The ＂Rising Mrica＂ narrative suffered a serious setback in 2016 when Africa expe- rienced the wot.＇st economic slowdown since the global financial crisis in 2008. However, the resilient growth in 2017 and signs of ...The ＂Rising Mrica＂ narrative suffered a serious setback in 2016 when Africa expe- rienced the wot.＇st economic slowdown since the global financial crisis in 2008. However, the resilient growth in 2017 and signs of a consolidated expansion in the mid-term are proving the recession is only a temporary situation.展开更多
Indeed, deficit-spending of massive amounts on public-works, lowering inter-est rates and promoting exports are the common phenomenon seen in today’s post-crisis Asia. But none of them is sustainable, nor a substitut...Indeed, deficit-spending of massive amounts on public-works, lowering inter-est rates and promoting exports are the common phenomenon seen in today’s post-crisis Asia. But none of them is sustainable, nor a substitute for the agonizing re-form, industrial restructuring and sci-tech innovations. The basis for long-term e-展开更多
With the continuous development of China's social economy, the demand for natural resources is also increasing day by day. As an important energy source for the economic development of our country, petroleum and c...With the continuous development of China's social economy, the demand for natural resources is also increasing day by day. As an important energy source for the economic development of our country, petroleum and chemical industry in our country is developing continuously with the progress of the society. At present, the petroleum and chemical industry in our country has gradually stepped into the forefront of the world. As a kind of non-renewable resources, oil is an important resource formed by the earth's geological process for thousands of years. Nowadays, the increasing demand for oil resources in the international community has resulted in the depletion of oil resources and the difficulty and complexity of oil exploitation projects. Therefore, under the current social environment of shortage of oil resources, effective measures must be taken to comprehensively enhance the geological exploration in the later stage, so as to fully cover the production benefits of oil field exploitation. This paper will sort out and analyze the geological potential tapping and efficiency enhancement in the later stage of oil field development.展开更多
Purpose–This study aims to analyze the development direction of track geometry inspection equipment for high-speed comprehensive inspection train in China.Design/methodology/approach–The development of track geometr...Purpose–This study aims to analyze the development direction of track geometry inspection equipment for high-speed comprehensive inspection train in China.Design/methodology/approach–The development of track geometry inspection equipment for highspeed comprehensive inspection train in China in the past 20 years can be divided into 3 stages.Track geometry inspection equipment 1.0 is the stage of analog signal.At the stage 1.0,the first priority is to meet the China’s railways basic needs of pre-operation joint debugging,safety assessment and daily dynamic inspection,maintenance and repair after operation.Track geometry inspection equipment 2.0 is the stage of digital signal.At the stage 2.0,it is important to improve stability and reliability of track geometry inspection equipment by upgrading the hardware sensors and improving software architecture.Track geometry inspection equipment 3.0 is the stage of lightweight.At the stage 3.0,miniaturization,low power consumption,self-running and green economy are co-developing on demand.Findings–The ability of track geometry inspection equipment for high-speed comprehensive inspection train will be expanded.The dynamic inspection of track stiffness changes will be studied under loaded and unloaded conditions in response to the track local settlement,track plate detachment and cushion plate failure.The dynamic measurement method of rail surface slope and vertical curve radius will be proposed,to reveal the changes in railway profile parameters of high-speed railways and the relationship between railway profile,track irregularity and subsidence of subgrade and bridges.The 200 m cut-off wavelength of track regularity will be researched to adapt to the operating speed of 400 km/h.Originality/value–The research can provide new connotations and requirements of track geometry inspection equipment for high-speed comprehensive inspection train in the new railway stage.展开更多
Coal reservoirs in the Qinshui Basin are characterized by high thermal evolution degree,low permeability,low reservoir pressure,lower gas saturation and strong heterogeneity,so its coalbed methane(CBM)development is q...Coal reservoirs in the Qinshui Basin are characterized by high thermal evolution degree,low permeability,low reservoir pressure,lower gas saturation and strong heterogeneity,so its coalbed methane(CBM)development is quite difficult.In this paper,the development practice of highrank CBM horizontal wells in the Fanzhuang-Zhengzhuang Block was analyzed in terms of geological and engineering factors to clarify the productivity influencing factors,suitable geological conditions and potential tapping countermeasures of multi-lateral horizontal wells.It is shown that the reasons for the low development efficiency of multi-lateral horizontal wells are divided into three types.The first one is geological factor,such as encountering low CBM content areas or faults.The second is engineering factor,such as drilling fluid plugging,drilling collapse,drainage collapse and dust coal blockage.The third is