Ichnofossils are well developed in clastic rock reservoirs in marine and transitional facies, which can considerably change the physical properties of the reservoir. However, this influence is not well understood, rai...Ichnofossils are well developed in clastic rock reservoirs in marine and transitional facies, which can considerably change the physical properties of the reservoir. However, this influence is not well understood, raising an important problem in the effective development of petroleum reservoirs. This paper analyzes continental shelf margin delta reservoirs through core observation, cast thin section observation and reservoir physical property test. Some important scientific insights are obtained:(1) The presence of Cruziana ichnofacies, including Asterosoma, Ophiomorpha, Planolites, Skolithos, Thalassinoides, and other ichnofossils can be used to identify in subaqueous distributary channels, subaqueous levee, frontal sheet sand, abandoned river channels, crevasse channels, main channels and channel mouth bars. Considerable differences in the types of ichnofossils and the degree of bioturbation can be observed in the different petrofacies.(2) Ichnofossils and bioturbation play a complex role in controlling reservoir properties. The reservoir physical properties have the characteristics of a decrease–increase–decrease curve with increasing bioturbation degree. This complex change is controlled by the sediment mixing and packing of bioturbation and the diagenetic environment controlled by the ichnofossils.(3) Sea-level cycle changes affect the modification of the reservoir through sediment packing. Bioturbation weakens the reservoir's physical property when sea level slowly rises and improves the reservoir's physical property when base level slowly falls.展开更多
Muddy baffles are one of the major geological factors controlling the underground fluid flow as well as the remaining oil distribution. This study used detailed drilling data from the E1f1 reservoir in the X Oilfield,...Muddy baffles are one of the major geological factors controlling the underground fluid flow as well as the remaining oil distribution. This study used detailed drilling data from the E1f1 reservoir in the X Oilfield, Subei Basin, China, to investigate the hierarchical muddy baffles developed on lacustrine delta fronts and their precise cross-well correlation.According to the theories on allogenic and autogenic cycles as well as the genesis and scales of muddy baffles, five orders of muddy baffles were classified, which provided various degrees of difficulty when attempting interwell correlation. Under the guidance of a reliable stratigraphic model, the precise cross-well correlation of muddy baffles could be achieved and the key point of establishment of this stratigraphic model was to calculate foreset angles of hierarchical muddy baffles during deposition. During calculation, the relationships between sediment flow direction, higher-order strata dipping direction,well types and well trajectory direction should all be taken into consideration and some other angles(referred to here as θ1,θ2 and θ3) should also be measured. Such new methods of cross-well correlation for hierarchical muddy baffles could greatly reduce the uncertainties and multiple solutions, which in turn would be significant for efficient development and oil recovery enhancement in the reservoirs.展开更多
Shallow lacustrine delta front (SLDF) comprises mainly sheetlike subaqueous distributary channels (SDC) formed in shallow, gentle, and tectonically steady slope (Cai and Zhu, 2011). SDC proves an important hydro...Shallow lacustrine delta front (SLDF) comprises mainly sheetlike subaqueous distributary channels (SDC) formed in shallow, gentle, and tectonically steady slope (Cai and Zhu, 2011). SDC proves an important hydrocarbon reservoir type in the Daqing oilfield, Changqing oilfield, and the newly discovered Moxizhuang oilfield in Central Junggar Basin. However, SDC tends to prograde quickly and move laterally frequently,展开更多
Changes in water level are one of the important factors controlling the constructive characteristics of deltas.The paper studies the influence of water level changes on sand bodies in the third member of the Shahejie ...Changes in water level are one of the important factors controlling the constructive characteristics of deltas.The paper studies the influence of water level changes on sand bodies in the third member of the Shahejie Formation(Es3)on the gentle southern slope of the Gubei Sag,Bohai Bay Basin and draw some conclusions that,for complex sand bodies,with the increase in water level the distributary channels bifurcate frequently,from a simple branching shape to a network shape along with the increase in the development of crevasse splays,mouth bars and sheet sands.For single sand bodies,with an increase in water level in the slope zone of the lake basin close to the source area,the superimposition style transitioned from vertical cutting-stacking and lateral isolation to vertical stitching,isolation and lateral stitching.However,in the central zone of the lake basin far from the source area,the superimposition style transitioned from vertical stitching and lateral stitching to vertical isolation and lateral isolation.When water level stays stable,the greater the distance from the source area the greater the disaggregation ratio of a single sand body.At the same distance from the source area,higher water level tends to result in greater disaggregation ratio of a single sand body.展开更多
