The construction of water conservancy projects should commence during optimal atmospheric conditions and non-flood period to ensure completion before the flood season begin in summer.In most areas of Northern China,th...The construction of water conservancy projects should commence during optimal atmospheric conditions and non-flood period to ensure completion before the flood season begin in summer.In most areas of Northern China,the temperature during winter remain at lower level,in which environmental factors play the most important role in the construction of water conservancy projects.In particular,low temperature directly affects the strength of concrete and delays its solidification,this highly affects the quality and progress of concrete construction.In order to overcome this barrier,better planning,for reasonable and effective construction techniques and targeted control measures should be adopted to reduce the adverse effects of low temperature to assure a strong and safe architecture.展开更多
Traffic forecasting with high precision aids Intelligent Transport Systems(ITS)in formulating and optimizing traffic management strategies.The algorithms used for tuning the hyperparameters of the deep learning models...Traffic forecasting with high precision aids Intelligent Transport Systems(ITS)in formulating and optimizing traffic management strategies.The algorithms used for tuning the hyperparameters of the deep learning models often have accurate results at the expense of high computational complexity.To address this problem,this paper uses the Tree-structured Parzen Estimator(TPE)to tune the hyperparameters of the Long Short-term Memory(LSTM)deep learning framework.The Tree-structured Parzen Estimator(TPE)uses a probabilistic approach with an adaptive searching mechanism by classifying the objective function values into good and bad samples.This ensures fast convergence in tuning the hyperparameter values in the deep learning model for performing prediction while still maintaining a certain degree of accuracy.It also overcomes the problem of converging to local optima and avoids timeconsuming random search and,therefore,avoids high computational complexity in prediction accuracy.The proposed scheme first performs data smoothing and normalization on the input data,which is then fed to the input of the TPE for tuning the hyperparameters.The traffic data is then input to the LSTM model with tuned parameters to perform the traffic prediction.The three optimizers:Adaptive Moment Estimation(Adam),Root Mean Square Propagation(RMSProp),and Stochastic Gradient Descend with Momentum(SGDM)are also evaluated for accuracy prediction and the best optimizer is then chosen for final traffic prediction in TPE-LSTM model.Simulation results verify the effectiveness of the proposed model in terms of accuracy of prediction over the benchmark schemes.展开更多
Bipolar plate is one of the key components of Proton Exchange Membrane Fuel Cell(PEMFC)and a reasonable flow field design for bipolar plate will improve cell performance.Herein,we have reviewed conventional and bionic...Bipolar plate is one of the key components of Proton Exchange Membrane Fuel Cell(PEMFC)and a reasonable flow field design for bipolar plate will improve cell performance.Herein,we have reviewed conventional and bionic flow field designs in recent literature with a focus on bionic flow fields.In particular,the bionic flow fields are summarized into two types:plant-inspired and animal-inspired.The conventional methodology for flow field design takes more time to find the optimum since it is based on experience and trial-and-error methods.In recent years,machine learning has been used to optimize flow field structures of bipolar plates owing to the advantages of excellent prediction and optimization capability.Artificial Intelligence(AI)-assisted flow field design has been summarized into two categories in this review:single-objective optimization and multi-objective optimization.Furthermore,a Threats-Opportunities-Weaknesses-Strengths(TOWS)analysis has been conducted for AI-assisted flow field design.It has been envisioned that AI can afford a powerful tool to solve the complex problem of bionic flow field design and significantly enhance the performance of PEMFC with bionic flow fields.展开更多
Field development practices in many shale gas regions(e.g.,the Changning region)have revealed a persistent issue of suboptimal reserve utilization,particularly in areas where the effective drainage width of production...Field development practices in many shale gas regions(e.g.,the Changning region)have revealed a persistent issue of suboptimal reserve utilization,particularly in areas where the effective drainage width of production wells is less than half the inter-well spacing(typically 400-500 m).To address this,infill drilling has become a widely adopted and effective strategy for enhancing reservoir contact andmobilizing previously untapped reserves.However,this approach has introduced significant inter-well interference,complicating production dynamics and performance evaluation.The two primary challenges hindering efficient deployment of infill wells are:(1)the quantitative assessment of hydraulic and pressure connectivity between infill wells and their associated parent wells,and(2)the accurate estimation of platform-scale Estimated Ultimate Recovery(EUR)following infill implementation.This study presents a novel framework to quantify inter-well connectivity by deriving a material balance equation tailored for shale gas infill well groups,explicitly incorporating gas adsorption and desorption mechanisms.The model simultaneously evaluates formation pressure evolution and crossflow behavior between wells,offering a robust analytical basis for performance prediction.For infill wells intersecting the drainage boundaries of parent wells,EUR is estimated using an analytical model developed for multi-stage hydraulically fractured horizontal wells.Meanwhile,the EUR of the parent wells is obtained by summing their pre-infill EUR with the final inter-well crossflow contribution.展开更多
The ocean,as one of Earth’s largest natural resources,covers over 70% of the planet’s surface and holds vast water energy potential.Building on this context,this study designs a hybrid generator(WWR-TENG)that integr...The ocean,as one of Earth’s largest natural resources,covers over 70% of the planet’s surface and holds vast water energy potential.Building on this context,this study designs a hybrid generator(WWR-TENG)that integrates a triboelectric nanogenerator(TENG)and an electromagnetic generator(EMG).TENG is a new technology that can capture mechanical energy from the environment and convert it into electrical energy,and is particularly suitable for common natural or man-made power sources such as human movement,wind power,and water flow.EMG is a device that converts mechanical energy into electrical energy through the principle of electromagnetic induction and can usually provide stable power output.The composite design leverages the complementary advantages of both technologies to efficiently capture and convert marine wave energy.By combining the TENG’s high energy conversion efficiency,lowcost,lightweight structure,and simple designwith the EMG’s capabilities,the systemprovides a sustainable solution for marine energy development.Experimental results demonstrate that at a rotational speed of 3.0 r/s,the TENG component of the WWR-TENG achieves an open-circuit voltage of approximately 280 V and a shortcircuit current of 20μA.At the same time,the EMG unit exhibits an open-circuit voltage of 14 V and a short-circuit current of 14 mA.Furthermore,when integrated with a power management circuit,the WWR-TENG charges a 680μF capacitor to 3 V within 10 s at a rotational speed of 3.0 r/s.A simulated wave environment platform was established,enabling the WWR-TENG to maintain the thermo-hygrometer in normal operation under simulated wave conditions.These findings validate the hybrid system’s effectiveness in harnessing and storingwave energy,highlighting its potential for practical marine energy applications.展开更多
