Because forecasting a development program during the target selection phase of exploration for coalbed methane （CBM） is impossible, the conventional method that relies on a conceptual （or detailed） development pro...Because forecasting a development program during the target selection phase of exploration for coalbed methane （CBM） is impossible, the conventional method that relies on a conceptual （or detailed） development pro- gram cannot be used during the economic evaluation of CBM resources. Hence, this study focuses on establishing an economic evaluation model based on the characteristics of the target selection phase. The discounted cashflow method is applied to the construction of the model with the assumption that there is a uniform distribution of produc- tion wells. The computational error generated by the assumption is corrected by introducing a correction factor based on the production profile of single CBM wells. The case study demonstrates that the blocks lacking economic value can be screened out, and the most advantageous targets can be found by computing the resource values in the best- and worst-case scenarios. This technique can help to reduce wasted investments and improve the quality of decision-making in selecting targets for exploration.展开更多
This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristic...This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristics of flue gas from Chinese refineries, three feasible CO2 separation technologies are selected. These are pressure swing adsorption （PSA）, chemical absorption （CA）, and membrane absorption （MA）. Secondly, an economic assessment of these three techniques is carried out in accordance with cash flow analysis. The results show that these three techniques all have economic feasibility and the PSA technique is the best. Finally, to further optimize the three techniques, a two-level fuzzy comprehensive evaluation model is established, including economic, technological, and environmental factors. Considering all the factors, PSA is optimal for Chinese refineries, followed by CA and MA. Therefore, to reduce Chinese refineries carbon emission, it is suggested that CO2 should be captured from off-gases using PSA.展开更多
This paper proposes a comprehensive framework for estimating the regional rooftop photovoltaic(PV)potential.The required rooftop information is extracted from Gao Fen-7 satellite images.In particular,the rooftop area ...This paper proposes a comprehensive framework for estimating the regional rooftop photovoltaic(PV)potential.The required rooftop information is extracted from Gao Fen-7 satellite images.In particular,the rooftop area is obtained using a semantic segmentation network.The azimuth and inclination angles are calculated based on the digital surface model.In addition,to improve the accuracy of the economic evaluation,buildings are divided into commercial and industrial buildings and residential buildings.Based on the difference in the roof inclination,the rooftops can be divided into flat roofs,on which the PV panels are installed with the optimal inclination angle,and sloped rooftops,on which the PV panels are installed in a lay-flat manner.The solar irradiation on the plane-of-array is calculated using the isotropic sky translocation model.Then,the available installed capacity and generation potential of the rooftop PV is obtained.Finally,the net present value,dynamic payback period,and internal rate of return are used to evaluate the economic efficiency of the rooftop PV project.The proposed framework is applied in the Da Xing district of Beijing,China,with a total area of 546.84 km^(2).The results show that the rooftop area and available installed capacity of PV are 25.63 km^(2)and 1487.45 MWp,respectively.The annual rooftop PV generation potential is 2832.23 GWh,with significant economic returns.展开更多
Key parameters and evaluation methods of shale gas show that it is not possible to guarantee the commercial and economic development of shale gas by sorting out geological sweet spots only according to technical indic...Key parameters and evaluation methods of shale gas show that it is not possible to guarantee the commercial and economic development of shale gas by sorting out geological sweet spots only according to technical indicators.A research method combining technical indicators including total organic carbon content and vitrinite reflectance with economic indicators including internal rate of return and investment payback period is proposed to screen the best technological and economic development sweet spots in undeveloped areas.This method was used to evaluate the best technological and economic development sweet spots in Cretaceous shale gas reservoirs S_(1) and S_(2) of Lurestan area,Iran.Twenty-one geologic sweet spots were picked out based on effective reservoir thickness,vitrinite reflectance and gas content.Based on analogy method,the pressure gradient,clay mineral content,buried depth and other parameters were taken as comparative indicators,the Eagle Ford shale as comparison object,recovery factor and production curve were extracted to estimate the technologically recoverable reserves of the study area.On this basis,the economic indexes such as internal rate of return and investment payback period were used to evaluate the economy of the geological sweet spots.In the case of P_(10) distribution,the total technologically recoverable reserves and economically recoverable reserves are 7875×10^(8)m^(3) and 4306×10^(8)m^(3) respectively,11 geological sweet spots have commercial development value,among which,No.1 sweet spot has the highest value,with a net present value of 35×10^(8) USD.展开更多
LHD's are expensive vehicles; therefore, it is important to accurately define the financial consequences associated with the investment of purchasing the mining equipment. This study concentrates on longterm incre...LHD's are expensive vehicles; therefore, it is important to accurately define the financial consequences associated with the investment of purchasing the mining equipment. This study concentrates on longterm incremental and sensitivity analysis to determine whether it is feasible to incorporate current battery technology into these machines. When revenue was taken into account, decreasing the amount of haulage in battery operated equipment by 5% or 200 kg per h amounts to a $4.0 × 10~4 loss of profit per year. On average it was found that using battery operated equipment generated $9.5 × 10~4 more in income annually, reducing the payback period from seven to two years to pay back the additional $1.0 × 10~5 investment of buying battery powered equipment over cheaper diesel equipment. Due to the estimated 5% increase in capital, it was observed that electric vehicles must possess a lifetime that is a minimum of one year longer than that of diesel equipment.展开更多
基金funded by the Beijing Natural Science Foundation (9144033)the National Social Science Fund for Major Projects (11&ZD164)
文摘Because forecasting a development program during the target selection phase of exploration for coalbed methane （CBM） is impossible, the conventional method that relies on a conceptual （or detailed） development pro- gram cannot be used during the economic evaluation of CBM resources. Hence, this study focuses on establishing an economic evaluation model based on the characteristics of the target selection phase. The discounted cashflow method is applied to the construction of the model with the assumption that there is a uniform distribution of produc- tion wells. The computational error generated by the assumption is corrected by introducing a correction factor based on the production profile of single CBM wells. The case study demonstrates that the blocks lacking economic value can be screened out, and the most advantageous targets can be found by computing the resource values in the best- and worst-case scenarios. This technique can help to reduce wasted investments and improve the quality of decision-making in selecting targets for exploration.
