Mesozoic-Palaeozoic marine carbonate rocks are crucial hydrocarbon reservoirs in the Central Uplift area of the South Yellow Sea Basin(SYSB).Due to the scarcity of boreholes and the significant heterogeneity of carbon...Mesozoic-Palaeozoic marine carbonate rocks are crucial hydrocarbon reservoirs in the Central Uplift area of the South Yellow Sea Basin(SYSB).Due to the scarcity of boreholes and the significant heterogeneity of carbonate reservoirs,the distribution of porous carbonate reservoirs and their related key controlling factors remain unclear.In this study,factors affecting the distribution of porous Carboniferous-Early Permian carbonate reservoirs in the SYSB were investigated through seismic inversion and isotope analysis.The log-seismic characteristics of porous carbonate reservoirs,sensitive lithology parameters,and physical property parameters were extracted and analyzed.The pre-stack simultaneous inversion technique was applied to predict the lithology and physical properties of porous carbonate reservoirs.Moreover,the sedimentary of carbonate was analyzed using isotopes of carbon,oxygen,and strontium.The results show that porous carbonate reservoirs are mainly developed in the open platform sediments with porosities of 3%-5%and are mainly distributed in the paleo-highland(Huanglong Formation and Chuanshan Formation)and the slope of paleo-highland(Hezhou Formation).The porous carbonate reservoirs of the Qixia Formation are only locally developed.In addition,the negativeδ13C excursions indicate a warm and humid tropical climate with three sea-level fluctuations in the study area from the Carboniferous to Early Permian.The favorable conditions for developing porous carbonate rocks include the sedimentary environment and diagenetic process.The primary pore tends to form in high-energy environments of the paleo-highland,and the secondary pore is increased by dissolution during the syngenetic or quasi-syngenetic period.According to the hydrocarbon potential analysis,the Late Ordovician Wufeng Formation and Lower Silurian Gaojiabian Formation are the source rocks in the high-maturity-over-maturity stage,the Carboniferous-Lower Permian carbonate is the good reservoirs,and the Late Permian Longtan-Dalong Formation is the stable seal,ensuring a huge hydrocarbon accumulation potential in SYSB.The methods proposed in this study can be applied to other carbonate-dominated strata worldwide.展开更多
AIM： To investigate the functional, morphological changes of the gut barrier during the restitution process after hemorrhagic shock, and the regional differences of the large intestine and small intestine in response...AIM： To investigate the functional, morphological changes of the gut barrier during the restitution process after hemorrhagic shock, and the regional differences of the large intestine and small intestine in response to ischemia/ reperfusion injury. METHODS： Forty-seven Sprague-Dawley rats with body weight of 250-300 g were divided into two groups： control group （sham shock n = 5） and experimental group （n = 42）. Experimental group was further divided into six groups （n = 7 each） according to different time points after the hemorrhagic shock, including 0^th group, 1^st group, 3^rd group, 6th h group, 12^th group and 24^th group. All the rats were gavaged with 2 mL of suspension of lactulose （L） （100 mg/2 mL） and mannitol （M） （50 mg/each） at the beginning and then an experimental rat model of hemorrhagic shock was set up. The specimens from jejunum, ileum and colon tissues and the blood samples from the portal vein were taken at 0, 1, 3, 6, 12 and 24 h after shock resuscitation, respectively. The morphological changes of the intestinal mucosa, including the histology of intestinal mucosa, the thickness of mucosa, the height of villi, the index of mucosal damage and the numbers of goblet cells, were determined by light microscope and/or electron microscope. The concentrations of the bacterial endotoxin lipopolysaccharides （LPS） from the portal vein blood, which reflected the gut barrier function, were examined by using Limulus test. At the same time point, to evaluate intestinal permeability, all urine was collected and the concentrations of the metabolically inactive markers such as L and M in urine were measured by using GC-9A gas chromatographic instrument.RESULTS： After the hemorrhagic shock, the mucosal epithelial injury was obvious in small intestine even at the 0th h, and it became more serious at the 1^stand the 3^rd h. The tissue restitution was also found after 3 h, though the injury was still serious. Most of the injured mucosal restitution was established after 6 h and completed in 24 h. Two distinct models of cell deathapoptosis and necrosis-were involved in the destruction of rat intestinal epithelial cells. The number of goblet cells on intestinal mucosa was reduced significantly from 0 to 24 h （the number from 243±13 to 157±9 for ileum, 310±19 to 248±18 for colon; r= -0.910 and -0.437 respectively, all P〈0.001）, which was the same with the large intestine, but the grade of injury was lighter with the values of mucosal damage index in 3 h for jejunum, ileum, and colon being 2.8, 2.6, 1.2, respectively. The mucosal thickness and the height of villi in jejunum and ileum diminished in 1 h （the average height decreased from 309±24 to 204±23 pm and 271±31 to 231±28 pm, r = -0.758 and -0.659, all P〈0.001, the thickness from 547±23 to 418±28μm and 483±45 to 364±35μm, r= -0.898 and -0.829, all P〈0.001）, but there was no statistical difference in the colon （F= 0.296, P = 0.934）. Compared with control group, the urine L/M ratio and the blood LPS concentration in the experimental groups raised significantly, reaching the peak in 3-6 h （L/M： control vs 3 h vs6 h was 0.029±0.09 vs 0.063±0.012 vs 0.078±0.021, r = -0.786, P〈0.001; LPS： control vs3 h vs6 h was 0.09±0.021 vs 0.063±0.012 vs0.25±0.023, r=- -0.623, P〈0.001）, and it kept increasing in 24 h. CONCLUSION： The gut barrier of the rats was seriously damaged at the early phase of ischemic reperfusion injury after hemorrhagic shock, which included the injury and atrophy in intestinal mucosa and the increasing of intestinal permeability. Simultaneously, the intestinal mucosa also showed its great repairing potentiality, such as the improvement of the intestinal permeability and the recovery of the morphology at different phases after ischemic reperfusion injury. The restitution of gut barrier function was obviously slower than that of the morphology and there was no direct correlation between them. Compared with the small intestine, the large intestine had stronger potentiality against injury. The reduction of the amount of intestinal goblet cells by injury did not influence the ability of intestinal mucosal restitution at a certain extent and it appeared to be intimately involved in the restitution of the epithelium.展开更多
