Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during fr...Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during frozen storage.Product indicators including pH,colour,thiobarbituric acid reactive substances(TBARS),total volatile basic nitrogen(TVB-N),texture,electronic nose(E-nose)response,and water-holding capacity(thawing and cooking losses)were determined.The results indicated that as storage time increased,water retention in Sichuan sausages with different moisture contents decreased,while the degree of protein and lipid oxidation increased.This led to an increase in pH value,a colour shift from red-bright to grey-brown,and a deterioration in palatability.Among the samples,sausages with 50% moisture content exhibited the lowest thawing and cooking losses,indicating superior water-holding capacity.After 8 weeks of storage,TBARS and TVB-N values for the 50% moisture group were 19.5%and 2.5%lower,respectively,than those of the 40%and 45%moisture groups,indicating a reduced degree of oxidation.Furthermore,Sichuan sausage with 50%moisture content demonstrated an appropriate pH and colour difference,along with excellent texture and flavour,as evidenced by its higher toughness and satisfactory hardness.In conclusion,Sichuan sausage with 50% moisture content demonstrated the highest overall quality under frozen storage conditions.展开更多
The Western Sichuan Foreland Basin(WSFB)in South China,a prolific hydrocarbon province,exhibits complex structural deformation influenced by Triassic salt tectonics.This paper integrates seismic data and well data to ...The Western Sichuan Foreland Basin(WSFB)in South China,a prolific hydrocarbon province,exhibits complex structural deformation influenced by Triassic salt tectonics.This paper integrates seismic data and well data to elucidate the role of Middle-Lower Triassic evaporite layers in shaping basin structures,focusing on Xinchang Tectonic Zone(XTZ).Salt layers facilitated decoupled deformation between supra-and sub-salt sequences,forming salt pillows and fault-related folds.Three distinct structural trends were identified in XTZ.Key findings reveal that salt thickness variations correlate with deformation styles:thicker salt promoted detachment folding,while thinner salt led to hard-linked fault systems.Sub-salt E-NE trending reverse faults formed horsetail terminations associated with the Pengzhou faults(PzF),deviating from the primary Longmenshan thrust belt(LmsTB)orientation.Structural evolution occurred in three stages:(1)Indosinian salt deposition and foreland basin initiation;(2)Yanshanian eastward propagation of thrust systems with salt-driven detachment folding;(3)Himalayan reactivation overprinting earlier structures with sub-NS trending folds.This work establishes a direct link between salt layers and structural traps,demonstrating how salt acted as a critical detachment layer during multi-stage compression.Results provide insights into the gas exploration of the Late Triassic Xujiahe Formation,emphasizing the importance of salt-influenced deformation in foreland basin systems.展开更多
The original online version of this article was revised:The layout update for Article 758 has impacted the page range in the published issue,but did not affect the scholarly content.To ensure consistency with the orig...The original online version of this article was revised:The layout update for Article 758 has impacted the page range in the published issue,but did not affect the scholarly content.To ensure consistency with the originally assigned pages(2595-2614),we will need to publish an erratum to correct the article and restore the original page range.The original article has been corrected.展开更多
Established in 1958,Sichuan Academy of Social Sciences(SASS)is a public institutionguided by the People’s Government of Sichuan Province.It is a comprehensive and specializedresearch institution in social sciences th...Established in 1958,Sichuan Academy of Social Sciences(SASS)is a public institutionguided by the People’s Government of Sichuan Province.It is a comprehensive and specializedresearch institution in social sciences that integrates research,education,editing,andconsulting services.It holds the registered trademark of“Tianfu Think Tank”and owns twocampuses:Baihuatan and Banzhuyuan.SASS consists of 16 research institutes as well as functional and educational departments,such as the Party Committee and the Graduate School.Currently,it has 450 employees,including a significant number of reputable scholars and recipients of national and provincial honors in the fields of culture and economy,such as national-level candidates for the Hundred,Thousand and Ten Thousand Talents Project,Leading Talent in Philosophy and Social Sciences in the National Ten Thousand Talents Program,participants in China’s Four-pronged Publicity Talent Program,Academic and Technology Leader of Sichuan Province,and Expert of Sichuan Province with Outstanding Contributions.展开更多
Deep shale gas reservoirs in the southern Sichuan Basin are typically characterized by significant horizontal stress anisotropy(expressed as stress difference),variable brittleness-ductility in rock mechanics,and stro...Deep shale gas reservoirs in the southern Sichuan Basin are typically characterized by significant horizontal stress anisotropy(expressed as stress difference),variable brittleness-ductility in rock mechanics,and strong heterogeneity.These complex geomechanical conditions lead to pronounced differences in hydraulic fracturing outcomes among wells and sections.To investigate hydraulic fracture propagation and fracturing fluid injection behavior under varying geomechanical settings,true triaxial physical simulation tests were performed on 400×400×400 mm artificial rock samples.The samples were designed with different media properties based on similarity criteria.A sensitivity analysis was conducted to assess the effects of brittleness-ductility characteristics,natural fractures,and in-situ stress conditions.The results reveal that:(i)brittle samples with lower stress difference are favorable for forming complex,perforable fracture networks;(ii)brittle samples with higher stress difference tend to develop simple,planar hydraulic fractures,with natural fractures only slightly activated during very short injection periods;(iii)ductile behavior enhances the activation of natural fractures but reduces fracture complexity compared with brittle samples,even under lower stress difference;and(iv)for typical deep shale formations,larger fluid injection volumes combined with high-density,multi-cluster fracturing techniques are recommended.展开更多
Based on the data of drilling,logging,experiment and gas testing in the Nanchuan area,southeastern Sichuan Basin,the hydrocarbon generation potential,gas genesis,occurrence state,migration,preservation conditions,pore...Based on the data of drilling,logging,experiment and gas testing in the Nanchuan area,southeastern Sichuan Basin,the hydrocarbon generation potential,gas genesis,occurrence state,migration,preservation conditions,pore and fracture features and accumulation evolution of the first member of Permian Maokou Formation(Mao 1 Member)are systematically studied,and the main controlling factors of unconventional gas enrichment and high production in marlstone assemblage of Mao 1 Member are discussed.(1)The enrichment and high yield of unconventional natural gas in the Mao 1 Member are controlled by three factors:carbon-rich fabric controlling hydrocarbon generation potential,good preservation controlling enrichment,and natural fracture controlling production.(2)The carbonate rocks of Mao 1 Member with carbon rich fabric have significant gas potential,exhibiting characteristics of self-generation and self-storage,which lays the material foundation for natural gas accumulation.(3)The occurrence state of natural gas is mainly free gas,which is prone to lateral migration,and good storage conditions are the key to natural gas enrichment.Positive structure is more conducive to natural gas accumulation,and a good compartment is created jointly by the self-sealing property of the Mao 1 Member and its top and bottom sealing property in monoclinal area,which is favorable for gas accumulation by retention.(4)Natural fractures are the main reservoir space and flow channel,and the more developed natural fractures are,the more conducive to the formation of high-quality porous-fractured reservoirs and the accumulation of natural gas,which is the core of controlling production.(5)The accumulation model of unconventional natural gas is proposed as“self-generation and self-storage,preservation controlling richness,and fractures controlling production”.(6)Identifying fracture development areas with good preservation conditions is the key to successful exploration,and implementing horizontal well staged acidizing and fracturing is an important means to increase production and efficiency.The study results are of referential significance for further understanding the natural gas enrichment in the Mao 1 Member and guiding the efficient exploration and development of new types of unconventional natural gas.展开更多
