Research On Jurassic Hydrocarbon Accumulation Process In Tugelming Area,Kuqa Depression

The evolution of fluids in the Kuqa Depression in the Tarim Basin is complex,and there are few studies on oil and gas accumulation in the Tugelming area,and little is known about the oil and gas distribution laws in this area.Therefore,in this paper,a total of 5 wells including Tuge 4,Well Tuxi 1,Tudong 2,Well Tudong 201,and Mingnan 1 were selected as the research objects,from source rock,reservoir evaluation,and oil and gas.Three aspects of the accumulation process were studied.The Jurassic source rocks in the Tugelming area of Kuqa Depression are characterized by large thickness,wide distribution,and high maturity.The thickness of the source rocks is concentrated between 80 m and 180 m,and the deep source rocks have reached the maturity stage,mainly producing condensate oil and condensate gas,which satisfies the source rock conditions for the formation of large oil and gas fields.The comparison of oil sources shows that the oil and gas in the Tugelming area is a mixed source charge,mainly from source rocks in the Jurassic horizon,and some source rocks from the Triassic horizon.Through the analysis of the mineral composition content of the reservoir in the Tugelming area of Kuqa Depression,it is found that quartz accounts for 70% to 90%,indicating that the lithology is relatively brittle.Vertically,the Jurassic Ahe Formation reservoirs are the most developed,and on the plane,the reservoirs in the northern wing slope area are the thickest.The reservoir is generally dense,with porosity less than 12%.Using the fluid inclusion fluorescence,uniform temperature and reservoir quantitative fluorescence technology,combined with the burial history,thermal evolution history and hydrocarbon generation history,the accumulation and evolution process in the Tugelming area was restored.Most of the Tugelming area has experienced three stages of oil and gas charging:(1)The first stage was in the early and middle stages of the Kangcun Formation(approximately 18/17 Ma to 10/9Ma from now),with low-mature heavy oil for charging,and the corresponding inclusions haveyellow,yellow-green fluorescence,QGF spectrum detection It shows that except the Tuxi 1 well in the central anticline area where no ancient reservoirs are developed,there are ancient reservoirs in the other structural belts.The Ming Nan 1 well is the most severely damaged and the crude oil escapes a lot;(2)The second phase is in the late Kangcun Formation(about 10/9Ma to 6Ma from now),and a large amount of highly mature condensate is produced,and blue-white hydrocarbons are formed during the charging process Inclusions;(3)The third phase was in the Kuqa Formation period(since 6Ma),in deep buried areas(ie,Tuxi 1 well and Mingnan 1 well),the source rock reached a high-over-mature stage A large amount of condensate gas was charged,and gas washing occurred,which caused an increase in asphalt content.Based on the above research,it is speculated that the eastern wing of the local structural high and central anticline in the Tugelming area are favorable accumulation areas for crude oil and condensate oil and gas,and have exploration potential.