To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically anal...To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically analyzed the effects of closure stress,proppant concentration,formation temperature,and proppant size combination.Conductivity experiments were conducted using the HXDL-2C long-term proppant conductivity evaluation system under simulated reservoir conditions to determine the time-dependent evolution of fracture conductivity.The results showed that the 50-h conductivity retention of the rock-plate experiments ranged from 22%to 28%.With increasing closure stress,fracture conductivity exhibited a rapid decline.Under a formation temperature of 120℃ and a proppant concentration of 5 kg·m^(-2),the short-term conductivity of 70/140 mesh quartz-sand-propped fractures was 2.37μm^(2)·cm,which decreased to 0.66μm^(2)·cm after long-term testing.When the closure stress increased to 80 MPa,the short-term and long-term conductivities further declined to 1.36μm^(2)·cm and 0.39μm^(2)·cm,respectively.Increasing the proppant concentration from 5 to 7.5 kg·m^(-2)at 120℃ and 80 MPa improved both short-term and long-term conductivities by enlarging the effective fracture width;however,the conductivity decay rate accelerated,and the 50-h retention dropped from 27.2%to 22.8%.Raising the temperature from 120℃ to 140℃ promoted proppant crushing and compaction,intensified shale creep,and accelerated fracture closure,reducing long-term conductivity from 0.37 to 0.30μm^(2)·cm.Under identical conditions,40/70 mesh ceramic proppants maintained significantly higher conductivities than 70/140 mesh quartz sand,with short-term and long-term values of 8.71 and 2.19μm^(2)·cm,respectively,at 120℃,80 MPa,and 5 kg·m^(-2).Pure quartz-sand systems failed to maintain effective conductivity under high-temperature and high-stress conditions,whereas adding 20%40/70 mesh ceramic proppant and thoroughly mixing it,the long-term conductivity has increased by 2.3 times,improving fracture stability while reducing overall cost.A predictive equation was derived from the experimental results to capture the dynamic decay characteristics of fracture conductivity.These outcomes provide a valuable experimental basis and technical support for optimizing fracturing fluid design,proppant selection,and operation parameters in deep shale formations.展开更多
Microorganisms carrying cbbL,pmoA and coxL genes play crucial roles in regulating soil-atmosphere exchanges of carbon trace gases(CO_(2),CH_(4),and CO).However,the geographical distribution patterns of these functiona...Microorganisms carrying cbbL,pmoA and coxL genes play crucial roles in regulating soil-atmosphere exchanges of carbon trace gases(CO_(2),CH_(4),and CO).However,the geographical distribution patterns of these functional genes in agricultural ecosystems and their environmental drivers remain poorly understood.Here,we surveyed agricultural soils across four climate zones(tropical,subtropical,warm temperate,and mid-temperate)in eastern China to quantify the abundances of CO_(2)-assimilating bacteria(cbbL gene),methanotrophs(pmoA gene),and CO-oxidizing bacteria(coxL gene).We found significant ecosystem-specific patterns:the cbbL gene was more abundant in upland soils(averaging 9.46×10^(9)copies g^(–1))than in paddy soils(6.44×10^(9) copies g^(–1)).In contrast,methanotrophs abundance was 1 to 3 orders of magnitude higher in paddy(averaging 1.17×10^(8) copies g^(–1))than in upland(5.78×10^(6)copies g^(–1))soils.The coxL gene maintained similar abundance levels across both soil types(averaging 6.12×10^(8) vs.5.91×10^(8) copies g^(–1)).Structural equation models revealed that spatial factors primarily shaped cbbL and pmoA in uplands,whereas total bacterial abundance was the dominant predictor for all three genes in paddy soils.These results highlight distinct ecological controls on microbial functional groups and provide a predictive framework for how land use and climate change may regulate microbial mediation of carbon gas fluxes across a continental-scale transect in eastern China.展开更多
Based on reanalysis data and CMIP6 simulations,this study investigates the distinct responses of the cross-equatorial flows(CEFs)over the Maritime Continent(MC)under the simultaneous summer condition of two types of E...Based on reanalysis data and CMIP6 simulations,this study investigates the distinct responses of the cross-equatorial flows(CEFs)over the Maritime Continent(MC)under the simultaneous summer condition of two types of ENSO:central Pacific(CP)and eastern Pacific(EP).Results indicate that CP ENSO tends to exert stronger impacts on CEF.In CP ENSO years,significant lower-level southerly anomalies can be observed across all CEF branches adjacent to MC,accompanied by broader and deeper upper-level northerly anomalies,indicating a well-organized strengthening of both upper-and lowerlevel CEFs.In contrast,CEF anomalies in EP ENSO years tend to be weaker,with significant meridional wind anomalies confined to the east of MC.The disparities in the CEF responses can be elucidated from the perspective of convection over MC,a crucial factor in triggering CEF.In CP ENSO years,westward-leaning sea surface temperature(SST)anomalies result in a distinct cooling in MC and suppressed convection above,driving pronounced CEF anomalies.Conversely,the absence of such organized SST cooling during EP ENSO results in weaker convective forcing and subdued CEF responses.Furthermore,historical simulations from 48 CMIP6 models are utilized to validate the observational findings.Results show that model simulations can successfully reproduce the stronger impacts of CP ENSO,with a remarkable intermodel consistency.This research contributes toward a comprehensive understanding of the diversity in the relationship between CEF and ENSO types,and has implications for seasonal forecasting of CEF variability.展开更多