The South Yellow Sea Basin is a large sedimentary basin superimposed by the Mesozoic-Paleozoic marine sedimentary basin and the Mesozoic-Cenozoic terrestrial sedimentary basin, where no oil and gas fields have been di...The South Yellow Sea Basin is a large sedimentary basin superimposed by the Mesozoic-Paleozoic marine sedimentary basin and the Mesozoic-Cenozoic terrestrial sedimentary basin, where no oil and gas fields have been discovered after exploration for 58 years. After the failure of oil and gas exploration in terrestrial basins, the exploration target of the South Yellow Sea Basin turned to the marine Mesozoic- Paleozoic strata. After more than ten years' investigation and research, a lot of achievements have been obtained. The latest exploration obtained effective seismic reflection data of deep marine facies by the application of seismic exploration technology characterized by high coverage, abundant low-frequency components and strong energy source for the deep South Yellow Sea Basin. In addition, some wells drilled the Middle-Upper Paleozoic strata, with obvious oil and gas shows discovered in some horizons. The recent petroleum geological research on the South Yellow Sea Basin shows that the structure zoning of the marine residual basin has been redetermined, the basin structure has been defined, and 3 seismic reflection marker layers are traceable and correlatable in the residual thick Middle-Paleozoic strata below the continental Meso-Cenozoic strata in the South Yellow Sea Basin. Based on these, the seismic sequence of the marine sedimentary strata was established. According to the avaliable oil and gas exploration and research, the marine Mesozoic-Paleozoic oil and gas prospects of the South Yellow Sea were predicted as follows.(1) The South Yellow Sea Basin has the same sedimentary formation and evolution history during the sedimentary period of the Middle-Paleozoic marine basin with the Sichuan Basin.(2) There are 3 regional high-quality source rocks.(3) The carbonate and clastic reservoirs are developed in the Mesozoic- Paleozoic strata.(4) The three source-reservoir-cap assemblages are relatively intact.(5) The Laoshan Uplift is a prospect area for the Lower Paleozoic oil and gas, and the Wunansha Uplift is one for the marine Upper Paleozoic oil and gas.(6) The Gaoshi stable zone in the Laoshan Uplift is a favorable zone.(7) The marine Mesozoic-Paleozoic strata in the South Yellow Sea Basin has the geological conditions required to form large oil and gas fields, with remarkable oil and gas resources prospect. An urgent problem to be addressed now within the South Yellow Sea Basin is to drill parametric wells for the Lower Paleozoic strata as the target, to establish the complete stratigraphic sequence since the Paleozoic period, to obtain resource evaluation parameters, and to realize the strategic discovery and achieve breakthrough in oil and gas exploration understanding.展开更多
Based on well logging and seismic data, combined with a comparative analysis of drilling data in the Lower Yangtze region, the sequence stratigraphic framework of the Qinglong Formation was established and divided int...Based on well logging and seismic data, combined with a comparative analysis of drilling data in the Lower Yangtze region, the sequence stratigraphic framework of the Qinglong Formation was established and divided into four third-order sequences. Each sequence is mainly composed of the transgress system tract (TST) and the high-stand system tract (HST). According to the lithology, logging curve and seismic reflection structure, the sedimentary filling characteristics and evolution law for the sequence are analyzed. The results show that each sequence is dominated by a half-cycle decline of sea level, and the rise-fall of sea level controls the distribution and evolution of sedimentary systems within the sequence. During the relative sea-level rise, sedimentation rates slow down and muddy sediments are developed. The characteristics of condensing intervals on the flooding surface are very obvious, and continental shelf and open platform deposition are mainly developed. During the relative decline of sea level, the thickness of sediments increased. The main developments were restricted platform and platform shoal environment, and locally developed evaporation platform environment.展开更多
Based on the seismic data gathered in past years and the correlation between the sea and land areas of the Lower Yangtze Platform,the structural characteristics of the South Yellow Sea Basin since the Indosinian tecto...Based on the seismic data gathered in past years and the correlation between the sea and land areas of the Lower Yangtze Platform,the structural characteristics of the South Yellow Sea Basin since the Indosinian tectonic movement is studied in this paper.Three stages of structural deformation can be distinguished in the South Yellow Sea Basin since the Indosinian.The first stage,Late Indosinian to Early Yanshanian, was dominated by foreland deformation including both the uplifting and subsidence stages under an intensively compressional environment.The second stage,which is called the Huangqiao Event in the middle Yanshanian,was a change for stress fields from compression to extension.While in the third stage (the Sanduo Event)in the Late Himalayan,the basin developed a depression in the Neogene-Quatemary after rifting in the Late Cretaceous-Paleogene.The long-time evolution controlled 3 basin formation stages from a foreland basin,then a fault basin to a final depression basin.In conclusion,since the Indosinian,the South Yellow Sea Basin has experienced compressional fold and thrust,collisional orogen,compressional and tensional pulsation,strike-slip,extensional fault block and inversion structures,compression and convergence.The NE,NEE,nearly EW and NW trending structures developed in the basin.From west to east,the structural trend changed from NEE to near EW to NW.While from north to south,they changed from NEE to near EW with a strong-weak-strong zoning sequence.Vertically,the marine and terrestrial facies basins show a "seesaw"pattern with fold and thrust in the early stages,which is strong in the north and weak in the south and an extensional fault in later stages,which is strong in the north and weak in the south.In the marine facies'basin,thrust deformation is more prevailing in the upper structural layer than that in the lower layer.The tectonic mechanism in the South Yellow Sea Basin is mainly affected by the collision between the Yangtze and North China Block,while the stress environment of large-scale strike- slip faults was owing to subduction of the Paleo-Pacific plate.The southern part of the Laoshan uplift is a weak deformation zone as well as a stress release zone,and the Meso-Paleozoic had been weakly reformed in later stages.The southern part of the Laoshan uplift is believed,therefore,to be a promising area for oil and gas exploration.展开更多
Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now.In this study,the onshore-offshore stratigraphic correlation and seis...Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now.In this study,the onshore-offshore stratigraphic correlation and seismic data interpretation were conducted to determine the oil and gas resource potential in the Offshore Indus Basin,Pakistan.Based on the comprehensive analysis of the results and previous data,it is considered that the Cretaceous may widely exist and three sets of source rocks may be developed in the Offshore Indus Basin.The presence of Miocene mudstones has been proven by drilling to be high-quality source rocks,while the Cretaceous and Paleocene–Eocene mudstones are potential source rocks.Tectonic-lithologic traps are developed in the northwestern part of the basin affected by the strike-slip faults along Murray Ridge.Furthermore,the Cretaceous and Paleocene–Eocene source rocks are thick and are slightly affected by volcanic activities.Therefore,it can be inferred that the northwestern part of Offshore Indus Basin enjoys good prospects of oil and gas resources.展开更多
1.Objectives The study of the paleo-reservoir is of great significance for oil and gas exploration.Firstly,the existence of paleoreservoirs can reflect there has been hydrocarbon accumulation process in this area,wher...1.Objectives The study of the paleo-reservoir is of great significance for oil and gas exploration.Firstly,the existence of paleoreservoirs can reflect there has been hydrocarbon accumulation process in this area,where there once was the advantageous condition with source-reservoir-cap combination;secondly,it can indicate that this area has certain resource potential.The purpose of this research is: through the study of the paleo-reservoir of CSDP-2 well in the Laoshan uplift of the South Yellow Sea Basin,which is a scientific investigation well,it can provide geological basis for marine oil and gas exploration of the Mesozoic and Paleozoic in the Laoshan uplift of the South Yellow Sea Basin,and at the same time can provide important information for future exploration target selection.展开更多
As cyclical orbital movements of Earth,Milankovitch cycles can be recorded in sedimentary strata.The time they reflect can be used to accurately divide and compare strata.Milankovitch cycles recorded in strata enrich ...As cyclical orbital movements of Earth,Milankovitch cycles can be recorded in sedimentary strata.The time they reflect can be used to accurately divide and compare strata.Milankovitch cycles recorded in strata enrich the stratigraphic theory,especially the theories of cycle stratigraphy,and thus they are widely used in geological survey engineering nowadays.This study explored the characteristics of the Milankovitch cycles recorded in the eastern depression of the North Yellow Sea Basin,highlighting their control over high-frequency stratigraphic sequences.The Eocene Milankovitch cycles in the depression were calculated based on the method proposed by J.Laskar,and their parameters primarily include eccentricity cycles of 125 ka and 99 ka,obliquity cycles of 51 ka and 39 ka,and precession cycles of 23 ka and 19 ka.Spectral analysis of gamma-ray(GR)and spontaneous potential(SP)log curves of the Eocene strata was carried out to divide and compare stratigraphic sequences,revealing that the spectral peaks correspond well to astronomical cycles.This indicates that the strata in the depression fully record Milankovitch cycles.Furthermore,there are long-,medium-,and short-term stratigraphic cycles in the eastern depression,with a thickness of 13.03-15.89 m,3.70-5.21 m,and 2.17-2.94 m,respectively.The sedimentation rates of the Eocene strata were calculated to be 121.2-127.12 m/Ma accordingly.From the uplift to the center of the lacustrine basin along the slope in the eastern depression,both the sedimentation duration and the sediment thickness increase,while the sedimentation rate remains relatively stable.The Eocene strata can be divided into six stages of high-frequency sequences by continuous wavelet transformation,namely E_(6)-E_(1) from bottom to top.The sedimentation duration and sedimentation rates of the sequences were calculated using spectral analysis with each of the sequences as a separate window.Moreover,the impacts of climate change on the sedimentary environment in the eastern depression were analyzed.It can be concluded that E_(6) was a lowstand system tract,E_(5) and E_(4) were lacustrine expansion system tracts,E_(3) was a highstand system tract,and E_(2) and E_(1) were lacustrine contraction system tracts.All these verify that Milankovitch cycles serve as an effective approach for the analysis of sedimentary cycles.展开更多
1.Objective Fluid inclusions are the only way to obtain the volatile components in the process of hydrocarbon accumulation. The Marine Paleozoic strata in the South Yellow Sea Basin are of great thickness and widely d...1.Objective Fluid inclusions are the only way to obtain the volatile components in the process of hydrocarbon accumulation. The Marine Paleozoic strata in the South Yellow Sea Basin are of great thickness and widely distributed. The Lower Paleozoic source rocks, reservoirs and caprocks are developed and have generally good hydrocarbon geological conditions.展开更多
In order to make a breakthrough in Mesozoic-Paleozoic shale gas exploration in the South Yellow Sea Basin,a comparison of the preservation conditions was made within the Barnett shale gas reservoirs in the Fortworth B...In order to make a breakthrough in Mesozoic-Paleozoic shale gas exploration in the South Yellow Sea Basin,a comparison of the preservation conditions was made within the Barnett shale gas reservoirs in the Fortworth Basin,the Jiaoshiba shale gas reservoirs in Sichuan Basin and potential shale gas reservoirs in Guizhou Province.The results show that the "Sandwich"structure is of great importance for shale gas accumulation.Therein to,the "Sandwich"structure is a kind of special reservoir-cap rock assemblage which consist of limestone or dolomite on the top,mudstone or shale layer in the middle and limestone or dolomite at the bottom.In consideration of the Mesozoic-Paleozoie in the Lower Yangtze,and Laoshan Uplift with weak Paleozoic deformation and thrust fault sealing On both flanks of the Laoshan Uplift,a conclusion can be drawn that the preservation conditions of shale gas probably developed "Sandwich" structures in the Lower Cambrian and Permian,which are key layers for the breakthrough of shale gas in the South Yellow Sea.Moreover,the preferred targets for shale gas drilling probably locate at both flanks of the Laoshan Uplift.展开更多
