In 2022,the risk exploration well Chongtan1(CT1)in the Sichuan Basin revealed commercial oil and gas flow during test in a new zone–the marl of the second submember of the third member of Leikoupo Formation(Lei-32)of...In 2022,the risk exploration well Chongtan1(CT1)in the Sichuan Basin revealed commercial oil and gas flow during test in a new zone–the marl of the second submember of the third member of Leikoupo Formation(Lei-32)of Middle Triassic,recording a significant discovery.However,the hydrocarbon accumulation in marl remains unclear,which restricts the selection and deployment of exploration area.Focusing on Well CT1,the hydrocarbon accumulation characteristics of Lei-32 marl are analyzed to clarify the potential zones for exploration.The following findings are obtained.First,according to the geochemical analysis of petroleum and source rocks,oil and gas in the Lei-32 marl of Well CT1 are originated from the same marl.The marl acts as both source rock and reservoir rock.Second,the Lei-32 marl in central Sichuan Basin is of lagoonal facies,with a thickness of 40–130 m,an area of about 40000 km^(2),a hydrocarbon generation intensity of(4–12)×10^(8) m^(3)/km^(2),and an estimated quantity of generated hydrocarbons of 25×10^(12) m^(3).Third,the lagoonal marl reservoirs are widely distributed in central Sichuan Basin.Typically,in Xichong–Yilong,Ziyang–Jianyang and Moxi South,the reservoirs are 20–60 m thick and cover an area of 7500 km^(2).Fourth,hydrocarbons in the lagoonal marl are generated and stored in the Lei-32 marl,which means that marl serves as both source rock and reservoir rock.They represent a new type of unconventional resource,which is worthy of exploring.Fifth,based on the interpretation of 2D and 3D seismic data from central Sichuan Basin,Xichong and Suining are defined as favorable prospects with estimated resources of(2000–3000)×10^(8) m^(3).展开更多
In fractured reservoirs characterized by low matrix permeability,fracture networks control the main fluid flow paths.However,in layered reservoirs,the vertical extension of fractures is often restricted to single laye...In fractured reservoirs characterized by low matrix permeability,fracture networks control the main fluid flow paths.However,in layered reservoirs,the vertical extension of fractures is often restricted to single layers.In this study,we explored the effect of changing marl/shale thickness on fracture extension using comprehensive field data and numerical modeling.The field data were sampled from coastal exposures of Liassic limestone-marl/shale alternations in Wales and Somerset(Bristol Channel Basin,UK).The vertical fracture traces of more than 4000 fractures were mapped in detail.Six sections were selected to represent a variety of layer thicknesses.Besides the field data also thin sections were analyzed.Numerical models of fracture extension in a two-layer limestone-marl system were based on field data and laboratory measurements of Young's moduli.The modeled principal stress magnitude σ3 along the lithological contact was used as an indication for fracture extension through marls.Field data exhibit good correlation(R^2=0.76) between fracture extension and marl thickness,the thicker the marl layer the fewer fractures propagate through.The model results show that almost no tensile stress reaches the top of the marl layer when the marls are thicker than 30 cm.For marls that are less than 20 cm,the propagation of stress is more dependent on the stiffness of the marls.The higher the contrast between limestone and marl stiffness the lower the stress that is transmitted into the marl layer.In both model experiments and field data the critical marl thickness for fracture extension is ca.15-20 cm.This quantification of critical marl thicknesses can be used to improve predictions of fracture networks and permeability in layered rocks.Up-or downsampling methods often ignore spatially continuous impermeable layers with thicknesses that are under the detection limit of seismic data.However,ignoring these layers can lead to overestimates of the overall permeability.Therefore,the understanding of how fractures propagate and terminate through impermeable layers will help to improve the characterization of conventional reservoirs.展开更多
The quality of designed structures embedded in rocks is strongly related to rock strength parameters of intact rock.Measuring different parameters from tests could be very expensive in designing phase of projects.Esti...The quality of designed structures embedded in rocks is strongly related to rock strength parameters of intact rock.Measuring different parameters from tests could be very expensive in designing phase of projects.Estimating some parameters from other ones can reduce costs and time of project procedure.In this paper,the relationships between static and dynamic parameters of marls are studied by using the single and multiple linear regressions.For this purpose,several marl core samples from Seydoon region,Khoozestan Province in Iran are collected and tested.Some equations with sufficient correlation have been obtained to predict the engineering parameters of marls,especially the uniaxial compressive strength(UCS).展开更多
