The relative permeability curve has been measured with simulation oil (refined oil) and gas (nitrogen or air) at room temperature and a lowpressure, both of which are very important parameters for depicting the flow ...The relative permeability curve has been measured with simulation oil (refined oil) and gas (nitrogen or air) at room temperature and a lowpressure, both of which are very important parameters for depicting the flow of fluid through porous media in a hydrocarbon reservoir. This basic measurement is often applied in exploitation evaluation, but the underground conditions with high temperature and pressure, and the phase equilibrium of oil and gas, are not taken into consideration when the relative permeability curve is tested. There is an important theoretical and practical sense in testing the diphase relative permeability curve of the equilibrium of oil and gas under the conditions of high temperature and pressure. The test method for the relative permeability curve is proposed in this paper. The relative permeability of the equilibrium of oil and gas and the standard one are tested in two fluids, and the differences between these two methods are stated. The research results can be applied to the simulation and prediction of CVD in long cores and then the phenomenon can better explain that the recovery of condensate gas rich in condensate oil is higher than that of CVD test in PVT. Meanwhile, the research shows that the relative permeability curve of equilibrium oil and gas is sensitive to the rate of exploitation, and the viewpoint proves that an improved gas recovery rate can properly increase the recovery of condensate oil.展开更多
Thermal power generation systems have stringent requirements for water and steam quality,i.e.,condensate water quality is one of the critical issues.In this paper,we designed a two-layer model based on an autoencoder ...Thermal power generation systems have stringent requirements for water and steam quality,i.e.,condensate water quality is one of the critical issues.In this paper,we designed a two-layer model based on an autoencoder and expert knowledge to achieve the early warning and causal analysis of condensate water quality abnormalities.An early warning model using an autoencoder model is built based on the historical data affecting the condensate water quality.Next,an analytical model of condensate water quality abnormalities was then developed by combining expert knowledge and trend test algorithms.Two different datasets were used to test the proposed model,respectively.The accuracy of the autoencoder model in the short-period test set is 88.83%,which shows that the early warning model can accurately analyze the condensate water quality data and achieve the purpose of early warning.For the long-time period test set,the model can correctly identify each abnormality and simultaneously indicates the cause of the abnormal condensate water quality.The proposed model can correctly identify abnormal working conditions and it is applicable to other thermal power plants.展开更多
Condensate gas reservoirs have attracted increasing attention in recent years due to their significant development potential and dual value from both natural gas and condensate oil.However,their exploitation is often ...Condensate gas reservoirs have attracted increasing attention in recent years due to their significant development potential and dual value from both natural gas and condensate oil.However,their exploitation is often hindered by the dual challenges of retrograde condensation and water invasion,which can markedly reduce recovery factors.CO_(2) injection offers a promising solution by alleviating condensate blockage,suppressing water influx,and simultaneously enabling geological CO_(2) storage.Accordingly,research on optimizing CO_(2) injection to mitigate formation damage is critical for the efficient development and management of edge-and bottom-water condensate gas reservoirs.In this study,a long-core displacement mechanism model was constructed using CMG-GEMTM andWinPropTM.The model simulates reservoir depletion from initial conditions(41.2 MPa,102.5℃)to the current reservoir pressure(13.5 MPa),followed by gas injection.It was then upscaled to the edge-and bottom-water reservoir scale to capture complex fluid phase behavior,enabling a multi-factor coupled optimization of CO_(2) injection strategies.Model reliability was verified through comparison with core experimental results.Subsequently,the effects of geological parameters(e.g.,reservoir permeability and rhythmic heterogeneity)and engineering parameters(e.g.,injection pressure and rate)on reservoir performance were systematically evaluated.The results indicate that appropriate target zone selection and optimization of injection pressure and rate—avoiding formation fracturing and preventing gas channeling—can substantially improve reservoir development outcomes.Applying this approach to the K Gas Reservoir,the optimal strategy involved injecting CO_(2) at a rate of 5×10^(4) m^(3)/d,restoring pressure to 22.5 MPa in a composite rhythmic reservoir with an average permeability of 10 mD.This scheme increased the condensate oil recovery factor by 18.7 percentage points(from 43.9%to 60.9%)while reducing the water-cut rise rate by approximately 34%.展开更多
Shale gas reservoirs typically contain numerous nanoscale pores,with pore size playing a significant role in influencing the gas behavior.To better understand the related mechanisms,this study employs the Gauge-GEMC m...Shale gas reservoirs typically contain numerous nanoscale pores,with pore size playing a significant role in influencing the gas behavior.To better understand the related mechanisms,this study employs the Gauge-GEMC molecular simulation method to systematically analyze the effects of various pore sizes(5,10,20,and 40 nm)on the phase behavior and dew point pressure of the shale gas reservoir components.The simulation results reveal that when pore sizes are smaller than 40 nm,the dew point pressure increases significantly as the pore size decreases.For instance,the dew point pressure in 5 nmpores is 20.3%higher than undermacroscopic conditions.Additionally,larger hydrocarbon molecules exhibit a tendency to aggregate in smaller pores,particularly in the 5–10 nm range,where the relative concentration of heavy hydrocarbons(C_(4+))increases markedly.Moreover,as the pore size becomes larger,the component distribution gradually aligns with experimental results observed under macroscopic conditions.This study demonstrates that pore effects are more pronounced for smaller sizes,directly influencing the aggregation of heavy hydrocarbons and the rise in dew point pressure.These phenomena could significantly impact the diffusivity of shale gas reservoirs and the recovery of condensate gas.The findings provide new theoretical insights into phase behavior changes in nanopores,offering valuable guidance for optimizing shale gas reservoir extraction strategies.展开更多
We propose schemes for realizing various forms of bright solitons,bright vortices,and breathing solitons in a non-resonant,incoherently pumped exciton-polariton condensate system by introducing a two-dimensional Moir&...We propose schemes for realizing various forms of bright solitons,bright vortices,and breathing solitons in a non-resonant,incoherently pumped exciton-polariton condensate system by introducing a two-dimensional Moirélattice external potential.The symmetric shape of the soliton,at the center of the potential field is determined by the rotation angle of the twodimensional Moirélattice external potential.Within a specific range of rotation angles,the stability of the soliton is governed by the depth of the second sub-lattice.These two parameters mutually influence and constrain the soliton’s characteristics,and under certain rotation angles and sub-lattice depths,a bright vortex can be formed.At low pumping levels and with carefully chosen peak-to-valley positions in the external potential,the rotation angle becomes the primary factor controlling the distinct forms of breathing bright solitons.Our proposal provides effective schemes for the formation and control of various types of bright solitons and bright vortices in systems employing Moirélattice external potentials.This scheme for realizing polariton Bose-Einstein condensates(BECs)within a Moirélattice external potential also holds promise for advancing research in fields such as superfluidity and superconductivity.展开更多