The basic geological characteristics of the Qiongzhusi Formation reservoirs and conditions for shale gas enrichment and high-yield were studied by using methods such as mineral scanning,organic and inorganic geochemis...The basic geological characteristics of the Qiongzhusi Formation reservoirs and conditions for shale gas enrichment and high-yield were studied by using methods such as mineral scanning,organic and inorganic geochemistry,breakthrough pressure,and triaxial mechanics testing based on the core,logging,seismic and production data.(1)Both types of silty shale,rich in organic matter in deep water and low in organic matter in shallow water,have good gas bearing properties.(2)The brittle mineral composition of shale is characterized by comparable feldspar and quartz content.(3)The pores are mainly inorganic pores with a small amount of organic pores.Pore development primarily hinges on a synergy between felsic minerals and total organic carbon content(TOC).(4)Dominated by Type I organic matters,the hydrocarbon generating organisms are algae and acritarch,with high maturity and high hydrocarbon generation potential.(5)Deep-and shallow-water shale gas exhibit in-situ and mixed gas generation characteristics,respectively.(6)The basic law of shale gas enrichment in the Qiongzhusi Formation was proposed as“TOC controlled accumulation and inorganic pore controlled enrichment”,which includes the in-situ enrichment model of“three highs and one over”(high TOC,high felsic mineral content,high inorganic pore content,overpressured formation)for organic rich shale represented by Well ZY2,and the in-situ+carrier-bed enrichment model of“two highs,one medium and one low”(high felsic content,high formation pressure,medium inorganic pore content,low TOC)for organic-poor shale gas represented by Well JS103.It is a new type of shale gas that is different from the Longmaxi Formation,enriching the formation mechanism of deep and ultra-deep shale gas.The deployment of multiple exploration wells has achieved significant breakthroughs in shale gas exploration.展开更多
Benthic bivalves,the most widely distributed mollusks since the Mesozoic era,often inhabited environments where their fossilized remains are found adjacent to or intermingled with organic-rich shale.Recent Jurassic sh...Benthic bivalves,the most widely distributed mollusks since the Mesozoic era,often inhabited environments where their fossilized remains are found adjacent to or intermingled with organic-rich shale.Recent Jurassic shale oil exploration in the Sichuan Basin has revealed that bioclastic layers,composed of abundant fossil bivalves and closely associated with shales and,exhibit significant hydrocarbon potentials.However,the microscopic structures of these bivalve fossils and their role in hydrocarbon storage and migration remain poorly understood.In this study,we characterized the microporosity of bivalve shells within the Middle-Lower Jurassic bioclastic shale in the northeastern Sichuan Basin using a combination of 2D imaging(thin section,SEM),3D reconstruction(FIB-SEM),and permeability simulation.The micropores within the shell fossils range from 100 to 1000 nm in radius and are uniformly distributed in a grid-like pattern within the shell interior,where they host liquid hydrocarbons.The bioclastic carbonate layers exhibit an overall porosity of approximately 0.8%.Comparative analysis with extant bivalve shells suggests that these micropores represent residual pores from the nacreous brick wall structure.Due to the regular orientation of the shells and their microporous nacres,permeability coefficients along the long bivalve fossil axes are three to five times higher than those along the short axes.These residual micropores within the bioclastic fossil shells have a positive influence on both the storage and migration of shale oil and gas,making bioclastic fossil-bearing shalespromising sweet spots for shale oil and gas exploration in similar sedimentary environments.展开更多
This paper discusses the characteristics and formation mechanism of thin dolomite reservoirs in the lower submember of the second member of the Permian Maokou Formation(lower Mao 2 Member)in the Wusheng-Tongnan area o...This paper discusses the characteristics and formation mechanism of thin dolomite reservoirs in the lower submember of the second member of the Permian Maokou Formation(lower Mao 2 Member)in the Wusheng-Tongnan area of the Sichuan Basin,SW China,through comprehensive analysis of geological,geophysical and geochemical data.The reservoir rocks of the lower Mao 2 Member are dominated by porphyritic vuggy dolomite and calcareous dolomite or dolomitic limestone,which have typical karst characteristics of early diagenetic stage.The dolomites at the edge of the karst system and in the fillings have dissolved estuaries,and the dolomite breccia has micrite envelope and rim cement at the edge,indicating that dolomitization is earlier than the early diagenetic karstification.The shoal facies laminated dolomite is primarily formed by the seepage reflux dolomitization of moderate-salinity seawater.The key factors of reservoir formation are the bioclastic shoal deposition superimposed with seepgae reflux dolomitization and the karstification of early diagenetic stage,which are locally reformed by fractures and hydrothermal processes.The development of dolomite vuggy reservoir is closely related to the upward-shallowing sequence,and mainly occurs in the late highstand of the fourth-order cycle.Moreover,the size of dolomite is closely related to formation thickness,and it is concentrated in the formation thickness conversion area,followed by the thinner area.According to the understanding of insufficient accommodation space in the geomorphic highland and the migration of granular shoal to geomorphic lowland in the late highstand of the third-order cycle,it is proposed that the large-scale shoal-controlled dolomite reservoirs are distributed along structural highs and slopes,and the reservoir-forming model with shoal,dolomitization and karstification jointly controlled by the microgeomorphy and sea-level fluctuation in the sedimentary period is established.On this basis,the paleogeomorphology in the lower Mao 2 Member is restored using well-seismic data,and the reservoir distribution is predicted.The prediction results have been verified by the latest results of exploration wells and tests,which provide an important reference for the prediction of thin dolomite reservoirs under similar geological setting.展开更多
The Yellow River Basin in Sichuan Province(YRS)is undergoing severe soil erosion and exacerbated ecological vulnerability,which collectively pose formidable challenges for regional water conservation(WC)and sustainabl...The Yellow River Basin in Sichuan Province(YRS)is undergoing severe soil erosion and exacerbated ecological vulnerability,which collectively pose formidable challenges for regional water conservation(WC)and sustainable development.While effectively enhancing WC necessitates a comprehensive understanding of its driving factors and corresponding intervention strategies,existing studies have largely neglected the spatiotemporal heterogeneity of both natural and socio-economic drivers.Therefore,this study explored the spatiotemporal heterogeneity of WC drivers in YRS using multi-scale geographically weighted regression(MGWR)and geographically and temporally weighted regression(GTWR)models from an eco-hydrological perspective.We discovered that downstream regions,which are more developed,achieved significantly better WC than upstream regions.The results also demonstrated that the influence of temperature and wind speed is consistently dominant and temporally stable due to climate stability,while the influence of vegetation shifted from negative to positive around 2010,likely indicating greater benefits from understory vegetation.Economic growth positively impacted WC in upstream regions but had a negative effect in the more developed downstream regions.These findings highlight the importance of targeted water conservation strategies,including locally appropriate revegetation,optimization of agricultural and economic structures,and the establishment of eco-compensation mechanisms for ecological conservation and sustainable development.展开更多
