Discussion on the formation mechanism of volcanic oil and gas reservoirs
试论火山岩油气藏成藏机理

Hydrocarbons in or around volcanic rocks have been found over 100 countries or areas. Volcanic rocks can form petroleum trap because of its good porosity in deeper formation. The traps can also be formed by reciprocity between volcanic structures and sedimentary layers. Igneous rocks have been changed from "forbidden area" to "target area" and become new object for petroleum exploration. Hydrocarbons in volcanic rock reservoirs are both biogenic and abiogenic. Volcanism can efficiently enhance the maturity, speed in the hydrocarbon-generation, afford materials of abiogenic hydrocarbon-formation and make migration pathway. Liquid and gas of volcanism positively influence on the migration of petroleum. Although the volume of volcanic rocks accounts for one quarter of the basin filling body in depression stage, the reserves of petroleum in volcanic rocks only occupy one percent of proven oil all over the world. There are volcanic rocks with different ages which have good relationship with source rocks in sedimentary basins in China. The abiogenic hydrocarbons are quite abundant. In a word, the volcanic rock reservoir is becoming an important area for petroleum exploration.