the combination of both factors.It is concluded that encountering low CBM content areas and faults,collapse and blockage are the main reasons for the low production of multi-lateral horizontal wells in the Zhengzhuang-Fanzhuang Block,with the CBM content higher than 20 m^(3)/t,the ratio of critical desorption pressure and reservoir pressure higher than 0.7 and vitrinite reflectance(R_(o))higher than 3.8.The prerequisite for an open-hole horizontal well in this area to produce CBM at a high rate is that the well lies in the tensile stress zone.Finally,the countermeasures to tap the potential of some inefficient wells were put forward.First,the inefficient wells which are blocked with dust coal or collapsed in the later stage should be stimulated based on classifications.And second,it is necessary to explore new types of horizontal wells so as to deal with borehole collapse and continue the operation in the later stage by using tree-like roof horizontal wells,single-lateral horizontal wells with casing or screen completion and fish-bone horizontal wells.展开更多
Purpose–This study aims to analyze the development direction of train speed,density and weight in China.Design/methodology/approach–The development of China’s railway in the past 40 years can be divided into 3 stag...Purpose–This study aims to analyze the development direction of train speed,density and weight in China.Design/methodology/approach–The development of China’s railway in the past 40 years can be divided into 3 stages.At the stage of potential tapping and capacity expansion,it is important to improve the train weight and density by upgrading the existing lines,and improving transportation capacity rapidly.At the stage of railway speed increase,the first priority is to increase train speed,reduce the travel time of passenger train,and synchronously take into account the increase of train density and weight.At the stage of developing high-speed railway,train speed,density and weight are co-developing on demand.Findings–The train speed of high-speed railway will be 400 km h1,the interval time of train tracking will be 3 min,and the traffic density will be more than 190 pairs per day.The running speed of high-speed freight EMU will reach 200 km h1 and above.The maximum speed of passenger train on mixed passenger and freight railway can reach 200 km h1.The minimum interval time of train tracking can be compressed to 5 min.The freight train weight of 850 m series arrival-departure track railway can be increased to 4,500–5,000 t and that of 1,050 m series to 5,500–6,400 t.EMU trains should gradually replace ordinary passenger trains to improve the quality of railway passenger service.Small formation trains will operate more in intercity railway,suburban railway and short-distance passenger transportation.Originality/value–The research can provide new connotations and requirements of railway train speed,density and weight in the new railway stage.展开更多
Side drilling and potential tapping technology is an effective way to tap the potential for the remaining oil in the old oil field in the middle and late stage of development. However, considering the economic benefit...Side drilling and potential tapping technology is an effective way to tap the potential for the remaining oil in the old oil field in the middle and late stage of development. However, considering the economic benefits and the surrounding environment of the oil field, it is an effective and economic way to improve the oil field and block recovery rate by implementing large displacement side drilling to replace the directional development of wells with the use of existing oil sites, facilities and equipment.展开更多
文摘The ＂Rising Mrica＂ narrative suffered a serious setback in 2016 when Africa expe- rienced the wot.＇st economic slowdown since the global financial crisis in 2008. However, the resilient growth in 2017 and signs of a consolidated expansion in the mid-term are proving the recession is only a temporary situation.
文摘Indeed, deficit-spending of massive amounts on public-works, lowering inter-est rates and promoting exports are the common phenomenon seen in today’s post-crisis Asia. But none of them is sustainable, nor a substitute for the agonizing re-form, industrial restructuring and sci-tech innovations. The basis for long-term e-
文摘With the continuous development of China's social economy, the demand for natural resources is also increasing day by day. As an important energy source for the economic development of our country, petroleum and chemical industry in our country is developing continuously with the progress of the society. At present, the petroleum and chemical industry in our country has gradually stepped into the forefront of the world. As a kind of non-renewable resources, oil is an important resource formed by the earth's geological process for thousands of years. Nowadays, the increasing demand for oil resources in the international community has resulted in the depletion of oil resources and the difficulty and complexity of oil exploitation projects. Therefore, under the current social environment of shortage of oil resources, effective measures must be taken to comprehensively enhance the geological exploration in the later stage, so as to fully cover the production benefits of oil field exploitation. This paper will sort out and analyze the geological potential tapping and efficiency enhancement in the later stage of oil field development.
基金supported by the National Natural Science Foundation of China(Grant No.52278465)Science and Technology Research and Development Plan of China Railway(Grant No.N2022G051)Key Project of China Academy of Railway Sciences(Grant No.2351JJ2401).
