Based on the macroscopic and microscopic observation of coal structure, the vitrinite reflectance analysis, and the mercury injection testing of coal samples collected from Huaibei coalfield and Qinshui basin, the characterization of coal reservoir and its restriction on the development of coalbed methane are studied. The results indicate that coal reservoir in study area can be classified as five types according to the coal metamorphism and deformation degrees, and they are respectively high grade metamorphic and medium deformational to strongly deformation coal (I), high grade metamorphic and comparatively weakly deformational coal (II), medium grade metamorphic and comparatively strongly deformational coal (III), medium grade metamorphic and comparatively weakly deformational coal (IV), and low grade metamorphic and strongly deformational coal (V). Furthermore, the type II and type IV coal reservoirs are favorable for the development of the coalbed methane because of the well absorptive capability and good permeability. Thus, southern part of Qinshui basin and south-central of Huaibei coal field are potential areas for coalbed methane exploration and development. 1. Introduction Coal is not only a kind of mineral fuel but also the reservoir of coalbed methane (CBM). CBM as an unconventional natural gas has gained much attention from researchers around the world. The exploration and development of CBM in America has commercialized over 20 years, and CBM production has industrialized in Australia and Canada in recent years. Based on the successful exploration and development of CBM in USA, the relevant progresses on CBM exploration and development have been summarized during recent years [1–4]. However, because of distinct difference in geological background and coal reservoir characterization, CBM exploration and development in China had not developed successfully as America. Coal is a kind of porous medium, and its pore structure not only affects gas content but also restricts permeability and recovery of coalbed methane. Currently, scholars have studied pore structure of coals and metamorphic deformational environment by using vitrinite reflectance testing, electronic scanning observation, mercury intrusion testing, low-temperature nitrogen adsorption experiment, nuclear magnetic resonance testing, and CT technology, and they have obtained better understanding on pore structure of coal reservoir, coalbed methane accumulation and recovery [2, 5, 6]. However, few scholars combined metamorphism with deformation of coal to discuss pore structure and its
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