0 INTRODUCTION Gas injection refers to the natural gas charging into pre-existing oil reservoirs,which often leads to notable changes in gas-oil ratio(GOR),oil density,and phase states,depending on the pressure-temper...0 INTRODUCTION Gas injection refers to the natural gas charging into pre-existing oil reservoirs,which often leads to notable changes in gas-oil ratio(GOR),oil density,and phase states,depending on the pressure-temperature condition of the reservoirs(Meulbroek et al.,1998;Blanc and Connan,1994;Evans et al.,1971).展开更多
There are limited quantitative studies on condensate gas using microfluidics under high-pressure and high-temperature conditions.This study employed microfluidics chips based on real porous media structures to conduct...There are limited quantitative studies on condensate gas using microfluidics under high-pressure and high-temperature conditions.This study employed microfluidics chips based on real porous media structures to conduct constant volume depletion experiments and investigate the microscopic mechanisms of condensate gas recovery.The aim of the experiments was to reveal the phase-behavior differences between bulk-phase gas and gas contained in porous media.The results revealed that condensate oil recovery in microfluidics experiments was higher than that in PVT cell tests,and nonuniform condensation and evaporation were exclusively observed in the microfluidics experiments.Furthermore,lower pore connectivity resulted in higher depletion recovery,while more developed fractures led to reduced recovery.Specifically,the chip with fewer fractures achieved the highest recovery(71.15%),whereas the highly fractured chip exhibited the lowest recovery(56.11%).These findings demonstrate that oil saturation during the process of constant volume depletion(CVD)of gas condensate within porous media is lower than that observed in the PVT cell,thus providing experimental evidence for optimizing condensate gas development in field applications.展开更多
To investigate the possible geometric structure of the proton,an improved stringy proton model is constructed beyond the smallest distance approximation and treats the constituent(up and down)quark-initiated gluon tub...To investigate the possible geometric structure of the proton,an improved stringy proton model is constructed beyond the smallest distance approximation and treats the constituent(up and down)quark-initiated gluon tubes separately,where the constituent quarks are connected by gluon tubes which merge at the Fermat point of the quark triangle.The exclusive diffractive vector meson production process in electron-proton deep inelastic scattering is used to test the stringy structure of the proton.We calculate the coherent and incoherent differential cross sections of the exclusive diffractive J/Ψphotoproduction in the framework of Color Glass Condensate.The results show that our calculations are in good agreement with HERA data.Especially,our results give a better description of the HERA data at small t as compared to the ones from the hot spot model where the constituent quarks are independently distributed in the proton.Meanwhile,the radius of the proton resulting from the improved stringy proton model is coincident with the one from fitting to the data from GlueX Collaboration at Jefferson Lab,which indicates that the predictive power of the stringy proton model is significantly improved once it goes beyond the smallest distance approximation and treats the constituent quarks separately,instead of using the same profile for the up and down quarks initiated gluon tubes.Moreover,we assume that the transverse shape of the gluon tube satisfies Gaussian distribution,and explore the distribution width of the individual gluon tubes.We find an interesting result that the up quark-initiated gluon tube seems to have a larger distribution width than the down quarkinitiated gluon tube,which is favored by the HERA data.展开更多
This paper introduces a novel numerical method based on an energy-minimizing normalized residual network(EMNorm Res Net)to compute the ground-state solution of Bose-Einstein condensates at zero or low temperatures.Sta...This paper introduces a novel numerical method based on an energy-minimizing normalized residual network(EMNorm Res Net)to compute the ground-state solution of Bose-Einstein condensates at zero or low temperatures.Starting from the three-dimensional Gross-Pitaevskii equation(GPE),we reduce it to the 1D and 2D GPEs because of the radial symmetry and cylindrical symmetry.The ground-state solution is formulated by minimizing the energy functional under constraints,which is directly solved using the EM-Norm Res Net approach.The paper provides detailed solutions for the ground states in 1D,2D(with radial symmetry),and 3D(with cylindrical symmetry).We use the Thomas-Fermi approximation as the target function to pre-train the neural network.Then,the formal network is trained using the energy minimization method.In contrast to traditional numerical methods,our neural network approach introduces two key innovations:(i)a novel normalization technique designed for high-dimensional systems within an energy-based loss function;(ii)improved training efficiency and model robustness by incorporating gradient stabilization techniques into residual networks.Extensive numerical experiments validate the method's accuracy across different spatial dimensions.展开更多
We consider two pointlike static impurities without direct interaction immersed in a three-dimensional Bose–Einstein condensate(BEC)at zero temperature.By solving the Gross–Pitaevskii(GP)equation in a perturbative m...We consider two pointlike static impurities without direct interaction immersed in a three-dimensional Bose–Einstein condensate(BEC)at zero temperature.By solving the Gross–Pitaevskii(GP)equation in a perturbative manner,we calculate the ground state energy in the region where the atom–impurity interaction is assumed to be weak.We obtain an analytical expression for the spatial distribution of atom number density and the effective force between these two impurities.The effective force is found to be closely related to the strength of the atom–impurity interaction and the relative distance between these two impurities.Two critical relative distances are found between the two impurities.The first one corresponds to the vanishing of the perturbed energy with impurities,although the effective force between the two impurities still exists.At the second critical value,the energy of the impurities changes linearly with the atom–impurity interaction;otherwise,it changes quadratically with the atom–impurity interaction.展开更多