文摘Purpose–This study aims to analyze the development direction of track geometry inspection equipment for high-speed comprehensive inspection train in China.Design/methodology/approach–The development of track geometry inspection equipment for highspeed comprehensive inspection train in China in the past 20 years can be divided into 3 stages.Track geometry inspection equipment 1.0 is the stage of analog signal.At the stage 1.0,the first priority is to meet the China’s railways basic needs of pre-operation joint debugging,safety assessment and daily dynamic inspection,maintenance and repair after operation.Track geometry inspection equipment 2.0 is the stage of digital signal.At the stage 2.0,it is important to improve stability and reliability of track geometry inspection equipment by upgrading the hardware sensors and improving software architecture.Track geometry inspection equipment 3.0 is the stage of lightweight.At the stage 3.0,miniaturization,low power consumption,self-running and green economy are co-developing on demand.Findings–The ability of track geometry inspection equipment for high-speed comprehensive inspection train will be expanded.The dynamic inspection of track stiffness changes will be studied under loaded and unloaded conditions in response to the track local settlement,track plate detachment and cushion plate failure.The dynamic measurement method of rail surface slope and vertical curve radius will be proposed,to reveal the changes in railway profile parameters of high-speed railways and the relationship between railway profile,track irregularity and subsidence of subgrade and bridges.The 200 m cut-off wavelength of track regularity will be researched to adapt to the operating speed of 400 km/h.Originality/value–The research can provide new connotations and requirements of track geometry inspection equipment for high-speed comprehensive inspection train in the new railway stage.
文摘Coal reservoirs in the Qinshui Basin are characterized by high thermal evolution degree,low permeability,low reservoir pressure,lower gas saturation and strong heterogeneity,so its coalbed methane(CBM)development is quite difficult.In this paper,the development practice of highrank CBM horizontal wells in the Fanzhuang-Zhengzhuang Block was analyzed in terms of geological and engineering factors to clarify the productivity influencing factors,suitable geological conditions and potential tapping countermeasures of multi-lateral horizontal wells.It is shown that the reasons for the low development efficiency of multi-lateral horizontal wells are divided into three types.The first one is geological factor,such as encountering low CBM content areas or faults.The second is engineering factor,such as drilling fluid plugging,drilling collapse,drainage collapse and dust coal blockage.The third is the combination of both factors.It is concluded that encountering low CBM content areas and faults,collapse and blockage are the main reasons for the low production of multi-lateral horizontal wells in the Zhengzhuang-Fanzhuang Block,with the CBM content higher than 20 m^(3)/t,the ratio of critical desorption pressure and reservoir pressure higher than 0.7 and vitrinite reflectance(R_(o))higher than 3.8.The prerequisite for an open-hole horizontal well in this area to produce CBM at a high rate is that the well lies in the tensile stress zone.Finally,the countermeasures to tap the potential of some inefficient wells were put forward.First,the inefficient wells which are blocked with dust coal or collapsed in the later stage should be stimulated based on classifications.And second,it is necessary to explore new types of horizontal wells so as to deal with borehole collapse and continue the operation in the later stage by using tree-like roof horizontal wells,single-lateral horizontal wells with casing or screen completion and fish-bone horizontal wells.
基金The study was funded by the National Key R&D Program of China[2018YFB1201403]Science and Technology R&D Program of China State Railway Group Co.,Ltd[J2021X007].
文摘Purpose–This study aims to analyze the development direction of train speed,density and weight in China.Design/methodology/approach–The development of China’s railway in the past 40 years can be divided into 3 stages.At the stage of potential tapping and capacity expansion,it is important to improve the train weight and density by upgrading the existing lines,and improving transportation capacity rapidly.At the stage of railway speed increase,the first priority is to increase train speed,reduce the travel time of passenger train,and synchronously take into account the increase of train density and weight.At the stage of developing high-speed railway,train speed,density and weight are co-developing on demand.Findings–The train speed of high-speed railway will be 400 km h1,the interval time of train tracking will be 3 min,and the traffic density will be more than 190 pairs per day.The running speed of high-speed freight EMU will reach 200 km h1 and above.The maximum speed of passenger train on mixed passenger and freight railway can reach 200 km h1.The minimum interval time of train tracking can be compressed to 5 min.The freight train weight of 850 m series arrival-departure track railway can be increased to 4,500–5,000 t and that of 1,050 m series to 5,500–6,400 t.EMU trains should gradually replace ordinary passenger trains to improve the quality of railway passenger service.Small formation trains will operate more in intercity railway,suburban railway and short-distance passenger transportation.Originality/value–The research can provide new connotations and requirements of railway train speed,density and weight in the new railway stage.
文摘Side drilling and potential tapping technology is an effective way to tap the potential for the remaining oil in the old oil field in the middle and late stage of development. However, considering the economic benefits and the surrounding environment of the oil field, it is an effective and economic way to improve the oil field and block recovery rate by implementing large displacement side drilling to replace the directional development of wells with the use of existing oil sites, facilities and equipment.
