The quest for enrichment model of continental shale oil in the Zhanhua Sag of the JiyangDepression in the Bohai Bay Basin to provide reference for exploration and development requires acomprehensive approach. Therefor...The quest for enrichment model of continental shale oil in the Zhanhua Sag of the JiyangDepression in the Bohai Bay Basin to provide reference for exploration and development requires acomprehensive approach. Therefore, this study employs rock pyrolysis, Scanning Electron Microscopy(SEM), X-Ray diffraction analysis (XRD), Nuclear Magnetic Resonance (NMR), and other experiments toanalyze the conditions for shale oil enrichment and establish its patterns. The results show that favorablehydrocarbon generation potential and appropriate thermal maturation degree control “in situ enrichment”;while the storage capacity and the mobility of shale oil determine “migration enrichment.” In the process,the TOC governs the oil-generating capacity of shale with medium to large pores and microfractures servingas the main enrichment spaces and migration pathways for shale oil. Based on the deposition model, thestudy area can be divided into five lithofacies stages (I-algal limestone, II-laminated marl, III-laminatedrecrystallized limestone, IV-laminated mudstones, and IV-blocky calcareous mudstones). Integrating thegeochemical parameters into the sedimentary patterns makes it clear that the study area underwent two phasesof hydrocarbon expulsion during the thermal evolution of source rocks (Stage II: 3 060–3 120 m and StageIV: 3 020–3 040 m). However, judging by the observed TOC (2% to 5.6%), thermal maturity (Ro>0.8%),S1 (>2 mg/g) and OSI (>100 mg/g) as well as moderate basin size, climate, and quantity of terrestrial input,the blocky calcareous mudstones (Stage IV) have better oil-prone characteristics and potential to generate asubstantial quantity of hydrocarbons at this stage. More so, with a brittleness index exceeding 60%, it exhibitsfavorable fracturability accounting for the main controlling factors and enrichment patterns of shale oil in thearea. Hence, this study further enriches and develops the theoretical understanding of shale oil enrichment inthe area, provides valuable insights for future exploration of continental shale oil in eastern China and othersimilar basin around the world.展开更多
Biomedical big data,characterized by its massive scale,multi-dimensionality,and heterogeneity,offers novel perspectives for disease research,elucidates biological principles,and simultaneously prompts changes in relat...Biomedical big data,characterized by its massive scale,multi-dimensionality,and heterogeneity,offers novel perspectives for disease research,elucidates biological principles,and simultaneously prompts changes in related research methodologies.Biomedical ontology,as a shared formal conceptual system,not only offers standardized terms for multi-source biomedical data but also provides a solid data foundation and framework for biomedical research.In this review,we summarize enrichment analysis and deep learning for biomedical ontology based on its structure and semantic annotation properties,highlighting how technological advancements are enabling the more comprehensive use of ontology information.Enrichment analysis represents an important application of ontology to elucidate the potential biological significance for a particular molecular list.Deep learning,on the other hand,represents an increasingly powerful analytical tool that can be more widely combined with ontology for analysis and prediction.With the continuous evolution of big data technologies,the integration of these technologies with biomedical ontologies is opening up exciting new possibilities for advancing biomedical research.展开更多
Wells CXD1 and CX2 have uncovered high-concentration potassium-and lithium-containing brines and substantial layers of halite-type polyhalite potash deposits within the 4th and 5th members of the Triassic Jialingjiang...Wells CXD1 and CX2 have uncovered high-concentration potassium-and lithium-containing brines and substantial layers of halite-type polyhalite potash deposits within the 4th and 5th members of the Triassic Jialingjiang Formation and the 1st Member of Leikoupo Formation(Jia 4 Member,Jia 5 Member,and Lei 1 Member)in the Puguang area,Sichuan Basin.These discoveries mark significant breakthroughs in the exploration of deep marine potassium and lithium resources within the Sichuan Basin.Utilizing the concept of“gas-potassium-lithium integrated exploration”and incorporating drilling,logging,seismic,and geochemical data,we have investigated the geological and enrichment conditions,as well as the metallogenic model of potassium-rich and lithium-rich brines and halite-type polyhalite.First,the sedimentary systems of gypsum-dolomite flats,salt lakes and evaporated flats were developed in Jia 4 Member,Jia 5 Member,and the 1st member of Leikoupo Formation(Lei 1 Member)in northeastern Sichuan Basin,forming three large-scale salt-gathering and potassium formation centers in Puguang,Tongnanba and Yuanba,and developing reservoirs with potassium-rich and lithium-rich brines,which are favorable for the deposition of potassium and lithium resources in both solid or liquid phases.Second,the soluble halite-type polyhalite has a large thickness and wide distribution,and the reservoir brine has a high content of K+and Li+.A solid-liquid superimposed“three-story structure”(with the lower thin-layer of brine reservoir in lower part of Jia 4 Member and Jia 5 Member,middle layer of halite-type polyhalite potash depositS,upper layer of potassium-rich and lithium-rich brine reservoir in Lei 1 Member)is formed.Third,the ternary enrichment and mineralization patterns for potassium and lithium resources were determined.Vertical superposition of polyhalite and green bean rocks is the mineral material basis of potassium-lithium resources featuring“dual-source replenishment and proximal-source release”,with primary seawater and gypsum dehydration as the main sources of deep brines,while multi-stage tectonic modification is the key to the enrichment of halite-type polyhalite and potassiumlithium brines.Fourth,the ore-forming process has gone through four stages:salt-gathering and potassium-lithium accumulation period,initial water-rock reaction period,transformation and aggregation period,and enrichment and finalization period.During this process,the halite-type polyhalite layer in Jia 4 Member and Jia 5 Member is the main target for potassium solution mining,while the brine layer in Lei 1 Member is the focus of comprehensive potassium-lithium exploration and development.展开更多
In addition to the organic matter type,abundance,thermal maturity,and shale reservoir space,the preservation conditions of source rocks play a key factor in affecting the quantity and quality of retained hydrocarbons ...In addition to the organic matter type,abundance,thermal maturity,and shale reservoir space,the preservation conditions of source rocks play a key factor in affecting the quantity and quality of retained hydrocarbons in source rocks of lacustrine shale,yet this aspect has received little attention.This paper,based on the case analysis,explores how preservation conditions influence the enrichment of mobile hydrocarbons in shale oil.Research showns that good preservation conditions play three key roles.(1)Ensure the retention of sufficient light hydrocarbons(C_(1)–C_(13)),medium hydrocarbons(C_(14)–C_(25))and small molecular aromatics(including 1–2 benzene rings)in the formation,which enhances the fluidity and flow of shale oil;(2)Maintain a high energy field(abnormally high pressure),thus facilitating the maximum outflow of shale oil;(3)Ensure that the retained hydrocarbons have the miscible flow condition of multi-component hydrocarbons(light hydrocarbons,medium hydrocarbons,heavy hydrocarbons,and heteroatomic compounds),so that the heavy hydrocarbons(C_(25+))and heavy components(non-hydrocarbons and asphaltenes)have improved fluidity and maximum flow capacity.In conclusion,in addition to the advantages of organic matter type,abundance,thermal maturity,and reservoir space,good preservation conditions of shale layers are essential for the formation of economically viable shale oil reservoirs,which should be incorporated into the evaluation criteria of shale oil-rich areas/segments and considered a necessary factor when selecting favorable exploration targets.展开更多
Coal seams can enrich a variety of harmful trace elements under specific geological conditions.The spatial distribution of harmful trace elements in coal is extremely uneven,and the distribution characteristics of eac...Coal seams can enrich a variety of harmful trace elements under specific geological conditions.The spatial distribution of harmful trace elements in coal is extremely uneven,and the distribution characteristics of each element content are different.The harmful elements released in the process of coal mining and utilization will cause serious harm to the environment and the human body.It is of great resource significance to study the geochemistry of coal that affects the enrichment and distribution characteristics of harmful trace elements.Based on the domestic and foreign literature on coal geochemistry in Guizhou published by previous investigators,this study counted 1097 sample data from 23 major coal-producing counties in Guizhou Province,systematically summarized the relevant research results of harmful trace elements in the coal of Guizhou,and revealed the overall distribution and enrichment characteristics of harmful trace elements in the coal of Guizhou.The results show that the average contents of Cd,Pb,Se,Cu,Mo,U,V,As,Hg,and Cr in coal of Guizhou are higher than those in Chinese coal and world coal.A variety of harmful trace elements in the coal of Guizhou have high background values,especially in Liupanshui,Xingyi and Qianbei coalfield.The enrichment of various harmful trace elements in the Late Permian coal in Guizhou is mainly related to the combined action of various geological and geochemical factors.The supply of terrigenous debris and sedimentary environment may be the basic background of the enrichment of harmful elements in western Guizhou,while low-temperature hydrothermal activity and volcanic ash deposition may be the main reasons for the enrichment of harmful elements in southwestern Guizhou.展开更多