The development of gas condensate reservoirs with a large gas cap,thin oil rim,strong bottom water,and natural barriers faces numerous challenges,including reservoir heterogeneity,coning effects,phase changes,and mult...The development of gas condensate reservoirs with a large gas cap,thin oil rim,strong bottom water,and natural barriers faces numerous challenges,including reservoir heterogeneity,coning effects,phase changes,and multiphase flow dynamics.The influx of gas and water may lead to a low recovery of the oil rim,while reservoir heterogeneity and natural barriers further exacerbate the uneven distribution of reservoir fluid,complicating development strategies.This paper aims to investigate innovative and effective development strategies for this type of reservoir.A detailed,proportionally scaled numerical simulation is performed based on the experimental results of an artificial sand-filled model,providing novel insights into the dynamic behavior of these reservoirs.By understanding the phase behavior and fluid flow characteristics of the reservoir,the study simulates various strategies for the rational and efficient development of the gas condensate reservoir.These strategies include well patterns and completions,the decision to develop the oil rim or gas cap,depletion rates,the bottom water control,and gas injection.The results show that horizontal wells or highly deviated wells are more suitable for the development of the oil rim,as they provide larger control ranges.The presence of strong bottom water is advantageous for displacement energy supply and pressure maintenance,but it intensifies water coning effects,leading to an earlier breakthrough and a sharp production decline.Therefore,it is preferable to apply highly deviated wells at the oil-gas contact,developing the oil rim at lower rates and smaller pressure gradients,followed by developing the gas cap.This approach can reduce water coning effects and improve recovery,with oil and gas recovery reaching 24.4%and 67.95%,respectively,which is an increase of 16.74%and 17.84%compared to direct depletion development of the gas cap.Due to the strong water bottom,continuous gas injection at the top of the reservoir becomes challenging.This study introduces gas assisted gravity drainage with water control technology,a novel and highly effective approach that addresses the impact of bottom water coning effects on the oil and gas zones and overcomes the limitations of gas flooding in reservoirs with strong bottom water.This method can significantly improve oil and gas recovery,achieving recovery of 39.74%and 84.50%,respectively.Compared to the conventional depletion strategy of sequential oil rim and gas cap development,this method achieves additional improvements of 15.33%and 16.55%in oil and gas recovery,respectively.展开更多
Kármán vortex street not only exists in nature,but also widely appears in engineering practice,which is of great significance for understanding superfluid.Parity-time(PT)symmetric potential provides a good p...Kármán vortex street not only exists in nature,but also widely appears in engineering practice,which is of great significance for understanding superfluid.Parity-time(PT)symmetric potential provides a good platform for the study of Kármán vortex streets.In this paper,different patterns of vortex shedding formed behind PT symmetric potential in Bose-Einstein condensate(BEC)are simulated numerically.Kármán vortex streets and others are discovered to emerge in the wake of a moving obstacle with appropriate parameters.Compared with BEC without PT symmetric potential,the frequency and amplitude of the drag force are more complex.The parametric regions of the combined modes are scattered around the Kármán vortex street.Numerical simulations indicate that the imaginary part of the PT symmetric potential affects the vortex structure patterns.Finally,we proposed an experimental protocol that may observe a Kármán vortex street.展开更多
We investigate the chaotic and regular spatial structures of Bose–Einstein condensates(BECs)with a spatially modulated atom-atom interaction and without an external trapping potential.A BEC with a spatially modulated...We investigate the chaotic and regular spatial structures of Bose–Einstein condensates(BECs)with a spatially modulated atom-atom interaction and without an external trapping potential.A BEC with a spatially modulated atom-atom interaction is equivalent to being constrained by a nonlinear optical lattice.Theoretical analyses show the existence of a steady atomic current in the BEC with a spatially varying phase.Under perturbative conditions,the Melnikov chaos criteria of BECs with a spatially varying phase and a constant one are theoretically obtained,respectively.When the perturbative conditions cannot be satisfied,for a repulsive BEC with a spatially varying phase,numerical simulations demonstrate that changing the initial condition can eliminate the chaotic spatial structure and then the system transitions into a biperiodic spatial structure.Increasing the chemical potential can result in a transition from the biperiodic spatial structure to a single-periodic spatial structure.For an attractive BEC with a spatially varying phase,numerical simulations show that decreasing the chemical potential can lead to a high atomic density,but when the wave number of the laser inducing the optical Feshbach resonance exceeds a critical value,the atomic density falls back to a finite range.Regardless of whether the BEC has a spatially varying phase or a constant one,modulating the laser wave number can effectively suppress the chaotic spatial structure in the BEC and then force it into a regular spatial structure.展开更多
Global climate change seriously threatens food security.To address this challenge,breeders have achieved remarkable results using multiple breeding strategies and technologies.In recent years,the application of biomol...Global climate change seriously threatens food security.To address this challenge,breeders have achieved remarkable results using multiple breeding strategies and technologies.In recent years,the application of biomolecular condensates to crop improvement has remained in its early stages.Nevertheless,growing evidence indicates their crucial roles in regulating crop development and stress adaptation.This review synthesizes recent advances in understanding biomolecular condensate functions across key plant developmental phases and their regulatory roles in abiotic and biotic stress responses.The regulatory mechanisms associated with these condensates primarily encompass transcriptional regulation,RNA processing and metabolism,translational control,and membrane organelle biogenesis,collectively establishing a solid theoretical foundation for agricultural molecular breeding.In the final section,we discuss the potential applications and challenges of biomolecular condensates in crop improvement.展开更多
We propose a superposed Bessel optical lattice formed by multiple Bessel optical lattices.The static and rotational structures are formed in the presence of a spin-orbit coupling(SOC)interaction in the atomic in Bose...We propose a superposed Bessel optical lattice formed by multiple Bessel optical lattices.The static and rotational structures are formed in the presence of a spin-orbit coupling(SOC)interaction in the atomic in Bose–Einstein condensates are investigated,it is shown that the two structures can be manipulated by adjusting the parameters of the superposed Bessel optical lattices.The results show that the SOC interaction has an important effect on the two structures in the superposed Bessel optical lattices,and the SOC interaction can enhance the robustness of the structures.The Gaussian,toroidal and vortex superposition structures in the superposition lattice are presented,the interference processes in the steady state structures are analyzed,and the effects of SOC interactions on the Gaussian vortex and toroidal vortex structures are investigated,and the angular momentum of the vortex states can be increased by SOC interactions.展开更多
