Comprehensive identification of natural gas/hydrate genesis types and gas sources in the northern continental margin basins of the South China Sea
The identification of the genetic types and gas sources of natural gas/hydrates is the core and key element of the study of natural gas/hydrate reservoir systems,and also the main basis for evaluating and predicting exploration targets of natural gas/hydrates. On the basis of previous studies and a large number of oil and gas exploration achievements and rich oil and gas geological data obtained in recent years,through systematic analysis,summary and comprehensive research on the genetic types of natural gas/hydrate and its gas source composition and distribution characteristics in the northern continental margin basin of the South China Sea,it is found that the biogenic gas and sub biogenic gas are widely distributed in the Yinggehai Basin,Qiongdongnan Basin and the Pearl River Mouth Basin (shallow water/deep water) shallow layers (<2300 m),and their gas supply is mainly from the Upper Miocene,Pliocene and Quaternary marine sedimentary organic matter;The oil type gas is mainly distributed in the Beibu Gulf Basin,the northern Qiongdongnan Basin and the shallow water area in the northern the Pearl River River Mouth Basin,which belongs to the associated gas of the oil field. Its gas supply is the same as that of the oil field group,and it comes from the Eocene mid deep lacustrine mixed sapropel hydrocarbon source rock;Mature high mature coal type gas and high mature over mature mixed type natural gas are mainly distributed in Yinggehai Basin,Qiongdongnan Basin and the south of Pearl River Mouth Basin. The former gas source is mainly supplied by Oligocene coal measures and shallow marine terrigenous partial humic source rocks and Miocene marine terrigenous partial humic source rocks,while the latter is mainly contributed by different types of source rocks of high mature over mature Eocene Miocene in wide and deep fault depression of the basin. Natural gas hydrates are mainly distributed in the south/southwest of Qiongdongnan Basin and the shallow seabed in the deep-water area of the continental slope in the southeast of the Pearl River River Mouth Basin. It is comprehensively recognized that the genetic type of natural gas hydrates is a mixed type dominated by biogas,that is,it is dominated by biogas,mixed with important contributions of deep and deep pyrolysis gas,and there is a genetic type of pyrolysis gas hydrates in local areas. This research result will provide certain guidance and refer-ence for the evaluation and prediction of oil and gas (hydrate) enrichment areas,as well as the decision-making of the next oil and gas (hydrate) exploration deployment.
northern South China Seatypes of natural gas/hydrate genesischaracteristics of gas source compositioncomprehensive identification
万方数据
维普