Taking the second member of the Xujiahe Formation of the Upper Triassic in the Xinchang structural belt as an example,based on data such as logging,production,seismic interpretation and test,a systematic analysis was ...Taking the second member of the Xujiahe Formation of the Upper Triassic in the Xinchang structural belt as an example,based on data such as logging,production,seismic interpretation and test,a systematic analysis was conducted on the structural characteristics and evolution,reservoir diagenesis and densification processes,and types and stages of faults/fractures,and revealing the multi-stage and multi-factor dynamic coupled enrichment mechanisms of tight gas reservoirs.(1)In the early Yanshan period,the paleo-structural traps were formed with low-medium maturity hydrocarbons accumulating in structural highs driven by buoyancy since reservoirs were not fully densified in this stage,demonstrating paleo-structure control on traps and early hydrocarbon accumulation.(2)In the middle-late Yanshan period,the source rocks became mature to generate and expel a large quantity of hydrocarbons.Grain size and type of sandstone controlled the time of reservoir densification,which restricted the scale of hydrocarbon charging,allowing for only a small-scale migration through sand bodies near the fault/fracture or less-densified matrix reservoirs.(3)During the Himalayan period,the source rocks reached overmaturity,and the residual oil cracking gas was efficiently transported along the late-stage faults/fractures.Wells with high production capacity were mainly located in Type I and II fault/fracture zones comprising the late-stage north-south trending fourth-order faults and the late-stage fractures.The productivity of the wells was controlled by the transformation of the late-stage faults/fractures.(4)The Xinchang structural belt underwent three stages of tectonic evolution,two stages of reservoir formation,and three stages of fault/fractures development.Hydrocarbons mainly accumulated in the paleo-structure highs.After reservoir densification and late fault/fracture adjustment,a complex gas-water distribution pattern was formed.Thus,it is summarized as the model of“near-source and low-abundance hydrocarbon charging in the early stage,and differential enrichment of natural gas under the joint control of fault-fold-fracture complex,high-quality reservoirs and structural highs in the late stage”.Faults/fractures with well-coupled fault-fold-fracture-pore are favorable exploration targets with high exploration effectiveness.展开更多
The faults and associated fracture zones in the tight sandstone reservoirs of the fifth member of the Triassic Xujiahe Formation(Xu-5 Member)in the Wubaochang area,northeastern Sichuan Basin,play a critical role in co...The faults and associated fracture zones in the tight sandstone reservoirs of the fifth member of the Triassic Xujiahe Formation(Xu-5 Member)in the Wubaochang area,northeastern Sichuan Basin,play a critical role in controlling gas well productivity.To delineate the distribution patterns of the faults and associated fracture zones in this area,a transfer-trained convolutional neural network(CNN)model and an XGBoost(eXtreme Gradient Boosting)-based intelligent seismic attribute fusion method were employed to identify faults and fracture zones,respectively,enabling precise characterization of their spatial distribution.The faults in the Wubaochang area are classified into first-to fourth-order structures,with the average fracture zone width on the hanging wall exceeding that of the footwall,demonstrating a strong positive correlation between fracture zone width and fault displacement.The study area is divided into three distinct deformation regions(southern,central and northern regions)featuring five fault structural styles(duplex,duplex-backthrust,imbricate thrust,synclinorium imbricate-backthrust,and anticlinorium imbricate-backthrust)and four corresponding fracture zone development patterns(duplex,duplex-backthrust,synclinorium imbricate-backthrust,and anticlinorium imbricate-backthrust).Based on the controlling effects of faults on gas enrichment,the dual-source hydrocarbon-supply zones are interpreted to be distributed in the northern and central regions,while the southern region is identified as gas-escape zones.By integrating the distribution of favorable reservoir development areas and fracture zones,two classes of gas enrichment zones(Class Ⅰ and Ⅱ)are delineated.Class Ⅰ zones are primarily distributed in the northern region and the transitional zone from the southern to central regions,whereas Class Ⅱ zones are concentrated in the central region.Class Ⅰ zones exhibit dual-source hydrocarbon-supply conditions,larger-scale fracture zone development,and higher favorability compared to Class Ⅱ zones.According to the defined gas accumulation effectiveness in different types of fracture zones,a high-productivity gas well model for the Wubaochang area is proposed,emphasizing“dual-source faults controlling enrichment,effective fracture zones controlling high production,and high matrix porosity ensuring sustained production”.Targeted drilling directions for different favorable zones are further optimized based on this model.展开更多
Xi Jinping Thought on Ecological Civilization contains new concepts,ideas,and strategies that feature Chinese characteristics and the spirit of the times and promote the progress of human civilization.Xi Jinping Thoug...Xi Jinping Thought on Ecological Civilization contains new concepts,ideas,and strategies that feature Chinese characteristics and the spirit of the times and promote the progress of human civilization.Xi Jinping Thought on Ecological Civilization is also the fundamental guide for compliance and action in terms of China’s practices in building an ecological civilization in the new era.Since the 18th National Congress of the Communist Party of China(CPC),Xi Jinping,general secretary of the Communist Party of China Central Committee,has made several inspection tours to Sichuan and given a series of important instructions on green development and building an ecological civilization in Sichuan province.This paper reviews the contemporary meaning and theoretical significance of Xi Jinping Thought on Ecological Civilization and uses them to systematically examine the overall performance of building a beautiful Sichuan,following the guidance of Xi Jinping’s important instructions for the governance of Sichuan.This paper selects and analyzes typical cases that demonstrate the national effect in Sichuan to summarize Sichuan’s unique experiences in the practice of Xi Jinping Thought on Ecological Civilization.展开更多
The occurrence types and controlling factors of organic matter in the sepiolite-containing successions of the first member of Mid-Permian Maokou Formation(Mao-1 Member for short)in the Eastern Sichuan Basin,SW China,h...The occurrence types and controlling factors of organic matter in the sepiolite-containing successions of the first member of Mid-Permian Maokou Formation(Mao-1 Member for short)in the Eastern Sichuan Basin,SW China,have been investigated through outcrop section measurement,core observation,thin section identification,argon ion polishing-field scanning electron microscopy,energy spectrum analysis,X-ray diffraction,total organic carbon content(TOC),major and trace element analysis.Finally,the symbiotic adsorption model of sepiolite for organic matter enrichment has been established.The results show that the sepiolite-containing successions of the Mao-1 Member are composed of the rhythmite of mudstone,argillaceous limestone and limestone,with five depositional intervals vertically and the organic matter mostly developed in the mudstone and argillaceous limestone layers within the lower three intervals.The organic matter occurrence types are mostly layered or nodular in macro to meso-scale,blocky-vein-like under a microscope,but scattered,interstitial or adsorbed at a mesoscopic scale.It underwent transition processes from lower to higher salinity,from oxygen-poor and anoxic reduction to oxygen-poor and localized oxygen enrichment on the palaeo-environment of the Mao-1 Member.The first two intervals of the early depositional phase of Mao-1 Member constitute the cyclothems of mudstone,argillaceous limestone and limestone and quantities of fibrous-feathered sepiolite settle down within the Tongjiang-Changshou sag with continuous patchy organic matter from adsorption of alginate by sepiolite in intercrystalline,bedding surfaces and interlayer pores.The third and fourth intervals in the mid-depositional phase are mostly composed of the mudstone and argillaceous limestone alternations with the continuous patchy or banded organic matter in the surface and inter-crystalline pores of fibrous,feathered and flaky sepiolite.And the fifth interval in the late depositional phase of the Mao-1 Member comprises the cyclothems of extremely thin layered argillaceous limestone and thick-layered limestone with the fibrous sepiolite depositing in the argillaceous limestone and irregular organic matter dispersing around the sepiolite.Therefore,the symbiotic adsorption between organic matter and sepiolite effectively enhances the preservation efficiency of organic matter and improves the source rock quality of the Mao-1 Member,which enhances our understanding on the enrichment model of the depositional organic matter.展开更多
The widespread dolomite of the Sinian Dengying Formation in the Sichuan Basin(China)serves as one of the most important oil and gas reservoir rocks of the basin.Well WT1,as an exploration well,is recently drilled in t...The widespread dolomite of the Sinian Dengying Formation in the Sichuan Basin(China)serves as one of the most important oil and gas reservoir rocks of the basin.Well WT1,as an exploration well,is recently drilled in the Kaijiang County,northeastern Sichuan Basin(SW China),and it drills through the Dengying Formation dolomite at the depth interval of 7500–7580 m.In this study,samples are systematically collected from the cores of that interval,followed by new analyses of carbon-oxygen isotope,major elements,trace elements,rare earth elements(REEs)and EP-MA.The Dengying Formation dolomites of Well WT1 haveδ13C values of 0.37‰to 2.91‰andδ18O values of-5.72‰to-2.73‰,indicating that the dolomitization fluid is derived from contemporary seawater in the near-surface environment,rather than the burial environment.Based on the REE patterns of EPMA-based in-situ data,we recognized the seawater-sourced components,the mixedsourced components and the terrigenous-sourced components,indicating the marine origin of the dolomite with detrital contamination and diagenetic alteration.Moreover,high Al,Th,and Zr contents indicate significant detrital contamination derived from clay and quartz minerals,and high Sr/Ba and Sr/Cu ratios imply a relatively dry depositional environment with extremely high seawater salinity,intensive evaporation,and strong influences of terrigenous sediment.展开更多
