验的缺点是不准确的控制温度。这可以以多种方式影响的结果。首先，温度在两个界面张力和接触角16-18强大的控制。此外，既SCCO 2和碳酸盐岩中的盐水中的溶解度也高度依赖于温度28。溶解度控制是至关重要的，因为当SCCO 2注入到盐水含水层碳酸盐就会溶解到驻地盐水洗涤，形成一个高反应性碳酸，这将在涂RN开始溶解任何方解石存在。因此，任何不准确的溶解度控制可以导致SCCO 2溶解/脱溶或固体溶解/沉淀。 以往的研究27采用热流体围加热片芯轴;然而，这是有问题的。它具有精确保持恒定的围压利用循环水供应，需要额外的加热浴对于供应的难度有关的缺点。此外，该系统只保持温度在加热浴的点的精确控制（未在芯保持器的点，并且限制流体将水浴和芯保持器之间的冷却）。它还需要一个入口和用于限制流体的出口，增加了附着到片芯轴流体管线和因此增加的流线负载的数量。 而是采用了热围液，灵活heati纳克护套被用来包围该芯保持器。这个非常简单的加热方法导致了非常小的片芯轴载荷，并且允许的精确和准确的加热。极薄的聚酰亚胺加热膜使用时，为了尽量减少样本大小。该薄膜的结构包括一个蚀刻铜箔元件0.0127毫米厚，的0.0508毫米聚酰亚胺膜的两层之间的包封。存在于夹套中的铜的元素没有明显地影响图像质量。使用热电偶坐在小区的围环形温度进行测定。它被定位在限制套筒，尽可能接近到芯的外侧，确保孔隙流体温度的精确，可靠和稳定的读数。热电偶和加热片连接到一个定制比例积分微分（PID）控制器和温度分别在±1控制 ℃。 为了保持完全控制OV呃相间的溶解度，并表示存在于该含水层远离注射部位，在注射之前将盐水平衡的SCCO 2通过两流体剧烈混合在一起与宿主岩石小颗粒（1-2毫米）的条件下在搅拌和加热的反应器中。该反应器内所有湿润部件均采用镍基合金，以尽量减少腐蚀。该反应器包含一个过滤汲取管，以允许更密集的流体被从反应器（盐水）的基部提取较少稠密流体被从反应器（SCCO 2）的顶部提取。高压注射泵，用于维持压力和控制流中的岩石的孔隙空间和在反应器中，用25.4 NL的位移精度。在这项研究中所使用的实验装置示于图1。用于实验的离子盐从其中代表性的结果被绘制为碘化钾（KI），因为它具有高的原子量，因此一高X射线衰减系数，使之成为一种有效的对比剂。少衰减的盐（例如NaCl），或混合物，也可以使用，但是，更大的盐度将需要实现相同的X射线衰减。

<table><tbody><tr><td>High Pressure Syringe Pump</td><td>Teledyne ISCO</td><td>1000D</td><td></td></tr><tr><td>Parr Reactor</td><td>Parr Instrument Company</td><td>4547A - hastelloy</td><td></td></tr><tr><td>PEEK Tubing</td><td>Kinesis</td><td>1560xL</td><td></td></tr><tr><td>Potassium Iodide Salt</td><td>Sigma Aldrich</td><td>30315-1KG</td><td></td></tr><tr><td>Carbon Dioxide</td><td>BOC</td><td>CO2 - size E</td><td></td></tr><tr><td>Thermocouple</td><td>Omega Engineering</td><td>KMTSS-IM300U-150</td><td></td></tr><tr><td>Kapton Flexible Heater</td><td>Omega Engineering</td><td>KH-112/10-P</td><td></td></tr><tr><td>X-Ray Microscope</td><td>Zeiss</td><td>Versa XRM 500</td><td></td></tr><tr><td>Snoop Leak Detector</td><td>Swagelok</td><td>MS-SNOOP-8OZ</td><td></td></tr><tr><td>Flouro-Elastomer Polymer (Viton) Sleeve</td><td>Fisher Scientific</td><td>11572583</td><td></td></tr><tr><td>Micro-CT Coreholder</td><td>Airborne Composites</td><td>262mm Coreholder</td><td>Constructed in conjunction with Imperial College</td></tr><tr><td>Tomographic program</td><td>Zeiss</td><td>XM-Reconstructor</td><td></td></tr><tr><td>ImageJ - image processing</td><td>NIH</td><td>ImageJ</td><td></td></tr><tr><td>Matlab</td><td>Mathworks</td><td>Matlab</td><td>Used for regression analysis</td></tr><tr><td>Avizo</td><td>FEI</td><td>Avizo</td><td></td></tr></tbody></table>

