The use of sequential stratigraphy concept, based on well logs, sedimentology, and biostratigraphy, has shed light on the complex mechanisms controlling sedimentary accumulations. Consequently, identifying these mecha...The use of sequential stratigraphy concept, based on well logs, sedimentology, and biostratigraphy, has shed light on the complex mechanisms controlling sedimentary accumulations. Consequently, identifying these mechanisms allows us to predict the hydrocarbon generation potential of source rocks. In the Ivorian offshore sedimentary basin, certain studies have contributed to understanding and characterizing the petroleum system. However, these previous works did not integrate biostratigraphic data to highlight sedimentary facies. This study, conducted on two wells in the Abidjan margin, is crucial as it helps us comprehend the geometry of fossil sediments in relation to sea level variations. It will also aid in reconstructing the basin-filling history and predicting the distribution of rocks capable of trapping oil, determining lowstand systems tracts (reservoir rocks), transgressive systems tracts, and highstand systems tracts (cap rocks). Lithological analysis revealed predominantly clayey sedimentation with sandy layers. Well log data facilitated the delineation of formation boundaries and highlighted reservoirs consisting of sands, sandstones, limestones, and occasionally intercalated shales. Integrating these analysis results with biostratigraphic interpretations based on foraminifera and palynomorphs revealed that the traversed formations were deposited in a transitional environment ranging from Coniacian to Maastrichtian ages. Applying sequential stratigraphy concept from well logging resolved dating issues encountered in microfossil-poor or microfossil-free zones. The results of the Coniacian-Maastrichtian age sequential subdivision were aligned with the chart.展开更多
The Jurassic in the East Fukang Slope can be divided into six sequences based on sequence stratigraphy by combining logging, core and seismic data. The indicators of sequence boundaries include unconformity, coal seam...The Jurassic in the East Fukang Slope can be divided into six sequences based on sequence stratigraphy by combining logging, core and seismic data. The indicators of sequence boundaries include unconformity, coal seams, change of spore and pollen abundance, scour surfaces and base conglomerate, change of logging curve and sedimentary facies. How to determine the location of the first flooding surfaces and the maximum flooding surface is the key step to divide the systems tract. There occurred a topographic slope break in the East Fukang Slope when the Jurassic was deposited, and therefore we can recognize the location of the first flooding surface and establish the sequence stratigraphic framework with the slope break in the study area. Coal seams regionally distributed are correlatable and isochronic, and record the termination of a depositional event or episode. So, the regional coal seam （more than 60 percent coverage） can be used as the genetic stratigraphic sequence boundary, while locally distributed coal seam （less than 60 percent coverage） can be used as the systems tract boundary. The thick coal seams distributed regionally in the middle of the Badaowan Formation and the lower part of the Xishanyao Formation in the study area act as the sequence boundaries, while the thin and locally distributed coal seam acts as the systems tract boundary, which results in the correlation of the division of sequence stratigraphy of the Jurassic to the whole basin where coal seams are developed extensively.展开更多
