Michigan Basin

Delaware Basin and Illinois Basin are the typical cratonic basins with shale gas plays in North America.This paper analyzed shale gas reservoir lithology

organic matter type

hydrocarbon generation

burial depth

thermal maturity

adsorbed gas content and the role of fracture in shale gas accumulation.We summarized two shale gas accumulation patterns:the Antrim shale gas accumulation pattern in Michigan Basin (A-pattern) and the Barnett shale gas accumulation pattern in Delaware Basin (B-pattern).The primary features of A-pattern is that

from the shallow periphery to the deep basin

biogenic gas

mixed gas and thermogenic gas occcur in sequence.The main characteristics of B-pattern are that the shale gas is of thermogenic origin and is indigenously generated and accumulated

Shale gas of different genetic types occur in areas with different thermal maturities.We suggested that the Barnett shale gas accumulation pattern(B-pattern)of Delaware Basin is of greater significance for shale gas exploration in China

and Antrim shale gas accumulation pattern in Michigan Basin (A-pattern) also cannot be ignored for shale gas exploration.