reservoir condition pore-scale imaging of multiple fluid phases using x-ray microtomography

X射线显微断层用于图像，以6.6微米，剩余的二氧化碳在神经节碳酸盐岩中的压力和温度的代表用于CO 2的存储典型地层的孔隙空间中的孔隙度配置的分辨率。用高压高温反应器中，复制条件远离注射部位的CO 2，盐水和岩石相之间的化学平衡被维持。采用高温高压注射泵的流体流进行控制。以保持代表在原位微CT扫描仪的碳纤维高压显微CT片芯轴被用来内的条件。扩散的CO 2穿过围套筒从岩石到限制流体的孔隙空间交换被阻止周围用铝箔的三重包裹的核心。使用多色X射线源重构盐水对比度进行建模和盐水组合物瓦特作为选择，以最大限度地提高两种流体和岩石之间的三相对比度。柔性流动管线被用来减小对样品的力量图像采集期间，有可能导致不想要的样品的运动，在先前的技术的一个主要缺点。一个内部的热电偶，置于直接相邻的岩心，加上外部加热柔性包装和PID控制器被用来保持流动单元内的恒定温度。 CO 2的大量被困，与0.203±0.013残余饱和度和较大容量节的大小服从幂律分布与渗流理论是一致的。

结果为单个碳酸盐，Ketton石灰石，从上部林肯郡灰岩的鲕分别在3D，以便识别和测量每个独特断开神经节，然后将其标记（ 图6）的体积进行分析。所有的处理是在Avizo火8.0和ImageJ的计划37内进行。 毛细管捕获能力-的分割部分饱和的图像，通过计算残余被困SCCO 2的体素的数量，以找到由被困SCCO 2占据的岩石体积的比例进行分析。这然后可以通过如使用氦法得到的孔隙率除以该值被转换为一个残余饱和度（S R）。 SCCO 2显著比例被困的残余饱和度，具有0.203±0.013的残余饱和度。这同意使用微以往的研究发现成果-CT 23。在这种岩石类型残余捕集较大的核心规模的研究显示出0.137±0.012 38较低的残余饱和度。 盐水进入到一个SCCO 2饱和的核心是一个吸的过程，其中的润湿液（盐水）侵入每个毛孔，取代非润湿液（SCCO 2）。在强水湿岩我们预计的水来填补大小顺序39,40的孔隙空间的领域，诱捕的过程被称为扣过断开节。这个过程应该是渗滤像41这样的预测可以由左右分离的簇的大小分布。簇的体积S的数目n（在体素测定）应扩展为，其中τ是费希尔指数42。网络模型表明，在三维立体定期格这个指数的价值大约是τ= 2.189 43。提取该指数从真实数据的一个自然的方式是绘制分级量，由迪亚斯和威尔金森41所定义。 <img alt="式（1）" fo:content-width="2in" src="/files/ftp_upload/52440/52440eq1.jpg" />这应该作为扩​​展: <img alt="公式2" fo:content-width="2in" src="/files/ftp_upload/52440/52440eq2.jpg" />这随后绘制在对数-对数曲线图，作为s的函数（ 图7），示出了用于大神经节幂律行为，但较小神经节的代表性不足相比，幂律模型。该指数的计算中排除节小于10像素5（幂律行为大致开始），并使用最小绝对残差强大的拟合算法进行46,47的Levenberg-Marquardt回归44,45。这使用商业软件包进行。费雪指数为这个系统是2.287±0.009，CLOSE到2.189的理论值，表明吸在该系统中确实是渗滤等。更一般地，这些结果证实了结论在较大的芯洪水实验38,48,49即SCCO 2作为在碳酸盐非湿式相。 <img alt="图1" src="/files/ftp_upload/52440/52440fig1.jpg" /> 图1.实验仪器，显示用于控制流量的泵，阀和电抗器和微CT机箱内的片芯轴的座位。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52440/52440fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/52440/52440fig2.jpg" /> 图2.归一化能量光谱的X射线入射到芯，音响<html>经过过滤的片芯轴，围套和围油。使用SpekCALC 29-31计算。 <img alt="图3" src="/files/ftp_upload/52440/52440fig3.jpg" /> 图3.不同的流体和岩石材料作为光子能量的函数的线性衰减系数。 <img alt="图4" src="/files/ftp_upload/52440/52440fig4.jpg" /> 图4.详细的核心组件，显示围绕核心三重铝套，防止跨flouro弹性体套扩散二氧化碳交换。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52440/52440fig4large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 0 / 52440fig5.jpg"/&gt; 图5.