Centering on the critical bottlenecks in the development of shale oil in the Jiyang Depression of Shengli Oilfield,key scientific and engineering issues are proposed in aspects such as the storage space and occurrence...Centering on the critical bottlenecks in the development of shale oil in the Jiyang Depression of Shengli Oilfield,key scientific and engineering issues are proposed in aspects such as the storage space and occurrence state of shale oil,the formation mechanisms of multi-scale flow spaces,the mobilization mechanisms of crude oil in pores and fractures,and the enhanced oil recovery(EOR)mechanisms during the late stage of elastic development.The research progress and mechanistic insights in recent years are reviewed with respect to experimental techniques,characteristics of pore-fracture structure and fluid occurrence,fracture evolution mechanisms,shale oil flow mechanisms and EOR techniques.Through improving the experimental methods,optimizing the testing conditions,and developing new technologies,we deeply understand the occurrence state,storage space and flow pattern of shale oil,and reveal the distribution pattern of“oil-bearing in all pore sizes and oil-rich in large pores”and the differences in fluid phase states under the confinement effect of nano-scale pores in the shales of the Jiyang Depression;depict the characteristics of“restricted vertical expansion and complex fracture networks”of induced fractures and the dynamic evolution of fracture networks during the fracturing-soaking-production process;establish a“easy flow-slow flow-stagnant flow”three-zone model and the elastic drive+imbibition drive synergistic energy replenishment mechanism;and carry out high-pressure injection to further enhance the mass transfer and diffusion capacity of CO_(2)within the shale pore-fracture system,and compete for the desorption of alkanes to improve the mobilization degree of shale oil.The research achievements provide crucial support for the formation of the theory of continental shale oil development and the construction of the technical system.The future research efforts will focus on mine-scale multi-field coupling physical simulation equipment,microscopic to macroscopic multi-scale experimental methods,pore/fracture fine characterization and post-fracturing core fracture description technologies,multi-media fluid-structure coupling numerical simulation algorithms,and low-cost EOR and low-quality shale oil in-situ upgrading technologies,in order to promote the large-scale and profitable development of shale oil in the Jiyang Depression.展开更多
Based on the plate tectonics theory,the sedimentary environment of paleotectonics along the passive continental margins on both sides of the South Atlantic Ocean was reconstructed using the paleomagnetic,regional geol...Based on the plate tectonics theory,the sedimentary environment of paleotectonics along the passive continental margins on both sides of the South Atlantic Ocean was reconstructed using the paleomagnetic,regional geological,and seismic data,and the intrinsic relationships of hydrocarbon distribution in the passive continental margin basins and the differential hydrocarbon accumulation patterns were analyzed.Results show that basins on both sides of the South Atlantic experienced two major extensional phases—rift and depression—and four evolutionary stages:the Early Cretaceous Berriasian-Barremian intracontinental rift stage,the Early Cretaceous Aptian-Albian intercontinental rift to initial drift transition stage,the Late Cretaceous-Paleogene drift-related marine transgressive depression stage,and the Neogene-Quaternary drift-related marine regressive depression stage.According to basin architecture and superposition style,the passive-margin basins are classified into two principal types:rift-continental marginal depression composite and continental marginal depression-dominated.The basins in the study area were further divided into six types based on the development degree of salt tectonics and the type of dominant sand bodies,i.e.salt-free rift-continental marginal gravity-flow composite type,salt-free rift-continental marginal delta composite type,salt-bearing rift-continental marginal gravity flow composite type,delta-dominated salt-bearing rift-continental marginal delta composite type,gravity-flow-dominated continental marginal depression type,and delta-dominated continental