The organic-rich mudstones and dolostones of the Permian Fengcheng Formation(Fm.)are typically alkaline lacustrine source rocks,which are typified by impressively abundantβ-carotane.Abundant β-carotane has been well...The organic-rich mudstones and dolostones of the Permian Fengcheng Formation(Fm.)are typically alkaline lacustrine source rocks,which are typified by impressively abundantβ-carotane.Abundant β-carotane has been well acknowledged as an effective indicator of biological sources or depositional environments.However,the specific biological sources of β-carotane and the coupling control of biological sources and environmental factors on the enrichment of β-carotane in the Fengcheng Fm.remains obscure.Based on a comprehensive investigation of the bulk,molecular geochemistry,and organic petrology of sedimentary rocks and the biochemistry of phytoplankton in modern alkaline lakes,we proposed a new understanding of the biological precursors of β-carotane and elucidated the enrichment mechanism of β-carotane in the Fengcheng Fm.The results show that the biological precursors crucially control the enrichment of β-carotane in the Fengcheng Fm.The haloalkaliphilic cyanobacteria are the primary biological sources of β-carotane,which is suggested by a good positive correlation between the 2-methylhopane index,7-+8-methyl heptadecanes/C_(max),C_(29%),and β-carotane/C_(max)in sedimentary rocks and the predominance of cyanobacteria with abundantβ-carotene in modern alkaline lakes.The enrichment of β-carotane requires the reducing condition,and the paleoredox state that affects the enrichment of β-carotane appears to have a threshold.The paleoclimate conditions do not considerably impact the enrichment of β-carotane,but they have some influence on the water's paleosalinity by affecting evaporation and precipitation.While it does not directly affect the enrichment of β-carotane in the Fengcheng Fm.,paleosalinity does have an impact on the cyanobacterial precursor supply and the preservation conditions.展开更多
Overpressure is widely developed in deep petroliferous strata in the hinterland of the Junggar Basin.However,a comprehensive understanding of its origin and effect on hydrocarbon distribution and enrichment remains la...Overpressure is widely developed in deep petroliferous strata in the hinterland of the Junggar Basin.However,a comprehensive understanding of its origin and effect on hydrocarbon distribution and enrichment remains lacking.In this study,we employ five empirical methods and comprehensive geological analysis to identify the origin of overpressure,and uncover the effect of overpressure on hydrocarbon enrichment.The results indicate that disequilibrium compaction is not a significant factor in overpressure generation.Instead,hydrocarbon generation,pressure transfer and diagenesis are the primary causes.The empirical methods support this conclusion.There is a positive correlation between overpressure intensity and source rock thickness and maturity.Notably,widespread cross-formational migration of hydrocarbon bearing fluid occurred,with sandstone overpressure exceeding that of adjacent shale in non-source strata.Furthermore,there is a distinct transformation from smectite to illite near the top of overpressure.Hydrocarbon generation pressurization and pressure transfer significantly effect hydrocarbon enrichment.The overpressure caused by hydrocarbon generation drives hydrocarbon migration and accumulation,establishing an optimal energy configuration between reservoir and cap rock.Faults play a crucial role in hydrocarbon vertical migration and pressure relief.The overpressure in reservoirs can reduce the porosity and permeability thresholds and enhance the charging capacity of oil and gas.展开更多
The Upper Cretaceous Qingshankou Formation black shales,deposited in the late Turonian(LTB shales),are the main source rocks of the Songliao Basin.The origins of organic matter enrichment of the shales is a contentiou...The Upper Cretaceous Qingshankou Formation black shales,deposited in the late Turonian(LTB shales),are the main source rocks of the Songliao Basin.The origins of organic matter enrichment of the shales is a contentious subject fuelling many ongoing debates.This study investigates the genesis of the organic matter-rich shale by using molecular geochemistry.The LTB shales can be divided into three sections.The SectionⅠshales were deposited in saline,stratified and anoxic water conditions,which are related to seawater incursion events.At least three episodic and periodic seawater incursion events were recognized during SectionⅠshale deposition.The SectionⅡshales deposited in brackish to fresh and deep lake-level conditions with high primary productivity,which are related to lake-level transgression.The SectionⅢshales were deposited under fresh and slightly oxidized water conditions,which are related to lake-level regression.Two organic matter enrichment models for the LTB shales are identified,that is,the seawater incursion model and the maximum lake-level transgression sedimentation model,which act on different shale sections,both playing significant roles in the enrichment of organic matter.展开更多
Cambrian shales in China and elsewhere contain abundant oil and gas resources.However,due to its deep burial and limited outcrop,there has been relatively little research conducted on it.The Cambrian shale of the Tado...Cambrian shales in China and elsewhere contain abundant oil and gas resources.However,due to its deep burial and limited outcrop,there has been relatively little research conducted on it.The Cambrian shale of the Tadong low uplift in the Tarim Basin of western China,specifically the Xidashan-Xishanbulake Formation(Fm.)and overlying Moheershan Fm.provide a case study through the use of organic petrology,mineralogy,organic and elemental geochemistry,with the aim of analyzing and exploring the hydrocarbon generation potential(PG)and organic matter(OM)enrichment mechanisms within these shale formations.The results indicate that:(1)the Cambrian shale of the Tadong low uplift exhibits relatively dispersed OM that consists of vitrinite-like macerals and solid bitumen.These formations have a higher content of quartz and are primarily composed of silica-based lithology;(2)shale samples from the Xidashan-Xishanbulake and Moheershan formations demonstrate high total organic carbon(TOC)and low pyrolytic hydrocarbon content(S_(2))content.The OM is predominantly typeⅠand typeⅡkerogens,indicating a high level of maturation in the wet gas period.These shales have undergone extensive hydrocarbon generation,showing characteristics of relatively poor PG;(3)the sedimentary environments of the Xidashan-Xishanbulake and Moheershan formations in the Tadong low uplift are similar.They were deposited in warm and humid climatic conditions,in oxygen-deficient environments,with stable terrigenous inputs,high paleoproductivity,high paleosalinity,weak water-holding capacity,and no significant hydrothermal activity;and(4)the relationship between TOC and the paleoproductivity parameter(P/Ti)is most significant in the Lower Cambrian Xidashan-Xishanbulake Fm.,whereas correlation with other indicators is not evident.This suggests a productivity-driven OM enrichment model,where input of landderived material was relatively small during the Middle Cambrian,and the ancient water exhibited lower salinity.A comprehensive pattern was formed under the combined control of paleoproductivity and preservation conditions.This study provides valuable guidance for oil and gas exploration in the Tarim Basin.展开更多
The black shale of the Mesoproterozoic Cuizhuang Formation in the Changcheng System in Yongji city,North China Craton,is a potential source rock.Understanding the organic matter enrichment mechanism is crucial for eva...The black shale of the Mesoproterozoic Cuizhuang Formation in the Changcheng System in Yongji city,North China Craton,is a potential source rock.Understanding the organic matter enrichment mechanism is crucial for evaluating source rock resources and understanding oil and gas accumulation mechanisms.In this study,we evaluated the sedimentary paleoenvironment and organic matter enrichment mechanisms of shale using thin section observations,mineral composition analysis,organic geochemistry,and elemental geochemistry.We found significant differences in the sedimentary paleoenvironment and organic matter enrichment mechanisms between the lower Cuizhuang Formation and the Beidajian Formation shale.The Cuizhuang Formation was deposited in a late-stage,restricted basin environment during the rift phase,and elemental and geochemical indicators showed that the Cuizhuang Formation was in a suboxic-anoxic water environment,that was influenced by a warm and humid paleoclimate and submarine hydrothermal activities,which promoted the accumulation of organic matter.However,the enrichment of organic matter in the Cuizhuang Formation was mainly controlled by redox conditions.The formation of suboxic-anoxic water environments may be closely related to the warm and humid paleoclimate and submarine hydrothermal activities.Warm conditions promote continental weathering and increase marine productivity,thereby consuming oxygen in the bottom water.Moreover,acidic hydrothermal activity also helps to establish an anoxic environment.Our results reveal the effects controlling various coupled mechanisms dominated by redox conditions,which may explain the development of source rocks in the Cuizhuang Formation.展开更多