Optical coherence tomography(OCT) is an optical imaging modality that performs high-resolution,cross-sectional,subsurface tomographic imaging of the microstructure of tissues.The physical principle of OCT is similar t...Optical coherence tomography(OCT) is an optical imaging modality that performs high-resolution,cross-sectional,subsurface tomographic imaging of the microstructure of tissues.The physical principle of OCT is similar to that of B-mode ultrasound imaging,except that it uses infrared light waves rather than acoustic waves.The in vivo resolution is 10-25 times better(about 10 μm) than with high-frequency ultrasound imaging,but the depth of penetration is limited to 1-3 mm,depending upon tissue structure,depth of focus of the probe used,and pressure applied to the tissue surface.In the last decade,OCT technology has evolved from an experimental laboratory tool to a new diagnostic imaging modality with a wide spectrum of clinical applications in medical practice,including the gastrointestinal(GI) tract and pancreatic-biliary ductal system.OCT imaging from the GI tract can be done in humans by using narrow-diameter,catheter-based probes that can be inserted through the accessory channel of either a conventional front-view endoscope,for investigating the epithelial structure of the GI tract,or a side-view endoscope,inside a standard transparent ERCP catheter,for investigating the pancreatico-biliary ductal system.Esophagus and the esophago-gastric junction has been the most widely investigated organ so far;more recently,also duodenum,colon and pancreatico-biliary ductal system have been extensively investigated.OCT imaging of the gastro-intestinal wall structure is characterized by a multiple-layer architecture that permits an accurate evaluation of the mucosa,lamina propria,muscularis mucosae,andpart of the submucosa.The technique may be,therefore,used to identify pre-neoplastic conditions of the GI tract,such as Barrett's epithelium and dysplasia,and evaluate the depth of penetration of early-stage neoplastic lesions.OCT imaging of the pancreatic and biliary ductal system could improve the diagnostic accuracy for ductal epithelial changes and the differential diagnosis between neoplastic and non-neoplastic lesions.展开更多
为进一步探索玛中平台区近4000.0 km 2勘探空白区的勘探潜力,扩大玛湖凹陷百口泉组勘探潜力,实现玛湖凹陷整体突破,综合利用地质、钻井、高精度地震等资料,对玛湖凹陷百口泉组地层划分进行了细化,将玛中平台区低位域砂体划分为百口泉组...为进一步探索玛中平台区近4000.0 km 2勘探空白区的勘探潜力,扩大玛湖凹陷百口泉组勘探潜力,实现玛湖凹陷整体突破,综合利用地质、钻井、高精度地震等资料,对玛湖凹陷百口泉组地层划分进行了细化,将玛中平台区低位域砂体划分为百口泉组零段(百零段)。在此基础上,结合区域沉积、构造背景,从烃源岩条件、疏导体系、沉积体系和成藏条件等方面对玛中平台区低位域百零段油气成藏条件及控制因素展开了综合分析。研究表明:二叠系风城组烃源岩具有碱湖双峰式生油特征,油气资源基础大,百零段更近源,更容易捕获深层油气;玛中平台区印支期走滑断裂直插深层烃源岩,搭接形成了高效的输导体系;百口泉组顶底板条件优越,百零段在大型地层超覆背景下叠置发育多期湖侵退积砂体,形成规模有效的储盖组合;百零段发育四大规模扇体,其扇三角洲平原亚相致密带、扇间泥岩、构造等值线相互配置,形成复合式多面遮挡,为扇三角洲前缘大面积成藏奠定了基础。类比研究认为,中拐扇前缘亚相上倾、侧向遮挡条件好,具有宏观整体成藏基础。该区前缘亚相有利勘探面积大,岩性目标叠置发育,落实程度高,是目前寻求百零段新层系突破的重点勘探目标。百零段的突破有望打开玛中平台区勘探局面,进而实现玛湖凹陷百口泉组整体突破。展开更多
Many evidences for gas hydrate bearing sediments had been found in the continental slope of the East China Sea,such as bottom simulating reflections(BSRs),undersea gas springs,pyrite associated with methane leakage,mu...Many evidences for gas hydrate bearing sediments had been found in the continental slope of the East China Sea,such as bottom simulating reflections(BSRs),undersea gas springs,pyrite associated with methane leakage,mud diapirs/mud volcanos,bottom-water methane anomalies and so on.In this study,six key stratigraphic interfaces including T_0(seafloor),T_1(LGM,23 kyr B.P.),T_2(2.58 Myr),T_3(5.33 Myr),T_4(11.02 Myr)and T_5(16.12 Myr)were identified,and then five third-order sequences of SQIII1 to SQIII5 were divided.However,T5 in southern continental slope is not found,which shows that the middle-northern Okinawa Trough had begun to rift in the early Miocene,earlier than the southern segment.Four system tracts including lowstand systems tract(LST),transgressive systems tract(TST),highstand systems tract(HST)and falling stage systems tract(FSST)are further divided.The marine erosion interface of 11.02 Myr and regressive unconformity interface of 23 kyr B.P.indicate two large-scale sea level drop events in the research area.Seven typical seismic facies identified in the continental slope are continental shelf-edge deltas,littoral fluvial-delta plains,incised channels or submarine canyons,slope fans,submarine fans or coastal sandbars,littoral-neritic finegrained sediments,mud volcanos and