Volcanic hydrocarbon accumulations in eastern and western China have both generality and discrepancy. The common features are as follows: their source-reservoir-caprock association is a near-source type; their reservoir properties are little affected by burial depth and possess strong heterogeneity; the main source rocks are coal measures mudstone and usually have a high geothermal evolution degree. In terms of reservoir types and controlling factors, the eastern reservoirs are mainly lithologic and structural-lithologic, with hydrocarbon accumulations controlled by effective source kitchens, deep-seated faults and volcanic eruption structures, and the in-situ features are obvious; the western reservoirs are mainly stratigraphic unconformity reservoirs, with hydrocarbon accumulations controlled by unconformities, source-reservoir-caprock associations and large faults, and both heterotopic and in-situ features exist.