"Sichuan Cuisine Cooking Skills"is a course that focuses on the traditional cooking skills of Sichuan Province in China.It covers not only the historical and cultural background of Sichuan cuisine,but also t..."Sichuan Cuisine Cooking Skills"is a course that focuses on the traditional cooking skills of Sichuan Province in China.It covers not only the historical and cultural background of Sichuan cuisine,but also the cooking techniques,ingredients selection,seasoning skills and dish innovation of Sichuan cuisine.Doing a good job in the teaching of"Sichuan Cuisine Cooking Skills"is of great significance to the cultivation and reserve of culinary professionals in China,and also has an important impact on students'employment competitiveness.Under the background of"new engineering education",the course reform of"Sichuan Cuisine Cooking Skills"was carried out in terms of the construction of teaching staff,teaching methods,students'participation degree and the innovation of course content,and specific reform suggestions were put forward,hoping to effectively promote the sustainable development of"Sichuan Cuisine Cooking Skills"and effectively improve the teaching quality.展开更多
Pore structure directly affects the occurrence and migration of shale hydrocarbon,and the lack of research on the mechanism of the pore structure is an important reason for the hindrance of shale hydrocarbon explorati...Pore structure directly affects the occurrence and migration of shale hydrocarbon,and the lack of research on the mechanism of the pore structure is an important reason for the hindrance of shale hydrocarbon exploration.By analysing the geochemistry and reservoir characteristics of Jurassic lacustrine shales in Sichuan Basin,this study recovers their paleoenvironments and further discusses paleoenvironmental constraints on pore structure.The results show that the Lower Jurassic lacustrine shales in the Sichuan Basin are in a warm and humid semi-anoxic to anoxic lake environment with high productivity,a strong stagnant environment,and a rapid sedimentation rate,with water depths ranging from about 11.54-55.22 m,and a mixture of type Ⅱ/Ⅲ kerogen is developed.In terms of reservoir characteristics,they are dominated by open-slit pores,and the pores are relatively complex.The percentage of mesopores is the highest,while the percentage of macropores is the lowest.Further analysis shows that paleoclimate controls the overall pore complexity and surface relaxation of shales by influencing the weathering rate of mother rocks.Paleoredox conditions control the proportion and complexity of shale pores by influencing TOC content.The research results will provide theoretical basis for improving the exploration efficiency of lacustrine shale resources and expanding exploration target areas.展开更多
As seismic signals propagate underground,the subsurface media absorb high-frequency components,decreasing seismic resolution and limiting the identification and characterization of thin reservoirs.To address the limit...As seismic signals propagate underground,the subsurface media absorb high-frequency components,decreasing seismic resolution and limiting the identification and characterization of thin reservoirs.To address the limitation,this paper proposes a multichannel spectral fitting(MSF)method.The MSF method aims to enhance seismic resolution by considering the spectral characteristics and the correlations between adjacent seismic traces.The key to the MSF method involves utilizing the amplitude spectrum of the attenuated Ricker wavelet to construct an objective function for spectral fitting,leading to improved seismic resolution.Furthermore,the MSF method establishes the correlation between adjacent seismic traces as a constraint to stably solve the target parameters based on the entire seismic spectrum,which helps obtain horizontally consistent and more realistic seismic signals.Synthetic and field seismic examples demonstrate that the proposed method not only provides higher-resolution seismic signals but also reveals more fine details of thin reservoirs compared to the time-variant spectral whitening method.It is concluded that the MSF method is a promising tool for seismic signal processing.展开更多
Widespread soil acidification driven by nitrogen(N)fertilization and precipitation challenges the conventional notion of the long-term stability of soil inorganic carbon(SIC)in agroecosystems.However,the changes in SI...Widespread soil acidification driven by nitrogen(N)fertilization and precipitation challenges the conventional notion of the long-term stability of soil inorganic carbon(SIC)in agroecosystems.However,the changes in SIC with precipitation and N fertilization remain ambiguous.Based on 4,000+soil samples collected in the 1980s and 2010s and by developing machine learning models to fill the missing SIC of soil samples,this study generated 3,697 paired soil samples between the two periods and then investigated the cropland SIC change and explored its relationship with precipitation and N fertilization across the Sichuan Basin,China.The results showed an overall SIC loss,with a decline of the mean SIC by 15.73%.SIC change varied with initial soil pH and initial SIC and exhibited an exponential relationship with soil pH change,indicating the changing role of carbonates in providing acid-buffering capacity.There was a parabolical relationship between the magnitude of SIC decline and N fertilizer rates,and low N fertilizer rates contributed to a reduction in SIC loss,while SIC loss was promoted by N fertilization occurred when N fertilizing rates exceeded 250 kg ha^(-1) yr^(-1).The change in SIC showed a sinusoidal variation with precipitation,with 950 mm being the threshold controlling whether SIC increased or decreased.Meanwhile,N fertilization did not alter the sinusoidal relationship between SIC change and precipitation.In areas with rainfall<950 mm,the high N fertilizer rate did not cause SIC loss,while higher precipitation could also cause larger SIC loss in areas with lower N fertilizer rates.These results suggest that SIC dynamics are jointly driven by precipitation and N fertilization and are controlled by acid-buffering mechanisms associated with initial pH and SIC,with precipitation being the predominant driver.These findings emphasize the need for more regional soil observations and in-depth studies of SIC change and its mechanisms for accurately estimating SIC change.展开更多
The carbonate-rich shale of the Permian Wujiaping Formation in Sichuan Basin exhibits significant heterogeneity in its lithology and pore structure,which directly influence its potential for shale gas extraction.This ...The carbonate-rich shale of the Permian Wujiaping Formation in Sichuan Basin exhibits significant heterogeneity in its lithology and pore structure,which directly influence its potential for shale gas extraction.This study assesses the factors that govern pore heterogeneity by analyzing the mineral composition of the shale,as well as its pore types and their multifractal characteristics.Three primary shale facies-siliceous,mixed,and calcareous-are identified based on mineralogy,and their multifractal characteristics reveal strongly heterogeneous pore structures.The brittleness of siliceous shale,rich in quartz and pyrite,is favorable for hydraulic fracturing;while calcareous shale,with higher levels of calcite,exhibits reduced brittleness.Multifractal analysis,using nitrogen adsorption isotherms,reveals complex pore structures across different shale facies,with siliceous shale showing better pore connectivity and uniformity.The types of pores in shales include organic matter pores,interparticle pores,and intraparticle pores,among which organic matter pores are the most abundant.Pore size distribution and connectivity are notably higher in siliceous shale compared to calcareous shale,which exhibit a predominance of micropores and more isolated pore structures.Pore heterogeneity of the carbonate-rich shale in the Wujiaping Formation is primarily governed by its intrinsic mineral composition,carbonate diagenesis,mechanical compaction,and its subsequent thermal maturation with the micro-migration of organic matter.This study highlights the importance of mineral composition,especially the presence of dolomite and calcite,in shaping pore heterogeneity.These findings emphasize the critical role of shale lithofacies and pore structure in optimizing shale gas extraction methods.展开更多
基金Supported by National Modern Agricultural Industry Technology System Sichuan Pig Innovation Team(SCCXTD-2026-8)Sichuan Science and Technology Program(2025ZYD0049)"Challenge and Leadership"Project for Key Core Technologies of Sui Ning in Sichuan(2025SNKBZ19).