Based on the abundant information from drilling, cores, and logging, the influence of topography, size of rivers and lakes, climate changes and the lake level's fluctuation on the sandbodies at shallow-water delta fr...Based on the abundant information from drilling, cores, and logging, the influence of topography, size of rivers and lakes, climate changes and the lake level's fluctuation on the sandbodies at shallow-water delta front are systematically summarized and the sedimentary dynamic processes are analyzed. The interwell communication among the sandbodies and their planar distribution revealed from the hydrodynamic features of the development wells are integrated during the analysis. The fundamental requirements for the development of the shallow-water delta included flat topography and uniform subsiding rate. The delta plain was connected smoothly with the wide delta front and predelta, without the three-fold structure of topset, foreset, and bottomset as defined in the Gilbert Delta Model. Because of the weak fluvial effect and the lake energy is strong, the small and scattered shallow-water delta is destroyed by the scouring-backwashing, coastal current, and lake wave, resulting in the coastal sheet deposition. As the fluvial effect became stronger and the lake energy became weaker, the shape of the shallow-water deltas transferred from sheets to lumps and then branches.展开更多
Core, well logging and seismic data were used to investigate sandbody architectural characteristics within Lower Member of Minghuazhen Formation in Neogene, Bohai BZ25 Oilfield, and to analyze the sedimentary microfac...Core, well logging and seismic data were used to investigate sandbody architectural characteristics within Lower Member of Minghuazhen Formation in Neogene, Bohai BZ25 Oilfield, and to analyze the sedimentary microfacies, distribution and internal architecture characteristics of the bar finger within shoal water delta front. The branched sand body within shoal water delta front is the bar finger, consisting of the mouth bar, distributary channel over bar, and levee. The distributary channel cuts through the mouth bar, and the thin levee covers the mouth bar which is located at both sides of distributary channel. The bar finger is commonly sinuous and its sinuosity increases basinward. The distributary channel changes from deeply incising the mouth bar to shallowly incising top of the mouth bar.The aspect ratio ranges from 25 to 50 and there is a double logarithmic linear positive relationship between the width and thickness for the bar finger, which is controlled by base-level changing in study area. For the bar finger, injection and production in the same distributary channel should be avoided during water flooding development. In addition, middle–upper distributary channel and undrilled mouth bar are focus of tapping remaining oil.展开更多
1 Introduction The shallow water delta reservoir in South Wen 79Block is in the stage of high water-cut stages,and is still on the rise.The degree of recovery is low,preferredflowing path is developed and surplus oil ...1 Introduction The shallow water delta reservoir in South Wen 79Block is in the stage of high water-cut stages,and is still on the rise.The degree of recovery is low,preferredflowing path is developed and surplus oil is generally distributed with local enrichment(Zhang,2009).The potential of surplus oil is considerable,while the difficulty is also great.And the basis of effective tapping for展开更多
Recently the explored reserves submitted in the oil field mainly situate at the end of deposit in delta front area. During the exploitation and production, problems mainly show on lithologic deposit, for example, rese...Recently the explored reserves submitted in the oil field mainly situate at the end of deposit in delta front area. During the exploitation and production, problems mainly show on lithologic deposit, for example, reserves are low and difficulty of producing is huge. Based on results of sand body dissection of dense well network of developed oil deposit, and combined with explored reserves, this article researches a relation between extent of well control and reserves precision of explored reserves of lithologic deposit in delta front area by well diluted method. This article has significant influence on objectively understanding our unexploited展开更多
目的:探讨Delta大通道内镜辅助下后路椎管减压椎间植骨融合术治疗退变性腰椎疾病的效果。方法:回顾性分析2021年9月~2022年9月我院收治的80例退变性腰椎疾病患者的病历资料,根据患者治疗方式分为观察组(38例,男17例,女21例,年龄61.0...目的:探讨Delta大通道内镜辅助下后路椎管减压椎间植骨融合术治疗退变性腰椎疾病的效果。方法:回顾性分析2021年9月~2022年9月我院收治的80例退变性腰椎疾病患者的病历资料,根据患者治疗方式分为观察组(38例,男17例,女21例,年龄61.0±4.9岁)和对照组(42例,男20例,女22例,年龄60.5±5.4岁),观察组患者采取Delta大通道内镜下Endo-PLIF治疗,对照组采取开放后路腰椎椎间融合术治疗,记录两组患者术中出血量、术后引流量、手术时间、手术切口长度、住院时间,比较患者并发症发生情况。于术前、术后1周、1个月、3个月、6个月使用视觉模拟量表(visual analogue scale,VAS)评分评估患者腰痛情况,并采用Oswestry功能障碍指数(Oswestry disability index,ODI)评估患者腰椎功能;使用改良Macnab标准对患者进行疗效评估。根据患者术后1年随访时的腰椎影像学复查结果,使用Bridwell椎间融合标准对患者手术节段融合情况进行评估。结果:观察组患者的术中出血量及术后引流量分别低于对照组(88.46±10.98mL vs 112.99±12.01mL、159.73±18.42mL vs 201.36±23.06mL,P<0.05),手术切口及住院时间分别短于对照组(1.54±0.36cm vs 5.43±1.01cm、6.79±1.22d vs 8.03±1.43d,P<0.05),手术时间长于对照组(162.33±19.57min vs 126.87±23.15min,P<0.05)。80例患者术后均获随访,随访时间15~40个月(19.0±6.3个月)。观察组患者术后1周、术后1个月的VAS评分分别为2.46±0.51分、1.21±0.38分,ODI分别为(17.84±4.15)%、(10.69±1.88)%,均低于对照组[VAS评分分别为3.68±0.62分、2.01±0.41分,ODI分别为(21.33±3.48)%、(12.33±2.17)%,均P<0.05],两组患者术后3个月、术后6个月的VAS评分比较无统计学差异(P>0.05)。观察组治疗优良率为92.11%,与对照组的85.71%比较无统计学意义(P=0.487)。两组患者融合分级比较,差异无统计学意义(Z=0.487,P=0.624)。观察组术后并发症发生率为5.26%,与对照组的9.52%比较无统计学差异(P=0.678)。结论:Delta大通道内镜辅助下后路椎管减压椎间植骨融合术治疗退变性腰椎疾病效果良好,可以减少术中出血量,缩短手术切口和住院时间,更快改善患者术后短期内疼痛、腰椎功能,安全性较好。展开更多
