Muddy baffles are one of the major geological factors controlling the underground fluid flow as well as the remaining oil distribution. This study used detailed drilling data from the E1f1 reservoir in the X Oilfield,...Muddy baffles are one of the major geological factors controlling the underground fluid flow as well as the remaining oil distribution. This study used detailed drilling data from the E1f1 reservoir in the X Oilfield, Subei Basin, China, to investigate the hierarchical muddy baffles developed on lacustrine delta fronts and their precise cross-well correlation.According to the theories on allogenic and autogenic cycles as well as the genesis and scales of muddy baffles, five orders of muddy baffles were classified, which provided various degrees of difficulty when attempting interwell correlation. Under the guidance of a reliable stratigraphic model, the precise cross-well correlation of muddy baffles could be achieved and the key point of establishment of this stratigraphic model was to calculate foreset angles of hierarchical muddy baffles during deposition. During calculation, the relationships between sediment flow direction, higher-order strata dipping direction,well types and well trajectory direction should all be taken into consideration and some other angles（referred to here as θ1,θ2 and θ3） should also be measured. Such new methods of cross-well correlation for hierarchical muddy baffles could greatly reduce the uncertainties and multiple solutions, which in turn would be significant for efficient development and oil recovery enhancement in the reservoirs.展开更多
Shallow lacustrine delta front （SLDF） comprises mainly sheetlike subaqueous distributary channels （SDC） formed in shallow, gentle, and tectonically steady slope （Cai and Zhu, 2011）. SDC proves an important hydro...Shallow lacustrine delta front （SLDF） comprises mainly sheetlike subaqueous distributary channels （SDC） formed in shallow, gentle, and tectonically steady slope （Cai and Zhu, 2011）. SDC proves an important hydrocarbon reservoir type in the Daqing oilfield, Changqing oilfield, and the newly discovered Moxizhuang oilfield in Central Junggar Basin. However, SDC tends to prograde quickly and move laterally frequently,展开更多
Changes in water level are one of the important factors controlling the constructive characteristics of deltas.The paper studies the influence of water level changes on sand bodies in the third member of the Shahejie ...Changes in water level are one of the important factors controlling the constructive characteristics of deltas.The paper studies the influence of water level changes on sand bodies in the third member of the Shahejie Formation(Es3)on the gentle southern slope of the Gubei Sag,Bohai Bay Basin and draw some conclusions that,for complex sand bodies,with the increase in water level the distributary channels bifurcate frequently,from a simple branching shape to a network shape along with the increase in the development of crevasse splays,mouth bars and sheet sands.For single sand bodies,with an increase in water level in the slope zone of the lake basin close to the source area,the superimposition style transitioned from vertical cutting-stacking and lateral isolation to vertical stitching,isolation and lateral stitching.However,in the central zone of the lake basin far from the source area,the superimposition style transitioned from vertical stitching and lateral stitching to vertical isolation and lateral isolation.When water level stays stable,the greater the distance from the source area the greater the disaggregation ratio of a single sand body.At the same distance from the source area,higher water level tends to result in greater disaggregation ratio of a single sand body.展开更多
Based on the abundant information from drilling, cores, and logging, the influence of topography, size of rivers and lakes, climate changes and the lake level＇s fluctuation on the sandbodies at shallow-water delta fr...Based on the abundant information from drilling, cores, and logging, the influence of topography, size of rivers and lakes, climate changes and the lake level＇s fluctuation on the sandbodies at shallow-water delta front are systematically summarized and the sedimentary dynamic processes are analyzed. The interwell communication among the sandbodies and their planar distribution revealed from the hydrodynamic features of the development wells are integrated during the analysis. The fundamental requirements for the development of the shallow-water delta included flat topography and uniform subsiding rate. The delta plain was connected smoothly with the wide delta front and predelta, without the three-fold structure of topset, foreset, and bottomset as defined in the Gilbert Delta Model. Because of the weak fluvial effect and the lake energy is strong, the small and scattered shallow-water delta is destroyed by the scouring-backwashing, coastal current, and lake wave, resulting in the coastal sheet deposition. As the fluvial effect became stronger and the lake energy became weaker, the shape of the shallow-water deltas transferred from sheets to lumps and then branches.展开更多
Core, well logging and seismic data were used to investigate sandbody architectural characteristics within Lower Member of Minghuazhen Formation in Neogene, Bohai BZ25 Oilfield, and to analyze the sedimentary microfac...Core, well logging and seismic data were used to investigate sandbody architectural characteristics within Lower Member of Minghuazhen Formation in Neogene, Bohai BZ25 Oilfield, and to analyze the sedimentary microfacies, distribution and internal architecture characteristics of the bar finger within shoal water delta front. The branched sand body within shoal water delta front is the bar finger, consisting of the mouth bar, distributary channel over bar, and levee. The distributary channel cuts through the mouth bar, and the thin levee covers the mouth bar which is located at both sides of distributary channel. The bar finger is commonly sinuous and its sinuosity increases basinward. The distributary channel changes from deeply incising the mouth bar to shallowly incising top of the mouth bar.The aspect ratio ranges from 25 to 50 and there is a double logarithmic linear positive relationship between the width and thickness for the bar finger, which is controlled by base-level changing in study area. For the bar finger, injection and production in the same distributary channel should be avoided during water flooding development. In addition, middle–upper distributary channel and undrilled mouth bar are focus of tapping remaining oil.展开更多