文摘Sichuan sausages with moisture contents of 40%,45%,50%,and 60% were stored at-18℃for durations of 0,2,4,6,and 8 weeks to evaluate the effect of moisture content on the quality attributes of Sichuan sausages during frozen storage.Product indicators including pH,colour,thiobarbituric acid reactive substances(TBARS),total volatile basic nitrogen(TVB-N),texture,electronic nose(E-nose)response,and water-holding capacity(thawing and cooking losses)were determined.The results indicated that as storage time increased,water retention in Sichuan sausages with different moisture contents decreased,while the degree of protein and lipid oxidation increased.This led to an increase in pH value,a colour shift from red-bright to grey-brown,and a deterioration in palatability.Among the samples,sausages with 50% moisture content exhibited the lowest thawing and cooking losses,indicating superior water-holding capacity.After 8 weeks of storage,TBARS and TVB-N values for the 50% moisture group were 19.5%and 2.5%lower,respectively,than those of the 40%and 45%moisture groups,indicating a reduced degree of oxidation.Furthermore,Sichuan sausage with 50%moisture content demonstrated an appropriate pH and colour difference,along with excellent texture and flavour,as evidenced by its higher toughness and satisfactory hardness.In conclusion,Sichuan sausage with 50% moisture content demonstrated the highest overall quality under frozen storage conditions.
基金supported by the National Science Foundation of China(Grant No.41602161,92255302)the National Science and Technology Major Project of China(Project No.2016ZX05033)Sinopec Science and Technology Development Project(Project No.P18089-1,P22085).
文摘The Western Sichuan Foreland Basin(WSFB)in South China,a prolific hydrocarbon province,exhibits complex structural deformation influenced by Triassic salt tectonics.This paper integrates seismic data and well data to elucidate the role of Middle-Lower Triassic evaporite layers in shaping basin structures,focusing on Xinchang Tectonic Zone(XTZ).Salt layers facilitated decoupled deformation between supra-and sub-salt sequences,forming salt pillows and fault-related folds.Three distinct structural trends were identified in XTZ.Key findings reveal that salt thickness variations correlate with deformation styles:thicker salt promoted detachment folding,while thinner salt led to hard-linked fault systems.Sub-salt E-NE trending reverse faults formed horsetail terminations associated with the Pengzhou faults(PzF),deviating from the primary Longmenshan thrust belt(LmsTB)orientation.Structural evolution occurred in three stages:(1)Indosinian salt deposition and foreland basin initiation;(2)Yanshanian eastward propagation of thrust systems with salt-driven detachment folding;(3)Himalayan reactivation overprinting earlier structures with sub-NS trending folds.This work establishes a direct link between salt layers and structural traps,demonstrating how salt acted as a critical detachment layer during multi-stage compression.Results provide insights into the gas exploration of the Late Triassic Xujiahe Formation,emphasizing the importance of salt-influenced deformation in foreland basin systems.
文摘The original online version of this article was revised:The layout update for Article 758 has impacted the page range in the published issue,but did not affect the scholarly content.To ensure consistency with the originally assigned pages(2595-2614),we will need to publish an erratum to correct the article and restore the original page range.The original article has been corrected.
文摘Established in 1958,Sichuan Academy of Social Sciences(SASS)is a public institutionguided by the People’s Government of Sichuan Province.It is a comprehensive and specializedresearch institution in social sciences that integrates research,education,editing,andconsulting services.It holds the registered trademark of“Tianfu Think Tank”and owns twocampuses:Baihuatan and Banzhuyuan.SASS consists of 16 research institutes as well as functional and educational departments,such as the Party Committee and the Graduate School.Currently,it has 450 employees,including a significant number of reputable scholars and recipients of national and provincial honors in the fields of culture and economy,such as national-level candidates for the Hundred,Thousand and Ten Thousand Talents Project,Leading Talent in Philosophy and Social Sciences in the National Ten Thousand Talents Program,participants in China’s Four-pronged Publicity Talent Program,Academic and Technology Leader of Sichuan Province,and Expert of Sichuan Province with Outstanding Contributions.
基金the National Natural Science Foundation of China(Nos.52204005,52192622,U20A20265)the Sichuan Science Fund for Young Scholars(23NSFSC4652).
文摘Deep shale gas reservoirs in the southern Sichuan Basin are typically characterized by significant horizontal stress anisotropy(expressed as stress difference),variable brittleness-ductility in rock mechanics,and strong heterogeneity.These complex geomechanical conditions lead to pronounced differences in hydraulic fracturing outcomes among wells and sections.To investigate hydraulic fracture propagation and fracturing fluid injection behavior under varying geomechanical settings,true triaxial physical simulation tests were performed on 400×400×400 mm artificial rock samples.The samples were designed with different media properties based on similarity criteria.A sensitivity analysis was conducted to assess the effects of brittleness-ductility characteristics,natural fractures,and in-situ stress conditions.The results reveal that:(i)brittle samples with lower stress difference are favorable for forming complex,perforable fracture networks;(ii)brittle samples with higher stress difference tend to develop simple,planar hydraulic fractures,with natural fractures only slightly activated during very short injection periods;(iii)ductile behavior enhances the activation of natural fractures but reduces fracture complexity compared with brittle samples,even under lower stress difference;and(iv)for typical deep shale formations,larger fluid injection volumes combined with high-density,multi-cluster fracturing techniques are recommended.
基金Supported by the National Science and Technology Major Project of China(2016ZX05061)Sinopec Science and Technology Department Project(P21042-4,P25030)。
文摘Based on the data of drilling,logging,experiment and gas testing in the Nanchuan area,southeastern Sichuan Basin,the hydrocarbon generation potential,gas genesis,occurrence state,migration,preservation conditions,pore and fracture features and accumulation evolution of the first member of Permian Maokou Formation(Mao 1 Member)are systematically studied,and the main controlling factors of unconventional gas enrichment and high production in marlstone assemblage of Mao 1 Member are discussed.(1)The enrichment and high yield of unconventional natural gas in the Mao 1 Member are controlled by three factors:carbon-rich fabric controlling hydrocarbon generation potential,good preservation controlling enrichment,and natural fracture controlling production.(2)The carbonate rocks of Mao 1 Member with carbon rich fabric have significant gas potential,exhibiting characteristics of self-generation and self-storage,which lays the material foundation for natural gas accumulation.(3)The occurrence state of natural gas is mainly free gas,which is prone to lateral migration,and good storage conditions are the key to natural gas enrichment.Positive structure is more conducive to natural gas accumulation,and a good compartment is created jointly by the self-sealing property of the Mao 1 Member and its top and bottom sealing property in monoclinal area,which is favorable for gas accumulation by retention.(4)Natural fractures are the main reservoir space and flow channel,and the more developed natural fractures are,the more conducive to the formation of high-quality porous-fractured reservoirs and the accumulation of natural gas,which is the core of controlling production.(5)The accumulation model of unconventional natural gas is proposed as“self-generation and self-storage,preservation controlling richness,and fractures controlling production”.(6)Identifying fracture development areas with good preservation conditions is the key to successful exploration,and implementing horizontal well staged acidizing and fracturing is an important means to increase production and efficiency.The study results are of referential significance for further understanding the natural gas enrichment in the Mao 1 Member and guiding the efficient exploration and development of new types of unconventional natural gas.
基金Supported by the Sinopec Major Science and Technology Project(P22081)National Natural Science Foundation of China(U24B60001).
