Buried-Hill Oil and Gas Pools in the North China Basin
Since the discovery of the Renqiu oil field in 1975, buried-hill oil and gas pools have become a new and main target of exploration efforts in the North China basin. The more than 40 buried-hill oil and gas pools already discovered are of varied types and widely distributed. Making the fullest use of all geologic data available, the writers discuss, in particular, the following aspects relating to the buried-hill oil and gas pools: (1) the evidence of "Tertiary oil in older reseroirs," and the principal modes of migration; (2) the factors affecting the reservoir properties of buried hills; and (3) the types of buried-hill oil and gas pools. Similar conditions exist all over the North China basin and, therefore, prospects are good for further exploration of this kind of pool.