Controlling factors of hydrocarbon distribution and source-migration-accumulation model in Fushan Depression
QI Zhenguo
LU Zhenghuan
JIANG Fujie
SONG Zezhang
CHEN Di
ZHANG Yuqi
GUO Jing
FANG Zhou
WANG Xirong
LIU Yilin
Abstract：As one of the few onshore hydrocarbon-rich depressions in it,Fushan depression,lo-cated in the northern margin of the South China Sea,is an important breakthrough point for the study of oil and gas accumulation in the Beibuwan Basin and even the entire South China Sea.The distribution of hydrocarbon in Fushan depression is characterized by"east gas and west oil","deep gas and shallow oil",and"central and eastern enrichment".However,the dominant factors of the process of hydrocarbon migration and accumulation are still unclear,which restricts the selection of exploration.Therefore,based on the analysis of petroleum geo-logical characteristics,combined with basin simulation,the analysis of the process of hydro-carbon migration and accumulation has been carried out,and the main controlling factors of hydrocarbon distribution also have been summarized from three key aspects:"source-migration-accumulation".The results show that the maturity of source rock in E2l2 in Bailian Sub sag is obviously higher than that in other areas due to the intrusion of igneous rock;The sand bodies of E2l1 and E2l3 are thick and have good porosity and permeability.The faults Shale Gouge Ratio is quite different from north to south but they have the highest activity rate during the Oligocene epoch,faults and sand bodies form the hydrocarbon transport system,controlled the process and direction of hydrocarbon;Trap types and hydrocarbon migration and accumu-lation units control the location of hydrocarbon accumulation.The hydrocarbon in Huangtong Sub sag mainly converge to the north(Yong'an),southeast(Hongguang,Huachang),and west(Chaoyang,Meitai),while the hydrocarbon in Bailian Sub sag mainly converge to the north(northern sea area),southeast(Jinfeng),and southwest(Huachang),which is consist-ent with the geochemical indicators of hydrocarbon migration.On the whole,there is a hydro-carbon accumulation model of"Heat promoted hydrocarbon generation,hydrocarbon supply from two depressions,fault sand transport,subsag earlier,subconvex later,deep shallow sep-aration,and composite reservoir formation"in Fushan Depression.
Keywords：source-migration-accumulation characteristicshydrocarbon migration and accumu-lationhydrocarbon accumulation modelFushan Depression
Publication Date：2024-07-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：16( 777-792 )