基金the China University of Petroleum Foundationthe Research Institute of Safety and Environment TechnologyChina National Petroleum Corporation
文摘This study aims at determining the optimal CO2 separation technology for Chinese refineries, based on current available technologies, by the method of comprehensive evaluation. Firstly, according to the characteristics of flue gas from Chinese refineries, three feasible CO2 separation technologies are selected. These are pressure swing adsorption （PSA）, chemical absorption （CA）, and membrane absorption （MA）. Secondly, an economic assessment of these three techniques is carried out in accordance with cash flow analysis. The results show that these three techniques all have economic feasibility and the PSA technique is the best. Finally, to further optimize the three techniques, a two-level fuzzy comprehensive evaluation model is established, including economic, technological, and environmental factors. Considering all the factors, PSA is optimal for Chinese refineries, followed by CA and MA. Therefore, to reduce Chinese refineries carbon emission, it is suggested that CO2 should be captured from off-gases using PSA.
基金supported by the Global Energy Interconnection Group Co.,Ltd.,Science and Technology Project(SGGEIG00JYJS2100032)。
文摘This paper proposes a comprehensive framework for estimating the regional rooftop photovoltaic(PV)potential.The required rooftop information is extracted from Gao Fen-7 satellite images.In particular,the rooftop area is obtained using a semantic segmentation network.The azimuth and inclination angles are calculated based on the digital surface model.In addition,to improve the accuracy of the economic evaluation,buildings are divided into commercial and industrial buildings and residential buildings.Based on the difference in the roof inclination,the rooftops can be divided into flat roofs,on which the PV panels are installed with the optimal inclination angle,and sloped rooftops,on which the PV panels are installed in a lay-flat manner.The solar irradiation on the plane-of-array is calculated using the isotropic sky translocation model.Then,the available installed capacity and generation potential of the rooftop PV is obtained.Finally,the net present value,dynamic payback period,and internal rate of return are used to evaluate the economic efficiency of the rooftop PV project.The proposed framework is applied in the Da Xing district of Beijing,China,with a total area of 546.84 km^(2).The results show that the rooftop area and available installed capacity of PV are 25.63 km^(2)and 1487.45 MWp,respectively.The annual rooftop PV generation potential is 2832.23 GWh,with significant economic returns.
文摘Key parameters and evaluation methods of shale gas show that it is not possible to guarantee the commercial and economic development of shale gas by sorting out geological sweet spots only according to technical indicators.A research method combining technical indicators including total organic carbon content and vitrinite reflectance with economic indicators including internal rate of return and investment payback period is proposed to screen the best technological and economic development sweet spots in undeveloped areas.This method was used to evaluate the best technological and economic development sweet spots in Cretaceous shale gas reservoirs S_(1) and S_(2) of Lurestan area,Iran.Twenty-one geologic sweet spots were picked out based on effective reservoir thickness,vitrinite reflectance and gas content.Based on analogy method,the pressure gradient,clay mineral content,buried depth and other parameters were taken as comparative indicators,the Eagle Ford shale as comparison object,recovery factor and production curve were extracted to estimate the technologically recoverable reserves of the study area.On this basis,the economic indexes such as internal rate of return and investment payback period were used to evaluate the economy of the geological sweet spots.In the case of P_(10) distribution,the total technologically recoverable reserves and economically recoverable reserves are 7875×10^(8)m^(3) and 4306×10^(8)m^(3) respectively,11 geological sweet spots have commercial development value,among which,No.1 sweet spot has the highest value,with a net present value of 35×10^(8) USD.
文摘LHD's are expensive vehicles; therefore, it is important to accurately define the financial consequences associated with the investment of purchasing the mining equipment. This study concentrates on longterm incremental and sensitivity analysis to determine whether it is feasible to incorporate current battery technology into these machines. When revenue was taken into account, decreasing the amount of haulage in battery operated equipment by 5% or 200 kg per h amounts to a $4.0 × 10~4 loss of profit per year. On average it was found that using battery operated equipment generated $9.5 × 10~4 more in income annually, reducing the payback period from seven to two years to pay back the additional $1.0 × 10~5 investment of buying battery powered equipment over cheaper diesel equipment. Due to the estimated 5% increase in capital, it was observed that electric vehicles must possess a lifetime that is a minimum of one year longer than that of diesel equipment.