The Sea of Japan is located in the southeast margin of Eurasia, in the triangle area of the western Pacific Ocean. Due to the interaction of the Pacific plate, Eurasian plate and Philippine plate, its tectonic environ...The Sea of Japan is located in the southeast margin of Eurasia, in the triangle area of the western Pacific Ocean. Due to the interaction of the Pacific plate, Eurasian plate and Philippine plate, its tectonic environment is complex, forming a typical trench-arc-basin system. At present, 148 oil and gas fields have been discovered in Japan, with an oil and gas resource of 255.78×10^(6) t, showing a good prospect for oil and gas exploration. Based on the previous research and the recently collected geological and geophysical data, the characteristics of tectonic-sedimentary evolution and geothermal field in the basins around the Sea of Japan are analyzed. The results show that the tectonic evolution of the basin is mainly controlled by plate subduction and back-arc oceanic crust expansion, and it mainly undergone four tectonic-sedimentary evolution stages: Subduction period, basin development period, subsidence period and compression deformation period. The overall heat flow value of Japan Sea is high, and it is distributed annularly along Yamato Ridge. The geothermal heat flow value is about 50–130 MW/m^(2), and the average heat flow is75.9±19.8 MW/m^(2), which has a typical “hot basin ”. The high heat flow background provides unique thermal evolution conditions for hydrocarbon generation, which leads to the high temperature and rapid evolution. The authors summarized as “early hydrocarbon generation, rapid maturity and shallow and narrow hydrocarbon generation window”. The type of oil and gas is mainly natural gas, and it mainly distributed in Neogene oil and gas reservoirs. The trap types are mainly structural traps, lithologic traps and composite traps. In addition, the pre-Neogene bedrock oil and gas reservoirs also show a good exploration prospect. The resource prospecting indicates that Niigata Basin, Ulleung Basin and kitakami Basin are the main target areas for future exploration and development.展开更多
To accurately identify the natural gas hydrates(NGH)in the sea area of the Makran Accretionary Prism,Pakistan,this paper presents the testing and analysis of major and trace elements in sediment samples taken from two...To accurately identify the natural gas hydrates(NGH)in the sea area of the Makran Accretionary Prism,Pakistan,this paper presents the testing and analysis of major and trace elements in sediment samples taken from two stations(S2 and S3)in the area by the China Geological Survey.As shown by testing results,all major elements are slightly different in content between the two stations except SiO2 and CaO.This also applies to the trace elements that include Sr and Ba primarily and Cr,Ni and Zn secondarily.It can be concluded in this study that the tectonic setting of the Makran Accretionary Prism is dominated by oceanic island arc and that provenance of the Makran Accretionary Prism is dominated by felsic igneous provenance,which is at the initial weathering stage and mainly consists of granodiorite.Besides terrigenous detritus,there are sediments possibly originating from Makran-Bela Ophiolite from the northwestern part and Murray Ridge igneous rocks from the southeastern part.The V/Cr,Ni/Co,and V/(V+Ni)ratios indicate that sediments of the two stations are in an oxidation-suboxidation environment.However,the authors infer that the sedimentary environment of the sediments 3.0 m below the seafloor tends to be gradually transformed into a reduction environment by comparison with the Qiongdongnan Basin in the South China Sea where NGH has been discovered.The sediments in the Makran Accretionary Prism are rich in organic matter,with total organic carbon(TOC)content greater than 1%.According to comprehensive research,the organic matter in the sediments mainly originates from marine algae and has high TOC content,which is favorable for the formation of NGH.展开更多
Background： Spinocerebellar ata^ias （SCAs） are a group ofneurodegenerative disorders that primarily cause the degeneration in the cerebellum, spinal cord, and brainstem. We study the clinical characteristics, radio...Background： Spinocerebellar ata^ias （SCAs） are a group ofneurodegenerative disorders that primarily cause the degeneration in the cerebellum, spinal cord, and brainstem. We study the clinical characteristics, radiological features and gene mutation in Chinese families with SCAs. Methods： In this study, we investigated 10 SCAs Chinese families with SCAI, SCA3/Machado-Joseph disease （MJD}, SCA7, SCAB. There were 27 people who were genetically diagnosed as SCA, of which 21 people showed clinical symptoms, and 6 people had no clinical phenotype that we called them presymptomatic patients. In addition, 3 people with cerebellar ataxia and cataracts were diagnosed according to the Harding diagnostic criteria but tailed to be recognized as SCAs on genetic testing. Clinical characteristic analyses of each type of SCAs and radiological examinations were perlbrmed. Results： We found that SCA3/MJD was the most common subtype in Hart population in China, and the ratio of the pontine tegmentum and the posterior fossa area was negatively con＇elated with the number of cytosine-adenine-guanine （CAG） repeats： the disease duration was positively correlated with the International Cooperative Ataxia Rating Scale score; and the CAG repeats number of abnormal alleles was negatively correlated with the age of onset. Conchlsions： Collectively our study is a systematic research on SCAs in China, which may help for the clinical diagnosis and prenatal screening of this disease, and it may also aid toward better understanding of this disease.展开更多
基金This study was supported by the project ofthe Science and Technology Innovation Fund of Command Center of Natural Resources Intergrated Survey entitled“Temporal and spatial distribution of paleochannel and origin of organic carbon burial in the Western Bohai Sea since 2.28Ma”(KC20220011)the project entitled“Characterization of Carboniferous-Early Permian heterogeneous porous carbonate reservoirs and hydrocarbon potential analysis in the central uplift of the South Yellow Sea Basin”(KLSG2304)+3 种基金by the Key laboratory of Submarine Science,Ministry of Natural Resources,the project entitled“1∶50000 Marine regional Geological survey in Caofeidian Sea Area,Bohai Sea”(ZD20220602)“1∶250000 Marine regional Geological survey in Weihai Sea Area,North Yellow Sea”(DD20230412)“Geological survey on tectonic and sedimentary conditions of Laoshan uplift”(DD2016015)by the China Geological Survey,and the project entitled“Study on Hydrocarbon Accumulation Failure and Fluid Evolution Reduction of the Permian Reservoir in the Laoshan Uplift,South Yellow Sea”(42076220)organized by the National Natural Science Foundation of China.
