The further development of society depends on the support of energy. Based on China's economic construction system, the importance of coal mines can not be ignored. With the increasing demand for coal, the demand ...The further development of society depends on the support of energy. Based on China's economic construction system, the importance of coal mines can not be ignored. With the increasing demand for coal, the demand for mining is also increasing. Therefore, it is necessary to maintain the safety and stability of coal mining with the help of tunneling support technology, and complete the core goal of coal mining under complex geological conditions. Based on this, this paper explores the efficient coal mine excavation support technology in complex terrain, hoping to provide some feasible reference opinions for the majority of colleagues.展开更多
The methods combined by test, field monitoring and theoretical analysis were adopted to do the systemic research on the rock mass from micro-structure to macro-deformation, and rheological model of Jinchuan rock mass ...The methods combined by test, field monitoring and theoretical analysis were adopted to do the systemic research on the rock mass from micro-structure to macro-deformation, and rheological model of Jinchuan rock mass was established to discuss the reasonable supporting time. Resuhs show that supporting after suitable stress and displacement release can benefit for the long-term stability of surrounding rock.展开更多
This foundation pit project is located in the flood plain area of the Yangtze River in Hexi, Nanjing, with complicated geological conditions, high underground water level, ultra-thick sand layer and rock entry. The fo...This foundation pit project is located in the flood plain area of the Yangtze River in Hexi, Nanjing, with complicated geological conditions, high underground water level, ultra-thick sand layer and rock entry. The foundation pit adopts a 50m-deep TRD underground water soil mixing wall and a 15m-deep MJS construction pile as the waterproof curtain outside the foundation pit. This paper discusses the construction technology of TRD combined with MJS waterproof curtain and the technical measures such as design optimization, equipment configuration, main process parameters, construction points, construction difficulties and treatment measures in the construction process, which largely solves the difficult problems of crossing ultra-deep fine sand layer, gravel layer and eventually entering rock, and the construction is difficult, and achieves good construction effect.展开更多
Exploration and development practices have proved that staged volumetric fracturing stimulation in horizontal wells is a key technology for tight sandstone gas development,and reservoir sweet spot is an important basi...Exploration and development practices have proved that staged volumetric fracturing stimulation in horizontal wells is a key technology for tight sandstone gas development,and reservoir sweet spot is an important basis for the perforation position selection and staged fracturing in the process of well location deployment and reservoir stimulation.Tight sandstone reservoirs are usually characterized by sandstone and mudstone interlayers with different thicknesses,and complex natural fracture distribution and geostress state.It is hard to predict“geological-engineering”dual sweet spots,and these two kinds of sweet spots are usually in different zones.As a result,there lacks a basis for the optimization of fracturing parameters to stimulate tight sandstone reservoirs.This paper establishes a geological sweet spot prediction model which takes into account total hydrocarbon content,reservoir porosity and other factors,then puts forward a 3D multi-scale engineering sweet spot evaluation method which takes into account lithology,fracture morphology,fracture mechanical behavior,and dilatation and shear dilation effect,andfinally a“geological-engineering”dual sweet spot evaluation model for tight sandstone reservoirs.Two wells in the tight sandstone gasfield in the Linxing Block of the Ordos Basin were selected as a case,and the dual sweet spot profiles,fracturing pressure and SRV were compared and analyzed.The results show that:1)shear dilation angle influences the distribution of engineering sweet spots at the most in the study area,followed by dissipated energy,elastic modulus and fracture energy;2)the geological sweet spot zone with a high coefficient is not necessarily the pay zone with high shale gas production;3)the engineering sweet spot zone with a high coefficient needs lower fracture pressure and can be stimulated relatively sufficiently;4)high-quality geological sweet spots and high-quality engineering sweet spots are poorly consistent in spatial location.In conclusion,the stimulation of tight sandstone gas reservoirs shall take geological sweet spot as the basis and engineering sweet spot as the guarantee,and the distribution of dual sweep spots should be considered comprehensively.The multi-scale“geological-engineering”dual sweet spot evaluation method proposed in this paper provides important technical support for the prediction of sweet spots of the tight sandstone gas and the optimization of development schemes in the study area.展开更多
文摘The further development of society depends on the support of energy. Based on China's economic construction system, the importance of coal mines can not be ignored. With the increasing demand for coal, the demand for mining is also increasing. Therefore, it is necessary to maintain the safety and stability of coal mining with the help of tunneling support technology, and complete the core goal of coal mining under complex geological conditions. Based on this, this paper explores the efficient coal mine excavation support technology in complex terrain, hoping to provide some feasible reference opinions for the majority of colleagues.
文摘The methods combined by test, field monitoring and theoretical analysis were adopted to do the systemic research on the rock mass from micro-structure to macro-deformation, and rheological model of Jinchuan rock mass was established to discuss the reasonable supporting time. Resuhs show that supporting after suitable stress and displacement release can benefit for the long-term stability of surrounding rock.
文摘This foundation pit project is located in the flood plain area of the Yangtze River in Hexi, Nanjing, with complicated geological conditions, high underground water level, ultra-thick sand layer and rock entry. The foundation pit adopts a 50m-deep TRD underground water soil mixing wall and a 15m-deep MJS construction pile as the waterproof curtain outside the foundation pit. This paper discusses the construction technology of TRD combined with MJS waterproof curtain and the technical measures such as design optimization, equipment configuration, main process parameters, construction points, construction difficulties and treatment measures in the construction process, which largely solves the difficult problems of crossing ultra-deep fine sand layer, gravel layer and eventually entering rock, and the construction is difficult, and achieves good construction effect.
文摘Exploration and development practices have proved that staged volumetric fracturing stimulation in horizontal wells is a key technology for tight sandstone gas development,and reservoir sweet spot is an important basis for the perforation position selection and staged fracturing in the process of well location deployment and reservoir stimulation.Tight sandstone reservoirs are usually characterized by sandstone and mudstone interlayers with different thicknesses,and complex natural fracture distribution and geostress state.It is hard to predict“geological-engineering”dual sweet spots,and these two kinds of sweet spots are usually in different zones.As a result,there lacks a basis for the optimization of fracturing parameters to stimulate tight sandstone reservoirs.This paper establishes a geological sweet spot prediction model which takes into account total hydrocarbon content,reservoir porosity and other factors,then puts forward a 3D multi-scale engineering sweet spot evaluation method which takes into account lithology,fracture morphology,fracture mechanical behavior,and dilatation and shear dilation effect,andfinally a“geological-engineering”dual sweet spot evaluation model for tight sandstone reservoirs.Two wells in the tight sandstone gasfield in the Linxing Block of the Ordos Basin were selected as a case,and the dual sweet spot profiles,fracturing pressure and SRV were compared and analyzed.The results show that:1)shear dilation angle influences the distribution of engineering sweet spots at the most in the study area,followed by dissipated energy,elastic modulus and fracture energy;2)the geological sweet spot zone with a high coefficient is not necessarily the pay zone with high shale gas production;3)the engineering sweet spot zone with a high coefficient needs lower fracture pressure and can be stimulated relatively sufficiently;4)high-quality geological sweet spots and high-quality engineering sweet spots are poorly consistent in spatial location.In conclusion,the stimulation of tight sandstone gas reservoirs shall take geological sweet spot as the basis and engineering sweet spot as the guarantee,and the distribution of dual sweep spots should be considered comprehensively.The multi-scale“geological-engineering”dual sweet spot evaluation method proposed in this paper provides important technical support for the prediction of sweet spots of the tight sandstone gas and the optimization of development schemes in the study area.