文摘The basic geological characteristics of the Qiongzhusi Formation reservoirs and conditions for shale gas enrichment and high-yield were studied by using methods such as mineral scanning,organic and inorganic geochemistry,breakthrough pressure,and triaxial mechanics testing based on the core,logging,seismic and production data.(1)Both types of silty shale,rich in organic matter in deep water and low in organic matter in shallow water,have good gas bearing properties.(2)The brittle mineral composition of shale is characterized by comparable feldspar and quartz content.(3)The pores are mainly inorganic pores with a small amount of organic pores.Pore development primarily hinges on a synergy between felsic minerals and total organic carbon content(TOC).(4)Dominated by Type I organic matters,the hydrocarbon generating organisms are algae and acritarch,with high maturity and high hydrocarbon generation potential.(5)Deep-and shallow-water shale gas exhibit in-situ and mixed gas generation characteristics,respectively.(6)The basic law of shale gas enrichment in the Qiongzhusi Formation was proposed as“TOC controlled accumulation and inorganic pore controlled enrichment”,which includes the in-situ enrichment model of“three highs and one over”(high TOC,high felsic mineral content,high inorganic pore content,overpressured formation)for organic rich shale represented by Well ZY2,and the in-situ+carrier-bed enrichment model of“two highs,one medium and one low”(high felsic content,high formation pressure,medium inorganic pore content,low TOC)for organic-poor shale gas represented by Well JS103.It is a new type of shale gas that is different from the Longmaxi Formation,enriching the formation mechanism of deep and ultra-deep shale gas.The deployment of multiple exploration wells has achieved significant breakthroughs in shale gas exploration.
基金supported by the National Natural Science Foundation of China(No.42173030)the Open Project from the Key Laboratory of Shale Gas Exploration,Ministry of Natural Resources(KLSGE-202406).
文摘Benthic bivalves,the most widely distributed mollusks since the Mesozoic era,often inhabited environments where their fossilized remains are found adjacent to or intermingled with organic-rich shale.Recent Jurassic shale oil exploration in the Sichuan Basin has revealed that bioclastic layers,composed of abundant fossil bivalves and closely associated with shales and,exhibit significant hydrocarbon potentials.However,the microscopic structures of these bivalve fossils and their role in hydrocarbon storage and migration remain poorly understood.In this study,we characterized the microporosity of bivalve shells within the Middle-Lower Jurassic bioclastic shale in the northeastern Sichuan Basin using a combination of 2D imaging(thin section,SEM),3D reconstruction(FIB-SEM),and permeability simulation.The micropores within the shell fossils range from 100 to 1000 nm in radius and are uniformly distributed in a grid-like pattern within the shell interior,where they host liquid hydrocarbons.The bioclastic carbonate layers exhibit an overall porosity of approximately 0.8%.Comparative analysis with extant bivalve shells suggests that these micropores represent residual pores from the nacreous brick wall structure.Due to the regular orientation of the shells and their microporous nacres,permeability coefficients along the long bivalve fossil axes are three to five times higher than those along the short axes.These residual micropores within the bioclastic fossil shells have a positive influence on both the storage and migration of shale oil and gas,making bioclastic fossil-bearing shalespromising sweet spots for shale oil and gas exploration in similar sedimentary environments.
基金Supported by the National Natural Science Foundation of China(42172166)National Natural Science Foundation and CNPC Joint Fund Project(U23B20154)CNPC-Southwest Petroleum University Science and Technology Cooperation Project(2020CX010000).
文摘This paper discusses the characteristics and formation mechanism of thin dolomite reservoirs in the lower submember of the second member of the Permian Maokou Formation(lower Mao 2 Member)in the Wusheng-Tongnan area of the Sichuan Basin,SW China,through comprehensive analysis of geological,geophysical and geochemical data.The reservoir rocks of the lower Mao 2 Member are dominated by porphyritic vuggy dolomite and calcareous dolomite or dolomitic limestone,which have typical karst characteristics of early diagenetic stage.The dolomites at the edge of the karst system and in the fillings have dissolved estuaries,and the dolomite breccia has micrite envelope and rim cement at the edge,indicating that dolomitization is earlier than the early diagenetic karstification.The shoal facies laminated dolomite is primarily formed by the seepage reflux dolomitization of moderate-salinity seawater.The key factors of reservoir formation are the bioclastic shoal deposition superimposed with seepgae reflux dolomitization and the karstification of early diagenetic stage,which are locally reformed by fractures and hydrothermal processes.The development of dolomite vuggy reservoir is closely related to the upward-shallowing sequence,and mainly occurs in the late highstand of the fourth-order cycle.Moreover,the size of dolomite is closely related to formation thickness,and it is concentrated in the formation thickness conversion area,followed by the thinner area.According to the understanding of insufficient accommodation space in the geomorphic highland and the migration of granular shoal to geomorphic lowland in the late highstand of the third-order cycle,it is proposed that the large-scale shoal-controlled dolomite reservoirs are distributed along structural highs and slopes,and the reservoir-forming model with shoal,dolomitization and karstification jointly controlled by the microgeomorphy and sea-level fluctuation in the sedimentary period is established.On this basis,the paleogeomorphology in the lower Mao 2 Member is restored using well-seismic data,and the reservoir distribution is predicted.The prediction results have been verified by the latest results of exploration wells and tests,which provide an important reference for the prediction of thin dolomite reservoirs under similar geological setting.
基金supported by the funding provided by the State Key Laboratory of Hydraulics and Mountain River Engineering(SKHL2210)National Natural Science Foundation of China(42171304)+1 种基金the Sichuan Science and Technology Program(2023YFS0380)Natural Science Foundation of Jiangsu Province of China(BK20242018)。
文摘The Yellow River Basin in Sichuan Province(YRS)is undergoing severe soil erosion and exacerbated ecological vulnerability,which collectively pose formidable challenges for regional water conservation(WC)and sustainable development.While effectively enhancing WC necessitates a comprehensive understanding of its driving factors and corresponding intervention strategies,existing studies have largely neglected the spatiotemporal heterogeneity of both natural and socio-economic drivers.Therefore,this study explored the spatiotemporal heterogeneity of WC drivers in YRS using multi-scale geographically weighted regression(MGWR)and geographically and temporally weighted regression(GTWR)models from an eco-hydrological perspective.We discovered that downstream regions,which are more developed,achieved significantly better WC than upstream regions.The results also demonstrated that the influence of temperature and wind speed is consistently dominant and temporally stable due to climate stability,while the influence of vegetation shifted from negative to positive around 2010,likely indicating greater benefits from understory vegetation.Economic growth positively impacted WC in upstream regions but had a negative effect in the more developed downstream regions.These findings highlight the importance of targeted water conservation strategies,including locally appropriate revegetation,optimization of agricultural and economic structures,and the establishment of eco-compensation mechanisms for ecological conservation and sustainable development.
基金Supported by the National Natural Science Foundation of China(42302141).