详细流通池，加热装置和液流电池内的核心组件的选址。热电偶必须放在尽可能靠近核心的入口面。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52440/52440fig5large.jpg" target="_blank">请点击此处查看该图的放大版本。 。</a> <img alt="图6" src="/files/ftp_upload/52440/52440fig6.jpg" /> 图碳酸盐6.图像排水和吸之后。 （A），其中每个非润湿相簇被赋予了不同的颜色引流后核心的3D渲染。（BF）为核心的五年后吸实验3D渲染，所描述的（A）着色。大范围的颜色表示连接不良的剩余阶段。（G）引流后核心的横截面。最黑暗的阶段是SCCO 2，中间相是盐水最轻的阶段是岩石纹理。（H）吸后核心的横截面。 <a href="https://www-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/52440/52440fig6large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图7" src="/files/ftp_upload/52440/52440fig7.jpg" /> 图7.图6中所示的剩余神经节的尺寸分布 。 <table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td>材料填充孔隙</td><td>真空</td><td> CO 2 </td><td> H 2Ø </td><td> H 2Ø - 7％重量的NaCl </td><td> H 2Ø - 7％（重量）KI </td><td>固体（ 碳酸钙 ） </td></tr><tr><td>传输因子</td><td> 0.25 </td><td> 0.247 </td><td> 0.243 </td><td> 0.242 </td><td> 0.224 </td><td> 0.202 </td></tr><tr><td>变化的因素相对传输真空</td><td> N / A </td><td> -0.003 </td><td> -0.007 </td><td> -0.008 </td><td> -0.026 </td><td> -0.048 </td></tr></tbody></table> 表1从模拟岩石和孔隙空间填充材料本研究期间成像的X射线的光学特性的结果（透射系数和改变相对于所述真空填充壳体透射系数）的综述。每一列代表一个不同的材料填充片芯轴内的岩石的孔隙空间。

Watch this Scientific Journal Video about Reservoir Condition Pore-scale Imaging of Multiple Fluid Phases Using X-ray Microtomography at JoVE.com

Reservoir Condition Pore-scale Imaging of Multiple Fluid Phases Using X-ray Microtomography

We present a methodology for the imaging of multiple fluid phases at reservoir conditions by the use of x-ray microtomography. We show some representative results of capillary trapping in a carbonate rock sample.

多重流体相储层孔隙条件级成像使用X射线微断层

X-ray microtomography was used to image, at a resolution of 6.6 &#181;m, the pore-scale arrangement of residual carbon dioxide ganglia in the pore-space ...

reservoir-condition-pore-scale-imaging-multiple-fluid-phases-using-x

Universidad San Sebastian

Research

JoVE Journal

Engineering

12.4K 次观看.  Imperial College London. We present a methodology for the imaging of multiple fluid phases at reservoir conditions by the use of x-ray microtomography. We show some representative results of capillary trapping in a carbonate rock sample.

