Fluid Inclusion Characteristics and Hydrocarbon Accumulation Process of Yangtake Area,Kuqa Foreland Basin

Liu Jianliang; Jiang Zhenxue; Liu Keyu; Gui Lili

doi:10.3799/dqkx.2016.096

Abstract：There are abundant oil and gas resources in the Yangtake area,Kuqa foreland basin,and it is significant for oil and gas exploration to study the hydrocarbon charge history and accumulation process in this area.Hydrocarbon accumulation process of the Yangtake area in the Kuqa foreland basin was investigated using an integrated fluid inclusion petrography,micro-thermometry,quantitative grain fluorescence analysis in combination with source rock thermal evolution and tectonic evolution in the Kuqa foreland basin in this study.The results indicate that hydrocarbon accumulated in the Yangtake area at the Late Ne-ocene and experienced adjustment after the initial accumulation.The Middle Jurassic Qiakemake source rock in the Kuqa de-pression reached maturity (R o >0.5%)at about 1 5 Ma,and initially charged into the Yangtake area at Late Neogene Kuqa pe-riod (around 4.0 Ma).Low abundance oil inclusions with yellow fluorescence were formed at that time.Oil was mainly charged into the study area at around 3.5 Ma.The Middle to Lower Jurassic coaly source rock reached maturity at about 26 Ma,while large amount of natural gas was charged into the Yangtake tectonic belt until at about 3.5 Ma.Natural gas washed early charged oil,and formed near blue fluorescence oil inclusions with various gas-liquid ratios.During the mutual interacting between oil and gas,the oil-water contact was once at 5 390.75 m in the Yangta-1 area.With the strengthening of the Himalayan orogeny, the Yangta-1 condensate gas reservoir was adjusted and the gas-water contact was shifted to its current depth of 5 379.70 m in the late deposition of the Kuqa Member.