文摘Taking the second member of the Xujiahe Formation of the Upper Triassic in the Xinchang structural belt as an example,based on data such as logging,production,seismic interpretation and test,a systematic analysis was conducted on the structural characteristics and evolution,reservoir diagenesis and densification processes,and types and stages of faults/fractures,and revealing the multi-stage and multi-factor dynamic coupled enrichment mechanisms of tight gas reservoirs.(1)In the early Yanshan period,the paleo-structural traps were formed with low-medium maturity hydrocarbons accumulating in structural highs driven by buoyancy since reservoirs were not fully densified in this stage,demonstrating paleo-structure control on traps and early hydrocarbon accumulation.(2)In the middle-late Yanshan period,the source rocks became mature to generate and expel a large quantity of hydrocarbons.Grain size and type of sandstone controlled the time of reservoir densification,which restricted the scale of hydrocarbon charging,allowing for only a small-scale migration through sand bodies near the fault/fracture or less-densified matrix reservoirs.(3)During the Himalayan period,the source rocks reached overmaturity,and the residual oil cracking gas was efficiently transported along the late-stage faults/fractures.Wells with high production capacity were mainly located in Type I and II fault/fracture zones comprising the late-stage north-south trending fourth-order faults and the late-stage fractures.The productivity of the wells was controlled by the transformation of the late-stage faults/fractures.(4)The Xinchang structural belt underwent three stages of tectonic evolution,two stages of reservoir formation,and three stages of fault/fractures development.Hydrocarbons mainly accumulated in the paleo-structure highs.After reservoir densification and late fault/fracture adjustment,a complex gas-water distribution pattern was formed.Thus,it is summarized as the model of“near-source and low-abundance hydrocarbon charging in the early stage,and differential enrichment of natural gas under the joint control of fault-fold-fracture complex,high-quality reservoirs and structural highs in the late stage”.Faults/fractures with well-coupled fault-fold-fracture-pore are favorable exploration targets with high exploration effectiveness.
基金Supported by National Natural Science Foundation of China and Enterprise Innovation and Development Joint Fund(U21B2062).
文摘The faults and associated fracture zones in the tight sandstone reservoirs of the fifth member of the Triassic Xujiahe Formation(Xu-5 Member)in the Wubaochang area,northeastern Sichuan Basin,play a critical role in controlling gas well productivity.To delineate the distribution patterns of the faults and associated fracture zones in this area,a transfer-trained convolutional neural network(CNN)model and an XGBoost(eXtreme Gradient Boosting)-based intelligent seismic attribute fusion method were employed to identify faults and fracture zones,respectively,enabling precise characterization of their spatial distribution.The faults in the Wubaochang area are classified into first-to fourth-order structures,with the average fracture zone width on the hanging wall exceeding that of the footwall,demonstrating a strong positive correlation between fracture zone width and fault displacement.The study area is divided into three distinct deformation regions(southern,central and northern regions)featuring five fault structural styles(duplex,duplex-backthrust,imbricate thrust,synclinorium imbricate-backthrust,and anticlinorium imbricate-backthrust)and four corresponding fracture zone development patterns(duplex,duplex-backthrust,synclinorium imbricate-backthrust,and anticlinorium imbricate-backthrust).Based on the controlling effects of faults on gas enrichment,the dual-source hydrocarbon-supply zones are interpreted to be distributed in the northern and central regions,while the southern region is identified as gas-escape zones.By integrating the distribution of favorable reservoir development areas and fracture zones,two classes of gas enrichment zones(Class Ⅰ and Ⅱ)are delineated.Class Ⅰ zones are primarily distributed in the northern region and the transitional zone from the southern to central regions,whereas Class Ⅱ zones are concentrated in the central region.Class Ⅰ zones exhibit dual-source hydrocarbon-supply conditions,larger-scale fracture zone development,and higher favorability compared to Class Ⅱ zones.According to the defined gas accumulation effectiveness in different types of fracture zones,a high-productivity gas well model for the Wubaochang area is proposed,emphasizing“dual-source faults controlling enrichment,effective fracture zones controlling high production,and high matrix porosity ensuring sustained production”.Targeted drilling directions for different favorable zones are further optimized based on this model.
文摘Xi Jinping Thought on Ecological Civilization contains new concepts,ideas,and strategies that feature Chinese characteristics and the spirit of the times and promote the progress of human civilization.Xi Jinping Thought on Ecological Civilization is also the fundamental guide for compliance and action in terms of China’s practices in building an ecological civilization in the new era.Since the 18th National Congress of the Communist Party of China(CPC),Xi Jinping,general secretary of the Communist Party of China Central Committee,has made several inspection tours to Sichuan and given a series of important instructions on green development and building an ecological civilization in Sichuan province.This paper reviews the contemporary meaning and theoretical significance of Xi Jinping Thought on Ecological Civilization and uses them to systematically examine the overall performance of building a beautiful Sichuan,following the guidance of Xi Jinping’s important instructions for the governance of Sichuan.This paper selects and analyzes typical cases that demonstrate the national effect in Sichuan to summarize Sichuan’s unique experiences in the practice of Xi Jinping Thought on Ecological Civilization.
基金Supported by National Natural Science Foundation of China(42572132,U24B6001,41872150,42230310,U2344209).
文摘The occurrence types and controlling factors of organic matter in the sepiolite-containing successions of the first member of Mid-Permian Maokou Formation(Mao-1 Member for short)in the Eastern Sichuan Basin,SW China,have been investigated through outcrop section measurement,core observation,thin section identification,argon ion polishing-field scanning electron microscopy,energy spectrum analysis,X-ray diffraction,total organic carbon content(TOC),major and trace element analysis.Finally,the symbiotic adsorption model of sepiolite for organic matter enrichment has been established.The results show that the sepiolite-containing successions of the Mao-1 Member are composed of the rhythmite of mudstone,argillaceous limestone and limestone,with five depositional intervals vertically and the organic matter mostly developed in the mudstone and argillaceous limestone layers within the lower three intervals.The organic matter occurrence types are mostly layered or nodular in macro to meso-scale,blocky-vein-like under a microscope,but scattered,interstitial or adsorbed at a mesoscopic scale.It underwent transition processes from lower to higher salinity,from oxygen-poor and anoxic reduction to oxygen-poor and localized oxygen enrichment on the palaeo-environment of the Mao-1 Member.The first two intervals of the early depositional phase of Mao-1 Member constitute the cyclothems of mudstone,argillaceous limestone and limestone and quantities of fibrous-feathered sepiolite settle down within the Tongjiang-Changshou sag with continuous patchy organic matter from adsorption of alginate by sepiolite in intercrystalline,bedding surfaces and interlayer pores.The third and fourth intervals in the mid-depositional phase are mostly composed of the mudstone and argillaceous limestone alternations with the continuous patchy or banded organic matter in the surface and inter-crystalline pores of fibrous,feathered and flaky sepiolite.And the fifth interval in the late depositional phase of the Mao-1 Member comprises the cyclothems of extremely thin layered argillaceous limestone and thick-layered limestone with the fibrous sepiolite depositing in the argillaceous limestone and irregular organic matter dispersing around the sepiolite.Therefore,the symbiotic adsorption between organic matter and sepiolite effectively enhances the preservation efficiency of organic matter and improves the source rock quality of the Mao-1 Member,which enhances our understanding on the enrichment model of the depositional organic matter.
基金financially supported by the Science Foundation of China University of Petroleum,Beijing(Nos.2462018YJRC030 and 2462020YXZZ020)the China Sponsorship Council(No.202306440071)。
文摘The widespread dolomite of the Sinian Dengying Formation in the Sichuan Basin(China)serves as one of the most important oil and gas reservoir rocks of the basin.Well WT1,as an exploration well,is recently drilled in the Kaijiang County,northeastern Sichuan Basin(SW China),and it drills through the Dengying Formation dolomite at the depth interval of 7500–7580 m.In this study,samples are systematically collected from the cores of that interval,followed by new analyses of carbon-oxygen isotope,major elements,trace elements,rare earth elements(REEs)and EP-MA.The Dengying Formation dolomites of Well WT1 haveδ13C values of 0.37‰to 2.91‰andδ18O values of-5.72‰to-2.73‰,indicating that the dolomitization fluid is derived from contemporary seawater in the near-surface environment,rather than the burial environment.Based on the REE patterns of EPMA-based in-situ data,we recognized the seawater-sourced components,the mixedsourced components and the terrigenous-sourced components,indicating the marine origin of the dolomite with detrital contamination and diagenetic alteration.Moreover,high Al,Th,and Zr contents indicate significant detrital contamination derived from clay and quartz minerals,and high Sr/Ba and Sr/Cu ratios imply a relatively dry depositional environment with extremely high seawater salinity,intensive evaporation,and strong influences of terrigenous sediment.