Water scarcity has always been one of the most important obstacles in the process of agricultural development in arid and low-rainfall climates. In farming, the water quality also plays an important role;as the poor q...Water scarcity has always been one of the most important obstacles in the process of agricultural development in arid and low-rainfall climates. In farming, the water quality also plays an important role;as the poor quality of water can be one of the limiting factors in this sector that in addition to the agricultural problems has also caused soil problems. In this paper, we introduce and study an indigenous method of water conservation and soil protection in the east of Iran termed as “water-colouring” and the role of geomorphologic features of marl hills in one of the rivers located in the southern slopes of the Joghtay Mountain (Kalateh-Sadat Watershed). In this study, field observation, sampling and analysis of water and sediment, physicochemical experiments, SPSS software for statistical analysis and satellite images have been used to produce digital models. Finally, the effects of muddy water and clear water have been compared in terms of chemical quality and productivity of agricultural land. The results show that the method of water-colouring is the best indigenous-economical method for moisture retention and regeneration of the agricultural land soil. Given the statistical reasons and studying the other researches in this field, water-colouring causes change texture and soil composition, fertility of agricultural land and reduce the losses due to evaporation and infiltration.展开更多
针对移动边缘计算中用户移动性导致服务器间负载分布不均,用户服务质量(Quality of Service,QoS)下降的问题,提出了一种移动性感知下的分布式任务迁移方案。首先,以优化网络中性能最差的用户QoS为目标,建立了一个长期极大极小化公平性问...针对移动边缘计算中用户移动性导致服务器间负载分布不均,用户服务质量(Quality of Service,QoS)下降的问题,提出了一种移动性感知下的分布式任务迁移方案。首先,以优化网络中性能最差的用户QoS为目标,建立了一个长期极大极小化公平性问题(Max Min Fairness,MMF),利用李雅普诺夫(Lyapunov)优化将原问题转化解耦。然后,将其建模为去中心化部分可观测马尔可夫决策过程(Decentralized Partially Observable Markov Decision Process,Dec-POMDP),提出一种基于多智能体柔性演员-评论家(Soft Actor-Critic,SAC)的分布式任务迁移算法,将奖励函数解耦为节点奖励和用户个体奖励,分别基于节点负载均衡度和用户QoS施加奖励。仿真结果表明,相比于现有任务迁移方案,所提算法能够在保证用户QoS的前提下降低任务迁移率,保证系统负载均衡。展开更多
Multi-Agent Reinforcement Learning(MARL)has proven to be successful in cooperative assignments.MARL is used to investigate how autonomous agents with the same interests can connect and act in one team.MARL cooperation...Multi-Agent Reinforcement Learning(MARL)has proven to be successful in cooperative assignments.MARL is used to investigate how autonomous agents with the same interests can connect and act in one team.MARL cooperation scenarios are explored in recreational cooperative augmented reality environments,as well as realworld scenarios in robotics.In this paper,we explore the realm of MARL and its potential applications in cooperative assignments.Our focus is on developing a multi-agent system that can collaborate to attack or defend against enemies and achieve victory withminimal damage.To accomplish this,we utilize the StarCraftMulti-Agent Challenge(SMAC)environment and train four MARL algorithms:Q-learning with Mixtures of Experts(QMIX),Value-DecompositionNetwork(VDN),Multi-agent Proximal PolicyOptimizer(MAPPO),andMulti-Agent Actor Attention Critic(MAA2C).These algorithms allow multiple agents to cooperate in a specific scenario to achieve the targeted mission.Our results show that the QMIX algorithm outperforms the other three algorithms in the attacking scenario,while the VDN algorithm achieves the best results in the defending scenario.Specifically,the VDNalgorithmreaches the highest value of battle wonmean and the lowest value of dead alliesmean.Our research demonstrates the potential forMARL algorithms to be used in real-world applications,such as controllingmultiple robots to provide helpful services or coordinating teams of agents to accomplish tasks that would be impossible for a human to do.The SMAC environment provides a unique opportunity to test and evaluate MARL algorithms in a challenging and dynamic environment,and our results show that these algorithms can be used to achieve victory with minimal damage.展开更多
