Analysis On Geochemical Characteristics And Potentials Of Xinhe Formation In Yabrai Basin

Based on drilling, logging, seismic datum and geochemical analysis results, this thesiscomprehensively researches and analyzes stratigraphic features, structural characteristics andevolution history, and reservoir-cap combinations of Yabulai basin. This thesis puts emphasison the distribution of hydrocarbon source rocks of Middle Jurassic Xinhe formation, itscorresponding geochemical features, hydrocarbon generation potential, and resource potential.Yabulai basin behaves as a rift basin which is a Jurassic residual basin. Indosinianmovement leads to the development of basement fault of Yabulai basin. Under the influence ofregional tensile stress, two EW trending normal faults developed along the northern margin ofthe North Mountain and southern margin of Yabulai Mountain, which formed the initial shapeof yabulai rift basin. Subsequently the formation, evolution and development of this basin arecontrolled by Yanshan movement and Himalayan movement which at present show twopositive structures, three negative structures of Jurassic depression. Source rock evaluationshows that for Xiaohuzi subsag Shacaohe and upper Xinhzu source rock are poor, lowerXinhezu source rosk is good and Qingtujing source rock is moderate; for Yanchang subsag,Shacaohe source rock is poor, upper Xinhe source rock is moderate, lower Xinhe source rockis good and Qingtujing source rock is moderate; for Suotuo subsag, Xinhe source rock is poorand Qingtujing source rock is moderate. In the terms of the whole basin, Xiaohuzi subsag isthe main area of effective source rock and lower Xinhe formation is the main source rock.Through applying basin modeling method and chloroform bitumen "A" method to calculateresource of Yabulai basin, it reaches0.71×108and0.62×108t respectively.