Features of gravity anomaly and its geological significance of Bohai Sea, China

Abstract

Gravity data was interpreted in Bohai Sea of China in order to study structural features and find out the distribution rules of oil and gas in this area. This paper, through data processing and synthetic interpretation of the gravity data in Bohai Sea, discusses characteristics of the gravity field and their geological significance, determines the fault system, divides structure unites and analyses the relationship between the features of local gravity anomaly and the distribution of oil and gas fields. The results show that Tanlu fault controlled the regional tectonic evolution and the boundary of the structure units of Bohai Sea in Bohai bay basin. Structurally, this area can be divided into seven units, including Huanghua sag, Chenning uplift, Bozhong sag, Jiyang sag, Liaohe sag, Yanshan fold belt and Jiaoliao uplift. In these sag, a lot of local structures and fault developed, and then many favorable traps and systems of migration and hydrocarbon reservoirs formed. There is a close relationship between the distribution of oil and gas fields and the local gravity highs. The relief areas surrounded by these petroleum generative depressions are the most favorable potential targets for the oil and gas exploration, and the intermediate zones between the depressions and the reliefs are also the significant areas in Bohai Sea.