Differences in and factors controlling organic matter enrichment in the Ziliujing Formation shale in the Sichuan Basin

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.

Environmental enrichment in combination with Bifidobacterium breve HNXY26M4 intervention amplifies neuroprotective benefits in a mouse model of Alzheimer's disease by modulating glutamine metabolism of the gut microbiome

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.

Enrichment factors of movable hydrocarbons in lacustrine shale oil and exploration potential of shale oil in Gulong Sag,Songliao Basin,NE China

The geological characteristics and production practices of the major middle-and high-maturity shale oil exploration areas in China are analyzed.Combined with laboratory results,it is clear that three essential conditions,i.e.economic initial production,commercial cumulative oil production of single well,and large-scale recoverable reserves confirmed by the testing production,determine whether the continental shale oil can be put into large-scale commercial development.The quantity and quality of movable hydrocarbons are confirmed to be crucial to economic development of shale oil,and focuses in evaluation of shale oil enrichment area/interval.The evaluation indexes of movable hydrocarbon enrichment include:(1)the material basis for forming retained hydrocarbon,including TOC>2%(preferentially 3%-4%),and typeⅠ-Ⅱkerogens;(2)the mobility of retained hydrocarbon,which is closely related to the hydrocarbon composition and flow behaviors of light/heavy components,and can be evaluated from the perspectives of thermal maturity(Ro),gas-oil ratio(GOR),crude oil density,quality of hydrocarbon components,preservation conditions;and(3)the reservoir characteristics associated with the engineering reconstruction,including the main pore throat distribution zone,reservoir physical properties(including fractures),lamellation feature and diagenetic stage,etc.Accordingly,13 evaluation indexes in three categories and their reference values are established.The evaluation indicates that the light shale oil zones in the Gulong Sag of Songliao Basin have the most favorable enrichment conditions of movable hydrocarbons,followed by light oil and black oil zones,containing 20.8×10^(8) t light oil resources in reservoirs with R_(0)>1.2%,pressure coefficient greater than 1.4,effective porosity greater than 6%,crude oil density less than 0.82 g/cm^(3),and GOR>100 m/m^(3).The shale oil in the Gulong Sag can be explored and developed separately by the categories(resource sweet spot,engineering sweet spot,and tight oil sweet spot)depending on shale oil flowability.The Gulong Sag is the most promising area to achieve large-scale breakthrough and production of continental shale oil in China.

Controlling factors and models of shale oil enrichment in Lower Permian Fengcheng Formation,Mahu Sag,Junggar Basin,NW China

Based on the combination of core observation,experimental analysis and testingand geological analysis,the main controlling factors of shale oil enrichment in the Lower Permian Fengcheng Formation in the Mahu Sag of the Junggar Basin are clarified,and a shale oil enrichment model is established.The results show that the enrichment of shale oil in the Fengcheng Formation in the Mahu Sag is controlled by the organic abundance,organic type,reservoir capacity and the amount of migration hydrocarbon in shale.The abundance of organic matter provides the material basis for shale oil enrichment,and the shales containing typesⅠandⅡorganic matters have good oil content.The reservoir capacity controls shale oil enrichment.Macropores are the main space for shale oil enrichment in the Fengcheng Formation,and pore size and fracture scale directly control the degree of shale oil enrichment.The migration of hydrocarbons in shale affects shale oil enrichment.The shale that has expelled hydrocarbons has poor oil content,while the shale that has received hydrocarbons migrated from other strata has good oil content.Lithofacies reflect the hydrocarbon generation and storage capacity comprehensively.The laminated felsic shale,laminated lime-dolomitic shale and thick-layered felsic shale have good oil content,and they are favorable lithofacies for shale oil enrichment.Under the control of these factors,relative migration of hydrocarbons occurred within the Fengcheng shale,which leads to the the difference in the enrichment process of shale oil.Accordingly,the enrichment mode of shale oil in Fengcheng Formation is established as"in-situ enrichment"and"migration enrichment".By superimposing favorable lithofacies and main controlling factors of enrichment,the sweet spot of shale oil in the Fengcheng Formation can be selected which has great significance for the exploration and development of shale oil.