1 Introduction The shallow water delta reservoir in South Wen 79Block is in the stage of high water-cut stages,and is still on the rise.The degree of recovery is low,preferredflowing path is developed and surplus oil ...1 Introduction The shallow water delta reservoir in South Wen 79Block is in the stage of high water-cut stages,and is still on the rise.The degree of recovery is low,preferredflowing path is developed and surplus oil is generally distributed with local enrichment(Zhang,2009).The potential of surplus oil is considerable,while the difficulty is also great.And the basis of effective tapping for展开更多
Ichnofossils are well developed in clastic rock reservoirs in marine and transitional facies, which can considerably change the physical properties of the reservoir. However, this influence is not well understood, rai...Ichnofossils are well developed in clastic rock reservoirs in marine and transitional facies, which can considerably change the physical properties of the reservoir. However, this influence is not well understood, raising an important problem in the effective development of petroleum reservoirs. This paper analyzes continental shelf margin delta reservoirs through core observation, cast thin section observation and reservoir physical property test. Some important scientific insights are obtained:(1) The presence of Cruziana ichnofacies, including Asterosoma, Ophiomorpha, Planolites, Skolithos, Thalassinoides, and other ichnofossils can be used to identify in subaqueous distributary channels, subaqueous levee, frontal sheet sand, abandoned river channels, crevasse channels, main channels and channel mouth bars. Considerable differences in the types of ichnofossils and the degree of bioturbation can be observed in the different petrofacies.(2) Ichnofossils and bioturbation play a complex role in controlling reservoir properties. The reservoir physical properties have the characteristics of a decrease–increase–decrease curve with increasing bioturbation degree. This complex change is controlled by the sediment mixing and packing of bioturbation and the diagenetic environment controlled by the ichnofossils.(3) Sea-level cycle changes affect the modification of the reservoir through sediment packing. Bioturbation weakens the reservoir's physical property when sea level slowly rises and improves the reservoir's physical property when base level slowly falls.展开更多
Recently the explored reserves submitted in the oil field mainly situate at the end of deposit in delta front area. During the exploitation and production, problems mainly show on lithologic deposit, for example, rese...Recently the explored reserves submitted in the oil field mainly situate at the end of deposit in delta front area. During the exploitation and production, problems mainly show on lithologic deposit, for example, reserves are low and difficulty of producing is huge. Based on results of sand body dissection of dense well network of developed oil deposit, and combined with explored reserves, this article researches a relation between extent of well control and reserves precision of explored reserves of lithologic deposit in delta front area by well diluted method. This article has significant influence on objectively understanding our unexploited展开更多
During the non-breeding season(September-April),Black-tailed Godwits(Limosa limosa)are commonly seen in coastal and inland wetlands of the Ganges-Brahmaputra-Meghna Delta in Bangladesh.We hypothesize that the Ganges-B...During the non-breeding season(September-April),Black-tailed Godwits(Limosa limosa)are commonly seen in coastal and inland wetlands of the Ganges-Brahmaputra-Meghna Delta in Bangladesh.We hypothesize that the Ganges-Brahmaputra-Meghna Delta,at the overlap between the Central Asian and East Asian-Australasian flyways,may host three subspecies that breed in disjunct areas of temperate and northern Asia:L.l.limosa,L.l.melanuroides,and L.l.bohaii.We used mitochondrial DNA(mt DNA)haplotype network and biometric analysis to determine subspecies in captured individuals,and deployed GPS-GSM transmitters to verify breeding areas of individuals with subspecies assignments.To test for differential habitat preferences,we sampled birds at two ecologically distinct habitats known to host the largest concentrations of non-breeding Black-tailed Godwits in Bangladesh:Nijhum Dweep National Park,a tidal coastal habitat with brackish water on the south-central coast,and Tanguar Haor(‘backmarsh'),a seasonal freshwater floodplain in the north.During the non-breeding seasons of 2021-2022 and 2022-2023,we sampled and measured 93 Black-tailed Godwits,54 of which were equipped with GPS-GSM transmitters.Our mt DNA haplotype network analysis confirmed the presence of limosa,melanuroides,and bohaii subspecies at the study sites.Thus,indeed,Black-tailed Godwits subspecies,despite having distinct breeding ranges,exhibit(partially)overlapping non-breeding ranges in Asia.The subspecies composition differed significantly between sites,with limosa and bohaii dominating in Tanguar Haor and melanuroides in Nijhum Dweep.Of the 21 individuals that were tracked to their breeding grounds,18 migrated to the expected breeding range of their respective subspecies.However,one bird with a limosa haplotype migrated to a known breeding area of bohaii,whereas two birds with melanuroides haplotypes migrated to the supposed breeding range of limosa.Therefore,while ecological factors at both ends of the flyways may shape the morphological and behavioural differences between Black-tailed Godwit subspecies,their delineations and possible gene flow require further studies.展开更多
