scholarly journals Numerical Study on the Influence of Well Layout on Electricity Generation Performance of Enhanced Geothermal Systems

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1474
Author(s):  
Yuchao Zeng ◽  
Fangdi Sun ◽  
Haizhen Zhai
Keyword(s):  
Energy Efficiency ◽  
Electric Power ◽  
Electricity Generation ◽  
Horizontal Well ◽  
Production Performance ◽  
Electricity Production ◽  
Fracture Permeability ◽  
Fracture Spacing ◽  
Vertical Well ◽  
Well Spacing

The energy efficiency of the enhanced geothermal system (EGS) measures the economic value of the heat production and electricity generation, and it is a key indicator of system production performance. Presently there is no systematic study on the influence of well layout on the system energy efficiency. In this work we numerically analyzed the main factors affecting the energy efficiency of EGS using the TOUGH2-EOS1 codes at Gonghe Basin geothermal field, Qinghai province. The results show that for the reservoirs of the same size, the electric power of the three horizontal well system is higher than that of the five vertical well system, and the electric power of the five vertical well system is higher than that of the three vertical well system. The energy efficiency of the three horizontal well system is higher than that of the five vertical well system and the three vertical well system. The reservoir impedance of the three horizontal well system is lower than that of the three vertical well system, and the reservoir impedance of the three vertical well system is lower than that of the five vertical system. The sensitivity analysis shows that well spacing has an obvious impact on the electricity production performance; decreasing well spacing will reduce the electric power, reduce the energy efficiency and only have very slight influence on the reservoir impedance. Fracture spacing has an obvious impact on the electricity production performance; increasing fracture spacing will reduce the electric power and reduce the energy efficiency. Fracture permeability has an obvious impact on the electricity production performance; increasing fracture permeability will improve the energy efficiency and reduce the reservoir impedance.

scholarly journals Numerical Investigation of Influence of Reservoir Heterogeneity on Electricity Generation Performance of Enhanced Geothermal System

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 202 ◽  
Author(s):  
Yuchao Zeng ◽  
Liansheng Tang ◽  
Nengyou Wu ◽  
Jing Song ◽  
Zhanlun Zhao
Keyword(s):  
Energy Efficiency ◽  
Pump Power ◽  
Electric Power ◽  
Electricity Generation ◽  
Production Performance ◽  
Geothermal System ◽  
Enhanced Geothermal System ◽  
Slight Effect ◽  
Reservoir Heterogeneity ◽  
Well Spacing

The enhanced geothermal system (EGS) reservoir consists of a heterogeneous fracture network and rock matrix, and the heterogeneity of the reservoir has a significant influence on the system’s electricity generation performance. In this study, we numerically investigated the influence of reservoir heterogeneity on system production performance based on geological data from the Gonghe Basin geothermal field, and analyzed the main factors affecting production performance. The results show that with the increase of reservoir heterogeneity, the water conduction ability of the reservoir gradually reduces, the water production rate slowly decreases, and this causes the electric power to gradually reduce, the reservoir impedance to gradually increase, the pump power to gradually decrease and the energy efficiency to gradually increase. The fracture spacing, well spacing and injection temperature all have a significant influence on electricity generation performance. Increasing the fracture spacing will significantly reduce electric power, while having only a very slight effect on reservoir impedance and pump power, thus significantly decreasing energy efficiency. Increasing the well spacing will significantly increase the electric power, while having only a very slight effect on the reservoir impedance and pump power, thus significantly increasing energy efficiency. Increasing the injection temperature will obviously reduce the electric power, decrease the reservoir impedance and pump power, and thus reduce energy efficiency.

scholarly journals Optimization of Fracture Spacing and Well Spacing in Utica Shale Play Using Fast Analytical Flow-Cell Model (FCM) Calibrated with Numerical Reservoir Simulator

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6736
Author(s):  
Ruud Weijermars
Keyword(s):  
Cell Model ◽  
Flow Cell ◽  
Production Performance ◽  
Design Parameters ◽  
Gas Wells ◽  
Production Rates ◽  
Fracture Spacing ◽  
Well Spacing ◽  
Wet Gas ◽  
Reservoir Simulator

Recently, a flow-cell model (FCM) was specifically developed to quickly generate physics-based forecasts of production rates and estimated ultimate resources (EURs) for infill wells, as the basis for the estimation of proven undeveloped reserves. Such reserves estimations provide operators with key collateral for further field development with reserves-based loans. FCM has been verified in previous studies to accurately forecast production rates and EURs for both black oil and dry gas wells. This study aims to expand the application range of FCM to predict the production performance and EURs of wells planned in undeveloped acreage of the wet gas window. Forecasts of the well rates and EURs with FCM are compared with the performance predictions generated with an integrated reservoir simulator for multi-fractured wells, using detailed field data from the Utica Field Experiment. Results of FCM, with adjustment factors to account for wet gas compressibility effects, match closely with the numerical performance forecasts. The advantage of FCM is that it can run on a fast spreadsheet template. Once calibrated for wet gas wells by a numerical reservoir simulator accounting for compositional flow, FCM can forecast the performance of future wells when completion design parameters, such as fracture spacing and well spacing, are changed.

