Based on outcrops

drilling and core data

combining with analysis of thin section

SEM

X-ray diffraction

mercury porosimetry and isothermal adsorption

this paper studied the accumulation conditions and characteristics of shale gas of the Lower Cambrian Niutitang Formation in Upper Yangtze Region

with focus on the stratigraphic

petrologic

geoche-mical and geophysical characteristics as well as gas storage capacity.The results show that the distribution of the organic-rich shale of the Lower Cambrian Niutitang Formation in Upper Yangtze Region is controlled by the shallow to deep water shelf sedimentary environment

where shale thickness generally ranges from 50 to 300 m.The shale has a total organic carbon content over 1.5% and is highly mature to over mature.The organic-rich shale has abundant brittle minerals and the clay minerals with high evolution are dominated by stable minerals such as illite but without any montmorillonite.The various types of pores and fractures provide effective reservoir space for shale gas

and the gas content reaches the lowest commercial development value(2.0 m

3

/t).Comprehensive analysis of these conditions reveals that the Ziyang-Zigong area

the northern Guizhou

eastsouthern Chongqing and eastern Hubei and Hunan Province are favorable exploration areas.