Rationale: The contamination of soil with crude oil poses significant environmental and ecological threats. Bioremediation, particularly through the use of organisms like Pleurotus ostreatus (mushroom) and Eisenia fet...Rationale: The contamination of soil with crude oil poses significant environmental and ecological threats. Bioremediation, particularly through the use of organisms like Pleurotus ostreatus (mushroom) and Eisenia fetida (earthworm), has emerged as a promising approach to mitigate crude oil pollution. Understanding the effectiveness of these organisms in reducing hydrocarbon levels in contaminated soil is crucial for devising sustainable remediation strategies. Objectives: This study aimed to evaluate the efficacy of Pleurotus ostreatus and Eisenia fetida in remediating crude oil-polluted soil. Specifically, it sought to assess the hydrocarbon profiles in soil treated with these organisms across varying concentrations of crude oil pollution. Method: Crude oil concentration levels ranging from 0% to 10% were applied to soil samples alongside control treatments, including soil only, soil with earthworms, and soil with mushrooms. Each treatment was replicated five times using a randomized complete block design. Standard methods were employed to determine the hydrocarbon contents of the soil. Results: The results indicated a significant increase (P Pleurotus ostreatus and Eisenia fetida exhibited noteworthy reductions in these hydrocarbon levels. At the three-month mark, mushrooms demonstrated a remarkable ability to reduce hydrocarbon content by 70% - 90% compared to the pollution treatment. In contrast, earthworms exhibited minimal potential for hydrocarbon reduction, particularly at both three and six-month intervals. For instance, TOC reduction reached a maximum of 96% with mushroom treatment and 85% with earthworm treatment at 5% crude oil pollution over six months. Conclusion: The findings highlight the effectiveness of Pleurotus ostreatus in significantly reducing hydrocarbon levels in crude oil-polluted soil compared to Eisenia fetida. Mushroom-treated soils consistently exhibited substantial reductions in TOC, TPH, TOG, PAH, and THC over the study period, suggesting their potential as a viable bioremediation agent. In contrast, while earthworms showed some capability in reducing hydrocarbon content, their effectiveness was comparatively limited. Recommendation: Based on the results, it is recommended to utilize Pleurotus ostreatus for the bioremediation of crude oil-polluted soils. Further research could explore optimizing remediation protocols involving mushroom-based treatments for enhanced efficiency. Statement of Significance: This study contributes valuable insights into the application of bioremediation techniques for mitigating crude oil contamination in soil. The demonstrated efficacy of Pleurotus ostreatus underscores its potential as a sustainable and eco-friendly solution for remediating hydrocarbon-polluted environments, offering a promising avenue for environmental restoration and conservation efforts.展开更多
BACKGROUND Objective and accurate assessment of blood loss during pancreaticoduodenectomy(PD)is crucial for ensuring the safety and efficacy of the procedure.While the visual method remains the most common clinical me...BACKGROUND Objective and accurate assessment of blood loss during pancreaticoduodenectomy(PD)is crucial for ensuring the safety and efficacy of the procedure.While the visual method remains the most common clinical metric,many scholars argue that it significantly differs from actual blood loss and is inherently subjective.AIM To assess blood loss in PD via delta hemoglobin(ΔHb)and compare it with the visual method to predict bleeding-related risk factors.METHODS In this retrospective analysis,1722 patients who underwent PD from 2017 to 2022 at Shandong Provincial Hospital were divided into three groups:Open PD(OPD),laparoscopic PD(LPD),and conversion to OPD(CTOPD).IntraoperativeΔHb(IΔHb)was calculated via preoperative and 72-hour-postoperative hemoglobin concentrations,and its association with visually obtained estimated blood loss(EBL)was analyzed.PerioperativeΔHb(PΔHb)was calculated via preoperative and predischarge hemoglobin concentrations.We compared the differences in IΔHb and PΔHb among the three groups,and performed univariate and multi-variate regression analyses of IΔHb and PΔHb.RESULTS The preoperative general information of patients showed no statistically si-gnificant difference among the three groups(P>0.05).The IΔHb in the OPD,LPD,and CTOPD groups were 22.00(12.00,36.00),21.00(10.00,33.00),and 33.00(18.12,52.24)g/L,respectively;And the PΔHb in the OPD,LPD,and CTOPD groups were 25.87(13.51,42.00),25.00(14.00,45.00),and 37.48(21.64,59.65)g/L,respectively,values significantly differed(P<0.05).IΔHb and EBL were significantly correlated(r=0.337,P<0.001).The results of univariate and multivariate regression analyses indicated that American Society of Anesthesiologists(ASA)classification IV[95%confidence interval(CI):2.330-37.811,P=0.049]and preoperative total bilirubin>200μmol/L(95%CI:2.805-8.673,P<0.001)were independent risk factors for IΔHb(P<0.05),and ASA classification IV(95%CI:45.934-105.485,P<0.001),body mass index>24 kg/m2(95%CI:1.285-9.890,P=0.011),and preoperative total bilirubin>200μmol/L(95%CI:6.948-16.797,P<0.001)were independent risk factors for PΔHb(P<0.05).CONCLUSION There is a correlation between IΔHb and EBL in PD,so we can assess the patients’intraoperative blood loss by theΔHb method.ASA classification IV,body mass index>24 kg/m²,and preoperative total bilirubin>200μmol/L increased perioperative bleeding risk.展开更多