Approximately 12-72 million people worldwide are co-infected with hepatitis B virus(HBV)and hepatitis delta virus(HDV).This concurrent infection can lead to several severe outcomes with hepatic disease,such as cirrhos...Approximately 12-72 million people worldwide are co-infected with hepatitis B virus(HBV)and hepatitis delta virus(HDV).This concurrent infection can lead to several severe outcomes with hepatic disease,such as cirrhosis,fulminant hepatitis,and hepatocellular carcinoma,being the most common.Over the past few decades,a correlation between viral hepatitis and autoimmune diseases has been reported.Furthermore,autoantibodies have been detected in the serum of patients co-infected with HBV/HDV,and autoimmune features have been reported.However,to date,very few cases of clinically significant autoimmune hepatitis(AIH)have been reported in patients with HDV infection,mainly in those who have received treatment with pegylated interferon.Interestingly,there are some patients with HBV infection and AIH in whom HDV infection is unearthed after receiving treatment with immunosuppressants.Consequently,several questions remain unanswered with the challenge to distinguish whether it is autoimmune or“autoimmune-like”hepatitis being the most crucial.Second,it remains uncertain whether autoimmunity is induced by HBV or delta virus.Finally,we investigated whether the cause of AIH lies in the previous treatment of HDV with pegylated interferon.These pressing issues should be elucidated to clarify whether new antiviral treatments for HDV,such as Bulevirtide or immu-nosuppressive drugs,are more appropriate for the management of patients with HDV and AIH.展开更多
With the loss of substantial natural wetlands in coastal zones,artificial wetlands provide alternative habitats for many shorebirds.Scientific management of artificial wetlands used by shorebirds plays an important ro...With the loss of substantial natural wetlands in coastal zones,artificial wetlands provide alternative habitats for many shorebirds.Scientific management of artificial wetlands used by shorebirds plays an important role in maintaining the stability of shorebird population.Satellite tracking technique can obtain high-precision location information of individuals day and night,providing a good technical support for the study of quantitative relationship between waterfowls and their habitats.In this study,satellite tracking method,Remote Sensing(RS)and Geographic Information System(GIS)technology were used to analyze the activity pattern and habitat utilization characteristics of Pied Avocet during breeding period in an artificial wetland complex in the Yellow River Delta(YRD),China.The results showed that the breeding Pied Avocets had a small range of activity,with a total core and main home range of 33.10 km^(2) and 216.30 km^(2),respectively.This species tended to forage in the pond and salt pan during the day and night,respectively,with an unfixed staying time in the breeding ground.The distance between breeding ground and feeding ground was less than 6 km.It is emphasized that in addition to improving the conditions of the remaining natural habitats,effective managing artificial habitats is a priority for shorebird conservation.This research could provide reference for the management of artificial wetlands in coastal zones and supply technique support for the protection of shorebirds and their habitats,and alleviate human-bird conflicts and sustainable development of coastal zones.展开更多
The coupling relationship between shelf-edge deltas and deep-water fan sand bodies is a hot and cutting-edge field of international sedimentology and deep-water oil and gas exploration.Based on the newly acquired high...The coupling relationship between shelf-edge deltas and deep-water fan sand bodies is a hot and cutting-edge field of international sedimentology and deep-water oil and gas exploration.Based on the newly acquired high-resolution 3D seismic,logging and core data of Pearl River Mouth Basin(PRMB),this paper dissected the shelf-edge delta to deep-water fan(SEDDF)depositional system in the Oligocene Zhuhai Formation of Paleogene in south subsag of Baiyun Sag,and revealed the complex coupling relationship from the continental shelf edge to deep-water fan sedimentation and its genetic mechanisms.The results show that during the deposition of the fourth to first members of the Zhuhai Formation,the scale of the SEDDF depositional system in the study area showed a pattern of first increasing and then decreasing,with deep-water fan developed in the third to first members and the largest plane distribution scale developed in the late stage of the second member.Based on the development of SEDDF depositional system along the source direction,three types of coupling relationships are divided,namely,deltas that are linked downdip to fans,deltas that lack downdip fans and fans that lack updip coeval deltas,with different depositional characteristics and genetic mechanisms.