Controlling factors analysis of Archaezoic metamorphic buried hill reservoirs in Liaoxi low salient

Based on the core,thin sections,imaging logging and seismic data,the study on petrography characteristics,the reservoir space types and the main controlling factors of facture development of JZ25-1S,the Archaezoic metamorphic buried hill reservoirs in Liaoxi low salient has been carried out.The results indicate the buried hill's lithology is of gneiss and cataclasite,and it has coarser mineral crystallization,lower dark mineral content and stronger fracture effect,which can provide a good material base for reservoir development and formation.Reservoir space types include fractures,solution caves and micro pores,and structural fractures are the main reservoir space.The formation of the fractures in the metamorphic buried hill reservoir is the superimposed result of the tensile stress field during member 3of Shahejie formation and the right-lateral strike-slip stress field during Dongying formation in Paleocene.In addition,there are other development controlling factors of the fractured reservoirs including reservoir lithology,ancient weathering,and later diagenesis and so on.