For gas reservoirs in the fold-thrust belts of foreland basins and in rift basins

faults constitute the main carrier systems

and hydrocarbons migrate mainly in vertical direction with short migration distance and high delivery efficiency.While for lithologic gas reservoirs in craton basins and gas reservoirs in slope zones of foreland basins

sandbodies act as the main carrier system

and hydrocarbons migrate both laterally and vertically with relatively long migration distance and low delivery efficiency.Sulige gas field is of lithologic gas reservoirs in craton basin

its main carrier system is of sandbody type

with a few fault type and sandbody-fault type carrier systems.The sandbody carrier system can be subdivided into thick belt sandbody

thin belt sandbody and lenticular sandbody.The delivery capacity of carrier system varied with time.It peaked in 200-150 Ma during the strongest dissolution and faulting.At the critical reservoiring period(J

3

-K

1

)

the framework of carrier system was high in the west and north and low in the east and south

and the major carrier system consisted of sandbodies

faults and fractures.Hydrocarbons migrated northwestward with high delivery efficiency.While in the post-reservoiring adjustment period(K

2

-Q)

the framework of carrier system was basically high in the east and north and low in the west and south

and the major carrier system consisted of sandbody and fractures.Hydrocarbon migration efficiency was low and not evident.