Transp Porous Med DOI 10.1007/s11242-014-0435-z Multi-scale Asymptotic Analysis of Gas Transport in Shale Matrix I. Yucel Akkutlu · Yalchin Efendiev · Viktoria Savatorova Received: 12 July 2014 / Accepted: 5 December 2014 © Springer Science+Business Media Dordrecht 2014 Abstract Organic-rich resource shales play an important role in global natural gas pro- duction. However, many uncertainties exist in an engineering analysis of gas transport and production such as the reservoir-scale flow simulation, history-matching, and optimization. In this work, we introduce a new set of governing equations to describe the characteristic features of porous structures of the organic-rich resource shale. We apply multi-scale analysis to mass balance equations, the equation of state (for free gas), and an adsorption isotherm. Using the macroscopic model, we study gas transport in shales, consisting of nanoporous organic material (kerogen) and the inorganic material. We conclude that both gas in-place and gas production rate depend on the amount of kerogen in the shale matrix. Adsorbed-phase transport by the organic pore walls is responsible for the increase in production rate. We investigate both Henry and Langmuir adsorption as well as different values of length scale ratio and diffusion coefficients. Keywords Gas transport · Adsorption · Shale · Kerogen · Nanopore · Multi-scale · Homogenization 1 Introduction Shale gas transport is an active area of research due to growing interest in producing natural gas from source rocks. Shale is a sedimentary rock made of fine-scale inorganic sediments. The pore volume is small relative to other conventional rocks (e.g., sandstone) consisting of irregularly shaped pores and micro-cracks. The resource shale, on the other hand, as a source rock, has added complexities due to the presence of organic matter, also known as kerogen. Kerogen brings in new fluid storage I. Y. Akkutlu · Y. Efendiev · V. Savatorova (B ) Texas A&M University, College Station, TX 77843, USA e-mail: vsavatorova@gmail.com V. Savatorova National Research Nuclear University “MEPhI”, Moscow 115409, Russia 123