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Records with Subject: Energy Systems
Showing records 376 to 400 of 9566. [First] Page: 12 13 14 15 16 17 18 19 20 Last
Renewable Energy Role in Climate Stabilization and Water Consumption Minimization in Jordan
Ayman Al-Quraan, Hiba Darwish, Ahmad M. A. Malkawi
September 21, 2023 (v1)
Keywords: climate change, CO2 emissions, GHG emissions, renewable energy projects, water consumption
Climate change is one of the most essential phenomena studied by several researchers in the last few decades. The main reason this phenomenon occurs is greenhouse gases (GHG), chiefly CO2 emissions. About 30% of the created GHG emissions are achieved by electricity generation. This article investigates the role of renewable energy projects in Jordan, specifically wind and solar energy, in mitigating climate change and water consumption reduction using RETScreen software. It was found that the cumulative water consumption reduction from 2017 to 2021 due to the use of wind and solar projects is equal to 6.9491 × 109 gallons. Finally, the results show that the future dependence on renewable energy projects in Jordan to meet the growth in demand by the year 2030 reduces the expected increment in the climate temperature by 1.047 °C by that year.
Oxidation Kinetics Analysis of Crude Oils with Different Viscosities
Bincheng Luo, Chunsheng Yu, Yuehao Chen, Kunhai Yue, Lifan Yue, Tao Chen
September 21, 2023 (v1)
Keywords: crude oil, heavy oil, kinetic parameters, oxidation reaction, reaction kinetics, viscosity
In order to compare the oxidation kinetics parameters of crude oils with different properties in the process of crude oil oxidation, six different crude oil samples were selected to analyze the oxidation characteristics of crude oils with different properties. In order to study the oxidation of crude oil, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) synchronous analyzer were used for crude oil in the oxygen environment between 25 °C and 900 °C at a heating rate of 20 °C/min. The experimental results were based on crude oil oxidation using TGA and DTG experimental data to evaluate the oxidation mechanism of different crude oils, so as to better understand the situation in the oxidation reaction process. At the same time, the oxidation stage of crude oil was divided according to DSC data. Arrhenius method was used to analyze the oxidation kinetic parameters of crude oils with different properties, and the activation energies and pre-exponential factors of... [more]
Review of Thermal Runaway Monitoring, Warning and Protection Technologies for Lithium-Ion Batteries
Sumiao Yin, Jianghong Liu, Beihua Cong
September 20, 2023 (v1)
Keywords: lithium-ion batteries, monitoring and warning, protection, thermal runaway
Due to their high energy density, long calendar life, and environmental protection, lithium-ion batteries have found widespread use in a variety of areas of human life, including portable electronic devices, electric vehicles, and electric ships, among others. However, there are safety issues with lithium-ion batteries themselves that must be emphasized. The safety of lithium-ion batteries is receiving increasing amounts of attention as incidents such as fires and explosions caused by thermal runaway have caused significant property damage and fatalities. Thermal runaway can easily occur when lithium-ion batteries experience issues such as electrical abuse and thermal abuse. This study compares various monitoring, warning, and protection techniques, summarizes the current safety warning techniques for thermal runaway of lithium-ion batteries, and combines the knowledge related to thermal runaway. It also analyzes and forecasts the future trends of battery thermal runaway monitoring, wa... [more]
Thermodynamic Analysis of Hydrogen Production from Bio-Oil Steam Reforming Utilizing Waste Heat of Steel Slag
Zhijun Ding, Yang Liu, Xin Yao, Yuekai Xue, Chenxiao Li, Zhihui Li, Shuhuan Wang, Jianwei Wu
September 20, 2023 (v1)
Keywords: bio-oil, heat recovery, Steam Reforming, steel slag, thermodynamic analysis
(1) Background: The discharged temperature of steel slag is up to 1450 °C, representing heat having a high calorific value. (2) Motivation: A novel technology, integrating bio-oil steam reforming with waste heat recovery from steel slag for hydrogen production, is proposed, and it is demonstrated to be an outstanding method via thermodynamic calculation. (3) Methods: The equilibrium productions of bio-oil steam reforming in steel slag under different temperatures and S/C ratios (the mole ratio of steam to carbon) are obtained by the method of minimizing the Gibbs free energy using HSC 6.0. (4) Conclusions: The hydrogen yield increases first and then decreases with the increasing temperature, but it increases with the increasing S/C. Considering equilibrium calculation and actual application, the optimal temperature and S/C are 706 °C and 6, respectively. The hydrogen yield and hydrogen component are 109.13 mol/kg and 70.21%, respectively, and the carbon yield is only 0.08 mol/kg under... [more]
