Study On The Main Controlling Factors Of Hydrocarbon Accumulation In The North Of Baijiahai Uplift,Junggar Basin

Baijiahai Uplift in Junggar Basin is an inherited palaeohigh that is formed earlier and there are three major oil source sags around it.Its location is very good,but in recent years,its exploration result is not ideal due to that the main controlling factors of hydrocarbon accumulation are unknown.In order to solve this problem,this study dissected the oil and gas reservoirs in the north of Baijiahai Uplift and got the result that under the background of the oil source faults,the controlling factors of hydrocarbon accumulation include culminations,thickness and distribution of sand layers,physical property of reservoir and so on,but the main controlling factor is favorable traps which are formed of the match of assemblages and fractures.After analyzing the previous research results,it's found that the source of oil and gas in study area is adequate.So,this study analyzed the conditions of Jurassic assemblages and the conditions of fractures and hydrocarbon accumulation in north of Baijiahai Uplift in detail using inversion and seismic attribute extraction and such geophysical techniques and drew the traps distribution maps of Jurassic different interval.Finally,combined the results of typical reservoirs autopsy,oil and gas accumulation conditions analysis and the positions of all the oil and gas wells in study area,this study analyzed principal controlling factors of oil and gas of different layers in detail and found that under the background of the oil source faults,hydrocarbon accumulation of Member 3 of Badaowan Formation are mainly controlled by the physical properties of reservoirs,culminations and sand layer thickness;the main controlling factors of Member 1 of Sangonghe Formation are the thickness and horizontal distribution of sands;the main controlling factors of Member 2 of Sangonghe Formation are culminations and lateral shelter;the main controlling factors of Member 1 of Xishanyao Formation are structural factors,lateral shelter and the physical properties of reservoirs;the main controlling factor of Toutunhe Formation and Qigu Formation is the match of channel sands and fractures.At the same time,prediction for favorable areas were carried out in the main oil and gas layers(Member 2 of Sangonghe Formation and Member 1 of Xishanyao Formation)and the direction of the study of exploration targets of Jurassic in this area in next step was given.