文摘Mesozoic-Palaeozoic marine carbonate rocks are crucial hydrocarbon reservoirs in the Central Uplift area of the South Yellow Sea Basin(SYSB).Due to the scarcity of boreholes and the significant heterogeneity of carbonate reservoirs,the distribution of porous carbonate reservoirs and their related key controlling factors remain unclear.In this study,factors affecting the distribution of porous Carboniferous-Early Permian carbonate reservoirs in the SYSB were investigated through seismic inversion and isotope analysis.The log-seismic characteristics of porous carbonate reservoirs,sensitive lithology parameters,and physical property parameters were extracted and analyzed.The pre-stack simultaneous inversion technique was applied to predict the lithology and physical properties of porous carbonate reservoirs.Moreover,the sedimentary of carbonate was analyzed using isotopes of carbon,oxygen,and strontium.The results show that porous carbonate reservoirs are mainly developed in the open platform sediments with porosities of 3%-5%and are mainly distributed in the paleo-highland(Huanglong Formation and Chuanshan Formation)and the slope of paleo-highland(Hezhou Formation).The porous carbonate reservoirs of the Qixia Formation are only locally developed.In addition,the negativeδ13C excursions indicate a warm and humid tropical climate with three sea-level fluctuations in the study area from the Carboniferous to Early Permian.The favorable conditions for developing porous carbonate rocks include the sedimentary environment and diagenetic process.The primary pore tends to form in high-energy environments of the paleo-highland,and the secondary pore is increased by dissolution during the syngenetic or quasi-syngenetic period.According to the hydrocarbon potential analysis,the Late Ordovician Wufeng Formation and Lower Silurian Gaojiabian Formation are the source rocks in the high-maturity-over-maturity stage,the Carboniferous-Lower Permian carbonate is the good reservoirs,and the Late Permian Longtan-Dalong Formation is the stable seal,ensuring a huge hydrocarbon accumulation potential in SYSB.The methods proposed in this study can be applied to other carbonate-dominated strata worldwide.
基金Supported by the Grants from the Health Research Foundation (A2003189) and the Science Research Project (2004B30601001) of Guangdong Province, China
文摘AIM： To investigate the functional, morphological changes of the gut barrier during the restitution process after hemorrhagic shock, and the regional differences of the large intestine and small intestine in response to ischemia/ reperfusion injury. METHODS： Forty-seven Sprague-Dawley rats with body weight of 250-300 g were divided into two groups： control group （sham shock n = 5） and experimental group （n = 42）. Experimental group was further divided into six groups （n = 7 each） according to different time points after the hemorrhagic shock, including 0^th group, 1^st group, 3^rd group, 6th h group, 12^th group and 24^th group. All the rats were gavaged with 2 mL of suspension of lactulose （L） （100 mg/2 mL） and mannitol （M） （50 mg/each） at the beginning and then an experimental rat model of hemorrhagic shock was set up. The specimens from jejunum, ileum and colon tissues and the blood samples from the portal vein were taken at 0, 1, 3, 6, 12 and 24 h after shock resuscitation, respectively. The morphological changes of the intestinal mucosa, including the histology of intestinal mucosa, the thickness of mucosa, the height of villi, the index of mucosal damage and the numbers of goblet cells, were determined by light microscope and/or electron microscope. The concentrations of the bacterial endotoxin lipopolysaccharides （LPS） from the portal vein blood, which reflected the gut barrier function, were examined by using Limulus test. At the same time point, to evaluate intestinal permeability, all urine was collected and the concentrations of the metabolically inactive markers such as L and M in urine were measured by using GC-9A gas chromatographic instrument.RESULTS： After the hemorrhagic shock, the mucosal epithelial injury was obvious in small intestine even at the 0th h, and it became more serious at the 1^stand the 3^rd h. The tissue restitution was also found after 3 h, though the injury was still serious. Most of the injured mucosal restitution was established after 6 h and completed in 24 h. Two distinct models of cell deathapoptosis and necrosis-were involved in the destruction of rat intestinal epithelial cells. The number of goblet cells on intestinal mucosa was reduced significantly from 0 to 24 h （the number from 243±13 to 157±9 for ileum, 310±19 to 248±18 for colon; r= -0.910 and -0.437 respectively, all P〈0.001）, which was the same with the large intestine, but the grade of injury was lighter with the values of mucosal damage index in 3 h for jejunum, ileum, and colon being 2.8, 2.6, 1.2, respectively. The mucosal thickness and the height of villi in jejunum and ileum diminished in 1 h （the average height decreased from 309±24 to 204±23 pm and 271±31 to 231±28 pm, r = -0.758 and -0.659, all P〈0.001, the thickness from 547±23 to 418±28μm and 483±45 to 364±35μm, r= -0.898 and -0.829, all P〈0.001）, but there was no statistical difference in the colon （F= 0.296, P = 0.934）. Compared with control group, the urine L/M ratio and the blood LPS concentration in the experimental groups raised significantly, reaching the peak in 3-6 h （L/M： control vs 3 h vs6 h was 0.029±0.09 vs 0.063±0.012 vs 0.078±0.021, r = -0.786, P〈0.001; LPS： control vs3 h vs6 h was 0.09±0.021 vs 0.063±0.012 vs0.25±0.023, r=- -0.623, P〈0.001）, and it kept increasing in 24 h. CONCLUSION： The gut barrier of the rats was seriously damaged at the early phase of ischemic reperfusion injury after hemorrhagic shock, which included the injury and atrophy in intestinal mucosa and the increasing of intestinal permeability. Simultaneously, the intestinal mucosa also showed its great repairing potentiality, such as the improvement of the intestinal permeability and the recovery of the morphology at different phases after ischemic reperfusion injury. The restitution of gut barrier function was obviously slower than that of the morphology and there was no direct correlation between them. Compared with the small intestine, the large intestine had stronger potentiality against injury. The reduction of the amount of intestinal goblet cells by injury did not influence the ability of intestinal mucosal restitution at a certain extent and it appeared to be intimately involved in the restitution of the epithelium.