Assessment of water quality by firefly algorithm based on BP neural network model(FA-BP model)is built.In this model,the evaluation index function is constructed by BP Artificial Neural Network Algorithm(BP model),and...Assessment of water quality by firefly algorithm based on BP neural network model(FA-BP model)is built.In this model,the evaluation index function is constructed by BP Artificial Neural Network Algorithm(BP model),and Firefly Algorithm(FA model)is introduced to optimize weight values and thresholds to find the optimal solution.Fuzzy Comprehensive Evaluation method,Grey Incidence Analysis Algorithm and FA-BP model will be applied to evaluate the water quality of the five main rivers in Lianyungang City including Longwei,Yudai,Dapu,Paidan,and Dongyan River.The results show that the Fuzzy Comprehensive Evaluation method is difficult to use for slight pollution rivers with several slightly over standard indexes.It will be easy to ignore the impact of extreme indexes by Grey Incidence Analysis Algorithm.FA-BP model solves the shortcomings of the two methods.The evaluation results provide an important reference for the formulation of reasonable measures.It is a relatively comprehensive evaluation method and has a good application prospect in water quality evaluation.展开更多
Figuring out rock strength plays essential roles in the sub ground mining activities,such as oil and gas well drilling and hydraulic fracturing,coal mining,tunneling,and other civil engineering scenarios.To help under...Figuring out rock strength plays essential roles in the sub ground mining activities,such as oil and gas well drilling and hydraulic fracturing,coal mining,tunneling,and other civil engineering scenarios.To help understand the effects of the mineralogical composition on evaluating the rock strength,this research tries to establish indirect prediction models of rock strength by specific input mineral contents for common sedimentary rocks.Using rock samples collected from the outcrops in the Sichuan Basin,uniaxial compression tests have been conducted to sandstone,carbonate,and shale cores.Combining with statistical analysis,the experimental data prove it true that the mineralogical composition can be utilized to predict the rock strength under specific conditions but the effects of mineralogical composition on the rock strength highly depend on the rock lithologies.According to the statistical analysis results,the predicted values of rock strengths by the mineral contents can get high accuracies in sandstone and carbonate rocks while no evidences can be found in shale rocks.The best indicator for predicting rock strength should be the quartz content for the sandstone rocks and the dolomite content for the carbonate rocks.Especially,to improve the evaluation accuracy,the rock strengths of sandstones can be obtained by substituting the mineral contents of quartz and clays,and those of carbonates can be calculated by the mineral contents of dolomite and calcite.Noticeably,the research data point out a significant contrast of quartz content in evaluating the rock strength of the sandstone rocks and the carbonate rocks.Increasing quartz content helps increase the sandstone strength but decrease the carbonate strength.As for shale rocks,no relationship exists between the rock strength and the mineralogical composition(e.g.,the clay fractions).To provide more evidences,detailed discussion also provides the readers more glances into the framework of the rock matrix,which can be further studied in the future.These findings can help understand the effects of mineralogical composition on the rock strengths,explain the contrasts in the rock strength of the responses to the same mineral content(e.g.,the quartz content),and provide another indirect method for evaluating the rock strength of common sedimentary rocks.展开更多
Shale,which is a fine-grained sedimentary rock,differs in reservoir quality(RQ)and completion quality(CQ)as the result of variations in its mineral and organic-matter compositions.The RQ and CQ directly affect shale g...Shale,which is a fine-grained sedimentary rock,differs in reservoir quality(RQ)and completion quality(CQ)as the result of variations in its mineral and organic-matter compositions.The RQ and CQ directly affect shale gas exploitation.Therefore,classification of the lithofacies types of shale,analysis of the reservoir differences of different lithofacies,and identification of the superior shale lithofacies with the best RQ and CQ are important for decisions on well placement,targeting the“sweet spot”zone and optimizing the expected ultimate recovery of a shale gas well.In this study,several methods including microscopic observation of thin sections,X-ray diffraction analysis,core analysis and elemental geochemistry were used to investigate the lithofacies types,reservoir characteristics and silica origin of the marine shales of the Wufeng FormationeLongmaxi Formation(WF Fm.eLMX Fm.)in the Luzhou area,southern Sichuan Basin,China.The lithofacies characteristics exhibit marked differences through the WFeLMX shale succession.Specifically,the lower gas-bearing zone(LMX-1)is mainly composed of siliceous shales and siliceouseargillaceous mixed shales,whereas the upper gas-bearing zone(LMX-4)mostly contains argillaceous shales and argillaceousesiliceous mixed shales.The lower shale gas reservoirs have a higher silica content and lower clay and carbonate contents than the upper zones,and thus superior petrophysical qualities.The upper part of the WF Fm.(WF-2)and the lower part of the LMX Fm(LMX-1,LMX-2)are rich in bio-chemical authigenic silica,whereas the silica minerals of other intervals are mainly derived from allochthonous terrigenous material.The siliceous shales and siliceouseargillaceous mixed shales with a biogenic quartz content greater than 40%have the best RQ and CQ and are the most promising lithofacies for shale gas in the Luzhou area.Although the upper gas-bearing zones represented by LMX-4 are also good shale gas reservoirs,the RQ,CQ and gas content are generally worse than those of the lower gas-bearing zones because of the silica origin and lithofacies types;thus,extracting shale gas from the upper zones would be a greater challenge.展开更多
It was showed that understanding of the diagenetic modifications and its associated products in the deeply to ultra-deeply buried tight sandstone reservoirs(DUDTSR)is great important for reservoir characterization and...It was showed that understanding of the diagenetic modifications and its associated products in the deeply to ultra-deeply buried tight sandstone reservoirs(DUDTSR)is great important for reservoir characterization and hydrocarbon prediction.However,the fine characterization of diagenetic evolution via geologic modelling in tight sandstones remains a great challenge as for complexity of lithology,temperature,pressure and formation fluid throughout the entire life cycle of tight sandstone reservoirs.To help get a comprehensive idea of the distribution of diagenetic processes on the formation of DUDTSR in the long geological period,type-I and type-II fine sections of diagenetic stage for clastic reservoirs were creatively proposed and its essence was illustrated using the Paleogene Huagang(EH)Formation in the southern Xihu Sag.Through combination of both quantitative and qualitative methods which began with current formation temperature,vitrinite analysis,illite and I/S mixed layers based on analytical testing of the EH Formation,(1)Paleotemperature(T),vitrinite reflectivity and smectite in mixed layer during burial processes were restored based on numerical analysis,(2)The accurate division of diagenetic evolution was identified from coarse to fine process using new model,(3)And finally the geological significance of fine division of the conventional diagenetic stage was illustrated for low-porosity and tight sandstone reservoirs.展开更多