文摘"Sichuan Cuisine Cooking Skills"is a course that focuses on the traditional cooking skills of Sichuan Province in China.It covers not only the historical and cultural background of Sichuan cuisine,but also the cooking techniques,ingredients selection,seasoning skills and dish innovation of Sichuan cuisine.Doing a good job in the teaching of"Sichuan Cuisine Cooking Skills"is of great significance to the cultivation and reserve of culinary professionals in China,and also has an important impact on students'employment competitiveness.Under the background of"new engineering education",the course reform of"Sichuan Cuisine Cooking Skills"was carried out in terms of the construction of teaching staff,teaching methods,students'participation degree and the innovation of course content,and specific reform suggestions were put forward,hoping to effectively promote the sustainable development of"Sichuan Cuisine Cooking Skills"and effectively improve the teaching quality.
基金supported from the Opening fund of State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development(33550000-22-ZC0613-0297)National Natural Science Foundation of China(42102196)the Natural Science Basis Research Plan in Shaanxi Province of China(2022JM-147).
文摘Pore structure directly affects the occurrence and migration of shale hydrocarbon,and the lack of research on the mechanism of the pore structure is an important reason for the hindrance of shale hydrocarbon exploration.By analysing the geochemistry and reservoir characteristics of Jurassic lacustrine shales in Sichuan Basin,this study recovers their paleoenvironments and further discusses paleoenvironmental constraints on pore structure.The results show that the Lower Jurassic lacustrine shales in the Sichuan Basin are in a warm and humid semi-anoxic to anoxic lake environment with high productivity,a strong stagnant environment,and a rapid sedimentation rate,with water depths ranging from about 11.54-55.22 m,and a mixture of type Ⅱ/Ⅲ kerogen is developed.In terms of reservoir characteristics,they are dominated by open-slit pores,and the pores are relatively complex.The percentage of mesopores is the highest,while the percentage of macropores is the lowest.Further analysis shows that paleoclimate controls the overall pore complexity and surface relaxation of shales by influencing the weathering rate of mother rocks.Paleoredox conditions control the proportion and complexity of shale pores by influencing TOC content.The research results will provide theoretical basis for improving the exploration efficiency of lacustrine shale resources and expanding exploration target areas.
基金supported in part by the National Natural Science Foundation of China under Grant 42174164 and Grant 41704132in part by the Key Program of the Joint Fund of the Science,Technology,and Education of Sichuan Province,China under Grant 2024NSFSC1955+4 种基金in part by the Natural Science Foundation of Sichuan Province,China under Grant 2024NSFSC0080in part by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project under Grant SKLGP2022Z011in part by the Chengdu University of Technology Postgraduate Innovative Cultivation Program:Spatiotemporal Characterization of Seismic Signals for Tight Channel Sandstone Gas Reservoirs in the Synchro-Squeezing/Extracting Transform Domain under Grant CDUT2023BJCx002in part by the Creative Research Groups of the Natural Science Foundation of Sichuan under Grant 2023NSFSC198414th Five Year Plan Major Science and Technology Project of CNOOC under Grant KJGG2022-0903.
文摘As seismic signals propagate underground,the subsurface media absorb high-frequency components,decreasing seismic resolution and limiting the identification and characterization of thin reservoirs.To address the limitation,this paper proposes a multichannel spectral fitting(MSF)method.The MSF method aims to enhance seismic resolution by considering the spectral characteristics and the correlations between adjacent seismic traces.The key to the MSF method involves utilizing the amplitude spectrum of the attenuated Ricker wavelet to construct an objective function for spectral fitting,leading to improved seismic resolution.Furthermore,the MSF method establishes the correlation between adjacent seismic traces as a constraint to stably solve the target parameters based on the entire seismic spectrum,which helps obtain horizontally consistent and more realistic seismic signals.Synthetic and field seismic examples demonstrate that the proposed method not only provides higher-resolution seismic signals but also reveals more fine details of thin reservoirs compared to the time-variant spectral whitening method.It is concluded that the MSF method is a promising tool for seismic signal processing.
基金supported by the National Natural Science Foundation of China(42330707 and 41930647)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(72221002)the Science and Technology Plan of Sichuan Province,China(2022NSFSC0104).
文摘Widespread soil acidification driven by nitrogen(N)fertilization and precipitation challenges the conventional notion of the long-term stability of soil inorganic carbon(SIC)in agroecosystems.However,the changes in SIC with precipitation and N fertilization remain ambiguous.Based on 4,000+soil samples collected in the 1980s and 2010s and by developing machine learning models to fill the missing SIC of soil samples,this study generated 3,697 paired soil samples between the two periods and then investigated the cropland SIC change and explored its relationship with precipitation and N fertilization across the Sichuan Basin,China.The results showed an overall SIC loss,with a decline of the mean SIC by 15.73%.SIC change varied with initial soil pH and initial SIC and exhibited an exponential relationship with soil pH change,indicating the changing role of carbonates in providing acid-buffering capacity.There was a parabolical relationship between the magnitude of SIC decline and N fertilizer rates,and low N fertilizer rates contributed to a reduction in SIC loss,while SIC loss was promoted by N fertilization occurred when N fertilizing rates exceeded 250 kg ha^(-1) yr^(-1).The change in SIC showed a sinusoidal variation with precipitation,with 950 mm being the threshold controlling whether SIC increased or decreased.Meanwhile,N fertilization did not alter the sinusoidal relationship between SIC change and precipitation.In areas with rainfall<950 mm,the high N fertilizer rate did not cause SIC loss,while higher precipitation could also cause larger SIC loss in areas with lower N fertilizer rates.These results suggest that SIC dynamics are jointly driven by precipitation and N fertilization and are controlled by acid-buffering mechanisms associated with initial pH and SIC,with precipitation being the predominant driver.These findings emphasize the need for more regional soil observations and in-depth studies of SIC change and its mechanisms for accurately estimating SIC change.
基金supported by research projects P23057 and JKK4624004 of Jianghan Oilfield Company,SINOPEC.
文摘The carbonate-rich shale of the Permian Wujiaping Formation in Sichuan Basin exhibits significant heterogeneity in its lithology and pore structure,which directly influence its potential for shale gas extraction.This study assesses the factors that govern pore heterogeneity by analyzing the mineral composition of the shale,as well as its pore types and their multifractal characteristics.Three primary shale facies-siliceous,mixed,and calcareous-are identified based on mineralogy,and their multifractal characteristics reveal strongly heterogeneous pore structures.The brittleness of siliceous shale,rich in quartz and pyrite,is favorable for hydraulic fracturing;while calcareous shale,with higher levels of calcite,exhibits reduced brittleness.Multifractal analysis,using nitrogen adsorption isotherms,reveals complex pore structures across different shale facies,with siliceous shale showing better pore connectivity and uniformity.The types of pores in shales include organic matter pores,interparticle pores,and intraparticle pores,among which organic matter pores are the most abundant.Pore size distribution and connectivity are notably higher in siliceous shale compared to calcareous shale,which exhibit a predominance of micropores and more isolated pore structures.Pore heterogeneity of the carbonate-rich shale in the Wujiaping Formation is primarily governed by its intrinsic mineral composition,carbonate diagenesis,mechanical compaction,and its subsequent thermal maturation with the micro-migration of organic matter.This study highlights the importance of mineral composition,especially the presence of dolomite and calcite,in shaping pore heterogeneity.These findings emphasize the critical role of shale lithofacies and pore structure in optimizing shale gas extraction methods.