(1)Deltas that are linked downdip to fans:with the development of shelf-edge deltas in the shelf area and deep-water fans in the downdip slope area,and the strong source supply and relative sea level decline are the two key factors which control the development of this type of source-to-sink(S2S).The development of channels on the continental shelf edge is conducive to the formation of this type of S2S system even with weak source supply and high sea level.(2)Deltas that lack downdip fans:with the development of shelf edge deltas in shelf area,while deep water fans are not developed in the downdip slope area.The lack of“sources”and“channels”,and fluid transformation are the three main reasons for the formation of this type of S2S system.(3)Fans that lack updip coeval deltas:with the development of deep-water fans in continental slope area and the absence of updip coeval shelf edge deltas,which is jointly controlled by the coupling of fluid transformation at the shelf edge and the“channels”in the continental slope area.展开更多
Based on the 3D seismic data and the analysis and test data of lithology,electricity,thin sections and chronology obtained from drilling of the Qiongdongnan Basin,the characteristics and the quantitative analysis of t...Based on the 3D seismic data and the analysis and test data of lithology,electricity,thin sections and chronology obtained from drilling of the Qiongdongnan Basin,the characteristics and the quantitative analysis of the source-sink system are studied of the third member of the Upper Oligocene Lingshui Formation(Ling 3 Member)in the southern fault step zone of the Baodao Sag.First,the YL10 denudation area of the Ling 3 Member mainly developed two fluvial systems in the east and west,resulting in the formation of two dominant sand transport channels and two delta lobes in southern Baodao Sag,which are generally large in the west and small in the east.The evolution of the delta has experienced four stages:initiation,prosperity,intermittence and rejuvenation.Second,the source-sink coupled quantitative calculation is performed depending on the parameters of the delta sand bodies,including development phases,distribution area,flattening thickness,area of different parent rocks,and sand-forming coefficient,showing that the study area has the material basis for the formation of large-scale reservoir.Third,the drilling reveals that the delta of the Ling 3 Member is dominated by fine sandstone,with total sandstone thickness of 109-138 m,maximum single-layer sandstone thickness of 15.5-30.0 m,and sand-to-strata ratio of 43.7%-73.0%,but the physical properties are different among the fault steps.Fourth,the large delta development model of the small source area in the step fault zone with multi-stage uplift is established.It suggests that the episodic uplift provides sufficient sediments,the fluvial system and watershed area control the scale of the sand body,the multi-step active fault steps dominate the sand body transport channel,and local fault troughs decide the lateral propulsion direction of the sand body.The delta of the Ling 3 Member is coupled with fault blocks to form diverse traps,which are critical exploration targets in southern Baodao Sag.展开更多
The Zambezi Delta basin is a passive marginal basin located on the East African coast that has good oil and gas exploration potential.Due to the special geological evolutionary background of the Beira High in the Zamb...The Zambezi Delta basin is a passive marginal basin located on the East African coast that has good oil and gas exploration potential.Due to the special geological evolutionary background of the Beira High in the Zambezi Delta basin,it has a low gravity anomaly,and the existing seismic survey lines do not cover the whole basin;therefore,it is difficult to interpret the structural characteristics of the whole basin based solely on gravity or seismic data.Based on satellite altimetry gravity anomaly data,this study infers the distribution characteristics of faults in the Zambezi Delta basin by using the normalized vertical derivative of the total horizontal derivative(NVDR-THDR)technique.Then,constrained by seismic data,the gravity anomaly at the Moho interface is extracted by using the fast forward method of the double-interface model of the gravity anomaly,and this anomaly is then removed from the Bouguer gravity anomaly to obtain the sedimentary layer gravity anomaly.The thickness of the sedimentary strata is obtained by inversing the sedimentary basement depth of the whole basin.Then,uplifts and depressions are divided based on a sedimentary layer thickness of 3 km.This research demonstrates that the Zambezi Delta basin mainly features nearly SN-trending and NE-trending faults and that these faults exhibit east-west partitioning.The nearly SN-trending strike-slip faults controlled the sedimentary development of the basin,and the NE-trending tensile faults may have acted as migration channels for oil,gas and magma.The“overcompensation”effect of the Moho interface gravity anomaly on the gravity anomaly of the sedimentary layer is caused by the depression of the Moho interface beneath the Beira High,which results in a low gravity anomaly value for the Beira High.The pattern of uplifts and depressions trends NE and has the structural characteristics of east-west blocks.展开更多