Molecular mechanisms underlying the neuroprotection of environmental enrichment in Parkinson’s disease

Parkinson’s disease is the most common movement disorder,affecting about 1%of the population over the age of 60 years.Parkinson’s disease is characterized clinically by resting tremor,bradykinesia,rigidity and postural instability,as a result of the progressive loss of nigrostriatal dopaminergic neurons.In addition to this neuronal cell loss,Parkinson’s disease is characterized by the accumulation of intracellular protein aggregates,Lewy bodies and Lewy neurites,composed primarily of the proteinα-synuclein.Although it was first described almost 200 years ago,there are no disease-modifying drugs to treat patients with Parkinson’s disease.In addition to conventional therapies,non-pharmacological treatment strategies are under investigation in patients and animal models of neurodegenerative disorders.Among such strategies,environmental enrichment,comprising physical exercise,cognitive stimulus,and social interactions,has been assessed in preclinical models of Parkinson’s disease.Environmental enrichment can cause structural and functional changes in the brain and promote neurogenesis and dendritic growth by modifying gene expression,enhancing the expression of neurotrophic factors and modulating neurotransmission.In this review article,we focus on the current knowledge about the molecular mechanisms underlying environmental enrichment neuroprotection in Parkinson’s disease,highlighting its influence on the dopaminergic,cholinergic,glutamatergic and GABAergic systems,as well as the involvement of neurotrophic factors.We describe experimental pre-clinical data showing how environmental enrichment can act as a modulator in a neurochemical and behavioral context in different animal models of Parkinson’s disease,highlighting the potential of environmental enrichment as an additional strategy in the management and prevention of this complex disease.

Upper Paleozoic total petroleum system and geological model of natural gas enrichment in Ordos Basin, NW China

Based on the analysis of Upper Paleozoic source rocks, source-reservoir-caprock assemblage, and gas accumulation characteristics in the Ordos Basin, the gas accumulation geological model of total petroleum system is determined. Then, taking the Carboniferous Benxi Formation and the Permian Taiyuan Formation and Shanxi Formation as examples, the main controlling factors of gas accumulation and enrichment are discussed, and the gas enrichment models of total petroleum system are established. The results show that the source rocks, faults and tight reservoirs and their mutual coupling relations control the distribution and enrichment of gas. Specifically, the distribution and hydrocarbon generation capacity of source rocks control the enrichment degree and distribution range of retained shale gas and tight gas in the source. The coupling between the hydrocarbon generation capacity of source rocks and the physical properties of tight reservoirs controls the distribution and sweet spot development of near-source tight gas in the basin center. The far-source tight gas in the basin margin is mainly controlled by the distribution of faults, and the distribution of inner-source, near-source and far-source gas is adjusted and reformed by faults. Generally, the Upper Paleozoic gas in the Ordos Basin is recognized in four enrichment models: inner-source coalbed gas and shale gas, inner-source tight sandstone gas, near-source tight gas, and far-source fault-transported gas. In the Ordos Basin, inner-source tight gas and near-source tight gas are the current focuses of exploration, and inner-source coalbed gas and shale gas and far-source gas will be important potential targets in the future.

Shale oil enrichment evaluation and production law in Gulong Sag,Songliao Basin,NE China