The Josephson effect,an important quantum supercurrent phenomenon,has been extensively studied in superconductors and superfluids.In this paper,we investigate the rich physics of one-dimensional Josephson junctions in...The Josephson effect,an important quantum supercurrent phenomenon,has been extensively studied in superconductors and superfluids.In this paper,we investigate the rich physics of one-dimensional Josephson junctions in a red-detuned optical lattice with sodium(Na)quantum gas.A one-dimensional Josephson array is formed by setting up an optical lattice using a red-detuned laser.By characterizing the dependence of Josephson oscillations of the lattice depth,we experimentally demonstrate the Josephson current.The lattice depth is controlled by altering the lattice power,and our observations are consistent with theoretical predictions.These findings offer valuable insights into quantum coherent transport and the intricate dynamics inherent to superfluidity.展开更多
Utilizing the dissipative Gross-Pitaevskii equation,we investigated the splitting dynamics of triply quantized vortices at finite temperature.Through linear perturbation analysis,we determined the excitation modes of ...Utilizing the dissipative Gross-Pitaevskii equation,we investigated the splitting dynamics of triply quantized vortices at finite temperature.Through linear perturbation analysis,we determined the excitation modes of these vortices across various dissipation parameters.We identified three unstable modes with p=2-,3-and 4-fold rotational symmetries,revealing a significant dynamic transition of the most unstable mode.That is,as the dissipation parameter increases the most unstable mode transitions from the p=2 mode to the p=3 mode.Throughout the entire range of dissipation parameters,the p=4 unstable mode is never the dominant mode.Subsequently,we performed nonlinear numerical simulations of the vortex splitting process.Under random perturbations we confirmed the dynamical transition,and under specific perturbations we confirmed the instability of the p=4 mode.Our findings on the finite temperature dependence of the splitting dynamics of triply quantized vortices are expected to be verifiable in experiments.展开更多
As an important component of light hydrocarbon compounds,alkylbenzene compounds lack indicators to indicate the source of organic matter of light oils and condensates.Forty-one oil samples from the Tarim Basin and Bei...As an important component of light hydrocarbon compounds,alkylbenzene compounds lack indicators to indicate the source of organic matter of light oils and condensates.Forty-one oil samples from the Tarim Basin and Beibuwan Basin were analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GC-TOFMS).The concentration distributions of thirteen light hydrocarbon compounds with organic matter source and sedimentary environment indication were studied.There is no significant difference in the concentrations of 1-methylpropylbenzene(MPB)in all studied oils.However,the concentrations of 2-MPB in the Tarim swamp oils are higher than that in the Beibuwan lacustrine oils and Tarim marine oils.Based on the significant concentration difference of 1-and 2-MPB in all studied oils,1-/2-MPB(MPBr)was proposed as an indicator to identify the source of organic matter in crude oils.The MPBr values greater than 1.5 indicate that the crude oil mainly comes from lower aquatic organisms,bacteria,and algae.The MPBr values greater than 1.0 and less than 1.5 indicate that crude oil was derived from the combined contributions of lower aquatic organisms,bacteria and algae,and terrestrial higher plants.The MPBr values less than 1.0 suggest that the crude oil was mainly derived from terrigenous higher plants.The MPBr values in crude oils basically are not or slightly affected by depositional environment and secondary alteration.The MPBr values can be used to infer the organic matter origin in sediments,especially for the lack of biomarkers of light oils and condensates.展开更多
Introducing PT-symmetric generalized Scarf-Ⅱpotentials into the three-coupled nonlinear Gross-Pitaevskii equations offers a new way to seek stable soliton states in quasi-onedimensional spin-1 Bose-Einstein condensat...Introducing PT-symmetric generalized Scarf-Ⅱpotentials into the three-coupled nonlinear Gross-Pitaevskii equations offers a new way to seek stable soliton states in quasi-onedimensional spin-1 Bose-Einstein condensates.In scenarios where the spin-independent parameter c_(0)and the spin-dependent parameter c_(2)vary,we use both analytical and numerical methods to investigate the three-coupled nonlinear Gross-Pitaevskii equations with PT-symmetric generalized Scarf-Ⅱpotentials.We obtain analytical soliton states and find that simply modulating c_(2)may change the analytical soliton states from unstable to stable.Additionally,we obtain numerically stable double-hump soliton states propagating in the form of periodic oscillations,exhibiting distinct behavior in energy exchange.For further investigation,we discuss the interaction of numerical double-hump solitons with Gaussian solitons and observe the transfer of energy among the three components.These findings may contribute to a deeper understanding of solitons in Bose-Einstein condensates with PT-symmetric potentials and may hold significance for both theoretical understanding and experimental design in related physics experiments.展开更多
We propose a theoretical framework,based on the two-component Gross-Pitaevskii equation(GPE),for the investigation of vortex solitons(VSs)in hybrid atomic-molecular Bose-Einstein condensates under the action of the st...We propose a theoretical framework,based on the two-component Gross-Pitaevskii equation(GPE),for the investigation of vortex solitons(VSs)in hybrid atomic-molecular Bose-Einstein condensates under the action of the stimulated Raman-induced photoassociation and square-optical-lattice potential.Stationary solutions of the coupled GPE system are obtained by means of the imaginary-time integration,while the temporal dynamics are simulated using the fourth-order Runge-Kutta algorithm.The analysis reveals stable rhombus-shaped VS shapes with topological charges m=1 and 2 of the atomic component.The stability domains and spatial structure of these VSs are governed by three key parameters:the parametric-coupling strength(χ),atomicmolecular interaction strength(g_(12)),and the optical-lattice potential depth(V_(0)).By varyingχand g_(12),we demonstrate a structural transition where four-core rhombus-shaped VSs evolve into eight-core square-shaped modes,highlighting the nontrivial nonlinear dynamics of the system.This work establishes a connection between interactions of cold atoms and topologically structured matter waves in hybrid quantum systems.展开更多
基金This paper was subsidized by the 15th National key Sci-Tech Project (NO.2001BA605A02-04-01)
文摘The relative permeability curve has been measured with simulation oil (refined oil) and gas (nitrogen or air) at room temperature and a lowpressure, both of which are very important parameters for depicting the flow of fluid through porous media in a hydrocarbon reservoir. This basic measurement is often applied in exploitation evaluation, but the underground conditions with high temperature and pressure, and the phase equilibrium of oil and gas, are not taken into consideration when the relative permeability curve is tested. There is an important theoretical and practical sense in testing the diphase relative permeability curve of the equilibrium of oil and gas under the conditions of high temperature and pressure. The test method for the relative permeability curve is proposed in this paper. The relative permeability of the equilibrium of oil and gas and the standard one are tested in two fluids, and the differences between these two methods are stated. The research results can be applied to the simulation and prediction of CVD in long cores and then the phenomenon can better explain that the recovery of condensate gas rich in condensate oil is higher than that of CVD test in PVT. Meanwhile, the research shows that the relative permeability curve of equilibrium oil and gas is sensitive to the rate of exploitation, and the viewpoint proves that an improved gas recovery rate can properly increase the recovery of condensate oil.
