Tight Oil System Particularity of Lucaogou Formation in Jimusaer Sag, Junggar Basin

Key words: 
• Jimusaer sag /
• Lucaogou Formation /
• tight oil /
• source rock /
• oil accumulation model

Abstract: Based on the analysis of source rock, reservoir, crude oil origin and spatial configuration relationship between source rock and reservoir, it was proposed of the stratiform and self-generating and self-preserving tight oil accumulation model of the Lucaogou Formation in the Jimusaer sag of the Junggar Basin. In salt water lake facies sedimentary rocks of the Lucaogou Formation, individual lithology had different content of original organic matter which trended to generate oil, in them, as main source rock, shale has the highest organic matter abundance and hydrocarbon potential, oil-prone parent matter type and the mature stage for oil generation. The sandstone and carbonate reservoirs which were distributed in source rock layer had reservoir background of low porosity and low permeability, and their oilness has a close relationship with physical property difference. The Lucaogou Formation had basic tight oil accumulation condition because of alternating layers between shale and reservoir, and reservoir involved in shale. The crudes oil in the Upper and the Lower member of the Lucaogou Formation, which having obvious density and geochemistry differences, came from the source rocks adjent to them, respectively. Comprhansive researches show the Lucaogou Formation has stratabound tight oil accumulation model with close migration distance and self-generating and self-reservoir in Jimusaer sag of Junggar Basin.