Reservoir characteristics and main controlling factors of Huanglong Formation in Northeastern Sichuan,China

The exploration of the oil and gas in Huanglong Formation is conditioned by two factors.One is that the Huanglong Formation reservoir is influenced by various diagenesis.The other is that the controlling factors of reservoir development have been not known clearly.In this paper,based on the analysis of petrography,sedimentary facies and reservoir characteristics,the authors think that the reservoir mainly occur in the dolomite of Member 2of Huanglong Formation.The reservoir is fracture-pore type with medium to low porosity and permeability.The reservoir spaces are mainly intercrystalline pores and secondary dissolved pores.The fractures improve the porosity and permeability and provide the efficient migrating pathway for hydrocarbon.The development of the reservoir is influenced by sedimentary facies,dolomitization and karstification.The reservoir is a complex reservoir that is based on sedimentary facies and dolomitization and overprinted by paleokarstification.All these provide evidences for the furthur oil and gas exploration of Carboniferous in Northeastern Sichuan.