Quantifying Fluid Flow in Stressed & Fractured Carbonates

我们迫切需要在英国开发新的可再生能源，这将使与这些国家的国际合作进一步沿着发展的道路。我们的项目将建立一个定量模型，该模型将通过裂缝石灰岩的流体流动与当地的原地应力状态联系起来，使用现有的数据和来自意大利和德国的专业知识。地热能对英国具有潜在的重要性，因为下石炭统石灰岩（LCL）地层位于大型城市地区的下方，例如，曼彻斯特，利物浦和布里斯托，是一个可行的地热能源，特别是用于供热。在LCL中，据信流体主要通过裂缝而不是通过裂缝之间的岩石颗粒流动。这意味着我们需要更好地了解在深层发生的自然应力下，流体如何在裂缝石灰岩中流动。已经提出了几种不同的模型和方法来解释这种联系，但我们还不能在英国测试这些模型，因为我们缺乏有关裂缝网络，流体流速和两公里或更深处的原地应力的相关数据。这项与意大利合作伙伴的新合作计划将使用之前对意大利南部-波滕扎附近的上阿格里山谷石灰岩研究的大型数据集。可用的数据集包括裂缝、水和石油钻孔的流体流速以及原地应力。我们将整理所有这些数据，并在德国新项目合作伙伴的帮助下，建立一个阿格里山谷地下裂缝的数字3D模型，跨度为30 x 10 x 5 km（长x宽x深）。在该模型中，我们将对裂缝施加应力（基于来自意大利的应力数据），并预测来自模拟钻孔的流体流动。通过比较这些模型预测的流体流动的测量钻孔流量从钻孔意大利，我们可以测试的主要控制压力石灰岩裂缝中的流体流动的竞争假说。然后，这提供了一个科学的强大的基础上，建立未来的分析潜在的流体流动在英国下面的裂缝和应力石灰岩。未来，我们将能够根据英国下石炭纪石灰岩的具体情况调整我们针对Agri山谷的测试模型，以帮助公司和其他机构制定计划，钻探安全且具有成本效益的地热能钻孔。

We urgently need to develop new renewable energy sources in the UK, and this will take international collaboration with those countries further along the development path. Our project will build a quantitative model that links the fluid flow through fractured limestone with the local state of in situ stress, using existing data and expertise from Italy and Germany. Geothermal energy is potentially important for the UK because the Lower Carboniferous Limestone (LCL) formation underlies large urban areas, e.g., Manchester, Liverpool and Bristol, and is a viable source of geothermal energy, especially for supplying heat. In the LCL, it is believed that fluid flows mainly through fractures rather than through the rock grains in between the fractures. This means that we need to better understand how fluid flows in fractured limestones under natural stresses occurring at depth. Several different models and methods have been proposed to explain this linkage but we cannot test these models in the UK yet, because we lack the relevant data on the fracture networks, the fluid flow rates and the in situ stress at depths of two or more kilometres. This proposed new collaboration with our Italian partner will use large datasets from previous studies on limestones in southern Italy - the Upper Agri valley near Potenza. The datasets available cover fractures, fluid flow rates from water and oil boreholes, and in situ stresses. We will collate all these data and, with help from new project partners in Germany, build a digital 3D model of the fractured subsurface beneath the Agri valley, spanning 30 x 10 x 5 km (length x width x depth). In this model, we will impose stresses on the fractures (based on the stress data from Italy) and predict the fluid flow from simulated boreholes. By comparing these model predictions of fluid flow to the measured borehole flow rates from boreholes Italy we can test the competing hypotheses for the dominant controls on fluid flow in stressed limestone fractures. This then provides a scientifically robust foundation on which to build future analyses of potential fluid flow in the fractured and stressed limestones beneath the UK. In the future, we will be able to adapt our tested model for the Agri valley to the specifics of the UK Lower Carboniferous Limestone, to help companies and other agencies to develop their plans to drill safe and cost-effective boreholes for geothermal energy.