Detecting shale oil hidden in nanopores using a novel electron microscopy method

Abstract

<p>Shale oil has revolutionized the global energy landscape, mostly existing in nanopores. However, there is no method for directly characterizing such a small oil cluster. This paper proposes a novel method for the direct characterization of shale oil at the nanoscale via controllable local charging imaging using electron microscopy. With this method, the potentially movable hydrocarbons of below one pmol (10^?12 mol) reserved in nanopores can be detected. The distribution of the shale oil clusters can be obtained through large-area two dimensional (2D) and three dimensional (3D) visualizations. Additionally, the amount of these resources can be calculated. Comparative analyses were conducted on reservoir samples from typical shale oil blocks in China and the US, and the results indicate the universality of the novel method, paving the way for accurate evaluation of shale oil resources and reasonable choice of exploitation technologies such as hydrofracturing and underground <i>in-situ</i> conversion processing.</p>