Due to the complicated lithology in the ES3 Member of the Shahejie Formation in the Shulu sag,Jizhong depression,it is difficult to classify the rock types and characterize the reservoirs at the marl intervals.In this...Due to the complicated lithology in the ES3 Member of the Shahejie Formation in the Shulu sag,Jizhong depression,it is difficult to classify the rock types and characterize the reservoirs at the marl intervals.In this paper,a four-element classification method has been proposed,and seven rock types have been identified by analyzing the mineral composition.The primary rock types are medium-high organic carbonate rocks and medium-high organic shaly-siliceous carbonate rocks.With the methods of field emission scanning electron microscopy,high-pressure mercury intrusion,nitrogen adsorption,and nano-CT,four types of reservoir spaces have been identified,including intra-granular pores,intergranular pores(inter-crystalline pores),organic pores,and micro-fractures.By combining the method of high-pressure mercury intrusion with the method of the nitrogen adsorption,the porosity of the marl has been measured,ranging from 0.73%to 5.39%.The distribution of the pore sizes is bimodal,and the pore types are dominated by micron pores.Through this study,it has been concluded that the sag area to the east of Well ST1H is the favorable area for the development of self-sourced and self-reservoired shale oil.According to the results of geochemical and reservoir analysis,the III Oil Group may have sweet spot layers.展开更多
Aims In eroded lands of the French Southern Alps,burial of early established seedlings under marly sediment weakens the effect of vegetation on soil stabilization and sediment trapping.Therefore,this protective role i...Aims In eroded lands of the French Southern Alps,burial of early established seedlings under marly sediment weakens the effect of vegetation on soil stabilization and sediment trapping.Therefore,this protective role is largely dependent on species’resistance to burial,and the understanding of species’tolerance to this environmental disturbance is highly valuable for basic knowledge on plant succession and for ecological restoration purposes.Methods The response of five woody species with contrasting ecological requirements and natural habitats—three tree species,Pinus nigra,Robinia pseudoacacia and Acer campestre,and two shrubs,Ononis fruticosa and Hippophae rhamnoides—to experimental burial under marly sediment was studied.Seedlings were exposed to three burial levels:no burial(control),partial burial(50%of seedling height)and complete burial(100%of seedling height).Burial tolerance was evaluated based on seedling survival,height and biomass.Biomass allocation to shoots and roots and soluble sugar and starch contents in roots and stems were measured to identify plant traits that determine species response to burial.Important Findings All species survived partial burial but only A.campestre seedlings emerged from complete burial.Tree species were more tolerant to burial and buried plants showed no significant differences with control.The two shrubs were found less tolerant and buried plants showed slower growth than controls.The results showed that species response was not related to initial soluble and starch content in roots and stems,but instead to biomass allocation pattern flexibility.展开更多
基金Supported by the PetroChina Science and Technology Project(2021DJ0501,2018A-0105).
文摘In 2022,the risk exploration well Chongtan1(CT1)in the Sichuan Basin revealed commercial oil and gas flow during test in a new zone–the marl of the second submember of the third member of Leikoupo Formation(Lei-32)of Middle Triassic,recording a significant discovery.However,the hydrocarbon accumulation in marl remains unclear,which restricts the selection and deployment of exploration area.Focusing on Well CT1,the hydrocarbon accumulation characteristics of Lei-32 marl are analyzed to clarify the potential zones for exploration.The following findings are obtained.First,according to the geochemical analysis of petroleum and source rocks,oil and gas in the Lei-32 marl of Well CT1 are originated from the same marl.The marl acts as both source rock and reservoir rock.Second,the Lei-32 marl in central Sichuan Basin is of lagoonal facies,with a thickness of 40–130 m,an area of about 40000 km^(2),a hydrocarbon generation intensity of(4–12)×10^(8) m^(3)/km^(2),and an estimated quantity of generated hydrocarbons of 25×10^(12) m^(3).Third,the lagoonal marl reservoirs are widely distributed in central Sichuan Basin.Typically,in Xichong–Yilong,Ziyang–Jianyang and Moxi South,the reservoirs are 20–60 m thick and cover an area of 7500 km^(2).Fourth,hydrocarbons in the lagoonal marl are generated and stored in the Lei-32 marl,which means that marl serves as both source rock and reservoir rock.They represent a new type of unconventional resource,which is worthy of exploring.Fifth,based on the interpretation of 2D and 3D seismic data from central Sichuan Basin,Xichong and Suining are defined as favorable prospects with estimated resources of(2000–3000)×10^(8) m^(3).