Agricultural production(especially intensive rice production)is a primary income source for over 2.0×10^(7) people in the Vietnamese Mekong River Delta.However,adverse climate change impacts,socio-economic change...Agricultural production(especially intensive rice production)is a primary income source for over 2.0×10^(7) people in the Vietnamese Mekong River Delta.However,adverse climate change impacts,socio-economic change,and high dependence on farm inputs for intensive production constrain the longer-term sustainability of rice systems.Government and agribusiness actors are encouraging more farmers to grow non-rice crops and supporting the upscaling of alternative crops to paddy rice.We used a qualitative approach to investigate the value chain characteristics,as well as constraints and opportunities of alternative crops via two case studies(baby corn and honeydew melon)in An Giang and Hau Giang provinces,Vietnam.Data collection involved focus group discussions with local farmers and interviews with farmers and industry experts.Thematic analysis was used to compile the findings,and the results were validated with local government staff.The baby corn value chain featured on-going and stable market demand(including value-addition)and better vertical coordination(e.g.,written contracts and financial support).The honeydew melon value chain featured positive relationships between farmers and traders despite less-developed vertical coordination.There are opportunities for value chain engagement through product quality certification,value-addition,and accessing high-value domestic and export markets.However,farmers require crop-specific and generic support from private and public sectors.Increased labour requirements and limited access to finance and credit limit value chain participation.Upscaling and marketing alternative crops can enhance farmer profitability and support non-farming agricultural business establishment,economic growth,and community development.Efficient value chains will be critical to ensure the adoption of alternative crops and development of crop-specific agribusiness models.These findings can inform policy-makers and change facilitators in designing targeted interventions to support the adoption of alternative crops in the study area as well as in Vietnam and globally.展开更多
The Anhui Provincial Bureau of Statistics announced in early March that Hefei’s permanent resident population had reached 10.002 million in 2024,surpassing the 10-million mark for the first time.This achievement posi...The Anhui Provincial Bureau of Statistics announced in early March that Hefei’s permanent resident population had reached 10.002 million in 2024,surpassing the 10-million mark for the first time.This achievement positions Hefei as the fourth most populated city in the Yangtze River Delta region,following Shanghai,Suzhou in Jiangsu Province,and Hangzhou in Zhejiang Province.展开更多
Despite its immense potential,the application of digital twin technology in real industrial scenarios still faces numerous challenges.This study focuses on industrial assembly lines in sectors such as microelectronics...Despite its immense potential,the application of digital twin technology in real industrial scenarios still faces numerous challenges.This study focuses on industrial assembly lines in sectors such as microelectronics,pharmaceuticals,and food packaging,where precision and speed are paramount,applying digital twin technology to the robotic assembly process.The innovation of this research lies in the development of a digital twin architecture and system for Delta robots that is suitable for real industrial environments.Based on this system,a deep reinforcement learning algorithm for obstacle avoidance path planning in Delta robots has been developed,significantly enhancing learning efficiency through an improved intermediate reward mechanism.Experiments on communication and interaction between the digital twin system and the physical robot validate the effectiveness of this method.The system not only enhances the integration of digital twin technology,deep reinforcement learning and robotics,offering an efficient solution for path planning and target grasping inDelta robots,but also underscores the transformative potential of digital twin technology in intelligent manufacturing,with extensive applicability across diverse industrial domains.展开更多
The historical movements of relative sea level(RSL)reflect the geomorphological dynamics around coastal regions in the past,and reconstructing the RSL curve contributes to the prediction of future RSL movements.On the...The historical movements of relative sea level(RSL)reflect the geomorphological dynamics around coastal regions in the past,and reconstructing the RSL curve contributes to the prediction of future RSL movements.On the basis of the sediment sequence and optical stimulated luminescence(OSL)dating data of three boreholes in the Yellow River Delta(YRD),the positions of paleo-coastlines and the movements of RSL in the last 2000 years were reconstructed.The main results are as follows:1)the YRD coast transformed from a tide-dominated silty coast to a wave-dominated sandy coast and back to a tide-dominated silty coast in the last 2000 years.2)The sand layers consisting of shell fragments indicated the locations of the coastline in 1855 AD,893 AD,and 40 BC,and their top elevations were close to the mean high water level in the corresponding years.3)The mean sea level elevation in 79 BC,1019 AD,and 1800 AD relative to the modern sea level was -4.52,-4.52,and-2.92 m,respectively.4)The RSL was almost stagnant during 79 BC-1019 AD,rose slowly during 1019-1800 AD due to the reverse change of global climate from the Little Ice Age to the Medieval Warm Period,and rose significantly after 1800 AD due to the warm period.5)The movement of RSL controlled the surface slope of YRD,which was a slope of approximately 0.022‰ at 893 AD,an inverted slope of 0.144‰ at 1855 AD,and a slope of 0.075‰ recently.These findings indicate that the modern YRD is far from being abandoned in the future,providing a historical geomorphological basis for the management of the Yellow River Estuary.展开更多