Source and Accumulation Process of Deep-Seated Oil and Gas in the Eastern Belt around the Penyijingxi Sag of the Junggar Basin, NW China
Jiangxiu Qu, Qinglan Zhang, Maoguo Hou, Xiujian Ding, Imin Ablimit
September 20, 2023 (v1)
Keywords: hydrocarbon accumulation period, hydrocarbon accumulation process, mixed oil, oil-source correlation, Penyijingxi sag
A breakthrough has been made in the recent exploration of the deep oil and gas bearing system in the eastern belt around the Penyijingxi sag of the Junggar Basin. These reservoirs are characterized by mixed sources and multi-stage accumulation. However, this process has not been thoroughly investigated, limiting our understanding of the fundamental rules of hydrocarbon migration and accumulation and making it difficult to determine exploration plans. This study mainly reconstructs this process using biomarkers, carbon isotopes, light hydrocarbons, and fluid inclusions. According to the biomarkers and carbon isotopes for oil-source correlation, Permian crude oil is a mixed-source oil from the Fengcheng Formation (P1f) and the Xiawuerhe Formation (P2w) source rocks, while Jurassic crude oil originates from the P2w source rock. The carbon isotope and light hydrocarbon data demonstrate that Jurassic natural gas has a mixed-gas characteristic with a preponderance of coal-type gas, in contra... [more]
Simulation Experiment and Mathematical Model of Liquid Carrying in the Entire Wellbore of Shale Gas Horizontal Wells
Jian Yang, Qingrong Wang, Fengjing Sun, Haiquan Zhong, Jian Yang
September 20, 2023 (v1)
Keywords: experimental research, K–H wave theory, liquid-carrying model, shale gas horizontal well
Shale gas is mostly produced using horizontal wells, since shale gas reservoirs have low porosity and permeability. It is challenging to predict a horizontal well’s critical liquid-carrying gas flow rate because horizontal wells have more complicated well structures and gas−liquid two-phase pipe flows than vertical wells. In addition, there are significant differences between shale gas reservoirs and conventional natural gas reservoirs as well as dynamic changes in the liquid production rate. The majority of critical liquid-carrying models currently in use in engineering are based on the force analysis of droplets in the gas stream or liquid film on the pipe wall in annular-mist flow in the vertical wellbore. However, they do not take into account the impact of changes to the entire wellbore structure and dynamic changes in the liquid production rate on gas−liquid two-phase flow patterns and liquid carrying in the wellbore. In order to perform the critical gas velocity test for liquid... [more]
Mineralogical Characteristics and Arsenic Release of High Arsenic Coals from Southwestern Guizhou, China during Pyrolysis Process
Bengen Gong, Chong Tian, Xiang Wang, Xiaoxiang Chen, Junying Zhang
September 20, 2023 (v1)
Keywords: arsenic release, low temperature ashing, mineral transformation, pyrolysis
Coal is the primary energy source in China, and coal pyrolysis is considered an essential and efficient method for clean coal utilization. Three high arsenic coals collected from the southwestern Guizhou province of China were chosen in this study. Low-temperature ashing plus X-ray diffraction analysis (XRD) was used to identify the minerals in coals. The three coals were pyrolyzed in a tube furnace in an N2 atmosphere at 950 °C, 1200 °C, and 1400 °C, respectively. Environment scanning electron microscope (ESEM), XRD, X-ray fluorescence analysis (XRF), and inductively coupled plasma-mass spectrometry (ICP-MS) were adopted to determine the morphology, mineral compositions, and element compositions and arsenic contents of the coal pyrolysis ashes, respectively. It can be found that minerals in coal are mainly composed of quartz, pyrite, muscovite, and rutile. The minerals in the ashes generated from coal pyrolysis mainly contain quartz, dehydroxylated muscovite, iron oxide minerals, mull... [more]
The Enhanced Oil Recovery Effect of Nitrogen-Assisted Gravity Drainage in Karst Reservoirs with Different Genesis: A Case Study of the Tahe Oilfield
Hong Cheng
September 20, 2023 (v1)
Keywords: carbonate reservoir, enhanced oil recovery, fracture vuggy, karst reservoirs with different genesis, nitrogen-assisted gravity drainage
