Neotectonism occurred intensively in the Bozhong depression in the Bohai Bay Basin, which was reflected vertically by dramatic subsidence and a number of uplifts and laterally by notable fault movements. This particul...Neotectonism occurred intensively in the Bozhong depression in the Bohai Bay Basin, which was reflected vertically by dramatic subsidence and a number of uplifts and laterally by notable fault movements. This particularity has resulted in the special petroleum geological conditions of the Bozhong depression which are different from those of adjacent lands. For example, the source rocks of the Shahejie Formation were overpressured and hydrocarbon generation occurred in the late stage; the Dongying Formation was deeply buried below the hydrocarbon-generating threshold, therefore there were sufficient oil sources. The rapid subsidence led to starved sedimentation of the Guantao Formation fine sandstone and the regional Minghuazhen Formation lacustrine shale, which formed the Neogene regional reservoir-caprock association. The active faults formed in the neotectonism became passages for oil to migrate from the Paleogene to Neogene. The traps formed by late fault activity and accompanied anticlines provided spaces for the formation of reservoirs. All the above factors match well with one another in the Bozhong depression, providing favorable conditions for the formation of a series of large oilfields in the region展开更多
Based on the available borehole temperature data and measurements of thermal conductivities on 10 core samples in the Southern South Yellow Sea Basin, 8 heat flow values are obtained. The results show that the mean va...Based on the available borehole temperature data and measurements of thermal conductivities on 10 core samples in the Southern South Yellow Sea Basin, 8 heat flow values are obtained. The results show that the mean values of temperature gradient and heat flow are 28.6℃/km and 69 mW/m2, respectively. The thermal history reconstruction from the inversion of vitrinite reflectance data, using the temperature-gradient method, indicates that the highest paleo-heat flow occurred at the end of the Mesozoic, and then the basin began to cool to present day. Tectonic subsidence analysis shows that the basin experienced at least four episodes of quick subsidence since the late Paleozoic and that the tectonic evolution was quite strong and complex.展开更多
基金This project is supported by the NationM Natural Science Foundation of China(No.40238059).
文摘Neotectonism occurred intensively in the Bozhong depression in the Bohai Bay Basin, which was reflected vertically by dramatic subsidence and a number of uplifts and laterally by notable fault movements. This particularity has resulted in the special petroleum geological conditions of the Bozhong depression which are different from those of adjacent lands. For example, the source rocks of the Shahejie Formation were overpressured and hydrocarbon generation occurred in the late stage; the Dongying Formation was deeply buried below the hydrocarbon-generating threshold, therefore there were sufficient oil sources. The rapid subsidence led to starved sedimentation of the Guantao Formation fine sandstone and the regional Minghuazhen Formation lacustrine shale, which formed the Neogene regional reservoir-caprock association. The active faults formed in the neotectonism became passages for oil to migrate from the Paleogene to Neogene. The traps formed by late fault activity and accompanied anticlines provided spaces for the formation of reservoirs. All the above factors match well with one another in the Bozhong depression, providing favorable conditions for the formation of a series of large oilfields in the region
基金supported by the National Natural Science Foundation of China(Grant No.40172100)China National Offshore Oil Corporation.
文摘Based on the available borehole temperature data and measurements of thermal conductivities on 10 core samples in the Southern South Yellow Sea Basin, 8 heat flow values are obtained. The results show that the mean values of temperature gradient and heat flow are 28.6℃/km and 69 mW/m2, respectively. The thermal history reconstruction from the inversion of vitrinite reflectance data, using the temperature-gradient method, indicates that the highest paleo-heat flow occurred at the end of the Mesozoic, and then the basin began to cool to present day. Tectonic subsidence analysis shows that the basin experienced at least four episodes of quick subsidence since the late Paleozoic and that the tectonic evolution was quite strong and complex.
