Abstract: Unconventional tight reservoirs pose a great challenge to researchers because of their complex porous structures and great heterogeneities. In this study, key issues of CT scanning, gas adsorption and MICP application in unconventional tight reservoirs were investigated. Optimization of these techniques led to higher resolution and multidimension representation in porous structure characterization by using a combination of static description and dynamic modeling. Six typical reservoir rocks, including conventional sandstones, tight sandstones, peperites, tuffs, shelly limestones and marine shales were analyzed systematically to understand the structural differences and define appropriate characterization methods for different porous structures. Moreover, the effects of pore size on physical property, resource economic and development technologies are discussed. Future research should be focused on integrating porous structure characterization performed at different structural scales, and evaluating the relationship between porous structure and mobile fluids & reservoir stimulation. Based on our multifield, multidiscipline and multiview study, the reservoir effectiveness can be assessed to provide technological support for the largescale “sweet spot” predictions.

Key words: tight reservoir rocks, pore structure, effectiveness, shales, unconventional oil and gas