Incomplete fault signal characteristics and ease of noise contamination are issues with the current rolling bearing early fault diagnostic methods,making it challenging to ensure the fault diagnosis accuracy and relia...Incomplete fault signal characteristics and ease of noise contamination are issues with the current rolling bearing early fault diagnostic methods,making it challenging to ensure the fault diagnosis accuracy and reliability.A novel approach integrating enhanced Symplectic geometry mode decomposition with cosine difference limitation and calculus operator(ESGMD-CC)and artificial fish swarm algorithm(AFSA)optimized extreme learning machine(ELM)is proposed in this paper to enhance the extraction capability of fault features and thus improve the accuracy of fault diagnosis.Firstly,SGMD decomposes the raw vibration signal into multiple Symplectic geometry components(SGCs).Secondly,the iterations are reset by the cosine difference limitation to effectively separate the redundant components from the representative components.Additionally,the calculus operator is performed to strengthen weak fault features and make them easier to extract,and the singular value decomposition(SVD)weighted by power spectrum entropy(PSE)can be utilized as the sample feature representation.Finally,AFSA iteratively optimized ELM is adopted as the optimized classifier for fault identification.The superior performance of the proposed method has been validated by various experiments.展开更多
The mission of the test field is to provide technical support to associates. The paper present the development of OE （ocean energy） field in China and outline the new technologies and best practice, resources condit...The mission of the test field is to provide technical support to associates. The paper present the development of OE （ocean energy） field in China and outline the new technologies and best practice, resources conditions, construction targets, generation device testing and standard system. The main purpose is to improve the level of China＇s ocean energy development. The Chinese ocean energy test field, which was started in 2008, involved a development divided in three phases （the overall design, construction, demonstration）. The methodology followed in the individual phases is described, and the standardization of testing wave and tidal current energy devices is introduced. The research revealed the development and the shortage of ocean energy technology in China.展开更多
Due to the wide application of closely spaced multi-well horizontal pads for developing unconventional gas reservoirs,interference between wells becomes a significant concern.Communication between wells mainly occurs ...Due to the wide application of closely spaced multi-well horizontal pads for developing unconventional gas reservoirs,interference between wells becomes a significant concern.Communication between wells mainly occurs through natural fractures.However,previous studies have found that interwell communication through natural fractures is varied,and non-communication also appears in the mid and late stages of production due to natural fracture closure.This study proposes a boundary element method for coupling multi-connected regions for the first time.Using this method,we coupled multiple flow fields to establish dual-well models with various connectivity conditions of the stimulated reservoir volume(SRV)region.These models also take into consideration of adsorption and desorption mechanism of natural gas as well as the impact of fracturing fluid retention.The study found that when considering the non-communication of SRV regions between multi-well horizontal pads,the transient behavior of the targeted well exhibits a transitional flow stage occurring before the well interference flow stage.In addition,sensitivity analysis shows that the well spacing and production regime,as well as the connectivity conditions of the SRV region,affect the timing of interwell interference.Meanwhile,the productivity of the two wells,reservoir properties,and fracturing operations affect the intensity of interwell interference.展开更多
The extent to which a country develops is anchored around its resources;and this is evidenced in how the revenue derived from natural resources (especially the oil and gas industries) has influenced national developme...The extent to which a country develops is anchored around its resources;and this is evidenced in how the revenue derived from natural resources (especially the oil and gas industries) has influenced national development strategies. This notwithstanding, the existence of natural resources does not always translate to development, as these often times lead to complacency and mismanagement;Nigeria may have suffered from this. This paper establishes the impact of gas production, utilization, and flaring on the estimated monetary value of the goods and services produced in Nigeria (GDP), using multiple linear regression analysis. The result shows that while gas utilization has a positive impact on the nation’s GDP, gas production and flaring are negatively associated with GDP. The paper concludes that for these to positively stimulate economic growth, there is need to invest more in infrastructure in the industry, and review the regulatory framework guiding operations of the oil and gas industry.展开更多
Dong Xu’s parents are both employees of the China Petroleum Pipeline Bureau.Therefore,it was wellreasoned for him to study in petroleum colleges and universities and work in the China Petroleum Pipeline Bureau.It nev...Dong Xu’s parents are both employees of the China Petroleum Pipeline Bureau.Therefore,it was wellreasoned for him to study in petroleum colleges and universities and work in the China Petroleum Pipeline Bureau.It never occurred to him that he could not work as a pipeline worker.Over the past 34 years,Dong Xu’s understanding of himself has changed from a“pipeline worker”to a“leader of pipeline engineering”,which proved the sublimation of his emotion to the pipeline when his role was changed from a spectator to participant and from a worker to a leader.展开更多
In the course of completion of an ultra-deep well newly drilled in the Yuanba Gasfield,Sichuan Basin,long-section and large-scale deformation occurred in the heavy casing section and nickel base alloy casing section o...In the course of completion of an ultra-deep well newly drilled in the Yuanba Gasfield,Sichuan Basin,long-section and large-scale deformation occurred in the heavy casing section and nickel base alloy casing section of the sealing Triassic limestone interval,so a new hole had to be sidetracked,which impels us to rediscover the applicability of conventional drilling and completion technology in ultra-deep wells.In this paper,based on the borehole condition and field operation data of this well,the borehole pressure field variation initiated by lost circulation in the low-pressure formation was analyzed from the perspective of dynamics,then,the variation pattern of differential pressure inside and outside the well bore at different time intervals was depicted,and the primary cause of such complication was theoretically revealed,i.e.,the pressure wave generated by instant lost circulation in low-pressure formation would result in redistribution of pressure inside the downhole confined space,and then the crush of casing in the vicinity of local low-pressure areas.Pertinent proposals for avoiding these kinds of engineering complexities were put forward:①when downhole sealing casing operation is conducted in open hole completion,liner completion or perforated hole,the potential damage of lost circulation to casing should be considered;②the downhole sealing point and sealing mode should be selected cautiously:the sealing point had better be selected in the section with good cementing quality or as close to the casing shoe as possible,and the sealing mode can be either cement plug or mechanical bridge plug.This paper finally points out that good cementing quality plays an important role in preventing this type of casing deformation.展开更多