视频: Reservoir Condition Pore-scale Imaging of Multiple Fluid Phases Using X-ray Microtomography

Energy Dispersive X-ray Tomography for 3D Elemental Mapping of Individual Nanoparticles

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial resolution, and is even capable of providing atomically resolved elemental maps. In this technique, a highly focused electron beam is incident upon a thin sample and the energy of emitted X-rays is measured in order to determine the atomic species of material within the beam path. This elementally sensitive spectroscopy technique can be extended to three dimensional tomographic imaging by acquiring multiple spectrum images with the sample tilted along an axis perpendicular to the electron beam direction.
Elemental distributions within single nanoparticles are often important for determining their optical, catalytic and magnetic properties. Techniques such as X-ray tomography and slice and view energy dispersive X-ray mapping in the scanning electron microscope provide elementally sensitive three dimensional imaging but are typically limited to spatial resolutions of &gt; 20 nm. Atom probe tomography provides near atomic resolution but preparing nanoparticle samples for atom probe analysis is often challenging. Thus, elementally sensitive techniques applied within the scanning transmission electron microscope are uniquely placed to study elemental distributions within nanoparticles of dimensions 10-100 nm.
Here, energy dispersive X-ray (EDX) spectroscopy within the STEM is applied to investigate the distribution of elements in single AgAu nanoparticles. The surface segregation of both Ag and Au, at different nanoparticle compositions, has been observed.

The use of energy dispersive X-ray tomography in the scanning transmission electron microscope to characterize elemental distributions within single nanoparticles in three dimensions is described.

能量色散X射线断层摄影术对个人纳米3D元素映射

Energy dispersive X-ray spectroscopy within the scanning transmission electron microscope (STEM) provides accurate elemental analysis with high spatial ...

科研

工程学

Failure Analysis of Batteries Using Synchrotron-based Hard X-ray Microtomography

Imaging morphological changes that occur during the lifetime of rechargeable batteries is necessary to understand how these devices fail. Since the advent of lithium-ion batteries, researchers have known that the lithium metal anode has the highest theoretical energy density of any anode material. However, rechargeable batteries containing a lithium metal anode are not widely used in consumer products because the growth of lithium dendrites from the anode upon charging of the battery causes premature cell failure by short circuit. Lithium dendrites can also form in commercial lithium-ion batteries with graphite anodes if they are improperly charged. We demonstrate that lithium dendrite growth can be studied using synchrotron-based hard X-ray microtomography. This non-destructive imaging technique allows researchers to study the growth of lithium dendrites, in addition to other morphological changes inside batteries, and subsequently develop methods to extend battery life.

Synchrotron-based hard X-ray microtomography is used to image the electrochemical growth of dendrites from a lithium metal electrode through a solid polymer electrolyte membrane.

电池的使用同步为基础的硬X射线微断层故障分析

Imaging morphological changes that occur during the lifetime of rechargeable batteries is necessary to understand how these devices fail. Since the advent ...

Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating

A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is reported. The measurements were demonstrated at the 1-BM bending magnet beamline of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). By using a 2-D checkerboard &#960;/2 phase-shift grating, transverse coherence lengths were obtained along the vertical and horizontal directions as well as along the 45&#176; and 135&#176; directions to the horizontal direction. Following the technical details specified in this paper, interferograms were measured at different positions downstream of the phase grating along the beam propagation direction. Visibility values of each interferogram were extracted from analyzing harmonic peaks in its Fourier Transformed image. Consequently, the coherence length along each direction can be extracted from the evolution of visibility as a function of the grating-to-detector distance. The simultaneous measurement of coherence lengths in four directions helped identify the elliptical shape of the coherence area of the Gaussian-shaped X-ray source. The reported technique for multiple-direction coherence characterization is important for selecting the appropriate sample size and orientation as well as for correcting the partial coherence effects in coherence scattering experiments. This technique can also be applied for assessing coherence preserving capabilities of X-ray optics.

The measurement protocol and data analysis procedure are given for obtaining transverse coherence of a synchrotron radiation X-ray source along four directions simultaneously using a single 2-D checkerboard phase grating. This simple technique can be applied for complete transverse coherence characterization of X-ray sources and X-ray optics.

使用2-D棋盘相位光栅X射线束相干测量沿多个方向

A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is ...