The lower Cambrian Qiongzhusi(Є1 q)shale in the Sichuan Basin,formerly considered a source rock,recently achieved high gas production(7.388×105 m^(3)·d^(-1))from well Z201 in the Deyang-Anyue rift trough(DAR...The lower Cambrian Qiongzhusi(Є1 q)shale in the Sichuan Basin,formerly considered a source rock,recently achieved high gas production(7.388×105 m^(3)·d^(-1))from well Z201 in the Deyang-Anyue rift trough(DART),marking an exploration breakthrough of the world’s oldest industrial shale gas reser-voir.However,the shale gas enrichment mechanism within the DART is not fully understood.This study reviews the formation of the Qiongzhusi shale gas reservoirs within the DART by comparing them with cotemporaneous deposits outside the DART,and several findings are presented.The gas production interval was correlated with the main phase of the Cambrian explosion(lower Cambrian stage 3).In the early Cambrian ecosystem,dominant animals likely accelerated the settling rates of organic matter(OM)in the upper 1st member ofЄ_(1) q(Є_(1) q_(12))by feeding on small planktonic organisms and producing larger organic fragments and fecal pellets.High primary productivity and euxinic con-ditions contributed to OM enrichment in the lower 1st member ofЄ1 q(Є_(1) q_(11)).Additionally,shale reservoirs inside the DART demonstrated better properties than those outside in terms of thickness,brittle minerals,gas content,and porosity.In particular,the abundant OM pores inside the DART facil-itated shale gas enrichment,whereas the higher thermal maturity of the shales outside the DART pos-sibly led to the graphitization and collapse of some OM pores.Meanwhile,the overpressure of high-production wells inside the DART generally reflects better shale gas preservation,benefiting from the shale’s self-sealing nature,"upper capping and lower plugging"configuration,and limited faults and microfractures.Considering these insights,we introduced a"ternary enrichment"model for the Qiongzhusi shale gas.Although the current high gas production of Z201 was found at the reservoir 3,two additional reservoirs were identified with significant potential,thus suggesting a"multilayer stereoscopic development"strategy in future shale gas exploration within the DART.展开更多
Based on drilling and logging data,as well as geological experiments,the geological characteristics and factors controlling high-yield and enrichment of hydrocarbons in ultra-deep clastic rocks in the Linhe Depression...Based on drilling and logging data,as well as geological experiments,the geological characteristics and factors controlling high-yield and enrichment of hydrocarbons in ultra-deep clastic rocks in the Linhe Depression,Hetao Basin,are studied.The results are obtained in four aspects.First,the inland saline lacustrine high-quality source rocks developed in the Paleogene in the Linhe Depression have the characteristics of early maturity,early expulsion,high hydrocarbon yield,and continuous and efficient hydrocarbon generation,providing an important resource basis for the formation of ultra-high pressure and high-yield reservoirs.Second,the weak compaction,early charging,and weak cementation for pore-preserving,together with the ultra-high pressure for pore-preserving and fracture expansion to improve the permeability,leads to the development of high-quality reservoirs with medium porosity(greater than 15%)and medium permeability(up to 226×10^(-3)μm^(2))in the ultra-deep strata(deeper than 6500 m),which represents a greatly expanded space for oil and gas exploration.Third,the Linhe Formation adjacent to the trough exhibits a low net-to-gross(NTG)and good reservoir-caprock assemblage,and it is overlaid by very thick high-quality mudstone caprock,which are conducive to the continuous and efficient hydrocarbon generation and pressurization and the formation of ultra-high pressure oil and gas reservoirs.Fourth,the most favorable targets for ultra-deep exploration are the zones adjacent to the hydrocarbon generating center of the Paleogene Linhe Formation and with good tectonic setting and structural traps,mainly including the Xinglong faulted structural zone and the Nalinhu faulted buried-hill zone.The significant breakthrough of ultra-deep oil and gas exploration in the Linhe Depression reveals the good potential of ultra-deep clastic rocks in this area,and provides valuable reference for oil and gas exploration of ultra-deep clastic rocks in other areas.展开更多
Lacustrine shale oil and gas are important fields for unconventional exploration and development in China,and organic-rich shale deposition lays down the critical foundation for hydrocarbon generation.There are two se...Lacustrine shale oil and gas are important fields for unconventional exploration and development in China,and organic-rich shale deposition lays down the critical foundation for hydrocarbon generation.There are two sets of shale,the Dongyuemiao and Da’anzhai Members,in the Ziliujing Formation in the Sichuan Basin.To identify the differential enrichment characteristics of organic matter and clarify its controlling factors,geochemical analyses of organic and inorganic geochemical analyses were performed.The results showed that the total organic carbon content of the Dongyuemiao shale(1.36%)is slightly higher than that of the Da’anzhai shale(0.95%).The enrichment of organic matter in the two shales resulted from the comprehensive controls of paleoproductivity,paleoenvironment,and terrigenous input,but different factors have different effects.In addition,driven by climate,the change in the sulfate concentration in the bottom water further led to the different intensities of bacterial sulfate reduction in early diagenesis.This made a great difference regarding organic matter accumulation in the two members.In general,climate may have played a dominant role in organic matter enrichment in the two sets of shale.展开更多
To explore the occurrence phases and enrichment mechanism of rare earth elements(REEs)in cobalt-rich crusts,this study analyzes the mineral composition and REE contents of the samples from Marcus-Wake Seamounts by XRD...To explore the occurrence phases and enrichment mechanism of rare earth elements(REEs)in cobalt-rich crusts,this study analyzes the mineral composition and REE contents of the samples from Marcus-Wake Seamounts by XRD,ICP-OES and ICP-MS.The results show that,(1)the cobalt-rich crusts contain the major crystalline mineral(vernadite),the secondary minerals(quartz,plagioclase and carbonate fluorapatite),and a large amount of amorphous ferric oxyhydroxides(FeOOH).(2)The cobalt-rich crusts contains higher Mn(10.83%to 28.76%)and Fe(6.14%to 18.86%)relative to other elements,and are enriched in REEs,with total REE contents of 1563−3238μg/g and Ce contents of 790−1722μg/g.Rare earth element contents of the old crusts are higher than those of the new crusts.Moreover,the non-phosphatized crusts have positive Ce and negative Y anomalies,and yet the phosphatized crusts have positive Ce and positive Y anomalies,indicating that cobalt-rich crusts is hydrogenetic and REEs mainly come from seawater.(3)Analytical data also show that the occurrence phases of elements in cobalt-rich crusts are closely related to their mineral phases.In the non-phosphatized crusts,REEs are adsorbed by colloidal particles into the crusts(about 67%of REEs in the Fe oxide phase,and about 17%of REEs in the Mn oxide phase).In contrast,in the phosphatized crusts(affected by the phosphatization),REEs may combine with phosphate to form rare earth phosphate minerals,and about 64%of REEs are enriched in the residual phase containing carbonate fluorapatite,but correspondingly the influence of Fe and Mn oxide phases on REEs enrichment is greatly reduced.In addition,the oxidizing environment of seawater,high marine productivity,phosphatization,and slow growth rate can promote the REE enrichment.This study provides a reference for the metallogenesis of cobalt-rich crusts in the Pacific.展开更多
To reveal the enrichment conditions and resource potential of coal-rock gas in the Ordos Basin,this paper presents a systematic research on the sedimentary environment,distribution,physical properties,reservoir charac...To reveal the enrichment conditions and resource potential of coal-rock gas in the Ordos Basin,this paper presents a systematic research on the sedimentary environment,distribution,physical properties,reservoir characteristics,gas-bearing characteristics and gas accumulation play of deep coals.The results show that thick coals are widely distributed in the Carboniferous–Permian of the Ordos Basin.The main coal seams Carboniferous 5~#and Permian 8~#in the Carboniferous–Permian have strong hydrocarbon generation capacity and high thermal evolution degree,which provide abundant materials for the formation of coal-rock gas.Deep coal reservoirs have good physical properties,especially porosity and permeability.Coal seams Carboniferous 5^(#)and Permian 8^(#)exhibit the average porosity of 4.1%and 6.4%,and the average permeability of 8.7×10^(-3)μm^(2)and 15.7×10^(-3)μm^(2),respectively.Cleats and fissures are developed in the coals,and together with the micropores,constitute the main storage space.With the increase of evolution degree,the micropore volume tends to increase.The development degree of cleats and fissures has a great impact on permeability.The coal reservoirs and their industrial compositions exhibit significantly heterogeneous distribution in the vertical direction.The bright coal seam,which is in the middle and upper section,less affected by ash filling compared with the lower section,and contains well-developed pores and fissures,is a high-quality reservoir interval.The deep coals present good gas-bearing characteristics in Ordos Basin,with the gas content of 7.5–20.0 m^(3)/t,and the proportion of free gas(greater than 10%,mostly 11.0%–55.1%)in coal-rock gas significantly higher than that in shallow coals.The enrichment degree of free gas in deep coals is controlled by the number of macropores and microfractures.The coal rock pressure testing shows that the coal-limestone and coal-mudstone combinations for gas accumulation have good sealing capacity,and the mudstone/limestone(roof)-coal-mudstone(floor)combination generally indicates high coal-rock gas values.The coal-rock gas resources in the Ordos Basin were preliminarily estimated by the volume method to be 22.38×10^(12)m^(3),and the main coal-rock gas prospects in the Ordos Basin were defined.In the central-east of the Ordos Basin,Wushenqi,Hengshan-Suide,Yan'an,Zichang,and Yichuan are coal-rock gas prospects for the coal seam#8 of the Benxi Formation,and Linxian West,Mizhi,Yichuan-Huangling,Yulin,and Wushenqi-Hengshan are coal-rock gas prospects for the coal seam#5 of the Shanxi Formation,which are expected to become new areas for increased gas reserves and production.展开更多
