OIL AND GAS DISTRIBUTION PATTERN AND PETROLEUM GEOLOGICAL CONDITION OF THE NORTH SEA BASIN

Based on the data from IHS database 2009, this paper analyzed the hydrocarbon resources distribution pattern in the North Sea Basin by counting up the numbers and reserves of oil and gas fields as well as giant oil and gas fields in different geological units and reservoirs. More than half of the hydrocarbon resources are preserved in the giant oil and gas fields over 5 billon barrels of oil equivalent. The northern North Sea Basin is rich in both oil and gas, but dominated by oil, while the southern North Sea is predominated by gas. The analysis of the petroleum geological condition shows that there are several petroleum systems developed in the North Sea Basin. The hydrocarbon distribution in the northern North Sea Basin is mainly controlled by of source and reservoir rocks. The Kimmeridge Clay Formation is the most important source rock, and the middle and lower Jurassic and the upper Permian System are the richest reservoirs which contains more than half of the reserves of the northern North Sea Basin. The Upper Carboniferous Westphalian coal is the source rock of the largest petroleum system of the Basin, and the most important reservoir is the Upper Permian Rotliegendian sandstone which stores more than 86% gas reserves in the southern North Sea Basin. The gas distribution is largely controlled by the availability of the regional cover of the Zechstein Series.>