To deal with the exploitation difficulties of gas fields in Northeast Sichuan with deep marine strata, after researching the relative standards domestic and abroad extensively, summarizing and promoting the successful...To deal with the exploitation difficulties of gas fields in Northeast Sichuan with deep marine strata, after researching the relative standards domestic and abroad extensively, summarizing and promoting the successful experiences and failure lessons of project construction technology application scientifically, Sinopec has established an integrated technical standard system for the exploration and development of ultra deep and high sour gas fields. The system consists of 51 enterprise standards and covers 7 professions including geophysical prospecting, drilling, drilling log, well logging, gas formation test and production, sour gas gathering and transferring system, and HSE (health,safety,environment). It guides and guarantees the safe, high-quality and high-efficiency project construction effectively by means of enhancing the engineering design criterion, recommending the data processing and interpretation methods, identifying the requirements of operation and field inspection and standardizing the application of technical equipments.展开更多
It is often argued that the core of organizational success is efficient collaboration.Some authors even posit that efficient collaboration is more important to organizational innovation and performance than individual...It is often argued that the core of organizational success is efficient collaboration.Some authors even posit that efficient collaboration is more important to organizational innovation and performance than individual skills or expertise.However,the lack of efficient models to manage collaboration properly is a major constraint for organizations to profit from internal and external collaborative initiatives.Currently,much of the collaboration in organizations occurs through virtual network channels,such as e-mail,Yammer,Jabber,Microsoft Teams,Skype,and Zoom.These are even more important in situations where different time zones and even threats of a pandemic constrain face-to-face human interactions.This work introduces a multidisciplinary heuristic model developed based on project risk management and social network analysis centrality metrics graph-theory to quantitatively measure dynamic organizational collaboration in the project environment.A case study illustrates the proposed model’s implementation and application in a real virtual project organizational context.The major benefit of applying this proposed model is that it enables organizations to quantitatively measure different collaborative,organizational,and dynamic behavioral patterns,which can later correlate with organizational outcomes.The model analyzes three collaborative project dimensions:network collaboration cohesion evolution,network collaboration degree evolution,and network team set variability evolution.This provides organizations an innovative approach to understand and manage possible collaborative project risks that may emerge as projects are delivered.Organizations can use the proposed model to identify projects’critical success factors by comparing successful and unsuccessful delivered projects’dynamic behaviors if a substantial number of both project types are analyzed.The proposed model also enables organizations to make decisions with more information regarding the support for changes in observed collaborative patterns as demonstrated by statistical models in general,and linear regressions in particular.Further,the proposed model provides organizations with a completely bias-free data-collection process that eliminates organizational downtime.Finally,applying the proposed model in organizations will reduce or eliminate the risks associated with virtual collaborative dynamics,leading to the optimized use of resources;this will transform organizations to become more lean-oriented and significantly contribute to economic,social,and environmental global sustainability.展开更多
Messenger ribonucleic acid(mRNA)-based vaccines have good patient tolerability,and the encoded molecules are readily accessible and versatile for potential future applications in cancer treatment.The development of li...Messenger ribonucleic acid(mRNA)-based vaccines have good patient tolerability,and the encoded molecules are readily accessible and versatile for potential future applications in cancer treatment.The development of lipid nanoparticles in conjunction with mRNA engineering may enable full application of cancer vaccines in immunotherapy to boost immune responses.These vaccines are easy to handle,quickly to produce in large quantities,and flexible enough to express full-length antigens with distinct epitopes without being restricted by the major histocompatibility complex(MHC).The use of mRNA vaccines in immunological and cancer treatments have advanced over the past few decades from theoretical conjecture to clinical practices.The high potency,quick development,inexpensive manufacture,and safe delivery of these vaccines provide a number of benefits over conventional vaccination methods.As luck would have it,most of the worries associated with all preexisting cancer treatments have been allayed by recent technological developments,which have led to the creation of many mRNA vaccine platforms against cancer and infectious diseases like COVID-19 virus.As a viable substitute for traditional vaccination methods and cancer treatments,this study emphasized the efficacy of mRNA vaccines for cancer immune responses.The goal of this paper is to present a comprehensive and in-depth analysis of mRNA vaccines,covering their modes of action and possible uses in cancer immunotherapy.The paper also examined the present status of mRNA vaccine technology and suggest potential paths for the advancement and application of this exciting vaccination platform as a common therapeutic choice.The study intends to further this ground-breaking method of treating cancer by offering a thorough overview and critical examination of mRNA vaccines.展开更多
Water flooding type-curves,recently receiving increasing attentions,play an essential role in evaluation of OOIP and prediction of future production.The study proposed a method modified form Weibull model and water fl...Water flooding type-curves,recently receiving increasing attentions,play an essential role in evaluation of OOIP and prediction of future production.The study proposed a method modified form Weibull model and water flooding type-curves to analyze the reservoir production performance,including predication of oil production and water injection rates.The results indicate that the method can estimate and provide solutions for oil production,water injection rate and injection-production ratio with a well accuracy.A case study is conducted to demonstrate the applicability and accuracy of model by field data.The matching results illustrate a good accordance between calculated values and field data.展开更多
文摘The construction of water conservancy projects should commence during optimal atmospheric conditions and non-flood period to ensure completion before the flood season begin in summer.In most areas of Northern China,the temperature during winter remain at lower level,in which environmental factors play the most important role in the construction of water conservancy projects.In particular,low temperature directly affects the strength of concrete and delays its solidification,this highly affects the quality and progress of concrete construction.In order to overcome this barrier,better planning,for reasonable and effective construction techniques and targeted control measures should be adopted to reduce the adverse effects of low temperature to assure a strong and safe architecture.