Microfluidic Devices for Characterizing Pore-scale Event Processes in Porous Media for Oil Recovery Applications

Microfluidic devices are versatile tools for studying transport processes at a microscopic scale. A demand exists for microfluidic devices that are resistant to low molecular-weight oil components, unlike traditional polydimethylsiloxane (PDMS) devices. Here, we demonstrate a facile method for making a device with this property, and we use the product of this protocol for examining the pore-scale mechanisms by which foam recovers crude oil. A pattern is first designed using computer-aided design (CAD) software and printed on a transparency with a high-resolution printer. This pattern is then transferred to a photoresist via a lithography procedure. PDMS is cast on the pattern, cured in an oven, and removed to obtain a mold. A thiol-ene crosslinking polymer, commonly used as an optical adhesive (OA), is then poured onto the mold and cured under UV light. The PDMS mold is peeled away from the optical adhesive cast. A glass substrate is then prepared, and the two halves of the device are bonded together. Optical adhesive-based devices are more robust than traditional PDMS microfluidic devices. The epoxy structure is resistant to swelling by many organic solvents, which opens new possibilities for experiments involving light organic liquids. Additionally, the surface wettability behavior of these devices is more stable than that of PDMS. The construction of optical adhesive microfluidic devices is simple, yet requires incrementally more effort than the making of PDMS-based devices. Also, though optical adhesive devices are stable in organic liquids, they may exhibit reduced bond-strength after a long time. Optical adhesive microfluidic devices can be made in geometries that act as 2-D micromodels for porous media. These devices are applied in the study of oil displacement to improve our understanding of the pore-scale mechanisms involved in enhanced oil recovery and aquifer remediation.

The goal of this procedure is to easily and rapidly produce a microfluidic device with customizable geometry and resistance to swelling by organic fluids for oil recovery studies. A polydimethylsiloxane mold is first generated, and then used to cast the epoxy-based device. A representative displacement study is reported.

微流体器件用于表征多孔介质中的孔隙尺度事件过程, 用于采油应用

Microfluidic devices are versatile tools for studying transport processes at a microscopic scale. A demand exists for microfluidic devices that are ...

环境科学

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data acquisition times with high spatial resolution. In the electronics industry there is serious interest in performing failure analysis on 3D microelectronic packages, many which contain multiple levels of high-density interconnections. Often in tomography there is a trade-off between image resolution and the volume of a sample that can be imaged. This inverse relationship limits the usefulness of conventional computed tomography (CT) systems since a microelectronic package is often large in cross sectional area 100-3,600 mm2, but has important features on the micron scale. The micro-tomography beamline at the Advanced Light Source (ALS), in Berkeley, CA USA, has a setup which is adaptable and can be tailored to a sample&#39;s properties, i.e., density, thickness, etc., with a maximum allowable cross-section of 36 x 36 mm. This setup also has the option of being either monochromatic in the energy range ~7-43 keV or operating with maximum flux in white light mode using a polychromatic beam. Presented here are details of the experimental steps taken to image an entire 16 x 16 mm system within a package, in order to obtain 3D images of the system with a spatial resolution of 8.7 &#181;m all within a scan time of less than 3 min. Also shown are results from packages scanned in different orientations and a sectioned package for higher resolution imaging. In contrast a conventional CT system would take hours to record data with potentially poorer resolution. Indeed, the ratio of field-of-view to throughput time is much higher when using the synchrotron radiation tomography setup. The description below of the experimental setup can be implemented and adapted for use with many other multi-materials.

For this study synchrotron radiation micro-tomography, a non-destructive three-dimensional imaging technique, is employed to investigate an entire microelectronic package with a cross-sectional area of 16 x 16 mm. Due to the synchrotron&#39;s high flux and brightness the sample was imaged in just 3 min&#160;with an 8.7 &#181;m spatial resolution.

利用同步辐射微断层调查的多尺度三维微电子封装

Synchrotron radiation micro-tomography (SR&#181;T) is a non-destructive three-dimensional (3D) imaging technique that offers high flux for fast data ...