Based on the results of drilling,tests and simulation experiments,the shales of the Cretaceous Qingshankou Formation in the Gulong Sag of the Songliao Basin are discussed with respect to hydrocarbon generation evolution,shale oil occurrence,and pore/fracture evolution mechanism.In conjunction with a substantial amount of oil testing and production data,the Gulong shale oil enrichment layers are evaluated and the production behaviors and decline law are analyzed.The results are drawn in four aspects.First,the Gulong shales are in the stage of extensive hydrocarbon expulsion when R_(0) is 1.0%-1.2%,with the peak hydrocarbon expulsion efficiency of 49.5%approximately.In the low-medium maturity stage,shale oil migrates from kerogen to rocks and organic pores/fractures.In the medium-high maturity stage,shale oil transforms from adsorbed state to free state.Second,the clay mineral intergranular pores/fractures,dissolution pores,and organic pores make up the majority of the pore structure.During the transformation,clay minerals undergo significant intergranular pore/fracture development between the minerals such as illite and illite/smectite mixed layer.A network of pores/fractures is formed by organic matter cracking.Third,free hydrocarbon content,effective porosity,total porosity,and brittle mineral content are the core indicators for the evaluation of shale oil enrichment layers.Class-I layers are defined as free hydrocarbon content equal or greater than 6.0 mg/g,effective porosity equal or greater than 3.5%,total porosity equal or greater than 8.0%,and brittle mineral content equal or greater than 50%.It is believed that the favourable oil layers are Q2-Q3 and Q8-Q9.Fourth,the horizontal wells in the core area of the light oil zone exhibit a high cumulative production in the first year,and present a hyperbolic production decline pattern,with the decline index of 0.85-0.95,the first-year decline rate of 14.5%-26.5%,and the single-well estimated ultimate recovery(EUR)greater than 2.0×10^(4)t.In practical exploration and production,more efforts will be devoted to the clarification of hydrocarbon generation and expulsion mechanisms,accurate testing of porosity and hydrocarbon content/phase of shale under formation conditions,precise delineation of the boundary of enrichment area,relationship between mechanical properties and stimulated reservoir volume,and enhanced oil recovery,in order to improve the EUR and achieve a large-scale,efficient development of shale oil.

Environmental Effects on Differential Organic Matter Enrichment of the Lower Cambrian Shale,Tarim Basin,NW China

Early Cambrian shale is an important petroleum source rock around the world.Because of little drilling data and poor seismic data,until recently,organic matter enrichment of the Lower Cambrian Yuertusi and Xishanbulake formations shale is still an enigma in the Tarim Basin,northwestern China.Total organic carbon(TOC),major and trace element data of Cambrian shale samples from five boreholes have been analyzed to decipher the mechanism of the organic matter enrichment.The results show that the shales deposited in the western restricted intraplatform have much higher TOC contents(3.2%-19.8%,on average 11.0%)than those from the eastern basin(2.2%-10.2%,on average 4.5%).The paleoproductivity proxies(Ba,Ba/Al,P/Al)in the western restricted platform are much higher than those in the eastern basin.The trace element indicators such as V/Cr,Ni/Co,Mo-TOC and Mo_(EF)-U_(EF)suggest an anoxic environment across the basin,but a more restricted environment in the western intraplatform.The paleoproductivity rather than anoxic condition and hydrothermal activity are concluded to have resulted in the differentiation of the organic matter enrichment from the western intraplatform to eastern basin in the early Cambrian shales;the restricted environment was favorable for paleoproductivity and preservation of organic matter.

Enrichment conditions and distribution characteristics of lacustrine medium-to-high maturity shale oil in China

