Carbonate reservoir characteristics of Upper Carboniferous Dapu Formation in Dushan area, southern Guizhou

The huge-thick carbonate rock developed in Upper Carboniferous in southern Guizhou, and it is charac-terized by wide distribution, integrated strata and huge sediment thickness. But its exploration degree is low. So doing a good job in the research of carbonate reservoir characteristics has significances to the evaluation of resource potentiality and prospect of marine strata in southern Guizhou. Based on field actual measurement data, cast slice, scanning electronic microscope and reservoir property test, the reservoir characteristics of different lithologies of Upper Carboniferous Dapu Formation are analyzed. The lithologies of Dapu Formation mainly are clastic limestone, microcry-stalline limestone, dolomitic limestone, limy dolomite and dolomite. The main reservoir space type is secondary pore, and the primary pore does not develop. The reservoir pore structure is complicated, belonging to low-porosity and low-permeability reservoirs. The controlling factors of reservoir development mainly contain lithology, diagenesis and structural fracture, except for sedimentary facies. The zone of concealed structural fracture and burial dolomitization may become the further important exploration areas.