scholarly journals Comparison and Optimization of Methane Hydrate Production Process Using Different Methods in a Single Vertical Well

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 124 ◽  
Author(s):  
Yun-Pei Liang ◽  
Shu Liu ◽  
Qing-Cui Wan ◽  
Bo Li ◽  
Hang Liu ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Natural Gas ◽  
Driving Force ◽  
Production Efficiency ◽  
Electric Heating ◽  
Gas Production ◽  
Production Performance ◽  
Water Production ◽  
Dual Decomposition ◽  
Vertical Well

Natural gas hydrate (NGH) is a potential type of clean and efficient energy that is widely distributed in the ocean and permafrost, and most of the present researches are mainly focused on finding out efficient exploitation methods. Taking the effects of natural gas productivity and extraction time into account, one of the exploitation methods that are most commonly investigated is depressurization combined with thermal stimulation. However, few studies considered the effect of different mining methods on NGH production in vertical wells, especially aiming at the in-situ electric heating without mass injection and the comparison of production efficiency in different modes. Considering the current research status, four exploitation methods which are pure depressurization (PD), pure heating (PH), simultaneous depressurization combined with electric heating (SDH) and huff and puff (H&P) were carried out in this paper to study the influences of different production methods on NGH exploitation in a vertical well. Some parameters such as gas production (VP), water production (CP) and the energy efficiency (η) were investigated to evaluate the production performance of these methods. The results suggest that the temperature in the reactor is affected by the exploitation methods as well as the water production during exploitation. For PD, although it has no extra energy consumption, the longest production period is seen in it due to the insufficient pressure driving force. On the contrary, the NGH cannot be completely exploited only triggered by heating driving force with PH method. So there is a limited decomposition effect with it. Taking the gas production time, the VP, and the NGH dissociation rate into account, the production effects of SDH are more beneficial than other methods as the dual decomposition driving force was adopted in it. Furthermore, a reasonable heating power can result in a better production performance. On the other hand, promoted by pressure difference and discontinuous heating, H&P shows its obvious advantage in shortening production duration and improving energy efficiency, which is therefore believed to have the best commercial exploitation value among the four methods.

scholarly journals Effect of Vertical Permeability Heterogeneity in Stratified Formation on Electricity Generation Performance of Enhanced Geothermal System

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 744
Author(s):  
Yuchao Zeng ◽  
Fangdi Sun ◽  
Haizhen Zhai
Keyword(s):  
Energy Efficiency ◽  
Pump Power ◽  
Electric Power ◽  
Production Rate ◽  
Electricity Generation ◽  
Injection Pressure ◽  
Water Production ◽  
Permeability Heterogeneity ◽  
Vertical Permeability ◽  
Water Production Rate

Because geologic sedimentation and hydrofracturing processes are not homogeneous, the reservoirs of enhanced geothermal systems (EGSs) are also heterogeneous; this has a significant influence on the electricity generation performance of EGS. Presently, there are a lack of systematic and profound studies on the effect of vertical permeability heterogeneity in stratified formation on the electricity generation performance of EGS. In order to uncover the effect of vertical permeability heterogeneity on electricity generation performance of EGS, in this work we analyzed the influence of vertical permeability heterogeneity on electricity generation performance of EGS through a numerical method based on geological data at the Yangbajing geothermal field. The results indicate that when the average permeability of stratified formations is constant for a homogeneous reservoir, the system attains maximum water production rate, maximum electric power, minimum reservoir impedance and maximum pump power; with the increasing of the vertical permeability heterogeneity, the water production rate gradually decreases, the electric power gradually declines, the reservoir impedance gradually increases and the pump power gradually declines. When the average permeability of stratified formations is constant, with the increasing of the vertical permeability heterogeneity, the injection pressure and energy efficiency only changes very slightly; this indicates that the vertical permeability heterogeneity is not the main factor affecting the system injection pressure and energy efficiency.

scholarly journals ELECTRIC POWER AS A FACTOR OF DEVELOPMENT OF THE RUSSIAN ECONOMY

2020 ◽  
Vol 30 (2) ◽  
pp. 191-199
Author(s):  
A.P. Dzyuba
Keyword(s):  
Energy Efficiency ◽  
Gross Domestic Product ◽  
Electric Power ◽  
Electricity Consumption ◽  
Electric Power Industry ◽  
Power Industry ◽  
Electricity Production ◽  
Domestic Product ◽  
Russian Economy ◽  
The World