Photoelectrochemical NO_(3)^(-)reduction(PEC NITRR)not only provides a promising solution for promoting the global nitrogen cycle,but also converts NO_(3)^(-)to the important chemicals(NH_(3)).However,it is still a gr...Photoelectrochemical NO_(3)^(-)reduction(PEC NITRR)not only provides a promising solution for promoting the global nitrogen cycle,but also converts NO_(3)^(-)to the important chemicals(NH_(3)).However,it is still a great challenge to prepare catalysts with excellent NO_(3)^(-)adsorption/activation capacity to achieve high NITRR.Herein,we designed a novel Fe^(2+)~Cu^(2+)Fe^(3+)LDH/BiVO_(4)(FCF-LDH/BVO)catalyst with synergistic effect of chemical adsorption and physical enrichment.Fe^(2+)in FCF-LDH/BVO provides the rich Lewis acid sites for the adsorption of NO_(3)^(-),and the appropriate layer spacing of FCF-LDH further promotes the physical enrichment of NO_(3)^(-)in its interior,thus realizing the effective contact between NO_(3)^(-)and active sites(Fe^(2+)).FCF-LDH/BVO showed excellent NH_(3)production performance(FE_(NH_(3))=66.1%,r_(NH_(3))=13.8μg h^(-1)cm^(-2))and selectivity(FE_(NO_(2)^(-))=2.5%,r_(NO_(2)^(-))=4.9μg h^(-1)cm^(-2))in 0.5 mol L^(-1)Na_(2)SO_(4)electrolyte.In addition,FCF-LDH/BVO maintains the desirable PEC stability for six cycle experiments,showing great potential for practical application.The^(14)NO_(3)^(-)and^(15)NO_(3)^(-)isotope test provides strong evidence for further verification of the origin of N in the generated NH_(3).This LDH catalyst has a great potential in PEC removal of NO_(3)^(-)from groundwater.展开更多
The gut microbiota-brain axis has emerged as a novel target for Alzheimer's disease(AD),a neurodegenerative disease characterised by behavioural and cognitive impairment.However,most previous microbiome-based inte...The gut microbiota-brain axis has emerged as a novel target for Alzheimer's disease(AD),a neurodegenerative disease characterised by behavioural and cognitive impairment.However,most previous microbiome-based intervention studies have focused on single factors and yielded only modest cognitive improvements.Here,we proposed a multidomain intervention strategy that combined Bifidobacterium breve treatment with environmental enrichment(EE)training.In this study,we found that compared with EE or B.breve treatment alone,B.breve intervention combined with EE amplified its neuroprotective effects on AD mice,as reflected by improved cognition,inhibited neuroinflammation and enhanced synaptic function.Moreover,using microbiome and metabolome profiling,we found that the combination of B.breve and EE treatment restored AD-related gut microbiota dysbiosis and reversed microbial metabolite changes.Finally,by integrating behavioural and neurological data with metabolomic profiles,we revealed that the underlying mechanism may involve the modulation of microbiota-derived glutamine metabolism via gut-brain interactions.Collectively,combined B.breve intervention with EE treatment can alleviate AD-related cognitive impairment and improve brain function by regulating glutamine metabolism of the gut microbiome.Our findings provide a promising multidomain intervention strategy,with a combination of dietary microbiome-based and lifestyle-targeted interventions,to promote brain function and delay the progression of AD.展开更多
Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics...Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics,the tight oil enrichment model and its major controlling factors.First,the Quantou Formation is overlaid by high-quality source rocks of the Upper Cretaceous Qingshankou Formation,with the development of nose structure around sag and the broad and continuous distribution of sand bodies.The reservoirs are tight on the whole.Second,the configuration of multiple elements,such as high-quality source rocks,reservoir rocks,fault,overpressure and structure,controls the tight oil enrichment in the Fuyu reservoirs.The source-reservoir combination controls the tight oil distribution pattern.The pressure difference between source and reservoir drives the charging of tight oil.The fault-sandbody transport system determines the migration and accumulation of oil and gas.The positive structure is the favorable place for tight oil enrichment,and the fault-horst zone is the key part of syncline area for tight oil exploration.Third,based on the source-reservoir relationship,transport mode,accumulation dynamics and other elements,three tight oil enrichment models are recognized in the Fuyu reservoirs:(1)vertical or lateral migration of hydrocarbon from source rocks to adjacent reservoir rocks,that is,driven by overpressure,hydrocarbon generated is migrated vertically or laterally to and accumulates in the adjacent reservoir rocks;(2)transport of hydrocarbon through faults between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downward through faults to the sandbodies that are separated from the source rocks;and(3)migration of hydrocarbon through faults and sandbodies between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downwards through faults to the reservoir rocks that are separated from the source rocks,and then migrates laterally through sandbodies.Fourth,the differences in oil source conditions,charging drive,fault distribution,sandbody and reservoir physical properties cause the differential enrichment of tight oil in the Fuyu reservoirs.Comprehensive analysis suggests that the Fuyu reservoir in the Qijia-Gulong Sag has good conditions for tight oil enrichment and has been less explored,and it is an important new zone for tight oil exploration in the future.展开更多
Drilling for karst hydrothermal resources in eastern China has posed challenges,including disparities between the temperature and yield of geothermal water.It is evident that relying solely on geothermal anomalies or ...Drilling for karst hydrothermal resources in eastern China has posed challenges,including disparities between the temperature and yield of geothermal water.It is evident that relying solely on geothermal anomalies or indications of karst reservoirs is inadequate for the exploration of karst hydrothermal resources.This study seeks to elucidate the cause of geothermal sweet spots by analyzing the interplay between geothermal anomalies and karst reservoirs and the underlying geological conditions for karst hydrothermal enrichment.Key findings include:(1)the Bohai Bay Basin has been geologically favorable for the development of karst hydrothermal resources since the Mesozoic era;(2)the karst hydrothermal enrichment varies significantly between the basin’s margin and its interior.On the basin margin,the enrichment is largely driven by groundwater activity and faults,particularly where faults facilitate the upwelling of geothermal water.In contrast,within the basin’s interior,karst hydrothermal resources are predominantly influenced by buried hills and are especially enriched in areas facilitating the discharge of deep geothermal waters.展开更多
Few studies have systematically investigated the factors controlling organic matter enrichment in shales from the Qiongzhusi Formation, within and surrounding the Sichuan Basin, under different depositional environmen...Few studies have systematically investigated the factors controlling organic matter enrichment in shales from the Qiongzhusi Formation, within and surrounding the Sichuan Basin, under different depositional environments. This has resulted in different academic understandings and limited clarity on the mechanisms of organic matter enrichment. On this premise, in this study, the basic geological characteristics and depositional paleoenvironments of shales along the passive continental margin, the western Hubei Trough, and the western Sichuan Trough were compared and analyzed using core, outcrop, and mineral testing. Furthermore, data from organic geochemical and elemental analyses were utilized to investigate the different enrichment mechanisms and formation modes of the organic matter in different periods. The results reveal that the organic matter enrichment in this region should be mainly influenced by the preservation conditions, paleo-productivity, and terrigenous input. However, there were clear differences in the main controlling factors in the different periods. In the Q1 phase, the region had a high sea level, had the strongest rifting, had the largest accommodation space, and exhibited characteristics of low terrestrial input and bottom water hypoxia. The changes in the paleo-productivity caused by upwelling currents were the main factors controlling the variations in the organic matter enrichment. In the Q2 phase, the weakened decreasing sea level co-occurred with a reduction in the accommodation space across the region. The organic matter enrichment was significantly controlled by the paleo-productivity, preservation conditions, and terrigenous inputs, and the organic matter enrichment conditions deteriorated from the passive continental margin to the western Hubei Trough and western Sichuan Trough. The total organic carbon(TOC) content of the shale decreased significantly. In the Q3 phase, the entire region entered an infilling stage, which was dominated by an oxygen-rich environment,and the preservation conditions were the decisive factor controlling the organic matter enrichment. The TOC content was low overall, and there were no evident differences across the different zones.展开更多
基金Supported by the National Natural Science Foundation of China for Young Scientists Fund(No.42102158)the Jilin Province Science and Technology Development Plan Project(No.20240101065JC)+2 种基金the project of Education Department of Jilin Provincial(No.JJKH20241292KJ)the Natural Science Foundation of Sichuan Province(No.2024NSFSC0087)Supported by Graduate Innovation Fund of Jilin University(No.2024CX238).
