Based on high-resolution 3D seismic data, we document the polygonal faults within the Miocene Meishan （梅山） Formation and Huangliu （黄流） Formation of the Qiongdongnan （琼东南） basin, northern South China Sea. ...Based on high-resolution 3D seismic data, we document the polygonal faults within the Miocene Meishan （梅山） Formation and Huangliu （黄流） Formation of the Qiongdongnan （琼东南） basin, northern South China Sea. Within the seismic section and time coherent slice, densely distributed extensional faults with small throw and polygonal shape were identified in map view. The orientation of the polygonal faults is almost isotropic, indicating a non-tectonic origin. The deformation is clearly layer-bounded, with horizontal extension of 11.2% to 16%, and 13.2% on average. The distribution of polygonal faults shows a negative correlation with that of gas chimneys. The development of polygonal faults may be triggered by over-pressure pore fluid which is restricted in the fine-grained sediments of bathyal facies when the sediments is compacted by the burden above. The polygonal faults developed to balance the volumetric contraction and restricted extension. The product of hydrocarbon in the Meishan Formation may have contributed to the development of the polygonal faults. In the study area, it was thought that the petroleum system of the Neogene post-rift sequence is disadvantageous because of poor migration pathway. However, the discovery of polygonal faults in the Miocene strata, which may play an important role on the fluid migration, may change this view. A new model of the petroleum system for the study area is proposed.展开更多
In order to research the influence of coal-rock mass morphology of mining space on the flow law of gas,the laboratory physical model and numerical computation methods were adopted to simulate coal mining activities.Th...In order to research the influence of coal-rock mass morphology of mining space on the flow law of gas,the laboratory physical model and numerical computation methods were adopted to simulate coal mining activities.The simulation results indicate that,after coal seam mining,the loose rock accumulation body of free caving,ordered rock arrangement body of plate damage rich in longitudinal and transverse fractures and horizontal fissure body formed by rock mass deformation imbalance are formed from bottom to top in the mining space.For these three types of accumulation bodies,there are essential differences in the accumulation state,rock size and gas breakover characteristics.According to this,the coal-rock mass in the mining space is classified into gas turbulence channel area,gas transitional flow channel area and gas seepage channel area.In the turbulence channel area,the gas is distributed transversely and longitudinally and gas diffuses in the form of convection with Reynolds number R_e more than100;in the transitional flow channel area,one-way or two-way gas channels are crisscross and gas is of transitional flow regime with R,.between 10 and 100.In the seepage channel area,there are a few vertical gas channels with R,.less than 10.In this paper,the researches on the gas orientation method in different partitions were further carried out,gas orientation methods of low-level pipe burying,middle-level interception and high-level extraction were determined and an on-site industrial test was conducted,achieving the effective diversion of gas and verifying the reasonableness of gas channel partition.展开更多
基金supported by the Formation Mechanism and Study on Geophysical Recognition Technology of Shallow Water Flow (No. 2006AA09Z349)the CAS Knowledge Inno-vation Program (No. KZCX2-YW-203), the National Basic Research Program of China (No. 2007CB411703)+1 种基金the MLR National Petroleum Resource Strategic Target Survey and Evaluation Programthe Taishan Scholarship Program of Shandong Province.
文摘Based on high-resolution 3D seismic data, we document the polygonal faults within the Miocene Meishan （梅山） Formation and Huangliu （黄流） Formation of the Qiongdongnan （琼东南） basin, northern South China Sea. Within the seismic section and time coherent slice, densely distributed extensional faults with small throw and polygonal shape were identified in map view. The orientation of the polygonal faults is almost isotropic, indicating a non-tectonic origin. The deformation is clearly layer-bounded, with horizontal extension of 11.2% to 16%, and 13.2% on average. The distribution of polygonal faults shows a negative correlation with that of gas chimneys. The development of polygonal faults may be triggered by over-pressure pore fluid which is restricted in the fine-grained sediments of bathyal facies when the sediments is compacted by the burden above. The polygonal faults developed to balance the volumetric contraction and restricted extension. The product of hydrocarbon in the Meishan Formation may have contributed to the development of the polygonal faults. In the study area, it was thought that the petroleum system of the Neogene post-rift sequence is disadvantageous because of poor migration pathway. However, the discovery of polygonal faults in the Miocene strata, which may play an important role on the fluid migration, may change this view. A new model of the petroleum system for the study area is proposed.
基金Financial supports for this work,provided by the State Key Basic Research Program of China(No.2011CB201204)
文摘In order to research the influence of coal-rock mass morphology of mining space on the flow law of gas,the laboratory physical model and numerical computation methods were adopted to simulate coal mining activities.The simulation results indicate that,after coal seam mining,the loose rock accumulation body of free caving,ordered rock arrangement body of plate damage rich in longitudinal and transverse fractures and horizontal fissure body formed by rock mass deformation imbalance are formed from bottom to top in the mining space.For these three types of accumulation bodies,there are essential differences in the accumulation state,rock size and gas breakover characteristics.According to this,the coal-rock mass in the mining space is classified into gas turbulence channel area,gas transitional flow channel area and gas seepage channel area.In the turbulence channel area,the gas is distributed transversely and longitudinally and gas diffuses in the form of convection with Reynolds number R_e more than100;in the transitional flow channel area,one-way or two-way gas channels are crisscross and gas is of transitional flow regime with R,.between 10 and 100.In the seepage channel area,there are a few vertical gas channels with R,.less than 10.In this paper,the researches on the gas orientation method in different partitions were further carried out,gas orientation methods of low-level pipe burying,middle-level interception and high-level extraction were determined and an on-site industrial test was conducted,achieving the effective diversion of gas and verifying the reasonableness of gas channel partition.