The article is devoted to the study of the characteristics and role of the Russian electric power industry in the national economy in comparison with the countries of the world. The materials provide an empirical comprehensive analysis of the performance indicators of the electric power industry sectors in the context of the countries of the world, with the identification of Russia's place in the world electric power balance. The information base of the study was the parameters of electricity consumption and the volume of gross domestic product of various countries of the world, as well as the characteristics of the structure of electricity production and consumption. The methods of analysis and synthesis, mathematical and statistical analysis were used. Based on the indicators of the electric intensity of the gross domestic product and electricity consumption per capita, a comparative assessment of the characteristics of the energy efficiency of Russia is carried out in comparison with various countries of the world. The materials provide a comparative analysis of the indicators of the structure of electricity generation by type of sources, as well as by type of fossil fuel used, with the identification of characteristics of electricity production in Russia. Based on the analysis, the author draws conclusions about the main advantages of the electric power complex of Russia over the countries of the world, as well as about the advantages existing over electricity consumers operating within the country. The analysis made it possible to develop recommendations on the general directions of the implementation of the policy in the field of increasing the energy efficiency of electricity consumption on the scale of the Russian economy.

scholarly journals Effects of Biofilm Transfer and Electron Mediators Transfer on Klebsiella quasipneumoniae sp.203 Electricity Generation Performance in MFCs

2020 ◽  
Author(s):  
Yating Guo ◽  
Guozhen Wang ◽  
Hao Zhang ◽  
Hongyu Wen ◽  
Wen Li
Keyword(s):  
Power Generation ◽  
Electron Transfer ◽  
Electricity Generation ◽  
Living Environment ◽  
Production Performance ◽  
Electricity Production ◽  
Redox Activity ◽  
Electron Mediator ◽  
Microfiltration Membrane ◽  
Electron Mediators

Abstract Background: Extracellular electron transfer ( EET ) is essential in improving the power generation performance of electrochemically active bacteria ( EAB ) in MFCs. Klebsiella has been proved to be an EAB capable of EET. Here, we cover the anode of MFC-1 with a layer of microfiltration membrane to block the effect of the biofilm mechanism, and then explore the EET of the electron mediator mechanism of Klebsiella quasipneumoniae sp.203 and electricity production performance of a K.quasipneumoniae sp.203-inoculated MFCs.Results: Herein, we covered the anode of microbial fuel cells (MFCs) with a layer of microfiltration membrane to block the effect of the biofilm mechanism, and then explore the EET of the electron mediator mechanism of K.quasipneumoniae sp.203 and electricity production performance. In the absence of short-range electron transfer, we found that K.quasipneumoniae sp.203 can still produce certain power generation efficiency and redox activity. It was proved that in the case that EAB cannot attach to the growth anode, K.quasipneumoniae sp.203 can still perform EET through the electron mediator mechanism. To further verify the effect of electron mediators on electrochemical performance of MFCs, in the first cycle of well-functioning MFCs, the self-produced sterile supernatant was added to the different stages of electricity generation performance. We found that adding electron mediators during the rising phase, the MFCs can reach a maximum output voltage of 442mV in about 24 hours, which is about 70mV higher than MFC-Normal. Therefore, the addition of electron mediators can effectively improve the electrical performance in the stable growth stage of anode EAB in MFCs. Finally, we combined the CV analysis and HPLC-MS to analyze the anode supernatant of MFCs. It was speculated that K.quasipneumoniae sp.203 produced more than one electron mediator, which were 2,6-DTBHQ, 2,6-DTBBQ, ACNQ and DHNA.Conclusions: To the best of our knowledge, the three modes of EET did not exist separately. K.quasipneumoniae sp.203 will adopt the corresponding electron transfer mode or multiple ways to realize EET according to the living environment to improve electricity generation performance.

scholarly journals Exploring the Effects of Industrial Structure, Technology, and Energy Efficiency on China’s Carbon Intensity and Their Contributions to Carbon Intensity Target

2020 ◽  
Vol 12 (19) ◽  
pp. 8016
Author(s):  
Feng Wang ◽  
Min Wu ◽  
Jiachen Hong
Keyword(s):  
Energy Efficiency ◽  
Energy Saving ◽  
Historical Development ◽  
Industrial Development ◽  
Industrial Structure ◽  
Electricity Production ◽  
Mitigation Measures ◽  
Carbon Intensity ◽  
Intermediate Input ◽  
Residential Energy