For the Tahe Oilfield, there are multiple sets of karst reservoirs with different genesis developed in carbonate fracture-vuggy reservoirs and the varying karst reservoir type has a considerable influence on the distribution of residual oil. The complex characteristics of different karst reservoirs and the difficulty in producing the remaining oil in the middle and lower part of the reservoir greatly restrict the recovery effects. This work managed to comprehensively investigate the action mechanism of nitrogen-assisted gravity drainage (NAGD) on remaining oil in reservoirs with different karst genesis through modeling and experiments. Based on geological characteristics and modeling results, a reservoir-profile model considering reservoir type, fracture distribution, and the fracture−cave combination was established, the displacement experiments of main reservoirs such as the epikarst zone, underground river, and fault karst were carried out, and the oil−gas−water multiphase flow was... [more]
Design and Implementation of a Three-Dimensional CAD Graphics Support Platform for Pumps Based on Open CASCADE
Houlin Liu, Zhicai Wu, Shuolei Yuan, Yong Wang, Liang Dong
September 20, 2023 (v1)
Keywords: centrifugal pump parameterized modeling, geometric kernel, rendering engine, three-dimensional computer-aided design, three-dimensional visualization
In the pump industry, designers commonly utilize mainstream three-dimensional computer-aided design (CAD) software (Unigraphics NX 12.0 and SolidWorks 2023). However, these CAD packages are generic and not optimized for the specific requirements of the pump industry. This leads to a lack of flexibility and increased complexity in their usage, as well as higher computational demands, resulting in elevated learning and operational costs. Additionally, there are concerns about potential information leaks and software restrictions. In this paper, we studied the organization architecture of commercial three-dimensional CAD software, and compared and analyzed the geometric kernels and rendering engines of mainstream three-dimensional software. Using the Open CASCADE geometric kernel and OpenSceneGraph rendering engine, together with the Visual Studio 2021 development environment and Qt interface library, we developed an autonomous copyright three-dimensional CAD graphics support platform for... [more]
High Dimensional Model Representation Approach for Prediction and Optimization of the Supercritical Water Gasification System Coupled with Photothermal Energy Storage
Haoxing Li, Jianhong Lei, Ming Jia, Hongpeng Xu, Shaohua Wu
September 20, 2023 (v1)
Keywords: high dimensional model representation (HDMR), multi-objective optimization, photothermal energy storage, supercritical water gasification
Supercritical water gasification (SCWG) coupled with solar energy systems is a new biomass gasification technology developed in recent decades. However, conventional solar-powered biomass gasification technology has intermittent operation issues and involves multi-variable characteristics, strong coupling, and nonlinearity. To solve the above problems, firstly, a solar-driven biomass supercritical water gasification technology combined with a molten salt energy storage system is proposed in this paper. This system effectively overcomes the intermittent problem of solar energy and provides a new method for the carbon-neutral process of hydrogen production. Secondly, the high dimensional model representation (HDMR) approach, as a surrogate model, was used to predict the production and lower heating value of syngas developed in Aspen Plus, which were validated using experimental data obtained from the literature. The ultimate analysis of biomass, temperature, pressure, and biomass-to-wate... [more]
Prediction of Marine Thin Shale Gas Reservoir with Seismic Phase-Controlled Nonlinear Stochastic Inversion
Qingming Xie, Yanming Wu, Qian Huang, Yunbing Hu, Xiaoliang Hu, Xiaozai Guo, Dongming Jia, Bin Wu
September 20, 2023 (v1)
Keywords: nonlinear stochastic inversion, reservoir prediction, seismic facies, shale gas, thin layer
Due to the complicated interference sources and low signal-to-noise ratio of seismic records, conventional seismic inversion methods are difficult to accurately identify shale gas reservoirs with a thickness of less than 10 m. This presents great challenges to shale gas exploration and development in China. Seismic phase-controlled nonlinear stochastic inversion (SPCNSI) is related to the heterogeneity of underground media. With the constraints of the stratigraphic sequence or seismic facies models, the minimum value between the seismic model and seismic record can be solved through iterative processes. Based on the solved acoustic velocity in formation, the constraints for SPCNSI can be formed with the matching relationship between target layers and different sequences in three-dimensional space. The prediction resolution of an unconventional reservoir can be effectively improved by combining logging, geological and seismic information. The method is suitable for predicting thin shale... [more]