基金supported by an Open Fund of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University, PLN1503)the National Natural Science Foundation of China (Nos. 41602145, 41402125, and 41602117)Scientific Research Starting Project of SWPU (No. 2014QHZ008)
文摘Muddy baffles are one of the major geological factors controlling the underground fluid flow as well as the remaining oil distribution. This study used detailed drilling data from the E1f1 reservoir in the X Oilfield, Subei Basin, China, to investigate the hierarchical muddy baffles developed on lacustrine delta fronts and their precise cross-well correlation.According to the theories on allogenic and autogenic cycles as well as the genesis and scales of muddy baffles, five orders of muddy baffles were classified, which provided various degrees of difficulty when attempting interwell correlation. Under the guidance of a reliable stratigraphic model, the precise cross-well correlation of muddy baffles could be achieved and the key point of establishment of this stratigraphic model was to calculate foreset angles of hierarchical muddy baffles during deposition. During calculation, the relationships between sediment flow direction, higher-order strata dipping direction,well types and well trajectory direction should all be taken into consideration and some other angles（referred to here as θ1,θ2 and θ3） should also be measured. Such new methods of cross-well correlation for hierarchical muddy baffles could greatly reduce the uncertainties and multiple solutions, which in turn would be significant for efficient development and oil recovery enhancement in the reservoirs.
基金financially supported by National Natural Science Foundation of China(Grant No.41272159 and 41372123)
文摘Shallow lacustrine delta front （SLDF） comprises mainly sheetlike subaqueous distributary channels （SDC） formed in shallow, gentle, and tectonically steady slope （Cai and Zhu, 2011）. SDC proves an important hydrocarbon reservoir type in the Daqing oilfield, Changqing oilfield, and the newly discovered Moxizhuang oilfield in Central Junggar Basin. However, SDC tends to prograde quickly and move laterally frequently,
基金supported by Research Foundation of China University of Petroleum-Beijing at Karamay(No.XQZX20210004)。
文摘Changes in water level are one of the important factors controlling the constructive characteristics of deltas.The paper studies the influence of water level changes on sand bodies in the third member of the Shahejie Formation(Es3)on the gentle southern slope of the Gubei Sag,Bohai Bay Basin and draw some conclusions that,for complex sand bodies,with the increase in water level the distributary channels bifurcate frequently,from a simple branching shape to a network shape along with the increase in the development of crevasse splays,mouth bars and sheet sands.For single sand bodies,with an increase in water level in the slope zone of the lake basin close to the source area,the superimposition style transitioned from vertical cutting-stacking and lateral isolation to vertical stitching,isolation and lateral stitching.However,in the central zone of the lake basin far from the source area,the superimposition style transitioned from vertical stitching and lateral stitching to vertical isolation and lateral isolation.When water level stays stable,the greater the distance from the source area the greater the disaggregation ratio of a single sand body.At the same distance from the source area,higher water level tends to result in greater disaggregation ratio of a single sand body.
文摘Based on the abundant information from drilling, cores, and logging, the influence of topography, size of rivers and lakes, climate changes and the lake level＇s fluctuation on the sandbodies at shallow-water delta front are systematically summarized and the sedimentary dynamic processes are analyzed. The interwell communication among the sandbodies and their planar distribution revealed from the hydrodynamic features of the development wells are integrated during the analysis. The fundamental requirements for the development of the shallow-water delta included flat topography and uniform subsiding rate. The delta plain was connected smoothly with the wide delta front and predelta, without the three-fold structure of topset, foreset, and bottomset as defined in the Gilbert Delta Model. Because of the weak fluvial effect and the lake energy is strong, the small and scattered shallow-water delta is destroyed by the scouring-backwashing, coastal current, and lake wave, resulting in the coastal sheet deposition. As the fluvial effect became stronger and the lake energy became weaker, the shape of the shallow-water deltas transferred from sheets to lumps and then branches.
基金Supported by the National Natural Science Foundation of China(41772101)China National Science and Technology Major Project(2017ZX05009001-002)
文摘Core, well logging and seismic data were used to investigate sandbody architectural characteristics within Lower Member of Minghuazhen Formation in Neogene, Bohai BZ25 Oilfield, and to analyze the sedimentary microfacies, distribution and internal architecture characteristics of the bar finger within shoal water delta front. The branched sand body within shoal water delta front is the bar finger, consisting of the mouth bar, distributary channel over bar, and levee. The distributary channel cuts through the mouth bar, and the thin levee covers the mouth bar which is located at both sides of distributary channel. The bar finger is commonly sinuous and its sinuosity increases basinward. The distributary channel changes from deeply incising the mouth bar to shallowly incising top of the mouth bar.The aspect ratio ranges from 25 to 50 and there is a double logarithmic linear positive relationship between the width and thickness for the bar finger, which is controlled by base-level changing in study area. For the bar finger, injection and production in the same distributary channel should be avoided during water flooding development. In addition, middle–upper distributary channel and undrilled mouth bar are focus of tapping remaining oil.