基金The National Natural Science Foundation of China under contract Nos 41872112 and 42077410the Key Research Project of Higher Education Institutions in Henan University under contract No. 20A170010+1 种基金the Program for Innovative Research Team (in Science and Technology) of Henan Polytechnic University under contract No. T2022-05the Foundation of Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Mineral under contract No. DMSM2018027。
文摘Ichnofossils are well developed in clastic rock reservoirs in marine and transitional facies, which can considerably change the physical properties of the reservoir. However, this influence is not well understood, raising an important problem in the effective development of petroleum reservoirs. This paper analyzes continental shelf margin delta reservoirs through core observation, cast thin section observation and reservoir physical property test. Some important scientific insights are obtained:(1) The presence of Cruziana ichnofacies, including Asterosoma, Ophiomorpha, Planolites, Skolithos, Thalassinoides, and other ichnofossils can be used to identify in subaqueous distributary channels, subaqueous levee, frontal sheet sand, abandoned river channels, crevasse channels, main channels and channel mouth bars. Considerable differences in the types of ichnofossils and the degree of bioturbation can be observed in the different petrofacies.(2) Ichnofossils and bioturbation play a complex role in controlling reservoir properties. The reservoir physical properties have the characteristics of a decrease–increase–decrease curve with increasing bioturbation degree. This complex change is controlled by the sediment mixing and packing of bioturbation and the diagenetic environment controlled by the ichnofossils.(3) Sea-level cycle changes affect the modification of the reservoir through sediment packing. Bioturbation weakens the reservoir's physical property when sea level slowly rises and improves the reservoir's physical property when base level slowly falls.
基金supported by an Open Fund of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University, PLN1503)the National Natural Science Foundation of China (Nos. 41602145, 41402125, and 41602117)Scientific Research Starting Project of SWPU (No. 2014QHZ008)
文摘Muddy baffles are one of the major geological factors controlling the underground fluid flow as well as the remaining oil distribution. This study used detailed drilling data from the E1f1 reservoir in the X Oilfield, Subei Basin, China, to investigate the hierarchical muddy baffles developed on lacustrine delta fronts and their precise cross-well correlation.According to the theories on allogenic and autogenic cycles as well as the genesis and scales of muddy baffles, five orders of muddy baffles were classified, which provided various degrees of difficulty when attempting interwell correlation. Under the guidance of a reliable stratigraphic model, the precise cross-well correlation of muddy baffles could be achieved and the key point of establishment of this stratigraphic model was to calculate foreset angles of hierarchical muddy baffles during deposition. During calculation, the relationships between sediment flow direction, higher-order strata dipping direction,well types and well trajectory direction should all be taken into consideration and some other angles(referred to here as θ1,θ2 and θ3) should also be measured. Such new methods of cross-well correlation for hierarchical muddy baffles could greatly reduce the uncertainties and multiple solutions, which in turn would be significant for efficient development and oil recovery enhancement in the reservoirs.
基金financially supported by National Natural Science Foundation of China(Grant No.41272159 and 41372123)
文摘Shallow lacustrine delta front (SLDF) comprises mainly sheetlike subaqueous distributary channels (SDC) formed in shallow, gentle, and tectonically steady slope (Cai and Zhu, 2011). SDC proves an important hydrocarbon reservoir type in the Daqing oilfield, Changqing oilfield, and the newly discovered Moxizhuang oilfield in Central Junggar Basin. However, SDC tends to prograde quickly and move laterally frequently,
基金supported by Research Foundation of China University of Petroleum-Beijing at Karamay(No.XQZX20210004)。
文摘Changes in water level are one of the important factors controlling the constructive characteristics of deltas.The paper studies the influence of water level changes on sand bodies in the third member of the Shahejie Formation(Es3)on the gentle southern slope of the Gubei Sag,Bohai Bay Basin and draw some conclusions that,for complex sand bodies,with the increase in water level the distributary channels bifurcate frequently,from a simple branching shape to a network shape along with the increase in the development of crevasse splays,mouth bars and sheet sands.For single sand bodies,with an increase in water level in the slope zone of the lake basin close to the source area,the superimposition style transitioned from vertical cutting-stacking and lateral isolation to vertical stitching,isolation and lateral stitching.However,in the central zone of the lake basin far from the source area,the superimposition style transitioned from vertical stitching and lateral stitching to vertical isolation and lateral isolation.When water level stays stable,the greater the distance from the source area the greater the disaggregation ratio of a single sand body.At the same distance from the source area,higher water level tends to result in greater disaggregation ratio of a single sand body.