Visual Impact of Renewable Energy Infrastructure: Implications for Deployment and Public Perception
Martin Beer, Radim Rybár, Ľubomíra Gabániová
September 20, 2023 (v1)
Keywords: questionnaire survey, renewable energy infrastructure, Slovak Republic, tourism, visual impacts
This study focuses on the specific topic of assessing the negative visual impacts associated with renewable energy infrastructure that may prevent their wider deployment in energy mix. The main objective of the paper is to quantify the perception of the visual impact of renewable energy infrastructure and to estimate potential changes in the visitation of a location after the construction of power plants. The research was conducted using a questionnaire survey in which 449 respondents evaluated edited photographic materials of seven locations with a fictitious power plant. The collected data served as input for the statistical testing of eight defined hypotheses using the U-Mann−Whitney test. The results confirmed trends regarding the influence of age, educational level, and power plant proximity on the overall acceptance of renewable energy infrastructure. Landscape-forming factors affecting the acceptance rate of power plants were also defined at the local level.
Multi-Fracture Growth Law for Temporary Plugging and Diversion Fracturing of Horizontal Well with Multiple Clusters in Shale Reservoir
Yanchao Li, Jianguo Shen, Longqing Zou, Yushi Zou, Xinfang Ma, Can Yang, Weiwei Wang
September 20, 2023 (v1)
Keywords: fracture morphology, fracturing stage, hydraulic fracturing, hydraulic sandblasting perforating, shale, temporary plugging and diversion
Temporary plugging and diversion fracturing (TPDF) is a common method to increase production and efficiency in shale gas reservoirs, but the growth law of diversion fractures and the temporary plugging mechanism are still unclear, which restricts the further optimization of temporary plugging fracturing schemes. Therefore, in this study, a series of simulation experiments of TPDF in a horizontal well with multi-clusters were carried out for the Longmaxi Shale outcrop by using a large true triaxial fracturing system. The laboratory method of “inner-fracture + inner-segment” TPDF with multiple clusters of perforation in horizontal wells was proposed, and the fracture initiation law and control factors, including the number of clusters and the method of perforating, were investigated. The experimental results show that the peak pressures of inner-fracture temporary plugging (IFTP) and inner-segment temporary plugging (ISTP) stages are higher, and the number of diversion fractures and the... [more]
Failure Analysis of Casing in Shale Oil Wells under Multistage Fracturing Conditions
Yisheng Mou, Han Zhao, Jian Cui, Zhe Wang, Fengqi Wei, Lihong Han
September 20, 2023 (v1)
Keywords: casing deformation, fracturing, liner, shale oil and gas wells, tieback
During the multistage fracturing in shale oil and gas wells with tieback and liner, one of the major challenges is the wellbore temperature variation due to the high-rate fracturing. In such a case, the axial shrinkage trend of the casing string could be caused due to the sudden drop in temperature, but the actual axial length of the casing string would not change due to the cement constraints. Therefore, this could lead to cementation damage between the casing and cement due to excessive load from the casing string. A wellbore seal that is out of control often leads to irreversible consequences, even well abandonment. In order to study the mechanism of casing deformation in shale oil and gas wells with tieback and liner quantitatively, in this paper, take LS1 well (a typical shale oil and gas well with tieback and liner, and casing deformation is caused) for example, the transient changes of temperature and pressure in the whole wellbore during multistage fracturing are studied. Moreo... [more]
Exergy and Energy Analysis of the Shell-and-Tube Heat Exchanger for a Poultry Litter Co-Combustion Process
Samuel O. Alamu, Seong W. Lee, Xuejun Qian
September 20, 2023 (v1)
Keywords: co-combustion process, exergetic efficiency, Exergy, flue gas, irreversibility, overall heat transfer coefficient, shell-and-tube heat exchanger