文摘The South Yellow Sea Basin is a large sedimentary basin superimposed by the Mesozoic-Paleozoic marine sedimentary basin and the Mesozoic-Cenozoic terrestrial sedimentary basin, where no oil and gas fields have been discovered after exploration for 58 years. After the failure of oil and gas exploration in terrestrial basins, the exploration target of the South Yellow Sea Basin turned to the marine Mesozoic- Paleozoic strata. After more than ten years' investigation and research, a lot of achievements have been obtained. The latest exploration obtained effective seismic reflection data of deep marine facies by the application of seismic exploration technology characterized by high coverage, abundant low-frequency components and strong energy source for the deep South Yellow Sea Basin. In addition, some wells drilled the Middle-Upper Paleozoic strata, with obvious oil and gas shows discovered in some horizons. The recent petroleum geological research on the South Yellow Sea Basin shows that the structure zoning of the marine residual basin has been redetermined, the basin structure has been defined, and 3 seismic reflection marker layers are traceable and correlatable in the residual thick Middle-Paleozoic strata below the continental Meso-Cenozoic strata in the South Yellow Sea Basin. Based on these, the seismic sequence of the marine sedimentary strata was established. According to the avaliable oil and gas exploration and research, the marine Mesozoic-Paleozoic oil and gas prospects of the South Yellow Sea were predicted as follows.(1) The South Yellow Sea Basin has the same sedimentary formation and evolution history during the sedimentary period of the Middle-Paleozoic marine basin with the Sichuan Basin.(2) There are 3 regional high-quality source rocks.(3) The carbonate and clastic reservoirs are developed in the Mesozoic- Paleozoic strata.(4) The three source-reservoir-cap assemblages are relatively intact.(5) The Laoshan Uplift is a prospect area for the Lower Paleozoic oil and gas, and the Wunansha Uplift is one for the marine Upper Paleozoic oil and gas.(6) The Gaoshi stable zone in the Laoshan Uplift is a favorable zone.(7) The marine Mesozoic-Paleozoic strata in the South Yellow Sea Basin has the geological conditions required to form large oil and gas fields, with remarkable oil and gas resources prospect. An urgent problem to be addressed now within the South Yellow Sea Basin is to drill parametric wells for the Lower Paleozoic strata as the target, to establish the complete stratigraphic sequence since the Paleozoic period, to obtain resource evaluation parameters, and to realize the strategic discovery and achieve breakthrough in oil and gas exploration understanding.
文摘Based on well logging and seismic data, combined with a comparative analysis of drilling data in the Lower Yangtze region, the sequence stratigraphic framework of the Qinglong Formation was established and divided into four third-order sequences. Each sequence is mainly composed of the transgress system tract (TST) and the high-stand system tract (HST). According to the lithology, logging curve and seismic reflection structure, the sedimentary filling characteristics and evolution law for the sequence are analyzed. The results show that each sequence is dominated by a half-cycle decline of sea level, and the rise-fall of sea level controls the distribution and evolution of sedimentary systems within the sequence. During the relative sea-level rise, sedimentation rates slow down and muddy sediments are developed. The characteristics of condensing intervals on the flooding surface are very obvious, and continental shelf and open platform deposition are mainly developed. During the relative decline of sea level, the thickness of sediments increased. The main developments were restricted platform and platform shoal environment, and locally developed evaporation platform environment.
文摘Based on the seismic data gathered in past years and the correlation between the sea and land areas of the Lower Yangtze Platform,the structural characteristics of the South Yellow Sea Basin since the Indosinian tectonic movement is studied in this paper.Three stages of structural deformation can be distinguished in the South Yellow Sea Basin since the Indosinian.The first stage,Late Indosinian to Early Yanshanian, was dominated by foreland deformation including both the uplifting and subsidence stages under an intensively compressional environment.The second stage,which is called the Huangqiao Event in the middle Yanshanian,was a change for stress fields from compression to extension.While in the third stage (the Sanduo Event)in the Late Himalayan,the basin developed a depression in the Neogene-Quatemary after rifting in the Late Cretaceous-Paleogene.The long-time evolution controlled 3 basin formation stages from a foreland basin,then a fault basin to a final depression basin.In conclusion,since the Indosinian,the South Yellow Sea Basin has experienced compressional fold and thrust,collisional orogen,compressional and tensional pulsation,strike-slip,extensional fault block and inversion structures,compression and convergence.The NE,NEE,nearly EW and NW trending structures developed in the basin.From west to east,the structural trend changed from NEE to near EW to NW.While from north to south,they changed from NEE to near EW with a strong-weak-strong zoning sequence.Vertically,the marine and terrestrial facies basins show a "seesaw"pattern with fold and thrust in the early stages,which is strong in the north and weak in the south and an extensional fault in later stages,which is strong in the north and weak in the south.In the marine facies'basin,thrust deformation is more prevailing in the upper structural layer than that in the lower layer.The tectonic mechanism in the South Yellow Sea Basin is mainly affected by the collision between the Yangtze and North China Block,while the stress environment of large-scale strike- slip faults was owing to subduction of the Paleo-Pacific plate.The southern part of the Laoshan uplift is a weak deformation zone as well as a stress release zone,and the Meso-Paleozoic had been weakly reformed in later stages.The southern part of the Laoshan uplift is believed,therefore,to be a promising area for oil and gas exploration.