文摘Based on the abundant information from drilling, cores, and logging, the influence of topography, size of rivers and lakes, climate changes and the lake level's fluctuation on the sandbodies at shallow-water delta front are systematically summarized and the sedimentary dynamic processes are analyzed. The interwell communication among the sandbodies and their planar distribution revealed from the hydrodynamic features of the development wells are integrated during the analysis. The fundamental requirements for the development of the shallow-water delta included flat topography and uniform subsiding rate. The delta plain was connected smoothly with the wide delta front and predelta, without the three-fold structure of topset, foreset, and bottomset as defined in the Gilbert Delta Model. Because of the weak fluvial effect and the lake energy is strong, the small and scattered shallow-water delta is destroyed by the scouring-backwashing, coastal current, and lake wave, resulting in the coastal sheet deposition. As the fluvial effect became stronger and the lake energy became weaker, the shape of the shallow-water deltas transferred from sheets to lumps and then branches.
基金Supported by the National Natural Science Foundation of China(41772101)China National Science and Technology Major Project(2017ZX05009001-002)
文摘Core, well logging and seismic data were used to investigate sandbody architectural characteristics within Lower Member of Minghuazhen Formation in Neogene, Bohai BZ25 Oilfield, and to analyze the sedimentary microfacies, distribution and internal architecture characteristics of the bar finger within shoal water delta front. The branched sand body within shoal water delta front is the bar finger, consisting of the mouth bar, distributary channel over bar, and levee. The distributary channel cuts through the mouth bar, and the thin levee covers the mouth bar which is located at both sides of distributary channel. The bar finger is commonly sinuous and its sinuosity increases basinward. The distributary channel changes from deeply incising the mouth bar to shallowly incising top of the mouth bar.The aspect ratio ranges from 25 to 50 and there is a double logarithmic linear positive relationship between the width and thickness for the bar finger, which is controlled by base-level changing in study area. For the bar finger, injection and production in the same distributary channel should be avoided during water flooding development. In addition, middle–upper distributary channel and undrilled mouth bar are focus of tapping remaining oil.
基金supported by Study on Modeling of Reservoir Configuration and Distribution of Remaining Oil (No. P15037)
文摘1 Introduction The shallow water delta reservoir in South Wen 79Block is in the stage of high water-cut stages,and is still on the rise.The degree of recovery is low,preferredflowing path is developed and surplus oil is generally distributed with local enrichment(Zhang,2009).The potential of surplus oil is considerable,while the difficulty is also great.And the basis of effective tapping for
文摘Recently the explored reserves submitted in the oil field mainly situate at the end of deposit in delta front area. During the exploitation and production, problems mainly show on lithologic deposit, for example, reserves are low and difficulty of producing is huge. Based on results of sand body dissection of dense well network of developed oil deposit, and combined with explored reserves, this article researches a relation between extent of well control and reserves precision of explored reserves of lithologic deposit in delta front area by well diluted method. This article has significant influence on objectively understanding our unexploited