Non-invasive 3D-Visualization with Sub-micron Resolution Using Synchrotron-X-ray-tomography

Little is known about the internal organization of many micro-arthropods with body sizes below 1 mm. The reasons for that are the small size and the hard cuticle which makes it difficult to use protocols of classical histology. In addition, histological sectioning destroys the sample and can therefore not be used for unique material. Hence, a non-destructive method is desirable which allows to view inside small samples without the need of sectioning.
We used synchrotron X-ray tomography at the European Synchrotron Radiation Facility (ESRF) in Grenoble (France) to non-invasively produce 3D tomographic datasets with a pixel-resolution of 0.7&micro;m. Using volume rendering software, this allows us to reconstruct the internal organization in its natural state without the artefacts produced by histological sectioning. These date can be used for quantitative morphology, landmarks, or for the visualization of animated movies to understand the structure of hidden body parts and to follow complete organ systems or tissues through the samples.

We used synchrotron X-ray tomography at the European Synchrotron Radiation Facility (ESRF) to non-invasively produce 3D tomographic datasets with a pixel-resolution of 0.7&micro;m. Using volume rendering software, this allows the reconstruction of internal structures in their natural state without the artefacts produced by histological sectioning.

非侵入性的三维可视化与亚微米分辨率使用同步加速器X射线断层扫描

Little is known about the internal organization of many micro-arthropods with body sizes below 1 mm. The reasons for that are the small size and the hard ...

生物学

Protocol of Electrochemical Test and Characterization of Aprotic Li-O2 Battery

We demonstrate a method for electrochemical testing of an aprotic Li-O2 battery. An aprotic Li-O2 battery is made of a Li-metal anode, an aprotic electrolyte, and an O2-breathing cathode. The aprotic electrolyte is a solution of lithium salt with aprotic solvent; and porous carbon is commonly used as the cathode substrate. To improve the performance, an electrocatalyst is deposited onto the porous carbon substrate by certain deposition methods, such as atomic layer deposition (ALD) and wet-chemistry reaction. The as-prepared cathode materials are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray absorption near edge structure (XANES). A Swagelok-type cell, sealed in a glass chamber filled with pure O2, is used for the electrochemical test on a battery test system. The cells are tested under either capacity-controlled mode or voltage controlled mode. The reaction products are investigated by electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, and Raman spectroscopy to study the possible pathway of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). This protocol demonstrates a systematic and efficient arrangement of routine tests of the aprotic Li-O2 battery, including the electrochemical test and characterization of battery materials.

Protocol of Electrochemical Test and Characterization of Aprotic Li-O2 Battery

A protocol for the electrochemical testing of an aprotic Li-O2 battery with the preparation of electrodes and electrolytes and an introduction of the frequently used methods of characterization is presented here.

电化学测试的协议及表征非质子锂的O<sub&gt; 2</sub&gt;电池

We demonstrate a method for electrochemical testing of an aprotic Li-O2 battery. An aprotic Li-O2 battery is made of a Li-metal anode, an aprotic ...

Dynamic Pore-scale Reservoir-condition Imaging of Reaction in Carbonates Using Synchrotron Fast Tomography

Underground storage permanence is a major concern for carbon capture and storage. Pumping CO2 into carbonate reservoirs has the potential to dissolve geologic seals and allow CO2 to escape. However, the dissolution processes at reservoir conditions are poorly understood. Thus, time-resolved experiments are needed to observe and predict the nature and rate of dissolution at the pore scale. Synchrotron fast tomography is a method of taking high-resolution time-resolved images of complex pore structures much more quickly than traditional &#181;-CT. The Diamond Lightsource Pink Beam was used to dynamically image dissolution of limestone in the presence of CO2-saturated brine at reservoir conditions. 100 scans were taken at a 6.1 &#181;m resolution over a period of 2 hours. The images were segmented and the porosity and permeability were measured using image analysis and network extraction. Porosity increased uniformly along the length of the sample; however, the rate of increase of both porosity and permeability slowed at later times.

Synchrotron fast tomography was used to dynamically image dissolution of limestone in the presence of CO2-saturated brine at reservoir conditions. 100 scans were taken at a 6.1 &#181;m resolution over a period of 2 h.