文摘The quest for enrichment model of continental shale oil in the Zhanhua Sag of the JiyangDepression in the Bohai Bay Basin to provide reference for exploration and development requires acomprehensive approach. Therefore, this study employs rock pyrolysis, Scanning Electron Microscopy(SEM), X-Ray diffraction analysis (XRD), Nuclear Magnetic Resonance (NMR), and other experiments toanalyze the conditions for shale oil enrichment and establish its patterns. The results show that favorablehydrocarbon generation potential and appropriate thermal maturation degree control “in situ enrichment”;while the storage capacity and the mobility of shale oil determine “migration enrichment.” In the process,the TOC governs the oil-generating capacity of shale with medium to large pores and microfractures servingas the main enrichment spaces and migration pathways for shale oil. Based on the deposition model, thestudy area can be divided into five lithofacies stages (I-algal limestone, II-laminated marl, III-laminatedrecrystallized limestone, IV-laminated mudstones, and IV-blocky calcareous mudstones). Integrating thegeochemical parameters into the sedimentary patterns makes it clear that the study area underwent two phasesof hydrocarbon expulsion during the thermal evolution of source rocks (Stage II: 3 060–3 120 m and StageIV: 3 020–3 040 m). However, judging by the observed TOC (2% to 5.6%), thermal maturity (Ro>0.8%),S1 (>2 mg/g) and OSI (>100 mg/g) as well as moderate basin size, climate, and quantity of terrestrial input,the blocky calcareous mudstones (Stage IV) have better oil-prone characteristics and potential to generate asubstantial quantity of hydrocarbons at this stage. More so, with a brittleness index exceeding 60%, it exhibitsfavorable fracturability accounting for the main controlling factors and enrichment patterns of shale oil in thearea. Hence, this study further enriches and develops the theoretical understanding of shale oil enrichment inthe area, provides valuable insights for future exploration of continental shale oil in eastern China and othersimilar basin around the world.
基金supported by the National Natural Science Foundation of China(61902095).
文摘Biomedical big data,characterized by its massive scale,multi-dimensionality,and heterogeneity,offers novel perspectives for disease research,elucidates biological principles,and simultaneously prompts changes in related research methodologies.Biomedical ontology,as a shared formal conceptual system,not only offers standardized terms for multi-source biomedical data but also provides a solid data foundation and framework for biomedical research.In this review,we summarize enrichment analysis and deep learning for biomedical ontology based on its structure and semantic annotation properties,highlighting how technological advancements are enabling the more comprehensive use of ontology information.Enrichment analysis represents an important application of ontology to elucidate the potential biological significance for a particular molecular list.Deep learning,on the other hand,represents an increasingly powerful analytical tool that can be more widely combined with ontology for analysis and prediction.With the continuous evolution of big data technologies,the integration of these technologies with biomedical ontologies is opening up exciting new possibilities for advancing biomedical research.
基金Supported by the National Research and Development Program(2017YFC0602804)Geological Bureau Program of Sichuan Province(SCDZ-KJXM202403).
文摘Wells CXD1 and CX2 have uncovered high-concentration potassium-and lithium-containing brines and substantial layers of halite-type polyhalite potash deposits within the 4th and 5th members of the Triassic Jialingjiang Formation and the 1st Member of Leikoupo Formation(Jia 4 Member,Jia 5 Member,and Lei 1 Member)in the Puguang area,Sichuan Basin.These discoveries mark significant breakthroughs in the exploration of deep marine potassium and lithium resources within the Sichuan Basin.Utilizing the concept of“gas-potassium-lithium integrated exploration”and incorporating drilling,logging,seismic,and geochemical data,we have investigated the geological and enrichment conditions,as well as the metallogenic model of potassium-rich and lithium-rich brines and halite-type polyhalite.First,the sedimentary systems of gypsum-dolomite flats,salt lakes and evaporated flats were developed in Jia 4 Member,Jia 5 Member,and the 1st member of Leikoupo Formation(Lei 1 Member)in northeastern Sichuan Basin,forming three large-scale salt-gathering and potassium formation centers in Puguang,Tongnanba and Yuanba,and developing reservoirs with potassium-rich and lithium-rich brines,which are favorable for the deposition of potassium and lithium resources in both solid or liquid phases.Second,the soluble halite-type polyhalite has a large thickness and wide distribution,and the reservoir brine has a high content of K+and Li+.A solid-liquid superimposed“three-story structure”(with the lower thin-layer of brine reservoir in lower part of Jia 4 Member and Jia 5 Member,middle layer of halite-type polyhalite potash depositS,upper layer of potassium-rich and lithium-rich brine reservoir in Lei 1 Member)is formed.Third,the ternary enrichment and mineralization patterns for potassium and lithium resources were determined.Vertical superposition of polyhalite and green bean rocks is the mineral material basis of potassium-lithium resources featuring“dual-source replenishment and proximal-source release”,with primary seawater and gypsum dehydration as the main sources of deep brines,while multi-stage tectonic modification is the key to the enrichment of halite-type polyhalite and potassiumlithium brines.Fourth,the ore-forming process has gone through four stages:salt-gathering and potassium-lithium accumulation period,initial water-rock reaction period,transformation and aggregation period,and enrichment and finalization period.During this process,the halite-type polyhalite layer in Jia 4 Member and Jia 5 Member is the main target for potassium solution mining,while the brine layer in Lei 1 Member is the focus of comprehensive potassium-lithium exploration and development.
基金Supported by the National Natural Science Foundation of China(U22B6004)Project of PetroChina Research Institute of Petroleum Exploration and Development(2022yjcq03)Core Technology Key Project of China Petroleum Changqing Oilfield Company(KJZX2023-01).
文摘In addition to the organic matter type,abundance,thermal maturity,and shale reservoir space,the preservation conditions of source rocks play a key factor in affecting the quantity and quality of retained hydrocarbons in source rocks of lacustrine shale,yet this aspect has received little attention.This paper,based on the case analysis,explores how preservation conditions influence the enrichment of mobile hydrocarbons in shale oil.Research showns that good preservation conditions play three key roles.(1)Ensure the retention of sufficient light hydrocarbons(C_(1)–C_(13)),medium hydrocarbons(C_(14)–C_(25))and small molecular aromatics(including 1–2 benzene rings)in the formation,which enhances the fluidity and flow of shale oil;(2)Maintain a high energy field(abnormally high pressure),thus facilitating the maximum outflow of shale oil;(3)Ensure that the retained hydrocarbons have the miscible flow condition of multi-component hydrocarbons(light hydrocarbons,medium hydrocarbons,heavy hydrocarbons,and heteroatomic compounds),so that the heavy hydrocarbons(C_(25+))and heavy components(non-hydrocarbons and asphaltenes)have improved fluidity and maximum flow capacity.In conclusion,in addition to the advantages of organic matter type,abundance,thermal maturity,and reservoir space,good preservation conditions of shale layers are essential for the formation of economically viable shale oil reservoirs,which should be incorporated into the evaluation criteria of shale oil-rich areas/segments and considered a necessary factor when selecting favorable exploration targets.
基金supported by National Natural Science Foundation of China(No.51964009)。
文摘Coal seams can enrich a variety of harmful trace elements under specific geological conditions.The spatial distribution of harmful trace elements in coal is extremely uneven,and the distribution characteristics of each element content are different.The harmful elements released in the process of coal mining and utilization will cause serious harm to the environment and the human body.It is of great resource significance to study the geochemistry of coal that affects the enrichment and distribution characteristics of harmful trace elements.Based on the domestic and foreign literature on coal geochemistry in Guizhou published by previous investigators,this study counted 1097 sample data from 23 major coal-producing counties in Guizhou Province,systematically summarized the relevant research results of harmful trace elements in the coal of Guizhou,and revealed the overall distribution and enrichment characteristics of harmful trace elements in the coal of Guizhou.The results show that the average contents of Cd,Pb,Se,Cu,Mo,U,V,As,Hg,and Cr in coal of Guizhou are higher than those in Chinese coal and world coal.A variety of harmful trace elements in the coal of Guizhou have high background values,especially in Liupanshui,Xingyi and Qianbei coalfield.The enrichment of various harmful trace elements in the Late Permian coal in Guizhou is mainly related to the combined action of various geological and geochemical factors.The supply of terrigenous debris and sedimentary environment may be the basic background of the enrichment of harmful elements in western Guizhou,while low-temperature hydrothermal activity and volcanic ash deposition may be the main reasons for the enrichment of harmful elements in southwestern Guizhou.