文摘Traffic forecasting with high precision aids Intelligent Transport Systems(ITS)in formulating and optimizing traffic management strategies.The algorithms used for tuning the hyperparameters of the deep learning models often have accurate results at the expense of high computational complexity.To address this problem,this paper uses the Tree-structured Parzen Estimator(TPE)to tune the hyperparameters of the Long Short-term Memory(LSTM)deep learning framework.The Tree-structured Parzen Estimator(TPE)uses a probabilistic approach with an adaptive searching mechanism by classifying the objective function values into good and bad samples.This ensures fast convergence in tuning the hyperparameter values in the deep learning model for performing prediction while still maintaining a certain degree of accuracy.It also overcomes the problem of converging to local optima and avoids timeconsuming random search and,therefore,avoids high computational complexity in prediction accuracy.The proposed scheme first performs data smoothing and normalization on the input data,which is then fed to the input of the TPE for tuning the hyperparameters.The traffic data is then input to the LSTM model with tuned parameters to perform the traffic prediction.The three optimizers:Adaptive Moment Estimation(Adam),Root Mean Square Propagation(RMSProp),and Stochastic Gradient Descend with Momentum(SGDM)are also evaluated for accuracy prediction and the best optimizer is then chosen for final traffic prediction in TPE-LSTM model.Simulation results verify the effectiveness of the proposed model in terms of accuracy of prediction over the benchmark schemes.
基金supported by the National Natural Science Foundation of China(52075214and 51975245)the National Key R&D Program of China(No.2022YFE0138500)+3 种基金Jilin Provincial Science&Technology Department(20220201115GX)Key Science and Technology R&D Projects of Jilin Province(2020C023-3)Program of Jilin University Science and Technology Innovative Research Team(2020TD-03)the Fundamental Research Funds for the Central Universities.
文摘Bipolar plate is one of the key components of Proton Exchange Membrane Fuel Cell(PEMFC)and a reasonable flow field design for bipolar plate will improve cell performance.Herein,we have reviewed conventional and bionic flow field designs in recent literature with a focus on bionic flow fields.In particular,the bionic flow fields are summarized into two types:plant-inspired and animal-inspired.The conventional methodology for flow field design takes more time to find the optimum since it is based on experience and trial-and-error methods.In recent years,machine learning has been used to optimize flow field structures of bipolar plates owing to the advantages of excellent prediction and optimization capability.Artificial Intelligence(AI)-assisted flow field design has been summarized into two categories in this review:single-objective optimization and multi-objective optimization.Furthermore,a Threats-Opportunities-Weaknesses-Strengths(TOWS)analysis has been conducted for AI-assisted flow field design.It has been envisioned that AI can afford a powerful tool to solve the complex problem of bionic flow field design and significantly enhance the performance of PEMFC with bionic flow fields.
文摘Field development practices in many shale gas regions(e.g.,the Changning region)have revealed a persistent issue of suboptimal reserve utilization,particularly in areas where the effective drainage width of production wells is less than half the inter-well spacing(typically 400-500 m).To address this,infill drilling has become a widely adopted and effective strategy for enhancing reservoir contact andmobilizing previously untapped reserves.However,this approach has introduced significant inter-well interference,complicating production dynamics and performance evaluation.The two primary challenges hindering efficient deployment of infill wells are:(1)the quantitative assessment of hydraulic and pressure connectivity between infill wells and their associated parent wells,and(2)the accurate estimation of platform-scale Estimated Ultimate Recovery(EUR)following infill implementation.This study presents a novel framework to quantify inter-well connectivity by deriving a material balance equation tailored for shale gas infill well groups,explicitly incorporating gas adsorption and desorption mechanisms.The model simultaneously evaluates formation pressure evolution and crossflow behavior between wells,offering a robust analytical basis for performance prediction.For infill wells intersecting the drainage boundaries of parent wells,EUR is estimated using an analytical model developed for multi-stage hydraulically fractured horizontal wells.Meanwhile,the EUR of the parent wells is obtained by summing their pre-infill EUR with the final inter-well crossflow contribution.
文摘The ocean,as one of Earth’s largest natural resources,covers over 70% of the planet’s surface and holds vast water energy potential.Building on this context,this study designs a hybrid generator(WWR-TENG)that integrates a triboelectric nanogenerator(TENG)and an electromagnetic generator(EMG).TENG is a new technology that can capture mechanical energy from the environment and convert it into electrical energy,and is particularly suitable for common natural or man-made power sources such as human movement,wind power,and water flow.EMG is a device that converts mechanical energy into electrical energy through the principle of electromagnetic induction and can usually provide stable power output.The composite design leverages the complementary advantages of both technologies to efficiently capture and convert marine wave energy.By combining the TENG’s high energy conversion efficiency,lowcost,lightweight structure,and simple designwith the EMG’s capabilities,the systemprovides a sustainable solution for marine energy development.Experimental results demonstrate that at a rotational speed of 3.0 r/s,the TENG component of the WWR-TENG achieves an open-circuit voltage of approximately 280 V and a shortcircuit current of 20μA.At the same time,the EMG unit exhibits an open-circuit voltage of 14 V and a short-circuit current of 14 mA.Furthermore,when integrated with a power management circuit,the WWR-TENG charges a 680μF capacitor to 3 V within 10 s at a rotational speed of 3.0 r/s.A simulated wave environment platform was established,enabling the WWR-TENG to maintain the thermo-hygrometer in normal operation under simulated wave conditions.These findings validate the hybrid system’s effectiveness in harnessing and storingwave energy,highlighting its potential for practical marine energy applications.