Successful breakthroughs have been made in shale oil exploration in several lacustrine basins in China,indicating a promising future for shale oil exploration and production.Current exploration results have revealed the following major conditions of lacustrine shale oil accumulation:(1)stable and widely distributed shale with a high organic abundance and appropriate thermal maturity acts as a fundamental basis for shale oil retention.This shale exhibits several critical parameters,such as total organic carbon content greater than 2%,with optimal values ranging from 3% to 4%,kerogen Ⅰ and Ⅱ_(1) as the dominant organic matter types,and vitrinite reflectance(R_(o))values greater than 0.9%(0.8% for brackish water environments).(2)Various types of reservoirs exhibiting brittleness and a certain volume of micro-nanoscale pores are critical conditions for shale oil accumulation,and these reservoirs have porosities greater than 3% to 6%.Moreover,when diagenesis is incipient,pure shales are not favorable for medium-to-high maturity shale oil enrichment,whereas tight sandstone and hybrid rocks with clay content less than 20% are favorable;however,for medium-to-late-stage diagenesis,pure shales with a clay content of 40% are favorable.(3)The retention of a large amount of high-quality hydrocarbons is the factor that best guarantees shale oil accumulation with good mobility.Free hydrocarbon content exceeding a threshold value of 2 mg/g is generally required,and the optimum value is 4 mg/g to 6 mg/g.Moreover,a gas-oil ratio exceeding a threshold value of 80 m^(3)/m^(3) is required,with the optimal value ranging from 150 m^(3)/m^(3) to 300 m^(3)/m^(3).(4)High-quality roof and floor sealing conditions are essential for the shale oil enrichment interval to maintain the overpressure and retain a sufficient amount of hydrocarbons with good quality.Lacustrine shale oil distributions exhibit the following characteristics:(1)major enrichment areas of shale oil are located in semi-deep to deep lacustrine depositional areas with external materials,such as volcanic ash fallout,hydrothermal solutions,and radioactive substances with catalytic action,as inputs;(2)intervals with“four high values and one preservation condition”govern the distribution of shale oil enrichment intervals;and(3)favorable assemblages of lithofacies/lithologies determine the distribution of enrichment area.According to preliminary estimates,China has 131×10^(8) to 163×10^(8) t of total shale oil resources with medium-to-high thermal maturity,among which 67×10^(8) to 84×10^(8) t is commercial.These resources are primarily located in the Chang 7^(1+2) interval in the Ordos Basin,Qing 1+2 members in Gulong sag in the Songliao Basin,Kongdian and Shahejie formations of Cangdong sag,Qikou sag and the Jiyang depression in the Bohai Bay Basin,and Lucaogou Formation in the Junggar Basin.

Click chemistry-based enrichment strategy for tracing cellular fatty acid metabolism by LC-MS/MS

Fatty acids(FAs),which were initially recognized as energy sources and essential building blocks of biomembranes,serve as the precursors of important signaling molecules.Tracing FA metabolism is essential to understanding the biochemical activity and role of FAs in physiological and pathological events.Inspired by the advances in click chemistry for protein enrichment,we herein established a click chemistry-based enrichment(CCBE)strategy for tracing the cellular metabolism of eicosapentaenoic acid(EPA,20:5 n-3)in neural cells.Terminal alkyne-labeled EPA(EPAA)used as a surrogate was incubated with N2a,mouse neuroblastoma cells,and alkyne-labeled metabolites(ALMs)were selectively captured by an azide-modified resin via a Cu(I)-catalyzed azide-alkyne cycloaddition reaction for enrichment.After removing unlabeled metabolites,ALMs containing a triazole moiety were cleaved from solid-phase resins and subjected to liquid chromatography mass spectrometry(LC-MS)analysis.The proposed CCBE strategy is highly selective for capturing and enriching alkyne-labeled metabolites from the complicated matrices.In addition,this method can overcome current detection limits by enhancing MS sensitivity of targets,improving the chromatographic separation of sn-position glycerophospholipid regioisomers,facilitating structural characterization of ALMs by a specific MS/MS fragmentation signature,and providing versatile fluorescence detection of ALMs for cellular distribution.This CCBE strategy might be expanded to trace the metabolism of other FAs,small molecules,or drugs.