基金This work was financially supported by National Natural Science Foundation of China(91858208,41406080,42076069)China Geological Survey(DD20190581).
文摘Oil and gas resources are short in Pakistan and no commercially viable oil and gas sources have been yet discovered in its offshore areas up to now.In this study,the onshore-offshore stratigraphic correlation and seismic data interpretation were conducted to determine the oil and gas resource potential in the Offshore Indus Basin,Pakistan.Based on the comprehensive analysis of the results and previous data,it is considered that the Cretaceous may widely exist and three sets of source rocks may be developed in the Offshore Indus Basin.The presence of Miocene mudstones has been proven by drilling to be high-quality source rocks,while the Cretaceous and Paleocene–Eocene mudstones are potential source rocks.Tectonic-lithologic traps are developed in the northwestern part of the basin affected by the strike-slip faults along Murray Ridge.Furthermore,the Cretaceous and Paleocene–Eocene source rocks are thick and are slightly affected by volcanic activities.Therefore,it can be inferred that the northwestern part of Offshore Indus Basin enjoys good prospects of oil and gas resources.
文摘1.Objectives The study of the paleo-reservoir is of great significance for oil and gas exploration.Firstly,the existence of paleoreservoirs can reflect there has been hydrocarbon accumulation process in this area,where there once was the advantageous condition with source-reservoir-cap combination;secondly,it can indicate that this area has certain resource potential.The purpose of this research is: through the study of the paleo-reservoir of CSDP-2 well in the Laoshan uplift of the South Yellow Sea Basin,which is a scientific investigation well,it can provide geological basis for marine oil and gas exploration of the Mesozoic and Paleozoic in the Laoshan uplift of the South Yellow Sea Basin,and at the same time can provide important information for future exploration target selection.
基金This study was supported by projects of the China Geological Survey entitled“Integrated Observation Data Integration and Application Service of Natural Resource Elements”(DD20208067)“Petroleum geological survey in key areas of Yellow Sea”(DD2021353)+1 种基金“Geological survey on tectonic and sedimentary conditions of Laoshan Uplift”(DD20190818)the project of National Natural Science Foundation of China entitled“Study on Hydrocarbon Accumulation Failure and Fluid Evolution Reduction of Permian Reservoir in Laoshan Uplift,South Yellow Sea”(42076220).
文摘As cyclical orbital movements of Earth,Milankovitch cycles can be recorded in sedimentary strata.The time they reflect can be used to accurately divide and compare strata.Milankovitch cycles recorded in strata enrich the stratigraphic theory,especially the theories of cycle stratigraphy,and thus they are widely used in geological survey engineering nowadays.This study explored the characteristics of the Milankovitch cycles recorded in the eastern depression of the North Yellow Sea Basin,highlighting their control over high-frequency stratigraphic sequences.The Eocene Milankovitch cycles in the depression were calculated based on the method proposed by J.Laskar,and their parameters primarily include eccentricity cycles of 125 ka and 99 ka,obliquity cycles of 51 ka and 39 ka,and precession cycles of 23 ka and 19 ka.Spectral analysis of gamma-ray(GR)and spontaneous potential(SP)log curves of the Eocene strata was carried out to divide and compare stratigraphic sequences,revealing that the spectral peaks correspond well to astronomical cycles.This indicates that the strata in the depression fully record Milankovitch cycles.Furthermore,there are long-,medium-,and short-term stratigraphic cycles in the eastern depression,with a thickness of 13.03-15.89 m,3.70-5.21 m,and 2.17-2.94 m,respectively.The sedimentation rates of the Eocene strata were calculated to be 121.2-127.12 m/Ma accordingly.From the uplift to the center of the lacustrine basin along the slope in the eastern depression,both the sedimentation duration and the sediment thickness increase,while the sedimentation rate remains relatively stable.The Eocene strata can be divided into six stages of high-frequency sequences by continuous wavelet transformation,namely E_(6)-E_(1) from bottom to top.The sedimentation duration and sedimentation rates of the sequences were calculated using spectral analysis with each of the sequences as a separate window.Moreover,the impacts of climate change on the sedimentary environment in the eastern depression were analyzed.It can be concluded that E_(6) was a lowstand system tract,E_(5) and E_(4) were lacustrine expansion system tracts,E_(3) was a highstand system tract,and E_(2) and E_(1) were lacustrine contraction system tracts.All these verify that Milankovitch cycles serve as an effective approach for the analysis of sedimentary cycles.
文摘1.Objective Fluid inclusions are the only way to obtain the volatile components in the process of hydrocarbon accumulation. The Marine Paleozoic strata in the South Yellow Sea Basin are of great thickness and widely distributed. The Lower Paleozoic source rocks, reservoirs and caprocks are developed and have generally good hydrocarbon geological conditions.
基金the Project of China Geological Survey (DD20160512, DD20160346)Science and Technology Development Fund Project of Shinan District (2018-4-006-ZH)+2 种基金Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology,Ministry of Land and Resources (MRE201311)National Natural Science Foundation (41776075,41702162)Natural Science Foundation of Shandong Province of China (ZR2017BD034).