基金supported by Study on Modeling of Reservoir Configuration and Distribution of Remaining Oil (No. P15037)
文摘1 Introduction The shallow water delta reservoir in South Wen 79Block is in the stage of high water-cut stages,and is still on the rise.The degree of recovery is low,preferredflowing path is developed and surplus oil is generally distributed with local enrichment(Zhang,2009).The potential of surplus oil is considerable,while the difficulty is also great.And the basis of effective tapping for
基金The National Natural Science Foundation of China under contract Nos 41872112 and 42077410the Key Research Project of Higher Education Institutions in Henan University under contract No. 20A170010+1 种基金the Program for Innovative Research Team (in Science and Technology) of Henan Polytechnic University under contract No. T2022-05the Foundation of Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Mineral under contract No. DMSM2018027。
文摘Ichnofossils are well developed in clastic rock reservoirs in marine and transitional facies, which can considerably change the physical properties of the reservoir. However, this influence is not well understood, raising an important problem in the effective development of petroleum reservoirs. This paper analyzes continental shelf margin delta reservoirs through core observation, cast thin section observation and reservoir physical property test. Some important scientific insights are obtained:(1) The presence of Cruziana ichnofacies, including Asterosoma, Ophiomorpha, Planolites, Skolithos, Thalassinoides, and other ichnofossils can be used to identify in subaqueous distributary channels, subaqueous levee, frontal sheet sand, abandoned river channels, crevasse channels, main channels and channel mouth bars. Considerable differences in the types of ichnofossils and the degree of bioturbation can be observed in the different petrofacies.(2) Ichnofossils and bioturbation play a complex role in controlling reservoir properties. The reservoir physical properties have the characteristics of a decrease–increase–decrease curve with increasing bioturbation degree. This complex change is controlled by the sediment mixing and packing of bioturbation and the diagenetic environment controlled by the ichnofossils.(3) Sea-level cycle changes affect the modification of the reservoir through sediment packing. Bioturbation weakens the reservoir's physical property when sea level slowly rises and improves the reservoir's physical property when base level slowly falls.
文摘Recently the explored reserves submitted in the oil field mainly situate at the end of deposit in delta front area. During the exploitation and production, problems mainly show on lithologic deposit, for example, reserves are low and difficulty of producing is huge. Based on results of sand body dissection of dense well network of developed oil deposit, and combined with explored reserves, this article researches a relation between extent of well control and reserves precision of explored reserves of lithologic deposit in delta front area by well diluted method. This article has significant influence on objectively understanding our unexploited
基金supported by The Embassy of the Royal Kingdom of the Netherlands in Dhaka,The Embassy of France in Dhaka,and Bangabandhu Science and Technology Fellowship Trust,MoST,Bangladesh。
文摘During the non-breeding season(September-April),Black-tailed Godwits(Limosa limosa)are commonly seen in coastal and inland wetlands of the Ganges-Brahmaputra-Meghna Delta in Bangladesh.We hypothesize that the Ganges-Brahmaputra-Meghna Delta,at the overlap between the Central Asian and East Asian-Australasian flyways,may host three subspecies that breed in disjunct areas of temperate and northern Asia:L.l.limosa,L.l.melanuroides,and L.l.bohaii.We used mitochondrial DNA(mt DNA)haplotype network and biometric analysis to determine subspecies in captured individuals,and deployed GPS-GSM transmitters to verify breeding areas of individuals with subspecies assignments.To test for differential habitat preferences,we sampled birds at two ecologically distinct habitats known to host the largest concentrations of non-breeding Black-tailed Godwits in Bangladesh:Nijhum Dweep National Park,a tidal coastal habitat with brackish water on the south-central coast,and Tanguar Haor(‘backmarsh'),a seasonal freshwater floodplain in the north.During the non-breeding seasons of 2021-2022 and 2022-2023,we sampled and measured 93 Black-tailed Godwits,54 of which were equipped with GPS-GSM transmitters.Our mt DNA haplotype network analysis confirmed the presence of limosa,melanuroides,and bohaii subspecies at the study sites.Thus,indeed,Black-tailed Godwits subspecies,despite having distinct breeding ranges,exhibit(partially)overlapping non-breeding ranges in Asia.The subspecies composition differed significantly between sites,with limosa and bohaii dominating in Tanguar Haor and melanuroides in Nijhum Dweep.Of the 21 individuals that were tracked to their breeding grounds,18 migrated to the expected breeding range of their respective subspecies.However,one bird with a limosa haplotype migrated to a known breeding area of bohaii,whereas two birds with melanuroides haplotypes migrated to the supposed breeding range of limosa.Therefore,while ecological factors at both ends of the flyways may shape the morphological and behavioural differences between Black-tailed Godwit subspecies,their delineations and possible gene flow require further studies.