Factors Controlling Organic Matter Enrichment in Alkaline Lacustrine Source Rocks:A Case Study of the Late Paleozoic Fengcheng Formation in the Junggar Basin,NW China

The late Paleozoic Fengcheng Formation shale(LPF shale)in the Junggar Basin,NW China,is the oldest alkaline source rock discovered in the world,providing a unique perspective with which to explore organic matter(OM)enrichment in alkaline lake environments.Combined with the organic carbon isotope profile and paleoenvironmental proxies,this study reveals that the LPF shale was deposited in an arid climate with high salinity and a strong reducing environment,accompanied by frequent volcanic activity.High TOC values are concentrated in two intervals with frequent fluctuations in OM types.A negative excursion due to changes in sedimentary OM source is found in the δ^(13)C_(org) profile.The excursion corresponds to the OM enrichment interval and is accompanied by abnormally high values of Sr/Ba and Sr/Cu.This implies that the extreme arid climate has led to high salinity,resulting in strong reducibility and changes in paleontological assemblages,which in turn controlled the differential enrichment of OM.The Fengcheng Fm.high-quality source rocks are the result of the combined action of climatic events,volcanism,high-salinity water environment and superior hydrocarbon-generating organisms.The results provide new insights into the formation conditions of terrestrial alkaline high-quality source rocks and the factors controlling alkaline OM enrichment.

Enlightenment of calcite veins in deep Ordovician Wufeng-Silurian Longmaxi shales fractures to migration and enrichment of shale gas in southern Sichuan Basin, SW China

The relationship between fracture calcite veins and shale gas enrichment in the deep Ordovician Wufeng Formation-Silurian Longmaxi Formation (Wufeng-Longmaxi) shales in southern Sichuan Basin was investigated through core and thin section observations, cathodoluminescence analysis, isotopic geochemistry analysis, fluid inclusion testing, and basin simulation. Tectonic fracture calcite veins mainly in the undulating part of the structure and non-tectonic fracture calcite veins are mainly formed in the gentle part of the structure. The latter, mainly induced by hydrocarbon generation, occurred at the stage of peak oil and gas generation, while the former turned up with the formation of Luzhou paleouplift during the Indosinian. Under the influence of hydrocarbon generation pressurization process, fractures were opened and closed frequently, and oil and gas episodic activities are recorded by veins. The formation pressure coefficient at the maximum paleodepth exceeds 2.0. The formation uplift stage after the Late Yanshanian is the key period for shale gas migration. Shale gas migrates along the bedding to the high part of the structure. The greater the structural fluctuation is, the more intense the shale gas migration activity is, and the loss is more. The gentler the formation is, the weaker the shale gas migration activity is, and the loss is less. The shale gas enrichment in the core of gentle anticlines and gentle synclines is relatively higher.

Filtration assisted pretreatment for rapid enrichment and accurate detection of Salmonella in vegetables

Rapid detection of target foodborne pathogens plays more and more significant roles in food safety,which requires the efficiency,sensitivity,and accuracy.In this research,we proposed a new st rategy of isothermal-molecular-amplification integrated with lateral-flow-strip for rapid detection of Salmonella without traditional enrichment-culture.Th e designed syringe-assisted-filtration can contribute to simultaneous collection and concentration of target bacterium from vegetable samples in just 3 min,resolving the drawbacks of traditional random sampling protocols.After simple and convenient ultrasonication,samples can be directly amplified at 39℃ in 25 min and the amplicons are qualitatively and quantitatively analyzed with the designed lateral-flow-strip in 5 min.Finally,satisfied results have been achieved within 40 min,which greatly improve the efficiency while the accuracy is also guaranteed.Furthermore,all detection steps can be completed under instrument-free conditions.This method will hold great promise for target pathogen detection in the resource-limited district,or for emergency on-site identification.

Petroleum geological features and hydrocarbon enrichment of Linhe Depression in Hetao Basin, NW China

