Comparison Of Hydrocarbon Accumulation Characteristics Between Huizhou Sag And Baiyun Sag In Pearl River Mouth Basin

Pearl river mouth basin de velopments multiple sag,more sets of hydrocarbon source rock,various types of transportation systems.The origin of crude oil,the trend and accumulation characteristics is weak,has become the important issues of the issue of oil and gas exploration in the region.This article reveals the similarities and differences between the two based on the study of the geochemical characteristics of Baiyun sag,combining previous research on geochemical characteristics of huizhou sag,comparing the two major hydrocarbon source rocks,geochemical characteristics of crude oil,oil and gas migration and accumulation patterns,to better service for oil and gas exploration work in this area.Results are as follows :1?There is little source rock samples in Baiyun sag and a small amount of sample data is not representative and typicality.With Huizhou sag has the same geological background,comparing two sets of hydrocarbon source rocks,concluding the common characteristics of Wenchang group and Enping group from Baiyun sag.2?In the geochemical characteristics of crude oil of the contrastbased on two sag,group composition,isoprenoid alkane,steroid terpane series standard,aromatic oil ?13C maturity,Huizhou sag and Baiyun sag in the sedimentary environment of crude oil and the original hydrocarbon generation of different parent material.The parameter for oil source correlation in Huizhou sag does not apply to Baiyun sag.Using the principal component analysis on the effectiveness evaluation parameters and combining with all oil isotope,it shows that oils from Baiyun sag were devided into three types.3?Based on the two concave conducting comparison system types and effective migration channel,it is concluded that the pearl river mouth basin are mainly sandstone,fault and unconformity three transportation systems.The difference between of the two is bottom split structure in baiyun sag,and it plays an important role in zhuhai group late oil and gas of vertical transportation.The sandstone and unconformity surface have lateral conducting effect,active faults have longitudinal conducting effect,the late active faults are secondary regulation in terms of hydrocarbon accumulation.All cooperate with each other,sandstone-fracture and the fracture-unconformity of conducting system,play role in the process of the hydrocarbon accumulation in the pearl river mouth basin.On the migration path,the Zhujiang group sand body of effective hydrocarbon migration space coefficient is big,and it is important for horizontal transport layer.The tectonic ridge located in the central uplift belt common controls two sag of the oil and gas migration direction.4?Based on two typical reservoir in anatomy,there is much similarity in accumulation mode between huizhou sag and baiyun sag,namely migration channel control hydrocarbon accumulation.It can be divided into fault-sand body/unconformity ladder shaped end of long-distance petroleum accumulation and fracture/split longitudinal conducting two modes,but also exists a certain differences.Fault-sand body/unconformity ladder shape distance conducting modes,huizhou sag is a fault to the vertical migration of source rocks of oil source faults to the zhujiang,zhuhai group conducting layer,and then to uplift by sandstone updip direction and fracture ladder gathered in conducting to trap accumulation;Baiyun sag along into hydrocarbon source rock is mainly from lateral migration of sandstone lose a conductor,and by fault and sand body or unconformable with lateral petroleum accumulation.Fracture/bottom split longitudinal conducting mode,huizhou sag and baiyun sag of oil and gas are all along the fault vertical migration from the source rocks,but at the bottom of the baiyun sag split structure of late zhuhai crude set of input plays an important role.