文摘Rationale: The contamination of soil with crude oil poses significant environmental and ecological threats. Bioremediation, particularly through the use of organisms like Pleurotus ostreatus (mushroom) and Eisenia fetida (earthworm), has emerged as a promising approach to mitigate crude oil pollution. Understanding the effectiveness of these organisms in reducing hydrocarbon levels in contaminated soil is crucial for devising sustainable remediation strategies. Objectives: This study aimed to evaluate the efficacy of Pleurotus ostreatus and Eisenia fetida in remediating crude oil-polluted soil. Specifically, it sought to assess the hydrocarbon profiles in soil treated with these organisms across varying concentrations of crude oil pollution. Method: Crude oil concentration levels ranging from 0% to 10% were applied to soil samples alongside control treatments, including soil only, soil with earthworms, and soil with mushrooms. Each treatment was replicated five times using a randomized complete block design. Standard methods were employed to determine the hydrocarbon contents of the soil. Results: The results indicated a significant increase (P Pleurotus ostreatus and Eisenia fetida exhibited noteworthy reductions in these hydrocarbon levels. At the three-month mark, mushrooms demonstrated a remarkable ability to reduce hydrocarbon content by 70% - 90% compared to the pollution treatment. In contrast, earthworms exhibited minimal potential for hydrocarbon reduction, particularly at both three and six-month intervals. For instance, TOC reduction reached a maximum of 96% with mushroom treatment and 85% with earthworm treatment at 5% crude oil pollution over six months. Conclusion: The findings highlight the effectiveness of Pleurotus ostreatus in significantly reducing hydrocarbon levels in crude oil-polluted soil compared to Eisenia fetida. Mushroom-treated soils consistently exhibited substantial reductions in TOC, TPH, TOG, PAH, and THC over the study period, suggesting their potential as a viable bioremediation agent. In contrast, while earthworms showed some capability in reducing hydrocarbon content, their effectiveness was comparatively limited. Recommendation: Based on the results, it is recommended to utilize Pleurotus ostreatus for the bioremediation of crude oil-polluted soils. Further research could explore optimizing remediation protocols involving mushroom-based treatments for enhanced efficiency. Statement of Significance: This study contributes valuable insights into the application of bioremediation techniques for mitigating crude oil contamination in soil. The demonstrated efficacy of Pleurotus ostreatus underscores its potential as a sustainable and eco-friendly solution for remediating hydrocarbon-polluted environments, offering a promising avenue for environmental restoration and conservation efforts.
基金Supported by the Shandong Provincial Natural Science Foundation General Project,No.ZR2020MH248.
文摘BACKGROUND Objective and accurate assessment of blood loss during pancreaticoduodenectomy(PD)is crucial for ensuring the safety and efficacy of the procedure.While the visual method remains the most common clinical metric,many scholars argue that it significantly differs from actual blood loss and is inherently subjective.AIM To assess blood loss in PD via delta hemoglobin(ΔHb)and compare it with the visual method to predict bleeding-related risk factors.METHODS In this retrospective analysis,1722 patients who underwent PD from 2017 to 2022 at Shandong Provincial Hospital were divided into three groups:Open PD(OPD),laparoscopic PD(LPD),and conversion to OPD(CTOPD).IntraoperativeΔHb(IΔHb)was calculated via preoperative and 72-hour-postoperative hemoglobin concentrations,and its association with visually obtained estimated blood loss(EBL)was analyzed.PerioperativeΔHb(PΔHb)was calculated via preoperative and predischarge hemoglobin concentrations.We compared the differences in IΔHb and PΔHb among the three groups,and performed univariate and multi-variate regression analyses of IΔHb and PΔHb.RESULTS The preoperative general information of patients showed no statistically si-gnificant difference among the three groups(P>0.05).The IΔHb in the OPD,LPD,and CTOPD groups were 22.00(12.00,36.00),21.00(10.00,33.00),and 33.00(18.12,52.24)g/L,respectively;And the PΔHb in the OPD,LPD,and CTOPD groups were 25.87(13.51,42.00),25.00(14.00,45.00),and 37.48(21.64,59.65)g/L,respectively,values significantly differed(P<0.05).IΔHb and EBL were significantly correlated(r=0.337,P<0.001).The results of univariate and multivariate regression analyses indicated that American Society of Anesthesiologists(ASA)classification IV[95%confidence interval(CI):2.330-37.811,P=0.049]and preoperative total bilirubin>200μmol/L(95%CI:2.805-8.673,P<0.001)were independent risk factors for IΔHb(P<0.05),and ASA classification IV(95%CI:45.934-105.485,P<0.001),body mass index>24 kg/m2(95%CI:1.285-9.890,P=0.011),and preoperative total bilirubin>200μmol/L(95%CI:6.948-16.797,P<0.001)were independent risk factors for PΔHb(P<0.05).CONCLUSION There is a correlation between IΔHb and EBL in PD,so we can assess the patients’intraoperative blood loss by theΔHb method.ASA classification IV,body mass index>24 kg/m²,and preoperative total bilirubin>200μmol/L increased perioperative bleeding risk.