Increasing production of poultry litter, and its associated problems, stimulates the need for generating useful energy in an environmentally friendly and efficient energy system, such as the use of shell-and-tube heat exchangers (STHE) in a fluidized-bed combustion (FBC) system. A holistic approach which involves the integration of the First Law of Thermodynamics (FLT) and Second Law of Thermodynamics (SLT) is required for conducting effective assessment of an energy system. In this study, the STHE designed by the CAESECT research group, which was integrated into the lab-scale FBC, was investigated to determine the maximum available work performed by the system and account for the exergy loss due to irreversibility. The effects of varying operating parameters and configuration of the space heaters connected to the STHE for space heating purposes were investigated in order to improve the thermal efficiency of the poultry litter-to-energy conversion process. Exergy and energy analysis pe... [more]
The Evolution of Variance and Entropy of the Granule Size Distribution in Fluidized Bed Agglomeration
Kevin Cronin, Francisco Javier Gutiérrez Ortiz
September 20, 2023 (v1)
Keywords: entropy, fluidized bed agglomeration, granule size distribution, variance
The evolution of the variance and entropy of granule size in the fluidized bed agglomeration process using two different aggregation kernels is examined. The first is a constant kernel (aggregation is independent of both time and granule size) and permits the most unconstrained agglomeration process that can occur where granules in any size class (up to a maximum size) can be formed at any point in time. This gives the fastest and largest increase in the variance and entropy of the resulting granule size distribution. The second kernel is a mechanistic kernel including a granule growth-limiting mechanism, in this case implemented by the consideration that not all collisions result in coalescence. This markedly changes the evolution of the variance and entropy of the distribution and reduces both significantly. Quantifying the entropy of the distribution provides another perspective on the change in the size distribution in an agglomeration process. It is shown that entropy can provide... [more]
Thermal-Hydraulic Characteristics of Carbon Dioxide in Printed Circuit Heat Exchangers with Staggered Airfoil Fins
Kun Xi, Xiang Zhao, Zhihui Xie, Fankai Meng, Zhuoqun Lu, Xiangkun Ji
September 20, 2023 (v1)
Keywords: airfoil fin, Carbon Dioxide, numerical computation, printed circuit heat exchanger, thermal-hydraulic characteristics
Airfoil fin printed circuit heat exchangers (PCHEs) have broad application prospects in the naval, aerospace, electric power, and petrochemical industries. The channel structure is a critical factor affecting their thermal-hydraulic characteristics. In this study, a novel PCHE channel structure with staggered NACA 0025 airfoil-shaped fins was proposed; accordingly, the thermal-hydraulic characteristics of the novel channel structure using carbon dioxide as the working fluid at different fin heights under different operating conditions (trans-, near-, and far-critical) were investigated. The results indicated that the thermal-hydraulic performance of the PCHE under the trans-critical operating condition was better than that under the near-critical and far-critical operating conditions. Compared with conventional airfoil fin channels, the novel airfoil fin channel attained comparable comprehensive performance while reducing the fin volume by 50%, thus achieving a more lightweight PCHE de... [more]
Effect of Fracture Geometry Parameters on the Permeability of a Random Three-Dimensional Fracture Network
Bochao Zhang, Lixin Wang, Jianming Liu
September 20, 2023 (v1)
Keywords: fracture parameters, groundwater, permeability, seepage, underground engineering
In numerous subterranean projects, the impact of groundwater on the safety of the engineering undertaking is of paramount significance. Fractures, functioning as the primary channels for seepage within subterranean rock masses, necessitate the complex and challenging task of accurately characterizing seepage patterns and quantitatively investigating the effect of fissure parameters on fluid dynamics within the rock masses. This article presents a stochastic fissure model incorporated within a finite element framework, which captures the probabilistic distribution of fissures found in nature. It provides a comprehensive analysis of the distribution of pore water pressure and Darcy velocity fields. It unveils the permeation patterns of fissured rock masses and establishes a series of fissure models, quantitatively investigating the correlations between matrix permeability, water pressure, fissure density, fissure length, the length power law, fissure angle, the dispersion coefficient, fi... [more]
