Multiscale Digital Rock Analysis for Shale Gas Exploration

页岩气革命对能源供应、消费和CO2减排产生了重大影响。在英国，非常规天然气资源可以取代迅速枯竭的北海储量，并有助于建立一个更强大、更环保、更有竞争力的经济。重要的是要量化非常规储层中常见的超致密多孔介质中的气体传输，这可以帮助我们确定页岩地层的泄油面积和寿命，并优化生产过程，例如减少钻井威尔斯的数量。然而，非常规天然气的生产对油藏工程师提出了前所未有的挑战，因为他们不能依赖以前的经验或方法。目前，还没有可靠地预测孔隙/亚岩心尺度流动特性的非均质性的工具，尽管这对于放大的储层模拟是必不可少的，例如通过表观渗透率的空间分布。超致密孔隙中的气流不仅密度高（因为压力高），而且由于孔隙尺寸小，气体流动是非平衡的，这意味着传统的流体动力学模型是不适用的。工程研究面临的挑战是为页岩介质中的天然气运输创建物理上真实的模型和有效的计算技术，这反过来又将使更可靠的储层模拟成为可能。流体动力学的这些发展也为学生和研究人员的最先进教育和培训提供了极好的机会。该研究项目的目的是开发一个独特的软件包，使超致密多孔介质中的稀薄气体流动的孔隙尺度模拟，并开发高档的方法来量化页岩的流动特性。主要目标是：改进和测试多孔介质流动的内部高性能计算代码;II.将求解器应用于不同类型的岩石样本;III.开发放大方法，以进行油藏模拟。

The shale gas revolution has made significant impact on energy supply, consumption, and reduction of CO2 emission. In the UK, unconventional gas resources could replace rapidly depleting North Sea reserves and help to build a stronger, greener and more competitive economy. It is important to quantify the gas transport in the ultra-tight porous media typically found in unconventional reservoirs, which can help us to determine the drainage area and life span of the shale formations, and to optimise the production process, e.g. reduced number of drilling wells. However, the production of unconventional gases poses an unprecedented challenge to reservoir engineers, as they cannot rely on previous experience or methods. Currently, there is no tool for reliably predicting heterogeneity in flow properties at the pore/sub-core scale, even though this is essential for upscaled reservoir simulations, e.g. through the spatial distribution of apparent permeability. Gas flows in ultra-tight pores are not only dense (because of the high pressures) but also, due to the small pore dimensions, thermodynamically non-equilibrium - which means that conventional fluid dynamic models are inapplicable. The engineering research challenge is to create physically realistic models and efficient computational techniques for the transport of gas in shale media, which will in turn enable more reliable reservoir simulations. These developments in fluid dynamics also provide excellent opportunities for state-of-the-art education and training of students and researchers. The aim of this research project is to develop a unique software package to enable the pore-scale simulation of rarefied gas flows in ultra-tight porous media, and to develop upscale method to quantify flow properties of shale rocks. The key objectives are to: I. improve and test the in-house high-performance computing code for porous media flows;II. apply the solver on different types of rock samples;III. develop upscaling method to enable reservoir simulation.