Impact of faults on fluid flow in microbial and hydrothermal carbonates

断层对地下流体流动有重大影响，这对于石油和天然气勘探和生产、地下水流动、二氧化碳储存和放射性废物处理等一系列应用来说是很重要的。特别是英国的学者和服务公司，已经取得了巨大的进步，他们开发了工具，可以预测断层对硅塑性沉积物（即砂页岩序列）中流体流动的影响。例如，我们已经：(i)建立了大量关于硅-塑性层序断层的单相和多相流特性的数据库（Fisher and Knipe, 2001）；（ii）开发了预测断层岩石沿断层分布的算法（yield等人，2010年）；（iii）开发了复杂的软件，利用这些数据和算法预测断层如何影响地下流体流动（例如Traptester、RDR fault Seal Plugin for Petrel）。不幸的是，此类工具尚未开发用于碳酸盐岩储层，碳酸盐岩储层包含世界上大部分剩余的常规石油资源和很大一部分非常规石油（请注意，许多页岩气主要由碳酸盐岩组成）。为了填补这一知识空白，利兹大学和巴德利地球科学公司建立了合作伙伴关系，建立了碳酸盐岩断层特性数据库，并开发了软件，利用这些数据来预测断层对碳酸盐岩储层流体流动的影响。该项目目前进展顺利，我们已经对欧洲白垩和Zechstein储层中的断层以及欧洲、中东和美国的石灰石进行了广泛的研究。断层对微生物和热液碳酸盐岩流体流动的影响是我们在知识和数据上的一个关键空白。这一点很重要，因为这些是目前在南美洲和西南非洲海底盐下勘探的一些最重要的储层。该项目将由四个不同的工作包（WP1-4）组成：- wp1 -进行实地工作，了解微生物和热液碳酸盐岩中的断层结构，控制断层岩石类型的分布，并收集样品进行实验室分析。在意大利、土耳其和巴西已经发现了露头，这些露头代表了一系列的构造环境和埋葬历史。WP2 -对从现场收集的断层岩石进行岩石物理性质（孔隙度、渗透率、毛细压力）的实验室测量，并将这些测量结果与微观结构研究（光学、CL和SEM）相结合，以确定断层流动性质的关键控制因素。WP3 -对从露头收集的未变形碳酸盐岩进行三轴实验，以进一步了解控制在现场识别的不同断层岩形成的因素（流变学和应力）。WP4 -开发方法和/或算法，将这些数据整合到软件产品中，用于模拟断层对碳酸盐岩储层流体流动的影响。

Faults have a major impact on subsurface fluid flow, which is important to understand for a range of applications such as oil and gas exploration and production, groundwater flow, as well as CO2 storage and radioactive waste disposal. Massive advances have been made, particularly by UK based academics and service companies, developing the tools to allow the impact of faults on fluid flow to be predicted in siliciclastic sediments (i.e. sand - shale sequences). For example, we have: (i) built massive databases on the single and multi-phase flow properties of faults in siliciclastic sequence (Fisher and Knipe, 2001); (ii) developed algorithms for predicting the distribution of fault rocks along faults (Yielding et al., 2010) and, (iii) developed sophisticated software that use these data and algorithms to predict how faults impact fluid flow in the subsurface (e.g. Traptester, RDR Fault Seal Plugin for Petrel). Unfortunately, such tools have not been developed for carbonate reservoirs, which contain most of the worlds remaining conventional petroleum resources and a large proportion of our unconventional petroleum (note that many shale gas plays are mainly composed of carbonates). To fill in this knowledge gap, a partnership between the University of Leeds and Badley Geoscience has been established to build a database of the properties of faults in carbonates and to develop software to use these data to predict the impact of faults on fluid flow in carbonate reservoirs. The project is currently progressing well in that we have already conducted extensive studies of faults within the chalk and Zechstein reservoirs in Europe as well as limestones from Europe, Middle East and the USA. A key gap in our knowledge and data is the impact of faults on fluid flow in microbial and hydrothermal carbonates. This is important because these are some of the most important reservoirs being currently explored in the sub-salt offshore South America and South West Africa.The project will be composed of four distinct work packages (WP1-4):-WP1 - Conducting field work to understand the structure of faults in microbial and hydrothermal carbonates, the control on the distribution of fault rock types and collect samples for laboratory analysis. Outcrops have already been identified in Italy, Turkey, and Brazil, which represent a range of tectonic environments and burial histories.WP2 - Conduct laboratory measurements of the petrophysical properties (porosity, permeability, capillary pressure) of fault rocks collected from the field and integrate these measurements with microstructural studies (optical, CL and SEM) to identify the key controls on the flow properties of the faults.WP3 - Conduct triaxial experiments on undeformed carbonates collected from outcrop to further understand the factors (rheology and stress) that control the formation of the different fault rocks that are identified in the field.WP4 - Develop methodologies and/or algorithms to incorporate this data into software products that can be used to model the impact of faults on fluid flow in carbonate reservoirs.