基金financial support from the National Key Research and Development Program of China(2019YFC0605502)the National Natural Science Foundation of China(42302156)+1 种基金the Major Projects of Petro China Science and Technology Fund(2021DJ0206)the Natural Science Foundation of China University of Petroleum(22CX06046A)。
文摘The organic-rich mudstones and dolostones of the Permian Fengcheng Formation(Fm.)are typically alkaline lacustrine source rocks,which are typified by impressively abundantβ-carotane.Abundant β-carotane has been well acknowledged as an effective indicator of biological sources or depositional environments.However,the specific biological sources of β-carotane and the coupling control of biological sources and environmental factors on the enrichment of β-carotane in the Fengcheng Fm.remains obscure.Based on a comprehensive investigation of the bulk,molecular geochemistry,and organic petrology of sedimentary rocks and the biochemistry of phytoplankton in modern alkaline lakes,we proposed a new understanding of the biological precursors of β-carotane and elucidated the enrichment mechanism of β-carotane in the Fengcheng Fm.The results show that the biological precursors crucially control the enrichment of β-carotane in the Fengcheng Fm.The haloalkaliphilic cyanobacteria are the primary biological sources of β-carotane,which is suggested by a good positive correlation between the 2-methylhopane index,7-+8-methyl heptadecanes/C_(max),C_(29%),and β-carotane/C_(max)in sedimentary rocks and the predominance of cyanobacteria with abundantβ-carotene in modern alkaline lakes.The enrichment of β-carotane requires the reducing condition,and the paleoredox state that affects the enrichment of β-carotane appears to have a threshold.The paleoclimate conditions do not considerably impact the enrichment of β-carotane,but they have some influence on the water's paleosalinity by affecting evaporation and precipitation.While it does not directly affect the enrichment of β-carotane in the Fengcheng Fm.,paleosalinity does have an impact on the cyanobacterial precursor supply and the preservation conditions.
基金supported by the National Natural Science Foundation of China(Grant Nos.42172147 and 41972141).
文摘Overpressure is widely developed in deep petroliferous strata in the hinterland of the Junggar Basin.However,a comprehensive understanding of its origin and effect on hydrocarbon distribution and enrichment remains lacking.In this study,we employ five empirical methods and comprehensive geological analysis to identify the origin of overpressure,and uncover the effect of overpressure on hydrocarbon enrichment.The results indicate that disequilibrium compaction is not a significant factor in overpressure generation.Instead,hydrocarbon generation,pressure transfer and diagenesis are the primary causes.The empirical methods support this conclusion.There is a positive correlation between overpressure intensity and source rock thickness and maturity.Notably,widespread cross-formational migration of hydrocarbon bearing fluid occurred,with sandstone overpressure exceeding that of adjacent shale in non-source strata.Furthermore,there is a distinct transformation from smectite to illite near the top of overpressure.Hydrocarbon generation pressurization and pressure transfer significantly effect hydrocarbon enrichment.The overpressure caused by hydrocarbon generation drives hydrocarbon migration and accumulation,establishing an optimal energy configuration between reservoir and cap rock.Faults play a crucial role in hydrocarbon vertical migration and pressure relief.The overpressure in reservoirs can reduce the porosity and permeability thresholds and enhance the charging capacity of oil and gas.
基金funded by a grant from the National Natural Science Foundation of China(Grant Nos.U2244207,42102200)the China Geological Survey Foundation(Grant Nos.DD20230257,DD20242404)。
文摘The Upper Cretaceous Qingshankou Formation black shales,deposited in the late Turonian(LTB shales),are the main source rocks of the Songliao Basin.The origins of organic matter enrichment of the shales is a contentious subject fuelling many ongoing debates.This study investigates the genesis of the organic matter-rich shale by using molecular geochemistry.The LTB shales can be divided into three sections.The SectionⅠshales were deposited in saline,stratified and anoxic water conditions,which are related to seawater incursion events.At least three episodic and periodic seawater incursion events were recognized during SectionⅠshale deposition.The SectionⅡshales deposited in brackish to fresh and deep lake-level conditions with high primary productivity,which are related to lake-level transgression.The SectionⅢshales were deposited under fresh and slightly oxidized water conditions,which are related to lake-level regression.Two organic matter enrichment models for the LTB shales are identified,that is,the seawater incursion model and the maximum lake-level transgression sedimentation model,which act on different shale sections,both playing significant roles in the enrichment of organic matter.
基金supported by the National Major Science and Technology Project of China(Grant Nos.2016ZX05066001-0022017ZX05064-003-001+3 种基金2017ZX05035-02 and 2016ZX05034-001-05)the Innovative Research Group Project of the National Natural Science Foundation of China(Grant Nos.4187213542072151 and 42372144)the Project of Education Department of Liaoning Province(Grant No.LJKMZ20220744)。
文摘Cambrian shales in China and elsewhere contain abundant oil and gas resources.However,due to its deep burial and limited outcrop,there has been relatively little research conducted on it.The Cambrian shale of the Tadong low uplift in the Tarim Basin of western China,specifically the Xidashan-Xishanbulake Formation(Fm.)and overlying Moheershan Fm.provide a case study through the use of organic petrology,mineralogy,organic and elemental geochemistry,with the aim of analyzing and exploring the hydrocarbon generation potential(PG)and organic matter(OM)enrichment mechanisms within these shale formations.The results indicate that:(1)the Cambrian shale of the Tadong low uplift exhibits relatively dispersed OM that consists of vitrinite-like macerals and solid bitumen.These formations have a higher content of quartz and are primarily composed of silica-based lithology;(2)shale samples from the Xidashan-Xishanbulake and Moheershan formations demonstrate high total organic carbon(TOC)and low pyrolytic hydrocarbon content(S_(2))content.The OM is predominantly typeⅠand typeⅡkerogens,indicating a high level of maturation in the wet gas period.These shales have undergone extensive hydrocarbon generation,showing characteristics of relatively poor PG;(3)the sedimentary environments of the Xidashan-Xishanbulake and Moheershan formations in the Tadong low uplift are similar.They were deposited in warm and humid climatic conditions,in oxygen-deficient environments,with stable terrigenous inputs,high paleoproductivity,high paleosalinity,weak water-holding capacity,and no significant hydrothermal activity;and(4)the relationship between TOC and the paleoproductivity parameter(P/Ti)is most significant in the Lower Cambrian Xidashan-Xishanbulake Fm.,whereas correlation with other indicators is not evident.This suggests a productivity-driven OM enrichment model,where input of landderived material was relatively small during the Middle Cambrian,and the ancient water exhibited lower salinity.A comprehensive pattern was formed under the combined control of paleoproductivity and preservation conditions.This study provides valuable guidance for oil and gas exploration in the Tarim Basin.
基金supported by the National Natural Science Foundation of China (Grant U19B6003-01-02,42102150,42372163)。
文摘The black shale of the Mesoproterozoic Cuizhuang Formation in the Changcheng System in Yongji city,North China Craton,is a potential source rock.Understanding the organic matter enrichment mechanism is crucial for evaluating source rock resources and understanding oil and gas accumulation mechanisms.In this study,we evaluated the sedimentary paleoenvironment and organic matter enrichment mechanisms of shale using thin section observations,mineral composition analysis,organic geochemistry,and elemental geochemistry.We found significant differences in the sedimentary paleoenvironment and organic matter enrichment mechanisms between the lower Cuizhuang Formation and the Beidajian Formation shale.The Cuizhuang Formation was deposited in a late-stage,restricted basin environment during the rift phase,and elemental and geochemical indicators showed that the Cuizhuang Formation was in a suboxic-anoxic water environment,that was influenced by a warm and humid paleoclimate and submarine hydrothermal activities,which promoted the accumulation of organic matter.However,the enrichment of organic matter in the Cuizhuang Formation was mainly controlled by redox conditions.The formation of suboxic-anoxic water environments may be closely related to the warm and humid paleoclimate and submarine hydrothermal activities.Warm conditions promote continental weathering and increase marine productivity,thereby consuming oxygen in the bottom water.Moreover,acidic hydrothermal activity also helps to establish an anoxic environment.Our results reveal the effects controlling various coupled mechanisms dominated by redox conditions,which may explain the development of source rocks in the Cuizhuang Formation.
基金supported by the National Natural Science Foundation of China(U23B20155 and 42303004)China Postdoctoral Science Foundation(2023M730038)+1 种基金the Science and Technology Research Project for the China National Petroleum Corporation(2021DJ1802 and 2021YJCQ03)the National Postdoctoral Researcher Program of China(GZC20233111).