To achieve the national carbon intensity (NCI) target, China should adopt effective mitigation measures. This paper aims to examine the effects of key mitigation measures on NCI. Using the input-output table in 2017, this paper establishes the elasticity model of NCI to investigate the effects of industrial development, intermediate input coefficients, energy efficiency, and residential energy saving on NCI, and further evaluates the contributions of key measures on achieving NCI target. The results are shown as follows. First, the development of seven sectors will promote the increase of NCI while that of 21 sectors will reduce NCI. Second, NCI will decrease significantly with the descending of intermediate input coefficients of sectors, especially electricity production and supply. Third, improving energy efficiency and residential energy saving degree could reduce NCI, but the latter has limited contribution. Fourth, the development of all sectors will reduce NCI by 10.11% in 2017–2022 if sectors could continue the historical development trends. Fifth, assuming that sectors with rising intermediate input coefficients would keep their coefficients unchanged in the predicting period and sectors with descending coefficients would continue the historical descending trend, the improvement of technology and management of all sectors will reduce NCI by 14.02% in 2017–2022.

scholarly journals Forecasting for Ultra-Short-Term Electric Power Load Based on Integrated Artificial Neural Networks

Symmetry ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1063 ◽  
Author(s):  
Horng-Lin Shieh ◽  
Fu-Hsien Chen
Keyword(s):  
Energy Efficiency ◽  
Electric Power ◽  
Production Efficiency ◽  
Load Forecasting ◽  
Short Term ◽  
Inference System ◽  
Power Load ◽  
Power Load Forecasting ◽  
New Energy ◽  
Electric Power Load

Energy efficiency and renewable energy are the two main research topics for sustainable energy. In the past ten years, countries around the world have invested a lot of manpower into new energy research. However, in addition to new energy development, energy efficiency technologies need to be emphasized to promote production efficiency and reduce environmental pollution. In order to improve power production efficiency, an integrated solution regarding the issue of electric power load forecasting was proposed in this study. The solution proposed was to, in combination with persistence and search algorithms, establish a new integrated ultra-short-term electric power load forecasting method based on the adaptive-network-based fuzzy inference system (ANFIS) and back-propagation neural network (BPN), which can be applied in forecasting electric power load in Taiwan. The research methodology used in this paper was mainly to acquire and process the all-day electric power load data of Taiwan Power and execute preliminary forecasting values of the electric power load by applying ANFIS, BPN and persistence. The preliminary forecasting values of the electric power load obtained therefrom were called suboptimal solutions and finally the optimal weighted value was determined by applying a search algorithm through integrating the above three methods by weighting. In this paper, the optimal electric power load value was forecasted based on the weighted value obtained therefrom. It was proven through experimental results that the solution proposed in this paper can be used to accurately forecast electric power load, with a minimal error.

scholarly journals Towards 100% Renewables by 2030: Transition Alternatives for a Sustainable Electricity Sector in Isla de la Juventud, Cuba

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2862
Author(s):  
Mika Korkeakoski
Keyword(s):  
Renewable Energy ◽  
Power System ◽  
Electric Power ◽  
Renewable Energy Sources ◽  
Electric Power System ◽  
Electricity Production ◽  
Energy Sources ◽  
Cuban Government ◽  
Isla De La Juventud ◽  
Near Future

Renewable Energy Sources (RES) have become increasingly desirable worldwide in the fight against global climate change. The sharp decrease in costs of especially wind and solar photovoltaics (PV) have created opportunities to move from dependency on conventional fossil fuel-based electricity production towards renewable energy sources. Renewables experience around 7% (in 2018) annual growth rate in the electricity production globally and the pace is expected to further increase in the near future. Cuba is no exception in this regard, the government has set an ambitious renewable energy target of 24% RES of electricity production by the year 2030. The article analyses renewable energy trajectories in Isla de la Juventud, Cuba, through different future energy scenarios utilizing EnergyPLAN tool. The goal is to identify the best fit and least cost options in transitioning towards 100% electric power systemin Isla de la Juventud, Cuba. The work is divided into analysis of (1) technical possibilities for five scenarios in the electricity production with a 40% increase of electricity consumption by 2030: Business As Usual (BAU 2030, with the current electric power system (EPS) setup), VISION 2030 (according to the Cuban government plan with 24% RES), Advanced Renewables (ARES, with 50% RES), High Renewables (HiRES, with 70% RES), and Fully Renewables (FullRES, with 100% RES based electricity system) scenarios and (2) defining least cost options for the five scenarios in Isla de la Juventud, Cuba. The results show that high penetration of renewables is technically possible even up to 100% RES although the best technological fit versus least cost options may not favor the 100% RES based systems with the current electric power system (EPS) setup. This is due to realities in access to resources, especially importation of state of the art technological equipment and biofuels, financial and investment resources, as well as the high costs of storage systems. The analysis shows the Cuban government vision of reaching 24% of RES in the electricity production by 2030 can be exceeded even up to 70% RES based systems with similar or even lower costs in the near future in Isla de la Juventud. However, overcoming critical challenges in the economic, political, and legal conditions are crucially important; how will the implementation of huge national capital investments and significant involvement of Foreign Direct Investments (FDI) actualize to support achievement of the Cuban government’s 2030 vision?

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