The research on reservoir characteristics and their impact on resource assessment is one of the bases for tight gas resource evaluation

production and efficient development.An integration of analyses of logging data

hydrocarbon generation conditions and production data

as well as thin section observation

is applied to investigate the reservoir characteristics

the distribution

thickness and superposition pattern of sand bodies in He 8 member and Shan 1 member in southwestern Sulige gas field

to select an applicable evaluation method according to the reservoir characteristics

and to explore the effect of reservoir characteristics on evaluation parameters.The results show that the reservoirs in Sulige gas field are characterized by low porosity

low permeability and strong heterogeneity

thus the volumetric method is suitable for its resource evaluation.The reservoir thickness and area are controlled by the distribution and superimposition pattern of sand bodies

and the distributary channels and composite sand bodies with large thickness and area are usually high in resource potentials and more productive.The reservoir porosity and permeability are controlled by debris composition and microscopic pore type

and are strongly modified by diagenesis at later stages.Compaction and cementation lower porosity

whereas dissolution may effectively increase it.The intensity of hydrocarbon generation fundamentally controls the distribution of the water producing zone and gas producing zone

while the sweet spots of tight gas are mainly located in areas of relatively high porosity and permeability in favorable reservoirs.For resource evaluation of tight sand gas reservoirs

the sedimentation controls the distribution and superimposition patterns of sand bodies

produces composite sand bodies of various types

determines reservoir area and thickness

and then controls the gas storage potential and production capacity.Diagenesis modifies reservoir porosity and permeability

thus mainly influences oil and gas reserves of the study area in a microscopic sense.