The Chaoyanggou oil field is a fractured low-permeability reservoir, where the distribution of oil and gas is controlled by the distribution and development of fractures.Based on outcrop, drilling core, thin section a...The Chaoyanggou oil field is a fractured low-permeability reservoir, where the distribution of oil and gas is controlled by the distribution and development of fractures.Based on outcrop, drilling core, thin section and log data, the development characteristics of fractures in this area are described.On this basis, the degree of fracture development was predicted by quantitative analysis of fracture strength and numerical simulation.The result shows that four groups of structural fractures, i.e., in near NS, and EW directions and in due NW and NE directions, were developed in the reservoir, with the nearly NS and EW fractures dominant, which are the along bedding decollement fractures formed by compressive folding action, while low angle shear fractures are related to thrusts.These fractures are mainly formed in the reversed tectonic stage at the end of the Mingshui formation during the Cretaceous period.The degree of fracture development is controlled by such factors as lithology, stratum thickness, faults, folds and depth.The fractures are developed with a clear zonation and are best developed in the northern zone, moderately developed towards the south and poorly developed in the middle zone.These prediction results are in good agreement with interpretation results from logs.展开更多
The Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was relocated using the Hypo2000 ＋ HypoDD algorithm with the seismic phase data from the Sichuan and Yunnan regional digital seismic networks, and the resul...The Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was relocated using the Hypo2000 ＋ HypoDD algorithm with the seismic phase data from the Sichuan and Yunnan regional digital seismic networks, and the results show that the epicenters are distributed in the near NS direction, the length of aftershock concentration zone is about 30kin, and the main shock is about 14km in depth. The depth of the sequence is distributed in the range of 0 -4km and 5 -20km, and the layer of 4 -5kin depth is an apparent earthquake absence layer. The cross-section along the fracture＇s long axis shows there is an irregular seismic gap in the middle segment of the aftershock region, which is the rupture region of 3 the M6 3/4earthquake in 1955, and this earthquake occurred in the south of the gap. We believe that the Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was a result of rupture of the residual asperity caused by the stress adjustment of the Wenchuan Ms8. 0 earthquake. The other two profiles perpendicular to the long axis show that the focal depth in the north segment is larger and the fault plane dips NW, which is consistent with the dip of the Hongge fault.展开更多
基金Project 40772086 supported by the National Natural Science Foundation of China
文摘The Chaoyanggou oil field is a fractured low-permeability reservoir, where the distribution of oil and gas is controlled by the distribution and development of fractures.Based on outcrop, drilling core, thin section and log data, the development characteristics of fractures in this area are described.On this basis, the degree of fracture development was predicted by quantitative analysis of fracture strength and numerical simulation.The result shows that four groups of structural fractures, i.e., in near NS, and EW directions and in due NW and NE directions, were developed in the reservoir, with the nearly NS and EW fractures dominant, which are the along bedding decollement fractures formed by compressive folding action, while low angle shear fractures are related to thrusts.These fractures are mainly formed in the reversed tectonic stage at the end of the Mingshui formation during the Cretaceous period.The degree of fracture development is controlled by such factors as lithology, stratum thickness, faults, folds and depth.The fractures are developed with a clear zonation and are best developed in the northern zone, moderately developed towards the south and poorly developed in the middle zone.These prediction results are in good agreement with interpretation results from logs.
基金funded jointly by the National Natural Science Foundation of China(40674040,41074062)the scientific investigation project of the M_S 7.0 Lushan earthquakethe special program for seismic network backbones of CEA(20150422)
文摘The Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was relocated using the Hypo2000 ＋ HypoDD algorithm with the seismic phase data from the Sichuan and Yunnan regional digital seismic networks, and the results show that the epicenters are distributed in the near NS direction, the length of aftershock concentration zone is about 30kin, and the main shock is about 14km in depth. The depth of the sequence is distributed in the range of 0 -4km and 5 -20km, and the layer of 4 -5kin depth is an apparent earthquake absence layer. The cross-section along the fracture＇s long axis shows there is an irregular seismic gap in the middle segment of the aftershock region, which is the rupture region of 3 the M6 3/4earthquake in 1955, and this earthquake occurred in the south of the gap. We believe that the Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was a result of rupture of the residual asperity caused by the stress adjustment of the Wenchuan Ms8. 0 earthquake. The other two profiles perpendicular to the long axis show that the focal depth in the north segment is larger and the fault plane dips NW, which is consistent with the dip of the Hongge fault.
