Multiscale Digital Rock Analysis for Shale Gas Exploration

页岩气革命对能源供应、消费和二氧化碳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天然气储备，帮助建立一个更强大、更环保、更具竞争力的经济。对非常规油藏中常见的超致密多孔介质中的天然气运移进行量化是很重要的，这有助于我们确定页岩地层的排水面积和寿命，并优化生产工艺，例如减少钻井数量。然而，非常规天然气的生产对油藏工程师构成了前所未有的挑战，因为他们不能依赖以前的经验或方法。目前，还没有在孔隙/次岩心尺度上可靠地预测渗流性质非均质性的工具，尽管这对于扩大油藏模拟来说是必不可少的，例如通过视渗透率的空间分布。超致密孔隙中的气体流动不仅是致密的(因为高压)，而且由于孔隙尺寸小，热力学上不平衡-这意味着传统的流体动力学模型不适用。工程研究的挑战是为页岩介质中的天然气输送创建物理上真实的模型和高效的计算技术，这反过来将使储集层模拟更加可靠。流体动力学的这些发展也为学生和研究人员的最先进的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种独特的软件包，以实现对稀薄气体在超致密多孔介质中流动的孔隙尺度模拟，并开发一种高级方法来量化页岩的流动特性。主要目标是：1.改进和测试内部用于多孔介质流动的高性能计算代码；2.将求解器应用于不同类型的岩石样品；3.开发可扩展的方法以实现油藏模拟。

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.