Preservation and deliverability characteristics of coalbed methane in east margin of Ordos Basin
ZHANG Song-hang
TANG Da-zhen
TANG Shu-heng
XU Hao
ZHANG Biao
CHEN Zhen-long
Abstract：Fifty eight coal samples from east margin of Ordos Basin were examined using the microfracture analysis by fluorescence microscope, liquid nitrogen adsorption analysis and mercury-injection analysis. The results show that the frequency of microfractures in coals is about 20～100 strips per 9 cm~2, and increases in the tectonically active areas. The porosity is relatively low. The pore is dominated by transition pores and micropores. Macropores take the second places, and mesopores develop least. The BET surface area is relatively high ranging from 0. 092 to 20. 480 m~2/g. The coal reservoirs have good adsorption capacity. Four reservoir types with different pore-fracture systems were classified by Q cluster analysis and the difference of reservoir physical property were analyzed. Type I with more microfractures, large porosity, reasonable pore structure, high specific surface area makes the good reservoir for CBM exploration and development. Type III with more structural microfractures, poor permeability,low porosity and specific surface area, less mesopores, is bad reservoir for CBM exploration and development. The characteristics of type II are between type I and III , which makes it to be the relatively favorable reservoir for CBM exploration and development. Type IV which has the good permeability, but the weak adsorption capacity is relatively beneficial for CBM exploration and development.
Keywords：coalbed methanecoal reservoirmicrofracturepore system
Publication Date：2009-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 1297-1304 )