some other geological bodies respectively.The minimum water depth for hydrate occurrence in the Okinawa Trough is 630 m,and the thickness of gas hydrate stability zone in continental slope is between 0 and 590 m.The calculated bottom boundary of hydrate stability zone is slightly deeper than BSRs on the seismic sections.The re-depositional turbidite sand bodies,such as canyon channels,slope fans and submarine fans developed in Quaternary strata,are the predominant hydrate reservoirs.According to developing process,the dynamic accumulation of hydrate systems can be divided into three evolutionary stages including canyon erosion and hydrate stability zone migration stage,sediments destabilizing and methane leakage stage,and channel filling and hydrate re-occurrence stage.展开更多
Systemic sclerosis is an autoimmune disease characterized by progressive skin thickening and tightness.Pulmonary interstitial fibrosis and kidney damage are the most important indicators for mortality;however,the gast...Systemic sclerosis is an autoimmune disease characterized by progressive skin thickening and tightness.Pulmonary interstitial fibrosis and kidney damage are the most important indicators for mortality;however,the gastrointestinal tract is the most commonly damaged system.Virtually all parts of the gastrointestinal(GI)tract can be involved,although the esophagus is the most frequently reported.The mechanisms that cause such extensive damage are generally unclear,but vascular changes,immunological abnormalities,excessive accumulation of collagen in the submucosa,smooth muscle atrophy and neuropathy may participate because these are the most common histological findings in biopsies and autopsies.Most patients with GI tract involvement complain about dyspepsia,nausea,vomiting,abdominal bloating/distension,and fecal incontinence.These symptoms are generally mild during the early stage of the disease and are likely ignored by physicians.As the disease becomes more advanced,however,patient quality of life is markedly influenced,whereby malnutrition and shortened survival are the usual consequences.The diagnosis for systemic sclerosis is based on manometry measurements and an endoscopy examination.Supportive and symptomatic treatment is the main therapeutic strategy;however,an early diagnosis is critical for successful management.展开更多
文摘The use of sequential stratigraphy concept, based on well logs, sedimentology, and biostratigraphy, has shed light on the complex mechanisms controlling sedimentary accumulations. Consequently, identifying these mechanisms allows us to predict the hydrocarbon generation potential of source rocks. In the Ivorian offshore sedimentary basin, certain studies have contributed to understanding and characterizing the petroleum system. However, these previous works did not integrate biostratigraphic data to highlight sedimentary facies. This study, conducted on two wells in the Abidjan margin, is crucial as it helps us comprehend the geometry of fossil sediments in relation to sea level variations. It will also aid in reconstructing the basin-filling history and predicting the distribution of rocks capable of trapping oil, determining lowstand systems tracts (reservoir rocks), transgressive systems tracts, and highstand systems tracts (cap rocks). Lithological analysis revealed predominantly clayey sedimentation with sandy layers. Well log data facilitated the delineation of formation boundaries and highlighted reservoirs consisting of sands, sandstones, limestones, and occasionally intercalated shales. Integrating these analysis results with biostratigraphic interpretations based on foraminifera and palynomorphs revealed that the traversed formations were deposited in a transitional environment ranging from Coniacian to Maastrichtian ages. Applying sequential stratigraphy concept from well logging resolved dating issues encountered in microfossil-poor or microfossil-free zones. The results of the Coniacian-Maastrichtian age sequential subdivision were aligned with the chart.