基金Research Project of Lianyungang Association for Science and Technology(Lkxyb1907)Research Project of"333 Project"of Jiangsu Province(BRA2019245)Research Project of"521"Project of Lianyungang City(LYG52105-2018090)。
文摘Assessment of water quality by firefly algorithm based on BP neural network model(FA-BP model)is built.In this model,the evaluation index function is constructed by BP Artificial Neural Network Algorithm(BP model),and Firefly Algorithm(FA model)is introduced to optimize weight values and thresholds to find the optimal solution.Fuzzy Comprehensive Evaluation method,Grey Incidence Analysis Algorithm and FA-BP model will be applied to evaluate the water quality of the five main rivers in Lianyungang City including Longwei,Yudai,Dapu,Paidan,and Dongyan River.The results show that the Fuzzy Comprehensive Evaluation method is difficult to use for slight pollution rivers with several slightly over standard indexes.It will be easy to ignore the impact of extreme indexes by Grey Incidence Analysis Algorithm.FA-BP model solves the shortcomings of the two methods.The evaluation results provide an important reference for the formulation of reasonable measures.It is a relatively comprehensive evaluation method and has a good application prospect in water quality evaluation.
基金supported by National Key Research and Development Program of China(2019YFA0708302)National Natural Science Foundation of China(Grant No.52004296,and Grant No.52274016)+1 种基金the Foundation of State Key Laboratory of Petroleum Resources and Prospecting(PRP/DX-2206)Science Foundation of China University of Petroleum-Beijing(No.2462022YXZZ007,No.2462022BJRC012).
文摘Figuring out rock strength plays essential roles in the sub ground mining activities,such as oil and gas well drilling and hydraulic fracturing,coal mining,tunneling,and other civil engineering scenarios.To help understand the effects of the mineralogical composition on evaluating the rock strength,this research tries to establish indirect prediction models of rock strength by specific input mineral contents for common sedimentary rocks.Using rock samples collected from the outcrops in the Sichuan Basin,uniaxial compression tests have been conducted to sandstone,carbonate,and shale cores.Combining with statistical analysis,the experimental data prove it true that the mineralogical composition can be utilized to predict the rock strength under specific conditions but the effects of mineralogical composition on the rock strength highly depend on the rock lithologies.According to the statistical analysis results,the predicted values of rock strengths by the mineral contents can get high accuracies in sandstone and carbonate rocks while no evidences can be found in shale rocks.The best indicator for predicting rock strength should be the quartz content for the sandstone rocks and the dolomite content for the carbonate rocks.Especially,to improve the evaluation accuracy,the rock strengths of sandstones can be obtained by substituting the mineral contents of quartz and clays,and those of carbonates can be calculated by the mineral contents of dolomite and calcite.Noticeably,the research data point out a significant contrast of quartz content in evaluating the rock strength of the sandstone rocks and the carbonate rocks.Increasing quartz content helps increase the sandstone strength but decrease the carbonate strength.As for shale rocks,no relationship exists between the rock strength and the mineralogical composition(e.g.,the clay fractions).To provide more evidences,detailed discussion also provides the readers more glances into the framework of the rock matrix,which can be further studied in the future.These findings can help understand the effects of mineralogical composition on the rock strengths,explain the contrasts in the rock strength of the responses to the same mineral content(e.g.,the quartz content),and provide another indirect method for evaluating the rock strength of common sedimentary rocks.
文摘Shale,which is a fine-grained sedimentary rock,differs in reservoir quality(RQ)and completion quality(CQ)as the result of variations in its mineral and organic-matter compositions.The RQ and CQ directly affect shale gas exploitation.Therefore,classification of the lithofacies types of shale,analysis of the reservoir differences of different lithofacies,and identification of the superior shale lithofacies with the best RQ and CQ are important for decisions on well placement,targeting the“sweet spot”zone and optimizing the expected ultimate recovery of a shale gas well.In this study,several methods including microscopic observation of thin sections,X-ray diffraction analysis,core analysis and elemental geochemistry were used to investigate the lithofacies types,reservoir characteristics and silica origin of the marine shales of the Wufeng FormationeLongmaxi Formation(WF Fm.eLMX Fm.)in the Luzhou area,southern Sichuan Basin,China.The lithofacies characteristics exhibit marked differences through the WFeLMX shale succession.Specifically,the lower gas-bearing zone(LMX-1)is mainly composed of siliceous shales and siliceouseargillaceous mixed shales,whereas the upper gas-bearing zone(LMX-4)mostly contains argillaceous shales and argillaceousesiliceous mixed shales.The lower shale gas reservoirs have a higher silica content and lower clay and carbonate contents than the upper zones,and thus superior petrophysical qualities.The upper part of the WF Fm.(WF-2)and the lower part of the LMX Fm(LMX-1,LMX-2)are rich in bio-chemical authigenic silica,whereas the silica minerals of other intervals are mainly derived from allochthonous terrigenous material.The siliceous shales and siliceouseargillaceous mixed shales with a biogenic quartz content greater than 40%have the best RQ and CQ and are the most promising lithofacies for shale gas in the Luzhou area.Although the upper gas-bearing zones represented by LMX-4 are also good shale gas reservoirs,the RQ,CQ and gas content are generally worse than those of the lower gas-bearing zones because of the silica origin and lithofacies types;thus,extracting shale gas from the upper zones would be a greater challenge.