基金supported by the Deutsche Forschungsgemeinschaft(DFG,grant PH 189/2-1)
文摘In fractured reservoirs characterized by low matrix permeability,fracture networks control the main fluid flow paths.However,in layered reservoirs,the vertical extension of fractures is often restricted to single layers.In this study,we explored the effect of changing marl/shale thickness on fracture extension using comprehensive field data and numerical modeling.The field data were sampled from coastal exposures of Liassic limestone-marl/shale alternations in Wales and Somerset(Bristol Channel Basin,UK).The vertical fracture traces of more than 4000 fractures were mapped in detail.Six sections were selected to represent a variety of layer thicknesses.Besides the field data also thin sections were analyzed.Numerical models of fracture extension in a two-layer limestone-marl system were based on field data and laboratory measurements of Young's moduli.The modeled principal stress magnitude σ3 along the lithological contact was used as an indication for fracture extension through marls.Field data exhibit good correlation(R^2=0.76) between fracture extension and marl thickness,the thicker the marl layer the fewer fractures propagate through.The model results show that almost no tensile stress reaches the top of the marl layer when the marls are thicker than 30 cm.For marls that are less than 20 cm,the propagation of stress is more dependent on the stiffness of the marls.The higher the contrast between limestone and marl stiffness the lower the stress that is transmitted into the marl layer.In both model experiments and field data the critical marl thickness for fracture extension is ca.15-20 cm.This quantification of critical marl thicknesses can be used to improve predictions of fracture networks and permeability in layered rocks.Up-or downsampling methods often ignore spatially continuous impermeable layers with thicknesses that are under the detection limit of seismic data.However,ignoring these layers can lead to overestimates of the overall permeability.Therefore,the understanding of how fractures propagate and terminate through impermeable layers will help to improve the characterization of conventional reservoirs.
文摘The quality of designed structures embedded in rocks is strongly related to rock strength parameters of intact rock.Measuring different parameters from tests could be very expensive in designing phase of projects.Estimating some parameters from other ones can reduce costs and time of project procedure.In this paper,the relationships between static and dynamic parameters of marls are studied by using the single and multiple linear regressions.For this purpose,several marl core samples from Seydoon region,Khoozestan Province in Iran are collected and tested.Some equations with sufficient correlation have been obtained to predict the engineering parameters of marls,especially the uniaxial compressive strength(UCS).
文摘Water scarcity has always been one of the most important obstacles in the process of agricultural development in arid and low-rainfall climates. In farming, the water quality also plays an important role;as the poor quality of water can be one of the limiting factors in this sector that in addition to the agricultural problems has also caused soil problems. In this paper, we introduce and study an indigenous method of water conservation and soil protection in the east of Iran termed as “water-colouring” and the role of geomorphologic features of marl hills in one of the rivers located in the southern slopes of the Joghtay Mountain (Kalateh-Sadat Watershed). In this study, field observation, sampling and analysis of water and sediment, physicochemical experiments, SPSS software for statistical analysis and satellite images have been used to produce digital models. Finally, the effects of muddy water and clear water have been compared in terms of chemical quality and productivity of agricultural land. The results show that the method of water-colouring is the best indigenous-economical method for moisture retention and regeneration of the agricultural land soil. Given the statistical reasons and studying the other researches in this field, water-colouring causes change texture and soil composition, fertility of agricultural land and reduce the losses due to evaporation and infiltration.
基金supported in part by United States Air Force Research Institute for Tactical Autonomy(RITA)University Affiliated Research Center(UARC)in part by the United States Air Force Office of Scientific Research(AFOSR)Contract FA9550-22-1-0268 awarded to KHA,https://www.afrl.af.mil/AFOSR/The contract is entitled:“Investigating Improving Safety of Autonomous Exploring Intelligent Agents with Human-in-the-Loop Reinforcement Learning,”and in part by Jackson State University.
