Research On Controlling Factors Of Hydrocarbon Accumulation In The Western Segment Of The North Qaidam

From the west to the east of the northern part of the northern margin of the Qaidam,the Oboliang structural belt,the Lenghu structural belt,and the Qianfu structural belt are developed.It is an important exploration area in the Qaidam Basin,with huge exploration potential,and there are also large exploration risks.The main problems are the differences in the geological conditions(structure activitiy intensity,structure formation period,and sedimentary characteristics)of the Sanpai structural belt.By comparing the differences in the three belts of structures in the western segment of the northern margin of the Qaidam,the hydrocarbon accumulation in different structural zones in the western segment of the northern margin of the Qaidam can be determined.The control factors provide a reliable basis for the evaluation of the traps and the optimization of targets in the work area.This paper mainly applys theories of sedimentary petrology,petroleum geology,and oil and gas field development geology.Based on previous research results,it makes full use of geological data,seismic data,logging data,geochemical data,and drilling data.Based on the petroleum geological conditions(structural evolution characteristics,sedimentary characteristics,and source rock characteristics),the main controlling factors for hydrocarbon accumulation in different structural zones are determined by analyzing the typical reservoirs in the three belts of structures.It is found that the main controlling factors for hydrocarbon accumulation in the Lenghu structural zone are hydrocarbon generation sags,reservoir quality,and fault distribution;the main controlling factors for hydrocarbon accumulation in the Eboliang structural zone are trap effectiveness,reservoir physical properties,and preservation conditions;The main controlling factors for hydrocarbon accumulation in Qianfu structural belts are trap effectiveness and reservoir physical properties.