基金funded by the 2022-2023 Australian Centre for International Agricultural Research(ACIAR)Alumni Research Support Facility(ARSF)programme:“Farmers’adaptive capacity and agricultural transformation in the Vietnamese Mekong Delta:understanding and supporting value chain engagement”the ACIAR-funded project“Farmer options for crops under saline conditions(FOCUS)in the Mekong River Delta,Vietnam”(SLaM/2018/144)to this study.
文摘Agricultural production(especially intensive rice production)is a primary income source for over 2.0×10^(7) people in the Vietnamese Mekong River Delta.However,adverse climate change impacts,socio-economic change,and high dependence on farm inputs for intensive production constrain the longer-term sustainability of rice systems.Government and agribusiness actors are encouraging more farmers to grow non-rice crops and supporting the upscaling of alternative crops to paddy rice.We used a qualitative approach to investigate the value chain characteristics,as well as constraints and opportunities of alternative crops via two case studies(baby corn and honeydew melon)in An Giang and Hau Giang provinces,Vietnam.Data collection involved focus group discussions with local farmers and interviews with farmers and industry experts.Thematic analysis was used to compile the findings,and the results were validated with local government staff.The baby corn value chain featured on-going and stable market demand(including value-addition)and better vertical coordination(e.g.,written contracts and financial support).The honeydew melon value chain featured positive relationships between farmers and traders despite less-developed vertical coordination.There are opportunities for value chain engagement through product quality certification,value-addition,and accessing high-value domestic and export markets.However,farmers require crop-specific and generic support from private and public sectors.Increased labour requirements and limited access to finance and credit limit value chain participation.Upscaling and marketing alternative crops can enhance farmer profitability and support non-farming agricultural business establishment,economic growth,and community development.Efficient value chains will be critical to ensure the adoption of alternative crops and development of crop-specific agribusiness models.These findings can inform policy-makers and change facilitators in designing targeted interventions to support the adoption of alternative crops in the study area as well as in Vietnam and globally.
文摘The Anhui Provincial Bureau of Statistics announced in early March that Hefei’s permanent resident population had reached 10.002 million in 2024,surpassing the 10-million mark for the first time.This achievement positions Hefei as the fourth most populated city in the Yangtze River Delta region,following Shanghai,Suzhou in Jiangsu Province,and Hangzhou in Zhejiang Province.
基金supported in part by the National Natural Science Foundation of China under Grants 62303098 and 62173073in part by China Postdoctoral Science Foundation under Grant 2022M720679+1 种基金in part by the Central University Basic Research Fund of China under Grant N2304021in part by the Liaoning Provincial Science and Technology Plan Project-Technology Innovation Guidance of the Science and Technology Department under Grant 2023JH1/10400011.
文摘Despite its immense potential,the application of digital twin technology in real industrial scenarios still faces numerous challenges.This study focuses on industrial assembly lines in sectors such as microelectronics,pharmaceuticals,and food packaging,where precision and speed are paramount,applying digital twin technology to the robotic assembly process.The innovation of this research lies in the development of a digital twin architecture and system for Delta robots that is suitable for real industrial environments.Based on this system,a deep reinforcement learning algorithm for obstacle avoidance path planning in Delta robots has been developed,significantly enhancing learning efficiency through an improved intermediate reward mechanism.Experiments on communication and interaction between the digital twin system and the physical robot validate the effectiveness of this method.The system not only enhances the integration of digital twin technology,deep reinforcement learning and robotics,offering an efficient solution for path planning and target grasping inDelta robots,but also underscores the transformative potential of digital twin technology in intelligent manufacturing,with extensive applicability across diverse industrial domains.
基金supported financially by the National Natural Science Foundation of China(Nos.42330406 and 42476163)。
文摘The historical movements of relative sea level(RSL)reflect the geomorphological dynamics around coastal regions in the past,and reconstructing the RSL curve contributes to the prediction of future RSL movements.On the basis of the sediment sequence and optical stimulated luminescence(OSL)dating data of three boreholes in the Yellow River Delta(YRD),the positions of paleo-coastlines and the movements of RSL in the last 2000 years were reconstructed.The main results are as follows:1)the YRD coast transformed from a tide-dominated silty coast to a wave-dominated sandy coast and back to a tide-dominated silty coast in the last 2000 years.2)The sand layers consisting of shell fragments indicated the locations of the coastline in 1855 AD,893 AD,and 40 BC,and their top elevations were close to the mean high water level in the corresponding years.3)The mean sea level elevation in 79 BC,1019 AD,and 1800 AD relative to the modern sea level was -4.52,-4.52,and-2.92 m,respectively.4)The RSL was almost stagnant during 79 BC-1019 AD,rose slowly during 1019-1800 AD due to the reverse change of global climate from the Little Ice Age to the Medieval Warm Period,and rose significantly after 1800 AD due to the warm period.5)The movement of RSL controlled the surface slope of YRD,which was a slope of approximately 0.022‰ at 893 AD,an inverted slope of 0.144‰ at 1855 AD,and a slope of 0.075‰ recently.These findings indicate that the modern YRD is far from being abandoned in the future,providing a historical geomorphological basis for the management of the Yellow River Estuary.