用同步快速反应层析成像动态孔隙规模油藏条件下成像碳酸盐

Underground storage permanence is a major concern for carbon capture and storage. Pumping CO2 into carbonate reservoirs has the potential to dissolve ...

Pore-scale Imaging and Characterization of Hydrocarbon Reservoir Rock Wettability at Subsurface Conditions Using X-ray Microtomography

In situ wettability measurements in hydrocarbon reservoir rocks have only been possible recently. The purpose of this work is to present a protocol to characterize the complex wetting conditions of hydrocarbon reservoir rock using pore-scale three-dimensional X-ray imaging at subsurface conditions. In this work, heterogeneous carbonate reservoir rocks, extracted from a very large producing oil field, have been used to demonstrate the protocol. The rocks are saturated with brine and oil and aged over three weeks at subsurface conditions to replicate the wettability conditions that typically exist in hydrocarbon reservoirs (known as mixed-wettability). After the brine injection, high-resolution three-dimensional images (2 &#181;m/voxel) are acquired and then processed and segmented. To calculate the distribution of the contact angle, which defines the wettability, the following steps are performed. First, fluid-fluid and fluid-rock surfaces are meshed. The surfaces are smoothed to remove voxel artefacts, and in situ contact angles are measured at the three-phase contact line throughout the whole image. The main advantage of this method is its ability to characterize in situ wettability accounting for pore-scale rock properties, such as rock surface roughness, rock chemical composition, and pore size. The in situ wettability is determined rapidly at hundreds of thousands of points. 
The method is limited by the segmentation accuracy and X-ray image resolution. This protocol could be used to characterize the wettability of other complex rocks saturated with different fluids and at different conditions for a variety of applications. For example, it could help in determining the optimal wettability that could yield an extra oil recovery (i.e., designing brine salinity accordingly to obtain higher oil recovery) and to find the most efficient wetting conditions to trap more CO2 in subsurface formations.

This protocol is presented to characterize the complex wetting conditions of an opaque porous medium (hydrocarbon reservoir rock) using three-dimensional images obtained by X-ray microtomography at subsurface conditions.

利用 X 射线层析在地下条件下油气储层岩石润湿性的孔隙度成像与表征

In situ wettability measurements in hydrocarbon reservoir rocks have only been possible recently. The purpose of this work is to present a protocol to ...

Visualization of Failure and the Associated Grain-Scale Mechanical Behavior of Granular Soils under Shear using Synchrotron X-Ray Micro-Tomography

The rapid development of X-ray imaging techniques with image processing and analysis skills has enabled the acquisition of CT images of granular soils with high-spatial resolutions. Based on such CT images, grain-scale mechanical behavior such as particle kinematics (i.e., particle translations and particle rotations), strain localization and inter-particle contact evolution of granular soils can be quantitatively investigated. However, this is inaccessible using conventional experimental methods. This study demonstrates the exploration of the grain-scale mechanical behavior of a granular soil sample under triaxial compression using synchrotron X-ray micro-tomography (&#956;CT). With this method, a specially fabricated miniature loading apparatus is used to apply confining and axial stresses to the sample during the triaxial test. The apparatus is fitted into a synchrotron X-ray tomography setup so that high-spatial resolution CT images of the sample can be collected at different loading stages of the test without any disturbance to the sample. With the capability of extracting information at the macro scale (e.g., sample boundary stresses and strains from the triaxial apparatus setup) and the grain scale (e.g., grain movements and contact interactions from the CT images), this procedure provides an effective methodology to investigate the multi-scale mechanics of granular soils.

The protocol describes procedures to acquire high-spatial resolution computed tomography (CT) images of a granular soil during triaxial compression, and to apply image processing techniques to these CT images to explore the grain-scale mechanical behavior of the soil under loading.

使用同步加速器 X 射线微断层扫描技术，在剪切下对颗粒土壤的故障和相关的颗粒级机械性能进行可视化

The rapid development of X-ray imaging techniques with image processing and analysis skills has enabled the acquisition of CT images of granular soils ...