基金supported by the Jingneng Shiyan Thermal Power Co.,Ltd.(TPRI/TR-CA-006-2023)Huaihe Energy Power Group Co.,Ltd.(TPRI/TR-CA-040-2023)Xi'an Thermal Power Research Institute Co.,Ltd.(TPRI/TR-CA-110-2021A/H1).
文摘Thermal power generation systems have stringent requirements for water and steam quality,i.e.,condensate water quality is one of the critical issues.In this paper,we designed a two-layer model based on an autoencoder and expert knowledge to achieve the early warning and causal analysis of condensate water quality abnormalities.An early warning model using an autoencoder model is built based on the historical data affecting the condensate water quality.Next,an analytical model of condensate water quality abnormalities was then developed by combining expert knowledge and trend test algorithms.Two different datasets were used to test the proposed model,respectively.The accuracy of the autoencoder model in the short-period test set is 88.83%,which shows that the early warning model can accurately analyze the condensate water quality data and achieve the purpose of early warning.For the long-time period test set,the model can correctly identify each abnormality and simultaneously indicates the cause of the abnormal condensate water quality.The proposed model can correctly identify abnormal working conditions and it is applicable to other thermal power plants.
基金supported by the National Natural Science Foundation of China(No.52474047).
文摘Condensate gas reservoirs have attracted increasing attention in recent years due to their significant development potential and dual value from both natural gas and condensate oil.However,their exploitation is often hindered by the dual challenges of retrograde condensation and water invasion,which can markedly reduce recovery factors.CO_(2) injection offers a promising solution by alleviating condensate blockage,suppressing water influx,and simultaneously enabling geological CO_(2) storage.Accordingly,research on optimizing CO_(2) injection to mitigate formation damage is critical for the efficient development and management of edge-and bottom-water condensate gas reservoirs.In this study,a long-core displacement mechanism model was constructed using CMG-GEMTM andWinPropTM.The model simulates reservoir depletion from initial conditions(41.2 MPa,102.5℃)to the current reservoir pressure(13.5 MPa),followed by gas injection.It was then upscaled to the edge-and bottom-water reservoir scale to capture complex fluid phase behavior,enabling a multi-factor coupled optimization of CO_(2) injection strategies.Model reliability was verified through comparison with core experimental results.Subsequently,the effects of geological parameters(e.g.,reservoir permeability and rhythmic heterogeneity)and engineering parameters(e.g.,injection pressure and rate)on reservoir performance were systematically evaluated.The results indicate that appropriate target zone selection and optimization of injection pressure and rate—avoiding formation fracturing and preventing gas channeling—can substantially improve reservoir development outcomes.Applying this approach to the K Gas Reservoir,the optimal strategy involved injecting CO_(2) at a rate of 5×10^(4) m^(3)/d,restoring pressure to 22.5 MPa in a composite rhythmic reservoir with an average permeability of 10 mD.This scheme increased the condensate oil recovery factor by 18.7 percentage points(from 43.9%to 60.9%)while reducing the water-cut rise rate by approximately 34%.
基金financially supported by the Hubei Province Education Department of China(Project Name:Research on the Formation Mechanism and Microscopic Characteristics of Tight Dolomite Reservoirs in Salt Lake Basins:A Case Study of the Xingouzui Formation in the Jianghan Basin,Grant No.B2020032).
文摘Shale gas reservoirs typically contain numerous nanoscale pores,with pore size playing a significant role in influencing the gas behavior.To better understand the related mechanisms,this study employs the Gauge-GEMC molecular simulation method to systematically analyze the effects of various pore sizes(5,10,20,and 40 nm)on the phase behavior and dew point pressure of the shale gas reservoir components.The simulation results reveal that when pore sizes are smaller than 40 nm,the dew point pressure increases significantly as the pore size decreases.For instance,the dew point pressure in 5 nmpores is 20.3%higher than undermacroscopic conditions.Additionally,larger hydrocarbon molecules exhibit a tendency to aggregate in smaller pores,particularly in the 5–10 nm range,where the relative concentration of heavy hydrocarbons(C_(4+))increases markedly.Moreover,as the pore size becomes larger,the component distribution gradually aligns with experimental results observed under macroscopic conditions.This study demonstrates that pore effects are more pronounced for smaller sizes,directly influencing the aggregation of heavy hydrocarbons and the rise in dew point pressure.These phenomena could significantly impact the diffusivity of shale gas reservoirs and the recovery of condensate gas.The findings provide new theoretical insights into phase behavior changes in nanopores,offering valuable guidance for optimizing shale gas reservoir extraction strategies.
基金support from the Natural Science Foundation of Zhejiang Province of China (Grant No. LZ22A050002)the National Natural Science Foundation of China (Grant Nos. 12074343 and 11835011)support from the postdoctoral fellowship of Zhejiang Normal University (Grant No. YS304123952)
文摘We propose schemes for realizing various forms of bright solitons,bright vortices,and breathing solitons in a non-resonant,incoherently pumped exciton-polariton condensate system by introducing a two-dimensional Moirélattice external potential.The symmetric shape of the soliton,at the center of the potential field is determined by the rotation angle of the twodimensional Moirélattice external potential.Within a specific range of rotation angles,the stability of the soliton is governed by the depth of the second sub-lattice.These two parameters mutually influence and constrain the soliton’s characteristics,and under certain rotation angles and sub-lattice depths,a bright vortex can be formed.At low pumping levels and with carefully chosen peak-to-valley positions in the external potential,the rotation angle becomes the primary factor controlling the distinct forms of breathing bright solitons.Our proposal provides effective schemes for the formation and control of various types of bright solitons and bright vortices in systems employing Moirélattice external potentials.This scheme for realizing polariton Bose-Einstein condensates(BECs)within a Moirélattice external potential also holds promise for advancing research in fields such as superfluidity and superconductivity.