文摘In order to make a breakthrough in Mesozoic-Paleozoic shale gas exploration in the South Yellow Sea Basin,a comparison of the preservation conditions was made within the Barnett shale gas reservoirs in the Fortworth Basin,the Jiaoshiba shale gas reservoirs in Sichuan Basin and potential shale gas reservoirs in Guizhou Province.The results show that the "Sandwich"structure is of great importance for shale gas accumulation.Therein to,the "Sandwich"structure is a kind of special reservoir-cap rock assemblage which consist of limestone or dolomite on the top,mudstone or shale layer in the middle and limestone or dolomite at the bottom.In consideration of the Mesozoic-Paleozoie in the Lower Yangtze,and Laoshan Uplift with weak Paleozoic deformation and thrust fault sealing On both flanks of the Laoshan Uplift,a conclusion can be drawn that the preservation conditions of shale gas probably developed "Sandwich" structures in the Lower Cambrian and Permian,which are key layers for the breakthrough of shale gas in the South Yellow Sea.Moreover,the preferred targets for shale gas drilling probably locate at both flanks of the Laoshan Uplift.
基金jointly supported by the Major Project of National Laboratory for Marine Science and Technology (Qingdao) (2021QNLM020001-1, 2021QNLM020001-4)the Project of China Geology Survey (DD20221723, DD20230317)+3 种基金the National Natural Science Foundation of China (41776075, 42076220 and 42206234)the Natural Science Foundation of Shandong Province (ZR2020QD038)the Major Basic Research Projects of Shandong Province (ZR2021ZD09)funded by the Qingdao Institute of Marine Geology, China Geological Survey。
文摘The Sea of Japan is located in the southeast margin of Eurasia, in the triangle area of the western Pacific Ocean. Due to the interaction of the Pacific plate, Eurasian plate and Philippine plate, its tectonic environment is complex, forming a typical trench-arc-basin system. At present, 148 oil and gas fields have been discovered in Japan, with an oil and gas resource of 255.78×10^(6) t, showing a good prospect for oil and gas exploration. Based on the previous research and the recently collected geological and geophysical data, the characteristics of tectonic-sedimentary evolution and geothermal field in the basins around the Sea of Japan are analyzed. The results show that the tectonic evolution of the basin is mainly controlled by plate subduction and back-arc oceanic crust expansion, and it mainly undergone four tectonic-sedimentary evolution stages: Subduction period, basin development period, subsidence period and compression deformation period. The overall heat flow value of Japan Sea is high, and it is distributed annularly along Yamato Ridge. The geothermal heat flow value is about 50–130 MW/m^(2), and the average heat flow is75.9±19.8 MW/m^(2), which has a typical “hot basin ”. The high heat flow background provides unique thermal evolution conditions for hydrocarbon generation, which leads to the high temperature and rapid evolution. The authors summarized as “early hydrocarbon generation, rapid maturity and shallow and narrow hydrocarbon generation window”. The type of oil and gas is mainly natural gas, and it mainly distributed in Neogene oil and gas reservoirs. The trap types are mainly structural traps, lithologic traps and composite traps. In addition, the pre-Neogene bedrock oil and gas reservoirs also show a good exploration prospect. The resource prospecting indicates that Niigata Basin, Ulleung Basin and kitakami Basin are the main target areas for future exploration and development.
基金This work was funded by the projects of the National Natural Science Foundation of China(91858208,42076069)the project of China Geological Survey(DD20190581)。
文摘To accurately identify the natural gas hydrates(NGH)in the sea area of the Makran Accretionary Prism,Pakistan,this paper presents the testing and analysis of major and trace elements in sediment samples taken from two stations(S2 and S3)in the area by the China Geological Survey.As shown by testing results,all major elements are slightly different in content between the two stations except SiO2 and CaO.This also applies to the trace elements that include Sr and Ba primarily and Cr,Ni and Zn secondarily.It can be concluded in this study that the tectonic setting of the Makran Accretionary Prism is dominated by oceanic island arc and that provenance of the Makran Accretionary Prism is dominated by felsic igneous provenance,which is at the initial weathering stage and mainly consists of granodiorite.Besides terrigenous detritus,there are sediments possibly originating from Makran-Bela Ophiolite from the northwestern part and Murray Ridge igneous rocks from the southeastern part.The V/Cr,Ni/Co,and V/(V+Ni)ratios indicate that sediments of the two stations are in an oxidation-suboxidation environment.However,the authors infer that the sedimentary environment of the sediments 3.0 m below the seafloor tends to be gradually transformed into a reduction environment by comparison with the Qiongdongnan Basin in the South China Sea where NGH has been discovered.The sediments in the Makran Accretionary Prism are rich in organic matter,with total organic carbon(TOC)content greater than 1%.According to comprehensive research,the organic matter in the sediments mainly originates from marine algae and has high TOC content,which is favorable for the formation of NGH.
文摘Background： Spinocerebellar ata^ias （SCAs） are a group ofneurodegenerative disorders that primarily cause the degeneration in the cerebellum, spinal cord, and brainstem. We study the clinical characteristics, radiological features and gene mutation in Chinese families with SCAs. Methods： In this study, we investigated 10 SCAs Chinese families with SCAI, SCA3/Machado-Joseph disease （MJD}, SCA7, SCAB. There were 27 people who were genetically diagnosed as SCA, of which 21 people showed clinical symptoms, and 6 people had no clinical phenotype that we called them presymptomatic patients. In addition, 3 people with cerebellar ataxia and cataracts were diagnosed according to the Harding diagnostic criteria but tailed to be recognized as SCAs on genetic testing. Clinical characteristic analyses of each type of SCAs and radiological examinations were perlbrmed. Results： We found that SCA3/MJD was the most common subtype in Hart population in China, and the ratio of the pontine tegmentum and the posterior fossa area was negatively con＇elated with the number of cytosine-adenine-guanine （CAG） repeats： the disease duration was positively correlated with the International Cooperative Ataxia Rating Scale score; and the CAG repeats number of abnormal alleles was negatively correlated with the age of onset. Conchlsions： Collectively our study is a systematic research on SCAs in China, which may help for the clinical diagnosis and prenatal screening of this disease, and it may also aid toward better understanding of this disease.