文摘The lower Cambrian Qiongzhusi(Є1 q)shale in the Sichuan Basin,formerly considered a source rock,recently achieved high gas production(7.388×105 m^(3)·d^(-1))from well Z201 in the Deyang-Anyue rift trough(DART),marking an exploration breakthrough of the world’s oldest industrial shale gas reser-voir.However,the shale gas enrichment mechanism within the DART is not fully understood.This study reviews the formation of the Qiongzhusi shale gas reservoirs within the DART by comparing them with cotemporaneous deposits outside the DART,and several findings are presented.The gas production interval was correlated with the main phase of the Cambrian explosion(lower Cambrian stage 3).In the early Cambrian ecosystem,dominant animals likely accelerated the settling rates of organic matter(OM)in the upper 1st member ofЄ_(1) q(Є_(1) q_(12))by feeding on small planktonic organisms and producing larger organic fragments and fecal pellets.High primary productivity and euxinic con-ditions contributed to OM enrichment in the lower 1st member ofЄ1 q(Є_(1) q_(11)).Additionally,shale reservoirs inside the DART demonstrated better properties than those outside in terms of thickness,brittle minerals,gas content,and porosity.In particular,the abundant OM pores inside the DART facil-itated shale gas enrichment,whereas the higher thermal maturity of the shales outside the DART pos-sibly led to the graphitization and collapse of some OM pores.Meanwhile,the overpressure of high-production wells inside the DART generally reflects better shale gas preservation,benefiting from the shale’s self-sealing nature,"upper capping and lower plugging"configuration,and limited faults and microfractures.Considering these insights,we introduced a"ternary enrichment"model for the Qiongzhusi shale gas.Although the current high gas production of Z201 was found at the reservoir 3,two additional reservoirs were identified with significant potential,thus suggesting a"multilayer stereoscopic development"strategy in future shale gas exploration within the DART.
基金Supported by the China National Petroleum Corporation(CNPC)Project(2023ZZ14-01)。
文摘Based on drilling and logging data,as well as geological experiments,the geological characteristics and factors controlling high-yield and enrichment of hydrocarbons in ultra-deep clastic rocks in the Linhe Depression,Hetao Basin,are studied.The results are obtained in four aspects.First,the inland saline lacustrine high-quality source rocks developed in the Paleogene in the Linhe Depression have the characteristics of early maturity,early expulsion,high hydrocarbon yield,and continuous and efficient hydrocarbon generation,providing an important resource basis for the formation of ultra-high pressure and high-yield reservoirs.Second,the weak compaction,early charging,and weak cementation for pore-preserving,together with the ultra-high pressure for pore-preserving and fracture expansion to improve the permeability,leads to the development of high-quality reservoirs with medium porosity(greater than 15%)and medium permeability(up to 226×10^(-3)μm^(2))in the ultra-deep strata(deeper than 6500 m),which represents a greatly expanded space for oil and gas exploration.Third,the Linhe Formation adjacent to the trough exhibits a low net-to-gross(NTG)and good reservoir-caprock assemblage,and it is overlaid by very thick high-quality mudstone caprock,which are conducive to the continuous and efficient hydrocarbon generation and pressurization and the formation of ultra-high pressure oil and gas reservoirs.Fourth,the most favorable targets for ultra-deep exploration are the zones adjacent to the hydrocarbon generating center of the Paleogene Linhe Formation and with good tectonic setting and structural traps,mainly including the Xinglong faulted structural zone and the Nalinhu faulted buried-hill zone.The significant breakthrough of ultra-deep oil and gas exploration in the Linhe Depression reveals the good potential of ultra-deep clastic rocks in this area,and provides valuable reference for oil and gas exploration of ultra-deep clastic rocks in other areas.
基金This work was funded by the National Natural Science Foundation of China(Grant No.42002139 and U20B6001)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA14010404).
文摘Lacustrine shale oil and gas are important fields for unconventional exploration and development in China,and organic-rich shale deposition lays down the critical foundation for hydrocarbon generation.There are two sets of shale,the Dongyuemiao and Da’anzhai Members,in the Ziliujing Formation in the Sichuan Basin.To identify the differential enrichment characteristics of organic matter and clarify its controlling factors,geochemical analyses of organic and inorganic geochemical analyses were performed.The results showed that the total organic carbon content of the Dongyuemiao shale(1.36%)is slightly higher than that of the Da’anzhai shale(0.95%).The enrichment of organic matter in the two shales resulted from the comprehensive controls of paleoproductivity,paleoenvironment,and terrigenous input,but different factors have different effects.In addition,driven by climate,the change in the sulfate concentration in the bottom water further led to the different intensities of bacterial sulfate reduction in early diagenesis.This made a great difference regarding organic matter accumulation in the two members.In general,climate may have played a dominant role in organic matter enrichment in the two sets of shale.
基金The fund of Laoshan Laboratory under contract Nos LSKJ202203602 and LSKJ202204103the China Ocean Mineral Resource Research and Development Association Research Program under contract No.DY135-C1-1-04the Taishan Scholarship from Shandong Province.
文摘To explore the occurrence phases and enrichment mechanism of rare earth elements(REEs)in cobalt-rich crusts,this study analyzes the mineral composition and REE contents of the samples from Marcus-Wake Seamounts by XRD,ICP-OES and ICP-MS.The results show that,(1)the cobalt-rich crusts contain the major crystalline mineral(vernadite),the secondary minerals(quartz,plagioclase and carbonate fluorapatite),and a large amount of amorphous ferric oxyhydroxides(FeOOH).(2)The cobalt-rich crusts contains higher Mn(10.83%to 28.76%)and Fe(6.14%to 18.86%)relative to other elements,and are enriched in REEs,with total REE contents of 1563−3238μg/g and Ce contents of 790−1722μg/g.Rare earth element contents of the old crusts are higher than those of the new crusts.Moreover,the non-phosphatized crusts have positive Ce and negative Y anomalies,and yet the phosphatized crusts have positive Ce and positive Y anomalies,indicating that cobalt-rich crusts is hydrogenetic and REEs mainly come from seawater.(3)Analytical data also show that the occurrence phases of elements in cobalt-rich crusts are closely related to their mineral phases.In the non-phosphatized crusts,REEs are adsorbed by colloidal particles into the crusts(about 67%of REEs in the Fe oxide phase,and about 17%of REEs in the Mn oxide phase).In contrast,in the phosphatized crusts(affected by the phosphatization),REEs may combine with phosphate to form rare earth phosphate minerals,and about 64%of REEs are enriched in the residual phase containing carbonate fluorapatite,but correspondingly the influence of Fe and Mn oxide phases on REEs enrichment is greatly reduced.In addition,the oxidizing environment of seawater,high marine productivity,phosphatization,and slow growth rate can promote the REE enrichment.This study provides a reference for the metallogenesis of cobalt-rich crusts in the Pacific.
基金Supported by the China National Petroleum Corporation Science and Technology Project(2023ZZ18)CNPC Changqing Oilfield Company Project(2022D-JB01)。
文摘To reveal the enrichment conditions and resource potential of coal-rock gas in the Ordos Basin,this paper presents a systematic research on the sedimentary environment,distribution,physical properties,reservoir characteristics,gas-bearing characteristics and gas accumulation play of deep coals.The results show that thick coals are widely distributed in the Carboniferous–Permian of the Ordos Basin.The main coal seams Carboniferous 5~#and Permian 8~#in the Carboniferous–Permian have strong hydrocarbon generation capacity and high thermal evolution degree,which provide abundant materials for the formation of coal-rock gas.Deep coal reservoirs have good physical properties,especially porosity and permeability.Coal seams Carboniferous 5^(#)and Permian 8^(#)exhibit the average porosity of 4.1%and 6.4%,and the average permeability of 8.7×10^(-3)μm^(2)and 15.7×10^(-3)μm^(2),respectively.Cleats and fissures are developed in the coals,and together with the micropores,constitute the main storage space.With the increase of evolution degree,the micropore volume tends to increase.The development degree of cleats and fissures has a great impact on permeability.The coal reservoirs and their industrial compositions exhibit significantly heterogeneous distribution in the vertical direction.The bright coal seam,which is in the middle and upper section,less affected by ash filling compared with the lower section,and contains well-developed pores and fissures,is a high-quality reservoir interval.The deep coals present good gas-bearing characteristics in Ordos Basin,with the gas content of 7.5–20.0 m^(3)/t,and the proportion of free gas(greater than 10%,mostly 11.0%–55.1%)in coal-rock gas significantly higher than that in shallow coals.The enrichment degree of free gas in deep coals is controlled by the number of macropores and microfractures.The coal rock pressure testing shows that the coal-limestone and coal-mudstone combinations for gas accumulation have good sealing capacity,and the mudstone/limestone(roof)-coal-mudstone(floor)combination generally indicates high coal-rock gas values.The coal-rock gas resources in the Ordos Basin were preliminarily estimated by the volume method to be 22.38×10^(12)m^(3),and the main coal-rock gas prospects in the Ordos Basin were defined.In the central-east of the Ordos Basin,Wushenqi,Hengshan-Suide,Yan'an,Zichang,and Yichuan are coal-rock gas prospects for the coal seam#8 of the Benxi Formation,and Linxian West,Mizhi,Yichuan-Huangling,Yulin,and Wushenqi-Hengshan are coal-rock gas prospects for the coal seam#5 of the Shanxi Formation,which are expected to become new areas for increased gas reserves and production.
