Abstract: Shale gas, an important unconventional natural gas resources, is transforming world energy and economic and political pattern. Permeability is one of the most important parameters of shale gas reservoirs that estimates their viability for commercial development. The mechanism of gas flow in the shale gas reservoirs is different from that of a conventional gas reservoir because of the tight nature of the rock matrix. Therefore, permeability measurements of shale reservoirs and flow model for shale gas have become one of hot topics for international research in nowadays. In this paper, theoretical and experimental studies of permeability measurements of shale reservoirs are summarized based on a simple presentation of shale gas production technique. Furthermore, the effects of gas adsorption on shale permeability are analyzed. Latest advances of shale gas flow model are reviewed; and accuracy of a dual-pore model describing gas transport is analyzed. Multistage transport models for desorption and diffusion and seepage of shale gas are presented, which can be used to describe behavior of gas flow in the homogeneous reservoirs. Brief reviews on greenhouse effect of shale gas extraction and its impact on groundwater are also addressed; and then shale gas production technique for waterless hydraulic fracturing is presented. That is, shale gas reservoirs are fractured multistage via carbon dioxide injection, and meanwhile carbon dioxide is sequestrated in the abandoned shale gas wells. A few of comments are also made on the future research directions and subjects on permeability measurements of shale reservoirs and shale gas flow model and waterless hydraulic fracturing technology.

Key words: shale gas, permeability, adsorption, flow model, environmental effect, waterless hydraulic fracturing