文摘目的:探讨Delta大通道内镜辅助下后路椎管减压椎间植骨融合术治疗退变性腰椎疾病的效果。方法:回顾性分析2021年9月~2022年9月我院收治的80例退变性腰椎疾病患者的病历资料,根据患者治疗方式分为观察组(38例,男17例,女21例,年龄61.0±4.9岁)和对照组(42例,男20例,女22例,年龄60.5±5.4岁),观察组患者采取Delta大通道内镜下Endo-PLIF治疗,对照组采取开放后路腰椎椎间融合术治疗,记录两组患者术中出血量、术后引流量、手术时间、手术切口长度、住院时间,比较患者并发症发生情况。于术前、术后1周、1个月、3个月、6个月使用视觉模拟量表(visual analogue scale,VAS)评分评估患者腰痛情况,并采用Oswestry功能障碍指数(Oswestry disability index,ODI)评估患者腰椎功能;使用改良Macnab标准对患者进行疗效评估。根据患者术后1年随访时的腰椎影像学复查结果,使用Bridwell椎间融合标准对患者手术节段融合情况进行评估。结果:观察组患者的术中出血量及术后引流量分别低于对照组(88.46±10.98mL vs 112.99±12.01mL、159.73±18.42mL vs 201.36±23.06mL,P<0.05),手术切口及住院时间分别短于对照组(1.54±0.36cm vs 5.43±1.01cm、6.79±1.22d vs 8.03±1.43d,P<0.05),手术时间长于对照组(162.33±19.57min vs 126.87±23.15min,P<0.05)。80例患者术后均获随访,随访时间15~40个月(19.0±6.3个月)。观察组患者术后1周、术后1个月的VAS评分分别为2.46±0.51分、1.21±0.38分,ODI分别为(17.84±4.15)%、(10.69±1.88)%,均低于对照组[VAS评分分别为3.68±0.62分、2.01±0.41分,ODI分别为(21.33±3.48)%、(12.33±2.17)%,均P<0.05],两组患者术后3个月、术后6个月的VAS评分比较无统计学差异(P>0.05)。观察组治疗优良率为92.11%,与对照组的85.71%比较无统计学意义(P=0.487)。两组患者融合分级比较,差异无统计学意义(Z=0.487,P=0.624)。观察组术后并发症发生率为5.26%,与对照组的9.52%比较无统计学差异(P=0.678)。结论:Delta大通道内镜辅助下后路椎管减压椎间植骨融合术治疗退变性腰椎疾病效果良好,可以减少术中出血量,缩短手术切口和住院时间,更快改善患者术后短期内疼痛、腰椎功能,安全性较好。
文摘Approximately 12-72 million people worldwide are co-infected with hepatitis B virus(HBV)and hepatitis delta virus(HDV).This concurrent infection can lead to several severe outcomes with hepatic disease,such as cirrhosis,fulminant hepatitis,and hepatocellular carcinoma,being the most common.Over the past few decades,a correlation between viral hepatitis and autoimmune diseases has been reported.Furthermore,autoantibodies have been detected in the serum of patients co-infected with HBV/HDV,and autoimmune features have been reported.However,to date,very few cases of clinically significant autoimmune hepatitis(AIH)have been reported in patients with HDV infection,mainly in those who have received treatment with pegylated interferon.Interestingly,there are some patients with HBV infection and AIH in whom HDV infection is unearthed after receiving treatment with immunosuppressants.Consequently,several questions remain unanswered with the challenge to distinguish whether it is autoimmune or“autoimmune-like”hepatitis being the most crucial.Second,it remains uncertain whether autoimmunity is induced by HBV or delta virus.Finally,we investigated whether the cause of AIH lies in the previous treatment of HDV with pegylated interferon.These pressing issues should be elucidated to clarify whether new antiviral treatments for HDV,such as Bulevirtide or immu-nosuppressive drugs,are more appropriate for the management of patients with HDV and AIH.
基金Under the auscpices of Shandong Provincial Natural Science Foundation (No.ZR2020QD090)Research Funds of Beijing VMinFull Limted (No.VMF2021RS)+1 种基金National Natural Science Foundation of China (No.42176221)Seed Project of Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences (No.YICE351030601)。
文摘With the loss of substantial natural wetlands in coastal zones,artificial wetlands provide alternative habitats for many shorebirds.Scientific management of artificial wetlands used by shorebirds plays an important role in maintaining the stability of shorebird population.Satellite tracking technique can obtain high-precision location information of individuals day and night,providing a good technical support for the study of quantitative relationship between waterfowls and their habitats.In this study,satellite tracking method,Remote Sensing(RS)and Geographic Information System(GIS)technology were used to analyze the activity pattern and habitat utilization characteristics of Pied Avocet during breeding period in an artificial wetland complex in the Yellow River Delta(YRD),China.The results showed that the breeding Pied Avocets had a small range of activity,with a total core and main home range of 33.10 km^(2) and 216.30 km^(2),respectively.This species tended to forage in the pond and salt pan during the day and night,respectively,with an unfixed staying time in the breeding ground.The distance between breeding ground and feeding ground was less than 6 km.It is emphasized that in addition to improving the conditions of the remaining natural habitats,effective managing artificial habitats is a priority for shorebird conservation.This research could provide reference for the management of artificial wetlands in coastal zones and supply technique support for the protection of shorebirds and their habitats,and alleviate human-bird conflicts and sustainable development of coastal zones.
基金Supported by the National Natural Science Foundation of China(91528303)CNOOC Technology Project(2021-KT-YXKY-05).