基金supported by the National Natural Science Foundation of China(NSFC)(No.42272169)the efficient exploration and development technologies and integrated demonstration project for deep and ultra-deep carbonate oil and gas reservoirs in the Tarim Basin(No.2025ZD1402301)+1 种基金the Integrated Project of the Joint Fund for Enterprise Innovation and Development of the National Natural Science Foundation of China(No.U24B6001)the Bureau-Level Scientific Research Project of Northwest Oilfield Company(No.KJ202501).
文摘0 INTRODUCTION Gas injection refers to the natural gas charging into pre-existing oil reservoirs,which often leads to notable changes in gas-oil ratio(GOR),oil density,and phase states,depending on the pressure-temperature condition of the reservoirs(Meulbroek et al.,1998;Blanc and Connan,1994;Evans et al.,1971).
基金supported by the National Natural Science Foundation of China(grant number 52404044).
文摘There are limited quantitative studies on condensate gas using microfluidics under high-pressure and high-temperature conditions.This study employed microfluidics chips based on real porous media structures to conduct constant volume depletion experiments and investigate the microscopic mechanisms of condensate gas recovery.The aim of the experiments was to reveal the phase-behavior differences between bulk-phase gas and gas contained in porous media.The results revealed that condensate oil recovery in microfluidics experiments was higher than that in PVT cell tests,and nonuniform condensation and evaporation were exclusively observed in the microfluidics experiments.Furthermore,lower pore connectivity resulted in higher depletion recovery,while more developed fractures led to reduced recovery.Specifically,the chip with fewer fractures achieved the highest recovery(71.15%),whereas the highly fractured chip exhibited the lowest recovery(56.11%).These findings demonstrate that oil saturation during the process of constant volume depletion(CVD)of gas condensate within porous media is lower than that observed in the PVT cell,thus providing experimental evidence for optimizing condensate gas development in field applications.
基金supported by the National Natural Science Foundation of China under Grant No.12165004 and and Key Grant No.12061141008the Basic and Applied Basic Research Project of Guangzhou Science and Technology Bureau under Grant No.202201011324+1 种基金the Education Department of Guizhou Province under Grant No.QJJ[2022]016the National Key Research and Development Program of China under Grant Nos.2024YFA1610800 and 2022YFA1602103。
文摘To investigate the possible geometric structure of the proton,an improved stringy proton model is constructed beyond the smallest distance approximation and treats the constituent(up and down)quark-initiated gluon tubes separately,where the constituent quarks are connected by gluon tubes which merge at the Fermat point of the quark triangle.The exclusive diffractive vector meson production process in electron-proton deep inelastic scattering is used to test the stringy structure of the proton.We calculate the coherent and incoherent differential cross sections of the exclusive diffractive J/Ψphotoproduction in the framework of Color Glass Condensate.The results show that our calculations are in good agreement with HERA data.Especially,our results give a better description of the HERA data at small t as compared to the ones from the hot spot model where the constituent quarks are independently distributed in the proton.Meanwhile,the radius of the proton resulting from the improved stringy proton model is coincident with the one from fitting to the data from GlueX Collaboration at Jefferson Lab,which indicates that the predictive power of the stringy proton model is significantly improved once it goes beyond the smallest distance approximation and treats the constituent quarks separately,instead of using the same profile for the up and down quarks initiated gluon tubes.Moreover,we assume that the transverse shape of the gluon tube satisfies Gaussian distribution,and explore the distribution width of the individual gluon tubes.We find an interesting result that the up quark-initiated gluon tube seems to have a larger distribution width than the down quarkinitiated gluon tube,which is favored by the HERA data.
基金supported by the National Natural Science Foundation of China(Grant No.11971411)。
文摘This paper introduces a novel numerical method based on an energy-minimizing normalized residual network(EMNorm Res Net)to compute the ground-state solution of Bose-Einstein condensates at zero or low temperatures.Starting from the three-dimensional Gross-Pitaevskii equation(GPE),we reduce it to the 1D and 2D GPEs because of the radial symmetry and cylindrical symmetry.The ground-state solution is formulated by minimizing the energy functional under constraints,which is directly solved using the EM-Norm Res Net approach.The paper provides detailed solutions for the ground states in 1D,2D(with radial symmetry),and 3D(with cylindrical symmetry).We use the Thomas-Fermi approximation as the target function to pre-train the neural network.Then,the formal network is trained using the energy minimization method.In contrast to traditional numerical methods,our neural network approach introduces two key innovations:(i)a novel normalization technique designed for high-dimensional systems within an energy-based loss function;(ii)improved training efficiency and model robustness by incorporating gradient stabilization techniques into residual networks.Extensive numerical experiments validate the method's accuracy across different spatial dimensions.
基金funding from the National Natural Science Foundation of China(Grant Nos.12174055 and 11674058)the Natural Science Foundation of Fujian(Grant No.2020J01195)funding from the National Natural Science Foundation of China(Grant No.12175027)。
文摘We consider two pointlike static impurities without direct interaction immersed in a three-dimensional Bose–Einstein condensate(BEC)at zero temperature.By solving the Gross–Pitaevskii(GP)equation in a perturbative manner,we calculate the ground state energy in the region where the atom–impurity interaction is assumed to be weak.We obtain an analytical expression for the spatial distribution of atom number density and the effective force between these two impurities.The effective force is found to be closely related to the strength of the atom–impurity interaction and the relative distance between these two impurities.Two critical relative distances are found between the two impurities.The first one corresponds to the vanishing of the perturbed energy with impurities,although the effective force between the two impurities still exists.At the second critical value,the energy of the impurities changes linearly with the atom–impurity interaction;otherwise,it changes quadratically with the atom–impurity interaction.