基金Major Projects of National Science and Technology"Large Oil and Gas Fields and CBM Development"(Grant No.2016ZX05027-02–007)the National Natural Science Fund(Grant No.42072119)Open Foundation of Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education(China University of Geosciences)(Grant No.TPR-2021–08)。
文摘It was showed that understanding of the diagenetic modifications and its associated products in the deeply to ultra-deeply buried tight sandstone reservoirs(DUDTSR)is great important for reservoir characterization and hydrocarbon prediction.However,the fine characterization of diagenetic evolution via geologic modelling in tight sandstones remains a great challenge as for complexity of lithology,temperature,pressure and formation fluid throughout the entire life cycle of tight sandstone reservoirs.To help get a comprehensive idea of the distribution of diagenetic processes on the formation of DUDTSR in the long geological period,type-I and type-II fine sections of diagenetic stage for clastic reservoirs were creatively proposed and its essence was illustrated using the Paleogene Huagang(EH)Formation in the southern Xihu Sag.Through combination of both quantitative and qualitative methods which began with current formation temperature,vitrinite analysis,illite and I/S mixed layers based on analytical testing of the EH Formation,(1)Paleotemperature(T),vitrinite reflectivity and smectite in mixed layer during burial processes were restored based on numerical analysis,(2)The accurate division of diagenetic evolution was identified from coarse to fine process using new model,(3)And finally the geological significance of fine division of the conventional diagenetic stage was illustrated for low-porosity and tight sandstone reservoirs.
基金supported by National Key Research and Development Project (2020YFE0204900)National Natural Science Foundation of China (Grant Numbers 62073193,61873333)Key Research and Development Plan of Shandong Province (Grant Numbers 2019TSLH0301,2021CXGC010204).
文摘Incomplete fault signal characteristics and ease of noise contamination are issues with the current rolling bearing early fault diagnostic methods,making it challenging to ensure the fault diagnosis accuracy and reliability.A novel approach integrating enhanced Symplectic geometry mode decomposition with cosine difference limitation and calculus operator(ESGMD-CC)and artificial fish swarm algorithm(AFSA)optimized extreme learning machine(ELM)is proposed in this paper to enhance the extraction capability of fault features and thus improve the accuracy of fault diagnosis.Firstly,SGMD decomposes the raw vibration signal into multiple Symplectic geometry components(SGCs).Secondly,the iterations are reset by the cosine difference limitation to effectively separate the redundant components from the representative components.Additionally,the calculus operator is performed to strengthen weak fault features and make them easier to extract,and the singular value decomposition(SVD)weighted by power spectrum entropy(PSE)can be utilized as the sample feature representation.Finally,AFSA iteratively optimized ELM is adopted as the optimized classifier for fault identification.The superior performance of the proposed method has been validated by various experiments.
文摘The mission of the test field is to provide technical support to associates. The paper present the development of OE （ocean energy） field in China and outline the new technologies and best practice, resources conditions, construction targets, generation device testing and standard system. The main purpose is to improve the level of China＇s ocean energy development. The Chinese ocean energy test field, which was started in 2008, involved a development divided in three phases （the overall design, construction, demonstration）. The methodology followed in the individual phases is described, and the standardization of testing wave and tidal current energy devices is introduced. The research revealed the development and the shortage of ocean energy technology in China.
基金supported by the National Science Fund for Excellent Young Scholars(No.52222402)State Key Program of National Natural Science Foundation of China(No.U23A2022)+7 种基金State Key Program of National Natural Science Foundation of China(No.52234003)Sichuan Science and Technology Program(No.2022JDJQ0009)National Natural Science Foundation of China(No.52074235)Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance(Nos.2020CX020202 and 2020CX030202)Shale Gas industry Development Institute of Sichuan Province111 Project(No.D18016)China Postdoctoral Science Foundation(No.2022M722637)the Science Foundation of Sichuan Province(No.2022NSFSC0186)。
文摘Due to the wide application of closely spaced multi-well horizontal pads for developing unconventional gas reservoirs,interference between wells becomes a significant concern.Communication between wells mainly occurs through natural fractures.However,previous studies have found that interwell communication through natural fractures is varied,and non-communication also appears in the mid and late stages of production due to natural fracture closure.This study proposes a boundary element method for coupling multi-connected regions for the first time.Using this method,we coupled multiple flow fields to establish dual-well models with various connectivity conditions of the stimulated reservoir volume(SRV)region.These models also take into consideration of adsorption and desorption mechanism of natural gas as well as the impact of fracturing fluid retention.The study found that when considering the non-communication of SRV regions between multi-well horizontal pads,the transient behavior of the targeted well exhibits a transitional flow stage occurring before the well interference flow stage.In addition,sensitivity analysis shows that the well spacing and production regime,as well as the connectivity conditions of the SRV region,affect the timing of interwell interference.Meanwhile,the productivity of the two wells,reservoir properties,and fracturing operations affect the intensity of interwell interference.
文摘The extent to which a country develops is anchored around its resources;and this is evidenced in how the revenue derived from natural resources (especially the oil and gas industries) has influenced national development strategies. This notwithstanding, the existence of natural resources does not always translate to development, as these often times lead to complacency and mismanagement;Nigeria may have suffered from this. This paper establishes the impact of gas production, utilization, and flaring on the estimated monetary value of the goods and services produced in Nigeria (GDP), using multiple linear regression analysis. The result shows that while gas utilization has a positive impact on the nation’s GDP, gas production and flaring are negatively associated with GDP. The paper concludes that for these to positively stimulate economic growth, there is need to invest more in infrastructure in the industry, and review the regulatory framework guiding operations of the oil and gas industry.
文摘Dong Xu’s parents are both employees of the China Petroleum Pipeline Bureau.Therefore,it was wellreasoned for him to study in petroleum colleges and universities and work in the China Petroleum Pipeline Bureau.It never occurred to him that he could not work as a pipeline worker.Over the past 34 years,Dong Xu’s understanding of himself has changed from a“pipeline worker”to a“leader of pipeline engineering”,which proved the sublimation of his emotion to the pipeline when his role was changed from a spectator to participant and from a worker to a leader.
