Abstract: The Carboniferous volcanic rocks in Wellblock A of Chepaizi oilfiled belong to the pore-fracture dual-media reservoirs, in which hydrocarbon accumulation and well productivity are affected by multiple factors including fault, lithology, lithofacies, porosity and fracture, leading to the complex hydrocarbon accumulation law and unstable well productivity. Based on the data of geology, well logging, lab analysis and seismic interpretation, the paper analyzes the configuration relationship between the productivity and reservoir factors such as lithology, lithofacies, matrix physical property and fracture, and confirms the hydrocarbon production characteristics of the Carboniferous volcanic reservoir. The results show that both the explosive facies and effusive facies near the volcanic vent are the predominant lithofacies where volcanic breccia and stomatal basalt are the favorable lithologies with good matrix physical properties and developed fractures. In the wellblock there are many high-yield wells whose logging curves are characterized by both negative anomaly in SP and a certain overlapping area between Rt and DEN. Considering well productivity and its controlling factors, three types of favorable reservoirs are classified in the plane and the type I is the best. On the basis of the above, combined with the logging curve characteristics, 9 existing wells are proposed to carry out formation test and 11 new development wells are suggested to be deployed on the C3 and C4 volcanic rock mass