基金the support from the National Natural Science Foundation of China(NSFC Grant No.:52004032)。
文摘The development of gas condensate reservoirs with a large gas cap,thin oil rim,strong bottom water,and natural barriers faces numerous challenges,including reservoir heterogeneity,coning effects,phase changes,and multiphase flow dynamics.The influx of gas and water may lead to a low recovery of the oil rim,while reservoir heterogeneity and natural barriers further exacerbate the uneven distribution of reservoir fluid,complicating development strategies.This paper aims to investigate innovative and effective development strategies for this type of reservoir.A detailed,proportionally scaled numerical simulation is performed based on the experimental results of an artificial sand-filled model,providing novel insights into the dynamic behavior of these reservoirs.By understanding the phase behavior and fluid flow characteristics of the reservoir,the study simulates various strategies for the rational and efficient development of the gas condensate reservoir.These strategies include well patterns and completions,the decision to develop the oil rim or gas cap,depletion rates,the bottom water control,and gas injection.The results show that horizontal wells or highly deviated wells are more suitable for the development of the oil rim,as they provide larger control ranges.The presence of strong bottom water is advantageous for displacement energy supply and pressure maintenance,but it intensifies water coning effects,leading to an earlier breakthrough and a sharp production decline.Therefore,it is preferable to apply highly deviated wells at the oil-gas contact,developing the oil rim at lower rates and smaller pressure gradients,followed by developing the gas cap.This approach can reduce water coning effects and improve recovery,with oil and gas recovery reaching 24.4%and 67.95%,respectively,which is an increase of 16.74%and 17.84%compared to direct depletion development of the gas cap.Due to the strong water bottom,continuous gas injection at the top of the reservoir becomes challenging.This study introduces gas assisted gravity drainage with water control technology,a novel and highly effective approach that addresses the impact of bottom water coning effects on the oil and gas zones and overcomes the limitations of gas flooding in reservoirs with strong bottom water.This method can significantly improve oil and gas recovery,achieving recovery of 39.74%and 84.50%,respectively.Compared to the conventional depletion strategy of sequential oil rim and gas cap development,this method achieves additional improvements of 15.33%and 16.55%in oil and gas recovery,respectively.
基金supported by the National Natural Science Foundation of China under Grant Nos.12065022,12147213。
文摘Kármán vortex street not only exists in nature,but also widely appears in engineering practice,which is of great significance for understanding superfluid.Parity-time(PT)symmetric potential provides a good platform for the study of Kármán vortex streets.In this paper,different patterns of vortex shedding formed behind PT symmetric potential in Bose-Einstein condensate(BEC)are simulated numerically.Kármán vortex streets and others are discovered to emerge in the wake of a moving obstacle with appropriate parameters.Compared with BEC without PT symmetric potential,the frequency and amplitude of the drag force are more complex.The parametric regions of the combined modes are scattered around the Kármán vortex street.Numerical simulations indicate that the imaginary part of the PT symmetric potential affects the vortex structure patterns.Finally,we proposed an experimental protocol that may observe a Kármán vortex street.
基金Projects supported by the Natural Science Foundation of Hunan Province(2016JJ6020)the Scientific Research Fund of Hunan Provincial Education Department(18A436)the Scientific Research Fund of Hunan First normal University(XYS13N16)。
文摘We investigate the chaotic and regular spatial structures of Bose–Einstein condensates(BECs)with a spatially modulated atom-atom interaction and without an external trapping potential.A BEC with a spatially modulated atom-atom interaction is equivalent to being constrained by a nonlinear optical lattice.Theoretical analyses show the existence of a steady atomic current in the BEC with a spatially varying phase.Under perturbative conditions,the Melnikov chaos criteria of BECs with a spatially varying phase and a constant one are theoretically obtained,respectively.When the perturbative conditions cannot be satisfied,for a repulsive BEC with a spatially varying phase,numerical simulations demonstrate that changing the initial condition can eliminate the chaotic spatial structure and then the system transitions into a biperiodic spatial structure.Increasing the chemical potential can result in a transition from the biperiodic spatial structure to a single-periodic spatial structure.For an attractive BEC with a spatially varying phase,numerical simulations show that decreasing the chemical potential can lead to a high atomic density,but when the wave number of the laser inducing the optical Feshbach resonance exceeds a critical value,the atomic density falls back to a finite range.Regardless of whether the BEC has a spatially varying phase or a constant one,modulating the laser wave number can effectively suppress the chaotic spatial structure in the BEC and then force it into a regular spatial structure.
基金supported by the Shanghai Agricultural Science and Technology Innovation Project(B2024003)the Innovation Program of Shanghai Municipal Education Commission(2023ZKZD05)the Shanghai Oriental Talent(Rural Revitalization)Top Talent Project(T2023102).
文摘Global climate change seriously threatens food security.To address this challenge,breeders have achieved remarkable results using multiple breeding strategies and technologies.In recent years,the application of biomolecular condensates to crop improvement has remained in its early stages.Nevertheless,growing evidence indicates their crucial roles in regulating crop development and stress adaptation.This review synthesizes recent advances in understanding biomolecular condensate functions across key plant developmental phases and their regulatory roles in abiotic and biotic stress responses.The regulatory mechanisms associated with these condensates primarily encompass transcriptional regulation,RNA processing and metabolism,translational control,and membrane organelle biogenesis,collectively establishing a solid theoretical foundation for agricultural molecular breeding.In the final section,we discuss the potential applications and challenges of biomolecular condensates in crop improvement.
基金supported by the Longdong University Doctoral Fund Program Projects(Grant Nos.XYBYZK2227,XYBYZK2219).
文摘We propose a superposed Bessel optical lattice formed by multiple Bessel optical lattices.The static and rotational structures are formed in the presence of a spin-orbit coupling(SOC)interaction in the atomic in Bose–Einstein condensates are investigated,it is shown that the two structures can be manipulated by adjusting the parameters of the superposed Bessel optical lattices.The results show that the SOC interaction has an important effect on the two structures in the superposed Bessel optical lattices,and the SOC interaction can enhance the robustness of the structures.The Gaussian,toroidal and vortex superposition structures in the superposition lattice are presented,the interference processes in the steady state structures are analyzed,and the effects of SOC interactions on the Gaussian vortex and toroidal vortex structures are investigated,and the angular momentum of the vortex states can be increased by SOC interactions.