A Study of Carbon Emission Driving Factors of a Metal Chemical Enterprise in China Based on the LMDI Model
Li Tan, Zao Feng, Guangfa Zheng, Chaoqun Li
September 20, 2023 (v1)
Keywords: carbon accounting, energy conservation and emission reduction, energy consumption, factor analysis
The chemical industry is a typical high-carbon emitting industry, and achieving the goal of net zero emissions by 2050 is challenging. Therefore, metal chemical enterprises have to explore a special path of low-carbon development. This article conducted a case study on a Chinese metal chemical production enterprise with a processing scale of 28,000 t/year. Starting from the analysis of energy consumption carbon emissions, this article used available statistical data at the enterprise level to build a carbon emission estimation model for the enterprise combining different emission categories. Moreover, we also calculated the carbon emissions and carbon emission intensity of the enterprise from 2014 to 2022. Further quantitative analyses on the impact of production scale, energy efficiency, energy structure, and emission coefficient on carbon increment were also conducted using a logarithmic mean divisia index (LMDI) model. The results showed that the reduction in carbon emissions of the... [more]
Energy Dissipation and Fracture Mechanism of Layered Sandstones under Coupled Hydro-Mechanical Unloading
Zhixiang Song, Junwen Zhang, Shaokang Wu
August 3, 2023 (v1)
Keywords: “Energy Flow” chain, coupled hydro-mechanical unloading, energy evolution, facture mechanism, rock burst
Rock burst is easy to occur in the water-rich roadway of coal mines, which is closely related to the energy dissipation and fracture mechanism of rocks under coupled hydro-mechanical (H-M) unloading. Therefore, in combination with the triaxial loading and unloading process and H-M coupling effect, the mechanical test of layered sandstones under coupled hydro-mechanical unloading (TLUTP) was conducted. The energy dissipation and fracture mechanism were revealed. The results show that: (1) The influence of layered angles on the peak volumetric strain is more sensitive than that of confining pressure under conventional triaxial loading with H-M coupling (CTLTP). On the contrary, the influence of confining pressure on the peak volumetric strain is more sensitive than that of layered angles under TLUTP. (2) With increasing layered angles, the peak elastic energy density under CTLTP shows the “W” shaped evolution characteristic, while that of under TLUTP shows the “N” shaped evolution charac... [more]
Biodiesel Production from Waste Cooking Oil Using Different Types of Catalysts
Ayse Hilal Ulukardesler
August 3, 2023 (v1)
Keywords: biodiesel, catalysts, Renewable and Sustainable Energy, transesterification, waste cooking oil
The global energy demand is increasing day by day. Fossil fuels such as crude oil, coal and gas are the main source of energy worldwide. However, fossil fuels, which cause acid rain, the greenhouse effect and other such environmental problems, will eventually be depleted, and renewable energy seems to be the most reasonable solution in this regard. Renewable biofuels have significant potential and can meet the world’s current energy demand. One of the important biofuels is biodiesel, and in the future it can replace petroleum. Waste cooking oil was used as a raw material in biodiesel production in order to reduce the production cost of the offered additive. In this study, the aim was to optimize the process parameters for biodiesel production within the acceptable limit values in the literature. Therefore, the molar ratio of methanol to waste cooking oil (9:1−15:1), catalyst concentration (1−5% by weight) and reaction time (60−120 min) were studied for two catalyst types, potassium hyd... [more]
Numerical Simulation of Multi-Fracture Propagation Based on the Extended Finite Element Method
Qiquan Ran, Xin Zhou, Jiaxin Dong, Mengya Xu, Dianxing Ren, Ruibo Li
August 3, 2023 (v1)
Keywords: fracture interference, hydraulic fracturing, stress shadow, XFEM