Based on paleogeomorphology, drilling and seismic data, this paper systematically studies the structural and sedimentary evolution, source rock characteristics, reservoir characteristics and formation mechanism, hydrocarbon accumulation model and enrichment law in the Linhe Depression of the Hetao Basin, NW China. The Hetao Basin mainly experienced three stages of evolution, namely, weak extensional fault depression, strong extensional fault depression and strike-slip transformation, giving rise to four positive structural belts(Jilantai, Shabu, Nalinhu and Xinglong), which are favorable areas for oil and gas accumulation. The two main saline lacustrine source rocks, Lower Cretaceous Guyang Formation and Oligocene Linhe Formation, are characterized by high sulfur content, rich algae, early maturity, early expulsion, and wide oil generation window. The large structural transition belt in the intermountain area around the Hetao Basin controls the formation of large-scale braided river delta deposits, which are characterized by high quartz content(50%-76%), long-term shallow burial and weak compaction, low cement content, and good reservoir properties in delta front sandbody. The burial depth of the effective Paleogene reservoirs is predicted to reach 8000 m. Three hydrocarbon accumulation models, nose-uplift near sag, buried hill surrounding sag, fault nose near source rock, are constructed. The law of hydrocarbon accumulation in the Linhe Depression is finally clarified as follows: near-source around the depression is the foundation, high-quality thick reservoir is the premise, good tectonic setting and trap conditions are the key.

Optimization of enrichment and pretreatment of low-activity radium isotopes in the open ocean

In the open ocean,radium isotopes are useful tracers of residence time and water-mass mixing.However,limited by the measurement resolution of commonly used gamma counters,the low activity of radium in the open ocean makes it necessary to enrich radium from large volumes of seawater and pretreat radium-enriched carriers prior to measurements.The commonly applied method of radium enrichment and pretreatment,however,has limitations of uneven coating of MnO_(2)on cartridges,relatively expensive cartridges,time-consuming issues during cartridge-ashing,ash loss during transfer,and changes of gamma counters efficiency caused by different ash weights.To address these issues,in this study we optimized the enrichment and pretreatment of low-activity radium prior to measurements.Firstly,we replaced commonly used acrylic cartridges with cheaper polypropylene cartridges,which took 6 h to be ashed,42 h shorter than for acrylic cartridges.Secondly,MnO_(2)-coated cartridges were prepared with a circulating hot acidic KMnO_(4)solution to ensure homogeneous coating.The radium extraction efficiency of this MnO_(2)-coated cartridge was 20%-61%higher than that prepared by directly immersing cartridges in the solution.The radium delayed coincidence counter efficiency for MnO_(2)-coated cartridge was stable with a moisture content of 0.05-1.Lastly,after ashing cartridges,instead of directly transferring the ash to a measurement vial,a mixture of hydroxylamine hydrochloride and hydrochloric acid was used to completely leach the ash for long-lived radium,followed by coprecipitation by BaSO_(4),to avoid potential loss of ash during transfer and variations in measurement geometry due to different ash weights.And the recovery of long-lived radium pretreatment was 94%-102%,which improved by 11%compared with the common method.In addition,the radium extraction efficiency of the MnO_(2)-coated cartridge varied from 3%to 4%within the in situ pump working flow rate of 4-7 L/min,which fell within the measurement errors.

Gulong shale oil enrichment mechanism and orderly distribution of conventional–unconventional oils in the Cretaceous Qingshankou Formation,Songliao Basin,NE China

Through the study of organic matter enrichment,hydrocarbon generation and accumulation process of black shale of the Cretaceous Qingshankou Formation in the Songliao Basin,the enrichment mechanism of Gulong shale oil and the distribution of conventional–unconventional oil are revealed.The Songliao Basin is a huge interior lake basin formed in the Early Cretaceous under the control of the subduction and retreat of the western Pacific plate and the massive horizontal displacement of the Tanlu Fault Zone in Northeast China.During the deposition of the Qingshankou Formation,strong terrestrial hydrological cycle led to the lake level rise of the ancient Songliao Basin and the input of a large amount of nutrients,resulting in planktonic bacteria and algae flourish.Intermittent seawater intrusion events promoted the formation of salinization stratification and anoxic environment in the lake,which were beneficial to the enrichment of organic matters.Biomarkers analysis confirms that the biogenic organic matter of planktonic bacteria and algae modified by microorganisms plays an important role in the formation of high-quality source rocks with high oil generation capability.There are four favorable conditions for the enrichment of light shale oil in the Qingshankou Formation of the Gulong Sag,Songliao Basin:the moderate organic matter abundance and high oil potential provide sufficient material basis for oil enrichment;high degree of thermal evolution makes shale oil have high GOR and good mobility;low hydrocarbon expulsion efficiency leads to a high content of retained hydrocarbons in the source rock;and the confinement effect of intra-layer cement in the high maturity stage induces the efficient accumulation of light shale oil.The restoration of hydrocarbon accumulation process suggests that liquid hydrocarbons generated in the early(low–medium maturity)stage of the Qingshankou Formation source rocks accumulated in placanticline and slope after long-distance secondary migration,forming high-quality conventional and tight oil reservoirs.Light oil generated in the late(medium–high maturity)stage accumulated in situ,forming about 15 billion tons of Gulong shale oil resources,which finally enabled the orderly distribution of conventional–unconventional oils that are contiguous horizontally and superposed vertically within the basin,showing a complete pattern of“whole petroleum system”with conventional oil,tight oil and shale oil in sequence.

