CMG Research: Multi-scale Flow and Transport Modeling of Large-vug Cretaceous Carbonates

有些碳酸盐岩层含有几厘米大小的溶洞或洞。 该项目结合了地质学家、地质工程师和数学家的专业知识，通过实验和计算研究了0.1至100米距离内溶洞岩石中溶质的流动和运输。将对德克萨斯州中部的Pipe Creek Reef露头进行实验研究：（1）在实验室中对10 - 20 cm以下尺度的样品进行测定，以确定岩石和孔洞的性质以及微尺度示踪剂运移特征;（2）在1 - 10m尺度上确定有效渗透率和示踪剂注入响应，（3）在1 - 100m尺度上利用探地雷达进行大比例尺地质填图。 这些数据将被用来构建一个详细的亚厘米尺度的传输过程的微观尺度模型和一个宏观尺度模型来代表系统，包括它的拓扑学洞穴互连性，时间尺度，和宏观分散至少1 - 100米的scaleson。 有效和准确的计算实现将允许测试和验证。 统计分析将量化数据中的不确定性，以供全实地规模使用。 该项目有望在宏观尺度上大大改进多孔介质中流动和输运的建模，为宏观尺度模型中有效参数的选择和参数不确定性的处理提供坚实的经验基础。它将照亮类似多孔介质的建模，如岩溶和裂隙系统，以及更普遍的相关多尺度系统。 该项目将影响三个博士。学生和加强两个外展到工业界，油藏表征研究实验室（RCRL）和中心地下建模（CSM）。 最后，由于碳酸盐岩构成了世界上许多含水层和储油层，因此，随着技术的进步，地下水资源得到更有效的保护，石油的生产也将使社会受益。一些碳酸盐岩层中含有几厘米大小的洞穴，称为溶洞。 流体在这些洞穴中比在岩石本身中更容易流动（即，岩石颗粒之间）。 地下水污染物等化学物质的迁移受到这些洞穴性质的强烈影响。 在相互连通的溶洞通道中，污染物可以非常迅速地流动，但当它重新进入岩石时，速度必须大大减慢。然而，目前对流体如何在这种溶洞岩石中长距离流动知之甚少。 该项目结合了地质学家、地质工程师和数学家的专业知识来解决这个问题。 将进行实验研究，以确定流体在10 - 20厘米以上的小溶洞和长达10米的溶洞通道内的流动行为。 探地雷达将用于绘制1 - 100米尺度的大尺度地质图。利用这些数据，将建立两个模型或计算机模拟代码。第一个模型将详细描述亚厘米尺度的流动。 第二种方法将只描述平均意义上的流量，以便在整个含水层或石油储层的现场尺度上有意义地使用。此外，统计分析将允许量化数据中的不确定性。 该项目预计将导致大大改善模拟流动和运输的溶洞介质在大尺度上。 该项目影响了三个博士的教育。学生，谁将在一个跨学科的环境中进行培训。 由于碳酸盐岩构成了世界上许多含水层和储油层，社会将间接受益。地下模拟是一种重要的工程工具。 可以通过有效、可预测且具有成本效益的修复或遏制策略的工程设计来修复或预防地下水污染。基于模拟研究的工程分析还用于量化、管理和降低与油藏管理相关的风险。

Some carbonate strata contain vugs or cavities about the size of a fewcentimeters. This project unites the expertise of geologists, geo-engineers,and mathematicians to study experimentally and computationally the flow andtransport of solutes in vuggy rocks over distances of 0.1 to 100 meters.Experimental studies of the Pipe Creek Reef outcrop in Central Texas will bemade: (1) in the laboratory on samples at the sub 10-20 cm scale to determinerock and vug properties and micro-scale tracer transport characteristics; (2)in the field over 1-10 m scales to determine effective permeabilities andtracer injection response; and (3) in the field using ground penetrating radarto map the large scale geology over 1-100 m scales. The data will be used toconstruct a micro-scale model of the transport process at the detailed sub-cmscale and a macro-scale model to represent the system, including itstopological vug interconnectivity, time-scales, and macro-dispersion on scalesof at least 1-100 m. Efficient and accurate computational implementation willallow testing and verification. Statistical analysis will quantify uncertaintyin the data for use at full field scales. The project is expected to result insubstantially improved modeling of flow and transport in vuggy media over themacro-scale, with a solid empirical basis for the selection of the effectiveparameters in the macro-scale model, and the handling of parameter uncertainty.It should illuminate modeling of similar porous media, such as karsts andfractured systems, and, more generally, related multi-scale systems. Theproject will impact three Ph.D. students and enhance two outreaches to theindustrial community, the the Reservoir Characterization Research Laboratory(RCRL) and the Center for Subsurface Modeling (CSM). Finally, since carbonaterocks comprise many of the world's aquifers and oil reservoirs, society willbenefit as progress allows more effective protection of groundwater suppliesand production of petroleum.Some carbonate rock strata contain cavities, called vugs, about the size of afew centimeters. Fluid can flow much more easily in these vugs than within therock itself (i.e., between the rock grains). The transport of chemicalspecies, such as groundwater contaminants, is strongly influenced by the natureof these vugs. Within an inter-connected vug path, the contaminant can flowquite rapidly, but it must slow considerably when it re-enters the rock.However, little is currently known about how fluid flows in such vuggy rocksover long distances. This project unites the expertise of geologists,geo-engineers, and mathematicians to address the problem. Experimental studieswill be made to determine the behavior of fluid flow in small vugs over 10-20centimeters, and within vug channels up to 10 meters long. Ground penetratingradar will be used to map the large scale geology over 1-100 meter scales.Using this data, two models, or computer simulation codes, will be constructed.The first model will describe the flow at the detailed sub-cm scale. Thesecond will describe the flow only in an average sense, so that it can be usedmeaningfully at the field scale of an entire aquifer or petroleum reservoir.Moreover, statistical analysis will allow for the quantification of uncertaintyin the data. The project is expected to result in substantially improvedmodeling of flow and transport in vuggy media over large scales. The projectwill impact the education of three Ph.D. students, who will be trained in aninterdisciplinary environment. Since carbonate rocks comprise many of theworld's aquifers and oil reservoirs, society will benefit indirectly.Subsurface simulation is an important engineering tool. Groundwatercontamination can be remediated or prevented through the engineering design ofvalid, predictable, and cost effective remediation or containment strategies.Engineering analysis based on simulation studies is also used to quantify,manage, and reduce risks related to oil reservoir management.