文摘Multi-Agent Reinforcement Learning(MARL)has proven to be successful in cooperative assignments.MARL is used to investigate how autonomous agents with the same interests can connect and act in one team.MARL cooperation scenarios are explored in recreational cooperative augmented reality environments,as well as realworld scenarios in robotics.In this paper,we explore the realm of MARL and its potential applications in cooperative assignments.Our focus is on developing a multi-agent system that can collaborate to attack or defend against enemies and achieve victory withminimal damage.To accomplish this,we utilize the StarCraftMulti-Agent Challenge(SMAC)environment and train four MARL algorithms:Q-learning with Mixtures of Experts(QMIX),Value-DecompositionNetwork(VDN),Multi-agent Proximal PolicyOptimizer(MAPPO),andMulti-Agent Actor Attention Critic(MAA2C).These algorithms allow multiple agents to cooperate in a specific scenario to achieve the targeted mission.Our results show that the QMIX algorithm outperforms the other three algorithms in the attacking scenario,while the VDN algorithm achieves the best results in the defending scenario.Specifically,the VDNalgorithmreaches the highest value of battle wonmean and the lowest value of dead alliesmean.Our research demonstrates the potential forMARL algorithms to be used in real-world applications,such as controllingmultiple robots to provide helpful services or coordinating teams of agents to accomplish tasks that would be impossible for a human to do.The SMAC environment provides a unique opportunity to test and evaluate MARL algorithms in a challenging and dynamic environment,and our results show that these algorithms can be used to achieve victory with minimal damage.
基金supported by the National Basic Research Program of China(973 Program)(No.2014CB239001).
文摘Due to the complicated lithology in the ES3 Member of the Shahejie Formation in the Shulu sag,Jizhong depression,it is difficult to classify the rock types and characterize the reservoirs at the marl intervals.In this paper,a four-element classification method has been proposed,and seven rock types have been identified by analyzing the mineral composition.The primary rock types are medium-high organic carbonate rocks and medium-high organic shaly-siliceous carbonate rocks.With the methods of field emission scanning electron microscopy,high-pressure mercury intrusion,nitrogen adsorption,and nano-CT,four types of reservoir spaces have been identified,including intra-granular pores,intergranular pores(inter-crystalline pores),organic pores,and micro-fractures.By combining the method of high-pressure mercury intrusion with the method of the nitrogen adsorption,the porosity of the marl has been measured,ranging from 0.73%to 5.39%.The distribution of the pore sizes is bimodal,and the pore types are dominated by micron pores.Through this study,it has been concluded that the sag area to the east of Well ST1H is the favorable area for the development of self-sourced and self-reservoired shale oil.According to the results of geochemical and reservoir analysis,the III Oil Group may have sweet spot layers.
基金This work resulted from the project‘Genie biologique sur la Durance’,funded by EDF(Electricitede France)Agence de l’eau Rhone Mediterranee et Corse,Region Provence Alpes Cote d’Azurthe European Union with FEDER funds.
文摘Aims In eroded lands of the French Southern Alps,burial of early established seedlings under marly sediment weakens the effect of vegetation on soil stabilization and sediment trapping.Therefore,this protective role is largely dependent on species’resistance to burial,and the understanding of species’tolerance to this environmental disturbance is highly valuable for basic knowledge on plant succession and for ecological restoration purposes.Methods The response of five woody species with contrasting ecological requirements and natural habitats—three tree species,Pinus nigra,Robinia pseudoacacia and Acer campestre,and two shrubs,Ononis fruticosa and Hippophae rhamnoides—to experimental burial under marly sediment was studied.Seedlings were exposed to three burial levels:no burial(control),partial burial(50%of seedling height)and complete burial(100%of seedling height).Burial tolerance was evaluated based on seedling survival,height and biomass.Biomass allocation to shoots and roots and soluble sugar and starch contents in roots and stems were measured to identify plant traits that determine species response to burial.Important Findings All species survived partial burial but only A.campestre seedlings emerged from complete burial.Tree species were more tolerant to burial and buried plants showed no significant differences with control.The two shrubs were found less tolerant and buried plants showed slower growth than controls.The results showed that species response was not related to initial soluble and starch content in roots and stems,but instead to biomass allocation pattern flexibility.