文摘In the course of completion of an ultra-deep well newly drilled in the Yuanba Gasfield,Sichuan Basin,long-section and large-scale deformation occurred in the heavy casing section and nickel base alloy casing section of the sealing Triassic limestone interval,so a new hole had to be sidetracked,which impels us to rediscover the applicability of conventional drilling and completion technology in ultra-deep wells.In this paper,based on the borehole condition and field operation data of this well,the borehole pressure field variation initiated by lost circulation in the low-pressure formation was analyzed from the perspective of dynamics,then,the variation pattern of differential pressure inside and outside the well bore at different time intervals was depicted,and the primary cause of such complication was theoretically revealed,i.e.,the pressure wave generated by instant lost circulation in low-pressure formation would result in redistribution of pressure inside the downhole confined space,and then the crush of casing in the vicinity of local low-pressure areas.Pertinent proposals for avoiding these kinds of engineering complexities were put forward:①when downhole sealing casing operation is conducted in open hole completion,liner completion or perforated hole,the potential damage of lost circulation to casing should be considered;②the downhole sealing point and sealing mode should be selected cautiously:the sealing point had better be selected in the section with good cementing quality or as close to the casing shoe as possible,and the sealing mode can be either cement plug or mechanical bridge plug.This paper finally points out that good cementing quality plays an important role in preventing this type of casing deformation.
文摘To deal with the exploitation difficulties of gas fields in Northeast Sichuan with deep marine strata, after researching the relative standards domestic and abroad extensively, summarizing and promoting the successful experiences and failure lessons of project construction technology application scientifically, Sinopec has established an integrated technical standard system for the exploration and development of ultra deep and high sour gas fields. The system consists of 51 enterprise standards and covers 7 professions including geophysical prospecting, drilling, drilling log, well logging, gas formation test and production, sour gas gathering and transferring system, and HSE (health,safety,environment). It guides and guarantees the safe, high-quality and high-efficiency project construction effectively by means of enhancing the engineering design criterion, recommending the data processing and interpretation methods, identifying the requirements of operation and field inspection and standardizing the application of technical equipments.
文摘It is often argued that the core of organizational success is efficient collaboration.Some authors even posit that efficient collaboration is more important to organizational innovation and performance than individual skills or expertise.However,the lack of efficient models to manage collaboration properly is a major constraint for organizations to profit from internal and external collaborative initiatives.Currently,much of the collaboration in organizations occurs through virtual network channels,such as e-mail,Yammer,Jabber,Microsoft Teams,Skype,and Zoom.These are even more important in situations where different time zones and even threats of a pandemic constrain face-to-face human interactions.This work introduces a multidisciplinary heuristic model developed based on project risk management and social network analysis centrality metrics graph-theory to quantitatively measure dynamic organizational collaboration in the project environment.A case study illustrates the proposed model’s implementation and application in a real virtual project organizational context.The major benefit of applying this proposed model is that it enables organizations to quantitatively measure different collaborative,organizational,and dynamic behavioral patterns,which can later correlate with organizational outcomes.The model analyzes three collaborative project dimensions:network collaboration cohesion evolution,network collaboration degree evolution,and network team set variability evolution.This provides organizations an innovative approach to understand and manage possible collaborative project risks that may emerge as projects are delivered.Organizations can use the proposed model to identify projects’critical success factors by comparing successful and unsuccessful delivered projects’dynamic behaviors if a substantial number of both project types are analyzed.The proposed model also enables organizations to make decisions with more information regarding the support for changes in observed collaborative patterns as demonstrated by statistical models in general,and linear regressions in particular.Further,the proposed model provides organizations with a completely bias-free data-collection process that eliminates organizational downtime.Finally,applying the proposed model in organizations will reduce or eliminate the risks associated with virtual collaborative dynamics,leading to the optimized use of resources;this will transform organizations to become more lean-oriented and significantly contribute to economic,social,and environmental global sustainability.
文摘Messenger ribonucleic acid(mRNA)-based vaccines have good patient tolerability,and the encoded molecules are readily accessible and versatile for potential future applications in cancer treatment.The development of lipid nanoparticles in conjunction with mRNA engineering may enable full application of cancer vaccines in immunotherapy to boost immune responses.These vaccines are easy to handle,quickly to produce in large quantities,and flexible enough to express full-length antigens with distinct epitopes without being restricted by the major histocompatibility complex(MHC).The use of mRNA vaccines in immunological and cancer treatments have advanced over the past few decades from theoretical conjecture to clinical practices.The high potency,quick development,inexpensive manufacture,and safe delivery of these vaccines provide a number of benefits over conventional vaccination methods.As luck would have it,most of the worries associated with all preexisting cancer treatments have been allayed by recent technological developments,which have led to the creation of many mRNA vaccine platforms against cancer and infectious diseases like COVID-19 virus.As a viable substitute for traditional vaccination methods and cancer treatments,this study emphasized the efficacy of mRNA vaccines for cancer immune responses.The goal of this paper is to present a comprehensive and in-depth analysis of mRNA vaccines,covering their modes of action and possible uses in cancer immunotherapy.The paper also examined the present status of mRNA vaccine technology and suggest potential paths for the advancement and application of this exciting vaccination platform as a common therapeutic choice.The study intends to further this ground-breaking method of treating cancer by offering a thorough overview and critical examination of mRNA vaccines.
基金This research is supported by The National Natural Science Fund(No.51574199),administered by the National Natural Science Foundation of China.
文摘Water flooding type-curves,recently receiving increasing attentions,play an essential role in evaluation of OOIP and prediction of future production.The study proposed a method modified form Weibull model and water flooding type-curves to analyze the reservoir production performance,including predication of oil production and water injection rates.The results indicate that the method can estimate and provide solutions for oil production,water injection rate and injection-production ratio with a well accuracy.A case study is conducted to demonstrate the applicability and accuracy of model by field data.The matching results illustrate a good accordance between calculated values and field data.