基金Project supported by the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302103)the National Natural Science Foundation of China(Grant Nos.62325505,62020106014,62175140,62475138,92165106,12104276)the Shanxi Province Graduate Student Research Innovation Project(Grant No.2024KY105)。
文摘The Josephson effect,an important quantum supercurrent phenomenon,has been extensively studied in superconductors and superfluids.In this paper,we investigate the rich physics of one-dimensional Josephson junctions in a red-detuned optical lattice with sodium(Na)quantum gas.A one-dimensional Josephson array is formed by setting up an optical lattice using a red-detuned laser.By characterizing the dependence of Josephson oscillations of the lattice depth,we experimentally demonstrate the Josephson current.The lattice depth is controlled by altering the lattice power,and our observations are consistent with theoretical predictions.These findings offer valuable insights into quantum coherent transport and the intricate dynamics inherent to superfluidity.
基金provided by the Guangdong Basic and Applied Basic Research Foundation of China(Grant Nos.2024A1515012552,2022A1515011938,2022A1515012425)the National Natural Science Foundation of China(Grant No.12005088)the support received from Lingnan Normal University(Grant Nos.YL20200203,ZL1930)。
文摘Utilizing the dissipative Gross-Pitaevskii equation,we investigated the splitting dynamics of triply quantized vortices at finite temperature.Through linear perturbation analysis,we determined the excitation modes of these vortices across various dissipation parameters.We identified three unstable modes with p=2-,3-and 4-fold rotational symmetries,revealing a significant dynamic transition of the most unstable mode.That is,as the dissipation parameter increases the most unstable mode transitions from the p=2 mode to the p=3 mode.Throughout the entire range of dissipation parameters,the p=4 unstable mode is never the dominant mode.Subsequently,we performed nonlinear numerical simulations of the vortex splitting process.Under random perturbations we confirmed the dynamical transition,and under specific perturbations we confirmed the instability of the p=4 mode.Our findings on the finite temperature dependence of the splitting dynamics of triply quantized vortices are expected to be verifiable in experiments.
基金supported by Doctor's Scientific Research Initiation Project of Yan'an University(YAU202213093)National Nature Science Foundation of China(Grant No.41503029).
文摘As an important component of light hydrocarbon compounds,alkylbenzene compounds lack indicators to indicate the source of organic matter of light oils and condensates.Forty-one oil samples from the Tarim Basin and Beibuwan Basin were analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GC-TOFMS).The concentration distributions of thirteen light hydrocarbon compounds with organic matter source and sedimentary environment indication were studied.There is no significant difference in the concentrations of 1-methylpropylbenzene(MPB)in all studied oils.However,the concentrations of 2-MPB in the Tarim swamp oils are higher than that in the Beibuwan lacustrine oils and Tarim marine oils.Based on the significant concentration difference of 1-and 2-MPB in all studied oils,1-/2-MPB(MPBr)was proposed as an indicator to identify the source of organic matter in crude oils.The MPBr values greater than 1.5 indicate that the crude oil mainly comes from lower aquatic organisms,bacteria,and algae.The MPBr values greater than 1.0 and less than 1.5 indicate that crude oil was derived from the combined contributions of lower aquatic organisms,bacteria and algae,and terrestrial higher plants.The MPBr values less than 1.0 suggest that the crude oil was mainly derived from terrigenous higher plants.The MPBr values in crude oils basically are not or slightly affected by depositional environment and secondary alteration.The MPBr values can be used to infer the organic matter origin in sediments,especially for the lack of biomarkers of light oils and condensates.
基金supported by NSFC under Grant No.12272403Beijing Training Program of Innovation under Grant No.S202410019024。
文摘Introducing PT-symmetric generalized Scarf-Ⅱpotentials into the three-coupled nonlinear Gross-Pitaevskii equations offers a new way to seek stable soliton states in quasi-onedimensional spin-1 Bose-Einstein condensates.In scenarios where the spin-independent parameter c_(0)and the spin-dependent parameter c_(2)vary,we use both analytical and numerical methods to investigate the three-coupled nonlinear Gross-Pitaevskii equations with PT-symmetric generalized Scarf-Ⅱpotentials.We obtain analytical soliton states and find that simply modulating c_(2)may change the analytical soliton states from unstable to stable.Additionally,we obtain numerically stable double-hump soliton states propagating in the form of periodic oscillations,exhibiting distinct behavior in energy exchange.For further investigation,we discuss the interaction of numerical double-hump solitons with Gaussian solitons and observe the transfer of energy among the three components.These findings may contribute to a deeper understanding of solitons in Bose-Einstein condensates with PT-symmetric potentials and may hold significance for both theoretical understanding and experimental design in related physics experiments.
基金supported by the National Natural Science Foundation of China(Grant No.62275075)the Natural Science Foundation of Hubei Soliton Research Association(Grant No.2025HBSRA09)+1 种基金joint supported by Hubei Provincial Natural Science Foundation and Xianning of China(Grant Nos.2025AFD401 and 2025AFD405)Israel Science Foundation(Grant No.1695/22).
文摘We propose a theoretical framework,based on the two-component Gross-Pitaevskii equation(GPE),for the investigation of vortex solitons(VSs)in hybrid atomic-molecular Bose-Einstein condensates under the action of the stimulated Raman-induced photoassociation and square-optical-lattice potential.Stationary solutions of the coupled GPE system are obtained by means of the imaginary-time integration,while the temporal dynamics are simulated using the fourth-order Runge-Kutta algorithm.The analysis reveals stable rhombus-shaped VS shapes with topological charges m=1 and 2 of the atomic component.The stability domains and spatial structure of these VSs are governed by three key parameters:the parametric-coupling strength(χ),atomicmolecular interaction strength(g_(12)),and the optical-lattice potential depth(V_(0)).By varyingχand g_(12),we demonstrate a structural transition where four-core rhombus-shaped VSs evolve into eight-core square-shaped modes,highlighting the nontrivial nonlinear dynamics of the system.This work establishes a connection between interactions of cold atoms and topologically structured matter waves in hybrid quantum systems.