Organic matter transformation ratio, hydrocarbon expulsion efficiency and shale oil enrichment type in Chang 7_(3) shale of Upper Triassic Yanchang Formation in Ordos Basin, NW China

The major enrichment type of shale oil in the Chang 7_(3) shale of Upper Triassic Yanchang Formation in the Ordos Basin is unknown.This paper analyzes the organic matter transformation ratio,hydrocarbon expulsion efficiency and roof/floor sealing conditions of the Chang 7_(3) shale,and evaluates the major enrichment type of shale oil in this interval.The average organic matter transformation ratio of the Chang 7_(3) shale is about 45%;in other words,more than 50%of the organic matters have not transformed to hydrocarbons,and the lower the maturity,the greater the proportion of untransformed organic matters.The cumulative hydrocarbon expulsion efficiency of the transformed hydrocarbon is 27.5% on average,and the total proportion of untransformed organic matters plus retained hydrocarbons is greater than 70%.The relative hydrocarbon expulsion efficiency of the Chang 7_(3) shale is 60%on average,that is,about 40% of hydrocarbons retain in the shale.The Chang 7_(3) shale corresponds to Chang 7_(1+2) and Chang 8 sandstones as the roof and floor,respectively,and is further overlaid by Chang 6 shale,where extensive low porosity and low permeability–tight oil reservoirs have formed in the parts with relatively good porosity and permeability.Moreover,the Chang 7_(3) shale is tested to be in a negative pressure system(the pressure coefficient of 0.80–0.85).Therefore,the roof/floor sealing conditions of the Chang 7_(3) shale are poor.The retained hydrocarbons appear mostly in absorbed status,with low mobility.It is concluded that the medium–high mature shale oil is not the major enrichment type of shale oil in the Chang 7_(3) shale,but there may be enrichment opportunity for shale oil with good mobility in the areas where the sealing conditions are good without faults and fractures and oil reservoirs are formed off Chang 7_(1+2),Chang 6 and Chang 8.Furthermore,low–medium mature shale oil is believed to have great potential and is the major enrichment type of shale oil in the Chang 7_(3) shale.It is recommended to prepare relevant in-situ conversion technologies by pilot test and figure out the resource availability and distribution.

Environmental Enrichment and Its Effect on the Welfare of Two Asian Elephants in Africam Safari Wildlife Conservation Park (Puebla, Mexico)