文摘The coupling relationship between shelf-edge deltas and deep-water fan sand bodies is a hot and cutting-edge field of international sedimentology and deep-water oil and gas exploration.Based on the newly acquired high-resolution 3D seismic,logging and core data of Pearl River Mouth Basin(PRMB),this paper dissected the shelf-edge delta to deep-water fan(SEDDF)depositional system in the Oligocene Zhuhai Formation of Paleogene in south subsag of Baiyun Sag,and revealed the complex coupling relationship from the continental shelf edge to deep-water fan sedimentation and its genetic mechanisms.The results show that during the deposition of the fourth to first members of the Zhuhai Formation,the scale of the SEDDF depositional system in the study area showed a pattern of first increasing and then decreasing,with deep-water fan developed in the third to first members and the largest plane distribution scale developed in the late stage of the second member.Based on the development of SEDDF depositional system along the source direction,three types of coupling relationships are divided,namely,deltas that are linked downdip to fans,deltas that lack downdip fans and fans that lack updip coeval deltas,with different depositional characteristics and genetic mechanisms.(1)Deltas that are linked downdip to fans:with the development of shelf-edge deltas in the shelf area and deep-water fans in the downdip slope area,and the strong source supply and relative sea level decline are the two key factors which control the development of this type of source-to-sink(S2S).The development of channels on the continental shelf edge is conducive to the formation of this type of S2S system even with weak source supply and high sea level.(2)Deltas that lack downdip fans:with the development of shelf edge deltas in shelf area,while deep water fans are not developed in the downdip slope area.The lack of“sources”and“channels”,and fluid transformation are the three main reasons for the formation of this type of S2S system.(3)Fans that lack updip coeval deltas:with the development of deep-water fans in continental slope area and the absence of updip coeval shelf edge deltas,which is jointly controlled by the coupling of fluid transformation at the shelf edge and the“channels”in the continental slope area.
基金Supported by the CNOOC Technology Research Project(KJGG2022-0102)。
文摘Based on the 3D seismic data and the analysis and test data of lithology,electricity,thin sections and chronology obtained from drilling of the Qiongdongnan Basin,the characteristics and the quantitative analysis of the source-sink system are studied of the third member of the Upper Oligocene Lingshui Formation(Ling 3 Member)in the southern fault step zone of the Baodao Sag.First,the YL10 denudation area of the Ling 3 Member mainly developed two fluvial systems in the east and west,resulting in the formation of two dominant sand transport channels and two delta lobes in southern Baodao Sag,which are generally large in the west and small in the east.The evolution of the delta has experienced four stages:initiation,prosperity,intermittence and rejuvenation.Second,the source-sink coupled quantitative calculation is performed depending on the parameters of the delta sand bodies,including development phases,distribution area,flattening thickness,area of different parent rocks,and sand-forming coefficient,showing that the study area has the material basis for the formation of large-scale reservoir.Third,the drilling reveals that the delta of the Ling 3 Member is dominated by fine sandstone,with total sandstone thickness of 109-138 m,maximum single-layer sandstone thickness of 15.5-30.0 m,and sand-to-strata ratio of 43.7%-73.0%,but the physical properties are different among the fault steps.Fourth,the large delta development model of the small source area in the step fault zone with multi-stage uplift is established.It suggests that the episodic uplift provides sufficient sediments,the fluvial system and watershed area control the scale of the sand body,the multi-step active fault steps dominate the sand body transport channel,and local fault troughs decide the lateral propulsion direction of the sand body.The delta of the Ling 3 Member is coupled with fault blocks to form diverse traps,which are critical exploration targets in southern Baodao Sag.
基金The Petrochina Basic Prospective Science and Technology Research Project–Overseas deepwater ultra-deepwater oil and gas exploration technology research topic,under contract No.2021DJ2403。
文摘The Zambezi Delta basin is a passive marginal basin located on the East African coast that has good oil and gas exploration potential.Due to the special geological evolutionary background of the Beira High in the Zambezi Delta basin,it has a low gravity anomaly,and the existing seismic survey lines do not cover the whole basin;therefore,it is difficult to interpret the structural characteristics of the whole basin based solely on gravity or seismic data.Based on satellite altimetry gravity anomaly data,this study infers the distribution characteristics of faults in the Zambezi Delta basin by using the normalized vertical derivative of the total horizontal derivative(NVDR-THDR)technique.Then,constrained by seismic data,the gravity anomaly at the Moho interface is extracted by using the fast forward method of the double-interface model of the gravity anomaly,and this anomaly is then removed from the Bouguer gravity anomaly to obtain the sedimentary layer gravity anomaly.The thickness of the sedimentary strata is obtained by inversing the sedimentary basement depth of the whole basin.Then,uplifts and depressions are divided based on a sedimentary layer thickness of 3 km.This research demonstrates that the Zambezi Delta basin mainly features nearly SN-trending and NE-trending faults and that these faults exhibit east-west partitioning.The nearly SN-trending strike-slip faults controlled the sedimentary development of the basin,and the NE-trending tensile faults may have acted as migration channels for oil,gas and magma.The“overcompensation”effect of the Moho interface gravity anomaly on the gravity anomaly of the sedimentary layer is caused by the depression of the Moho interface beneath the Beira High,which results in a low gravity anomaly value for the Beira High.The pattern of uplifts and depressions trends NE and has the structural characteristics of east-west blocks.