基金National Natural Science Foundation of China(22075112)Jiangsu Province and Education Ministry Co-Sponsored Synergistic Innovation Center of Modern Agricultural Equipment(XTCX2027)Jiangsu Province Innovation Support Program International Science and Technology Cooperation Project(BZ2022045)。
文摘Photoelectrochemical NO_(3)^(-)reduction(PEC NITRR)not only provides a promising solution for promoting the global nitrogen cycle,but also converts NO_(3)^(-)to the important chemicals(NH_(3)).However,it is still a great challenge to prepare catalysts with excellent NO_(3)^(-)adsorption/activation capacity to achieve high NITRR.Herein,we designed a novel Fe^(2+)~Cu^(2+)Fe^(3+)LDH/BiVO_(4)(FCF-LDH/BVO)catalyst with synergistic effect of chemical adsorption and physical enrichment.Fe^(2+)in FCF-LDH/BVO provides the rich Lewis acid sites for the adsorption of NO_(3)^(-),and the appropriate layer spacing of FCF-LDH further promotes the physical enrichment of NO_(3)^(-)in its interior,thus realizing the effective contact between NO_(3)^(-)and active sites(Fe^(2+)).FCF-LDH/BVO showed excellent NH_(3)production performance(FE_(NH_(3))=66.1%,r_(NH_(3))=13.8μg h^(-1)cm^(-2))and selectivity(FE_(NO_(2)^(-))=2.5%,r_(NO_(2)^(-))=4.9μg h^(-1)cm^(-2))in 0.5 mol L^(-1)Na_(2)SO_(4)electrolyte.In addition,FCF-LDH/BVO maintains the desirable PEC stability for six cycle experiments,showing great potential for practical application.The^(14)NO_(3)^(-)and^(15)NO_(3)^(-)isotope test provides strong evidence for further verification of the origin of N in the generated NH_(3).This LDH catalyst has a great potential in PEC removal of NO_(3)^(-)from groundwater.
基金supported by the National Natural Science Foundation of China(31972052,32021005,31820103010)the Fundamental Research Funds for the Central Universities(JUSRP22006,JUSRP51501)the Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province。
文摘The gut microbiota-brain axis has emerged as a novel target for Alzheimer's disease(AD),a neurodegenerative disease characterised by behavioural and cognitive impairment.However,most previous microbiome-based intervention studies have focused on single factors and yielded only modest cognitive improvements.Here,we proposed a multidomain intervention strategy that combined Bifidobacterium breve treatment with environmental enrichment(EE)training.In this study,we found that compared with EE or B.breve treatment alone,B.breve intervention combined with EE amplified its neuroprotective effects on AD mice,as reflected by improved cognition,inhibited neuroinflammation and enhanced synaptic function.Moreover,using microbiome and metabolome profiling,we found that the combination of B.breve and EE treatment restored AD-related gut microbiota dysbiosis and reversed microbial metabolite changes.Finally,by integrating behavioural and neurological data with metabolomic profiles,we revealed that the underlying mechanism may involve the modulation of microbiota-derived glutamine metabolism via gut-brain interactions.Collectively,combined B.breve intervention with EE treatment can alleviate AD-related cognitive impairment and improve brain function by regulating glutamine metabolism of the gut microbiome.Our findings provide a promising multidomain intervention strategy,with a combination of dietary microbiome-based and lifestyle-targeted interventions,to promote brain function and delay the progression of AD.
基金Supported by the PetroChina Science and Technology Major Project(2016E0201)。
文摘Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics,the tight oil enrichment model and its major controlling factors.First,the Quantou Formation is overlaid by high-quality source rocks of the Upper Cretaceous Qingshankou Formation,with the development of nose structure around sag and the broad and continuous distribution of sand bodies.The reservoirs are tight on the whole.Second,the configuration of multiple elements,such as high-quality source rocks,reservoir rocks,fault,overpressure and structure,controls the tight oil enrichment in the Fuyu reservoirs.The source-reservoir combination controls the tight oil distribution pattern.The pressure difference between source and reservoir drives the charging of tight oil.The fault-sandbody transport system determines the migration and accumulation of oil and gas.The positive structure is the favorable place for tight oil enrichment,and the fault-horst zone is the key part of syncline area for tight oil exploration.Third,based on the source-reservoir relationship,transport mode,accumulation dynamics and other elements,three tight oil enrichment models are recognized in the Fuyu reservoirs:(1)vertical or lateral migration of hydrocarbon from source rocks to adjacent reservoir rocks,that is,driven by overpressure,hydrocarbon generated is migrated vertically or laterally to and accumulates in the adjacent reservoir rocks;(2)transport of hydrocarbon through faults between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downward through faults to the sandbodies that are separated from the source rocks;and(3)migration of hydrocarbon through faults and sandbodies between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downwards through faults to the reservoir rocks that are separated from the source rocks,and then migrates laterally through sandbodies.Fourth,the differences in oil source conditions,charging drive,fault distribution,sandbody and reservoir physical properties cause the differential enrichment of tight oil in the Fuyu reservoirs.Comprehensive analysis suggests that the Fuyu reservoir in the Qijia-Gulong Sag has good conditions for tight oil enrichment and has been less explored,and it is an important new zone for tight oil exploration in the future.
基金financially supported by a project of the Ministry of Science and Technology,SINOPEC(No.P13071)a project of the Petroleum Exploration and Production Research Institute,SINOPEC(No.YK514003).
文摘Drilling for karst hydrothermal resources in eastern China has posed challenges,including disparities between the temperature and yield of geothermal water.It is evident that relying solely on geothermal anomalies or indications of karst reservoirs is inadequate for the exploration of karst hydrothermal resources.This study seeks to elucidate the cause of geothermal sweet spots by analyzing the interplay between geothermal anomalies and karst reservoirs and the underlying geological conditions for karst hydrothermal enrichment.Key findings include:(1)the Bohai Bay Basin has been geologically favorable for the development of karst hydrothermal resources since the Mesozoic era;(2)the karst hydrothermal enrichment varies significantly between the basin’s margin and its interior.On the basin margin,the enrichment is largely driven by groundwater activity and faults,particularly where faults facilitate the upwelling of geothermal water.In contrast,within the basin’s interior,karst hydrothermal resources are predominantly influenced by buried hills and are especially enriched in areas facilitating the discharge of deep geothermal waters.
基金supported by the Hubei Province Natural Science Geological Innovation Development Joint Funding Project (2024AFD388)。
文摘Few studies have systematically investigated the factors controlling organic matter enrichment in shales from the Qiongzhusi Formation, within and surrounding the Sichuan Basin, under different depositional environments. This has resulted in different academic understandings and limited clarity on the mechanisms of organic matter enrichment. On this premise, in this study, the basic geological characteristics and depositional paleoenvironments of shales along the passive continental margin, the western Hubei Trough, and the western Sichuan Trough were compared and analyzed using core, outcrop, and mineral testing. Furthermore, data from organic geochemical and elemental analyses were utilized to investigate the different enrichment mechanisms and formation modes of the organic matter in different periods. The results reveal that the organic matter enrichment in this region should be mainly influenced by the preservation conditions, paleo-productivity, and terrigenous input. However, there were clear differences in the main controlling factors in the different periods. In the Q1 phase, the region had a high sea level, had the strongest rifting, had the largest accommodation space, and exhibited characteristics of low terrestrial input and bottom water hypoxia. The changes in the paleo-productivity caused by upwelling currents were the main factors controlling the variations in the organic matter enrichment. In the Q2 phase, the weakened decreasing sea level co-occurred with a reduction in the accommodation space across the region. The organic matter enrichment was significantly controlled by the paleo-productivity, preservation conditions, and terrigenous inputs, and the organic matter enrichment conditions deteriorated from the passive continental margin to the western Hubei Trough and western Sichuan Trough. The total organic carbon(TOC) content of the shale decreased significantly. In the Q3 phase, the entire region entered an infilling stage, which was dominated by an oxygen-rich environment,and the preservation conditions were the decisive factor controlling the organic matter enrichment. The TOC content was low overall, and there were no evident differences across the different zones.