Animal welfare is important in zoos to maintain the physical well-being and psychological health of individuals. An animal is considered to have welfare if it has good nutrition and also expresses its innate behavior, including sensations and feelings experienced as a result of physical health. The objective of this study was to evaluate the effect of environmental enrichment on the behaviors of two Asian elephants in a wildlife conservation park. The behavior of two Asian elephants, a 46-year-old male and a 59-year-old female, was observed. Behavior was measured by quantifying the frequency, latency, and duration of behavioral actions. Measurements were done with ad libitum sampling during 5 days of testing, then observations were recorded with focal sampling for 25 days with environmental enrichment and 25 days without enrichment. Data were analyzed with the Chi-square statistical test using the statistical program SPSS 20, observing significant differences (P the application of environmental enrichment. The frequency of maintenance behaviors was higher when environmental enrichment was provided, and the frequency of social conducts (affiliative and agonistic) decreased. In fact, the behaviors most frequently presented by elephants with and without environmental enrichment were definitely maintenance behaviors. The environmental enrichment program helped to reduce the duration of abnormal behaviors and increase the frequency of typical behaviors of the species. It also increased independent movements within the exhibition area and helped to know each of the elephants individually in order to apply each enrichment combination according to their needs.

C_4作物FACE(free-air CO_2 enrichment)研究进展

持续迅速上升的大气二氧化碳浓度([CO2])是全球变暖最大的驱动因子,但其作为光合作用底物直接增加了作物的生产力。相比C3作物,人们对未来高浓度CO2情形下C4作物的响应规律认识较少。与封闭或半封闭气室研究相比,FACE(free-airCO2 enrichment)试验在空气自由流动的大田条件下对作物表现进行研究,它提供了对未来作物生长环境的真实模拟,因此提供了评估CO2肥料效应以及揭示植物响应机制的最好机会。作为人类重要的粮食和饲料来源,高粱和玉米是最重要的C4作物。在简介美国玉米和高粱FACE系统的基础上,综述了FACE情形下高浓度CO2(模拟本世纪中叶大气CO2浓度,即550μmol/mol)对两大作物生理、生长和产量以及土壤特性等方面的影响,同时比较了与气室研究结果的异同点。(1)FACE使干旱条件下两作物光合作用显著增强,但湿润条件下没有影响;FACE条件下高粱出现光合适应现象,而玉米没有;(2)FACE使两作物气孔导度大幅下降,导致叶温升高、蒸腾速率下降、蒸发蒸腾总量减少或没有变化、叶片总水势和水分利用效率增加或没有变化;(3)FACE对两作物物候期和化学组分影响很少;(4)FACE使干旱条件下两作物生长和产量略有增加,但湿润条件下没有影响;(5)FACE使高粱田土壤丛枝状菌根真菌的长度和易提取胶状物质浓度显著增加,导致水稳性土壤团聚体增加;FACE对高粱田N2O或含氮气体(N2O+N2)的排放没有影响;(6)高浓度CO2对两作物气孔导度的影响FACE试验明显大于气室试验,而对生长和产量的影响呈相反趋势。阐明CO2与基因型、土壤湿度和大气温度间的互作效应及其机制是下一轮C4作物FACE研究优先考虑的方向,技术的不断进步已为利用大型FACE系统来研究这些互作效应提供了可能。

Enrichment of tight oil and its controlling factors in central and western China

Taking the tight oil of the Zhongnan sag in the Ordos Basin,Jimusar sag in the Junggar Basin and Qingxi sag in the Jiuquan Basin as study objects,based on field survey,dissection of tight oil reservoirs,sample test,modeling experiment and comprehensive analysis,this study reveals that the tight oil accumulates at start-up pressure,advances under differential pressure,diffuses at alternating fast and low speeds,charges in stepped large area and migrates rapidly through fractures,and enriches in dominant fractures and pores.The root cause of ladder-like charge is the multiple scales of pores.The widespread source rock with high hydrocarbon generation intensity is the material basis for tight oil enrichment;the dominant source reservoir assemblage is the basic unit for tight oil enrichment;fractures and beddings are conducive to local rapid migration of tight oil;fractures and pores work together to control the enrichment of tight oil.Two typical accumulation models of tight oil are established,namely"source reservoir in coexistence,four optimal factors controlling enrichment around central area,and large-scale continuous distribution"for a large freshwater lake clastic rock basin and"source reservoir integration,four optimal factors controlling enrichment,central area distribution,small in size but high in enrichment degree"for a small saline lake diamictite depression.