文摘The Jurassic in the East Fukang Slope can be divided into six sequences based on sequence stratigraphy by combining logging, core and seismic data. The indicators of sequence boundaries include unconformity, coal seams, change of spore and pollen abundance, scour surfaces and base conglomerate, change of logging curve and sedimentary facies. How to determine the location of the first flooding surfaces and the maximum flooding surface is the key step to divide the systems tract. There occurred a topographic slope break in the East Fukang Slope when the Jurassic was deposited, and therefore we can recognize the location of the first flooding surface and establish the sequence stratigraphic framework with the slope break in the study area. Coal seams regionally distributed are correlatable and isochronic, and record the termination of a depositional event or episode. So, the regional coal seam （more than 60 percent coverage） can be used as the genetic stratigraphic sequence boundary, while locally distributed coal seam （less than 60 percent coverage） can be used as the systems tract boundary. The thick coal seams distributed regionally in the middle of the Badaowan Formation and the lower part of the Xishanyao Formation in the study area act as the sequence boundaries, while the thin and locally distributed coal seam acts as the systems tract boundary, which results in the correlation of the division of sequence stratigraphy of the Jurassic to the whole basin where coal seams are developed extensively.
文摘Optical coherence tomography(OCT) is an optical imaging modality that performs high-resolution,cross-sectional,subsurface tomographic imaging of the microstructure of tissues.The physical principle of OCT is similar to that of B-mode ultrasound imaging,except that it uses infrared light waves rather than acoustic waves.The in vivo resolution is 10-25 times better(about 10 μm) than with high-frequency ultrasound imaging,but the depth of penetration is limited to 1-3 mm,depending upon tissue structure,depth of focus of the probe used,and pressure applied to the tissue surface.In the last decade,OCT technology has evolved from an experimental laboratory tool to a new diagnostic imaging modality with a wide spectrum of clinical applications in medical practice,including the gastrointestinal(GI) tract and pancreatic-biliary ductal system.OCT imaging from the GI tract can be done in humans by using narrow-diameter,catheter-based probes that can be inserted through the accessory channel of either a conventional front-view endoscope,for investigating the epithelial structure of the GI tract,or a side-view endoscope,inside a standard transparent ERCP catheter,for investigating the pancreatico-biliary ductal system.Esophagus and the esophago-gastric junction has been the most widely investigated organ so far;more recently,also duodenum,colon and pancreatico-biliary ductal system have been extensively investigated.OCT imaging of the gastro-intestinal wall structure is characterized by a multiple-layer architecture that permits an accurate evaluation of the mucosa,lamina propria,muscularis mucosae,andpart of the submucosa.The technique may be,therefore,used to identify pre-neoplastic conditions of the GI tract,such as Barrett's epithelium and dysplasia,and evaluate the depth of penetration of early-stage neoplastic lesions.OCT imaging of the pancreatic and biliary ductal system could improve the diagnostic accuracy for ductal epithelial changes and the differential diagnosis between neoplastic and non-neoplastic lesions.