Multi-stage, multi-cluster fracturing in horizontal wells is widely used as one of the most effective methods for unconventional reservoir transformation. This study is based on the extended finite element method and establishes a multi-hydraulic fracturing propagation model that couples rock damage, stress, and fluid flow, and the influence of horizontal stress difference and cluster spacing on fracture propagation is quantitatively analyzed. The simulation results show that changes in horizontal stress differences and inter-cluster spacing have a significant impact on the final propagation morphology of hydraulic fractures, and the change of the fracture initiation sequence forms different stress shadow areas, which in turn affects the propagation morphology of the fractures. When two fractures simultaneously propagate, they will eventually form a “repulsive” deviation, and a smaller stress difference and a decrease in inter-cluster spacing will lead to a more significant deviation o... [more]
Cryogenic Fracture Proliferation from Boreholes under Stresses
Minsu Cha, Naif B. Alqahtani, Lei Wang
August 3, 2023 (v1)
Keywords: cryogenic fracturing, enhanced geothermal system, fracture propagation, hot dry rock, hydraulic fracturing, liquid nitrogen, thermal fracture, thermal shock, thermal stress, unconventional reservoir, well stimulation
Cryogenic fracturing has been explored in recent years as a waterless fracturing method for well stimulation to avoid issues encountered in water-based hydraulic fracturing. Cryogenic stimulation using liquid nitrogen applies large thermal gradients on reservoir rocks to induce fractures. This study investigates the initiation and proliferation of cryogenic fractures from boreholes under external stress on specimens. We flowed liquid nitrogen through boreholes drilled through the center of transparent PMMA cylinders under uniaxial stress and monitored fracture proliferation, temperatures, and borehole pressures. Our results show that the effect of stress resembles that of hydraulic fractures such that fractures propagate more in the direction of the stress. Under loading perpendicular to the borehole axis, a cloud of annular and longitudinal fractures extends more in the direction of loading. Under loading parallel to the borehole axis, longitudinal fractures dominate, and annular frac... [more]
Crucial Adoption Factors of Renewable Energy Technology: Seeking Green Future by Promoting Biomethane
Juan Wu, Desire Wade Atchike, Munir Ahmad
August 3, 2023 (v1)
Keywords: barriers, biomethane digester, crucial factors, driving forces, logistic regression model, Pakistan
To reduce the dependence on fossil fuels to fulfill energy needs and give rural areas better access to energy, biomethane generation technology (BG-TECH) can help in these situations. However, several crucial factors might influence BG-TECH’s acceptance by households. In order to eradicate the barriers to and strengthen the driving forces of BG-TECH acceptance, it becomes inevitable to explore those crucial factors. Therefore, the core objective of this research is to analyze the factors impacting BG-TECH acceptance by households in rural Pakistan. This research will enrich the existing literature by comprehensively analyzing factors driving or impeding BG-TECH acceptance. To collect relevant data, a questionnaire was developed and distributed in four districts of Pakistan. In this respect, 150 users and 150 non-users of biomethane were selected through stratified random sampling. To analyze the factors affecting the acceptance of BG-TECH, a logistic regression model was utilized. As p... [more]
Characteristics and Geological Impact Factors of Coalbed Methane Production in the Taiyuan Formation of the Gujiao Block
Gang Wang, Yiwei Xie, Huizhen Chang, Liqiang Du, Qi Wang, Tao He, Shuaiyi Zhang
August 3, 2023 (v1)
Keywords: coalbed methane, gas production, geological impact factors, Gujiao Block, water production
The coalbed methane resources of the Gujiao Block are abundant, and the exploration degree is high. The gas production and water production of different CBM (coalbed methane) wells vary greatly. The average gas production of CBM wells in the study area is mostly less than 1000 m3/d, while the average water production is mostly less than 5 m3/d. The gas production of CBM wells near the core of the Malan syncline is relatively high. A series of large faults exist in the central and eastern parts of the study area, and CBM wells nearby produce more water but less gas. The salinity of water discharged from CBM wells ranges from 810.34 to 3115.48 mg/L, which is consistent with the trend of a gradual increase from north to south. The gas content distribution follows this same gradually increasing north to south trend. Coal thickness and buried depth have little effect on gas production, but have some effects on water production. The endogenous fracture system in the coal reservoir is extreme... [more]
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