文摘为进一步探索玛中平台区近4000.0 km 2勘探空白区的勘探潜力,扩大玛湖凹陷百口泉组勘探潜力,实现玛湖凹陷整体突破,综合利用地质、钻井、高精度地震等资料,对玛湖凹陷百口泉组地层划分进行了细化,将玛中平台区低位域砂体划分为百口泉组零段(百零段)。在此基础上,结合区域沉积、构造背景,从烃源岩条件、疏导体系、沉积体系和成藏条件等方面对玛中平台区低位域百零段油气成藏条件及控制因素展开了综合分析。研究表明:二叠系风城组烃源岩具有碱湖双峰式生油特征,油气资源基础大,百零段更近源,更容易捕获深层油气;玛中平台区印支期走滑断裂直插深层烃源岩,搭接形成了高效的输导体系;百口泉组顶底板条件优越,百零段在大型地层超覆背景下叠置发育多期湖侵退积砂体,形成规模有效的储盖组合;百零段发育四大规模扇体,其扇三角洲平原亚相致密带、扇间泥岩、构造等值线相互配置,形成复合式多面遮挡,为扇三角洲前缘大面积成藏奠定了基础。类比研究认为,中拐扇前缘亚相上倾、侧向遮挡条件好,具有宏观整体成藏基础。该区前缘亚相有利勘探面积大,岩性目标叠置发育,落实程度高,是目前寻求百零段新层系突破的重点勘探目标。百零段的突破有望打开玛中平台区勘探局面,进而实现玛湖凹陷百口泉组整体突破。
基金supported by the National Natural Science Foundation of China (Nos. 41806073, 41530963)the Natural Science Foundation of Shandong Province (No. ZR 2017BD014)+1 种基金the Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Minerals, Shandong University of Science and Technology (No. DMSM 2017042)the Fundamental Research Funds for the Central Universities (Nos. 201964016, 201851023)
文摘Many evidences for gas hydrate bearing sediments had been found in the continental slope of the East China Sea,such as bottom simulating reflections(BSRs),undersea gas springs,pyrite associated with methane leakage,mud diapirs/mud volcanos,bottom-water methane anomalies and so on.In this study,six key stratigraphic interfaces including T_0(seafloor),T_1(LGM,23 kyr B.P.),T_2(2.58 Myr),T_3(5.33 Myr),T_4(11.02 Myr)and T_5(16.12 Myr)were identified,and then five third-order sequences of SQIII1 to SQIII5 were divided.However,T5 in southern continental slope is not found,which shows that the middle-northern Okinawa Trough had begun to rift in the early Miocene,earlier than the southern segment.Four system tracts including lowstand systems tract(LST),transgressive systems tract(TST),highstand systems tract(HST)and falling stage systems tract(FSST)are further divided.The marine erosion interface of 11.02 Myr and regressive unconformity interface of 23 kyr B.P.indicate two large-scale sea level drop events in the research area.Seven typical seismic facies identified in the continental slope are continental shelf-edge deltas,littoral fluvial-delta plains,incised channels or submarine canyons,slope fans,submarine fans or coastal sandbars,littoral-neritic finegrained sediments,mud volcanos and some other geological bodies respectively.The minimum water depth for hydrate occurrence in the Okinawa Trough is 630 m,and the thickness of gas hydrate stability zone in continental slope is between 0 and 590 m.The calculated bottom boundary of hydrate stability zone is slightly deeper than BSRs on the seismic sections.The re-depositional turbidite sand bodies,such as canyon channels,slope fans and submarine fans developed in Quaternary strata,are the predominant hydrate reservoirs.According to developing process,the dynamic accumulation of hydrate systems can be divided into three evolutionary stages including canyon erosion and hydrate stability zone migration stage,sediments destabilizing and methane leakage stage,and channel filling and hydrate re-occurrence stage.
文摘Systemic sclerosis is an autoimmune disease characterized by progressive skin thickening and tightness.Pulmonary interstitial fibrosis and kidney damage are the most important indicators for mortality;however,the gastrointestinal tract is the most commonly damaged system.Virtually all parts of the gastrointestinal(GI)tract can be involved,although the esophagus is the most frequently reported.The mechanisms that cause such extensive damage are generally unclear,but vascular changes,immunological abnormalities,excessive accumulation of collagen in the submucosa,smooth muscle atrophy and neuropathy may participate because these are the most common histological findings in biopsies and autopsies.Most patients with GI tract involvement complain about dyspepsia,nausea,vomiting,abdominal bloating/distension,and fecal incontinence.These symptoms are generally mild during the early stage of the disease and are likely ignored by physicians.As the disease becomes more advanced,however,patient quality of life is markedly influenced,whereby malnutrition and shortened survival are the usual consequences.The diagnosis for systemic sclerosis is based on manometry measurements and an endoscopy examination.Supportive and symptomatic treatment is the main therapeutic strategy;however,an early diagnosis is critical for successful management.