marginal depression type.The salt-free rift-continental marginal gravity flow and delta composite basins are mainly distributed in the southern segment.The salt-bearing rift-continental marginal gravity flow and delta composite basins are mainly distributed in the central segment.The gravity-flow-dominated continental marginal depression basins are mainy distributed in the northern segment.The delta-dominated passive-margin depression basins are distributed in three segments from north to south.In different types of basins,distinctive depositional systems and source-reservoir-caprock assemblages were formed in each upper/lower structure layer.The superimposition and evolution of multi-phase prototype basins result in the orderly hydrocarbon accumulation vertically and laterally,which are“segmented along-strike,zoned across-strike,and layered vertically”.展开更多
The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a su...The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a subduction setting,the distinct investigation reveals the necessity for reassessment.To address this,the authors employ integrated methods encompassing petrological,zircon U-Pb geochronological,Lu-Hf isotopic and geochemical methods for sedimentary rocks from the upper Shenshan subgroup and Banxi Group.The geochemical results indicate that they were formed through the recycling deposition of intermediate-acidic igneous source material and experienced moderate chemical weathering.Additionally,both sedimentary sequences exhibit characteristics consistent with those formed in an intracontinental extensional rift setting since ca.810 Ma.The provenance analysis indicates that the upper Shenshan subgroup primarily originates from the Yangtze Domain,while the Banxi Group from both the Yangtze and Cathaysia domains.Synthesizing with previous studies,the Shenshan Group should be subdivided into the lower and upper subgroups which represent distinct tectonic backgrounds.The lower subgroup is inferred to have formed in an Early Neoproterozoic fore-arc setting,akin to the Zhoutan group.The upper subgroup corresponds to the Banxi Group,representing the Middle Neoproterozoic postorogenic rift setting,responding to the breakup of Rodinia.展开更多
Mineral resources in Asia continent and its mining industry play a significant role in the economic growth and industrialization of both Asia and the world.Asia continent boasts the most comprehensive kinds of mineral...Mineral resources in Asia continent and its mining industry play a significant role in the economic growth and industrialization of both Asia and the world.Asia continent boasts the most comprehensive kinds of minerals,with reserves of at least 38 of over 80 widely used minerals worldwide accounting for more than30%of the global total reserves.Asia continent experienced three main tectonic evolution and mineralization stages:The Precambrian,the Paleozoic,and the Mesozoic to Cenozoic.The abundant mineral resources in this continent can be divided into seven first-order metallogenic belts(metallogenic domains),18 second-order metallogenic belts(metallogenic provinces),61 third-order metallogenic belts(metallogenic zones),and nine main minerogenetic series.Asia continent exhibits the most significant metallogenic specialization among all continents.Specifically,granite belts of Asia continent manifest pronounced metallogenic specialization of tin,rare metals,and porphyry Cu-Au-Mo deposits.Its maficultramafic rock belts and ophiolite belts display notable metallogenic specialization of lateritic nickel deposits and magmatic type chromite deposits,while its Mesozoic to Cenozoic basalt belts show remarkable metallogenic specialization of lateritic bauxite deposits.Consequently,many giant metallogenic belts were formed,including the Southeast Asian tin belt,the Qinghai-Xizang Plateau rare metal metallogenic belt,the Tethyan porphyry Cu-Au-Mo metallogenic belt,the circum-Pacific porphyry Cu-Au-Mo metallogenic belt,the Southeast Asian lateritic bauxite metallogenic belt,the Deccan Plateau lateritic bauxite metallogenic belt in India,the Southeast Asian lateritic nickel metallogenic belt,and the Tethyan magmatic type chromite metallogenic belt—all of which are significant metallogenic belts in Asia continent.Future mineral exploration in Asia should focus primarily on the Precambrian mineralization of ancient cratons,the Paleozoic mineralization of the Central Asian-Mongolian orogenic belt,and the Mesozoic to Cenozoic mineralization of the Tethyan and circum-Pacific mobile belts.Asia's mining industry not only underpins its own economic growth but also propels global economic development and industrialization,contributing significantly to the world economy.Asia boasts the highest production value of minerals,the largest annual production of minerals,and the greatest trade value of mineral products among all the continents,having emerged as the trade center of global mineral products and the center of the mining industry economy.China is identified as one of the few countries that possess the most comprehensive kinds of minerals,and its mining industry has supported and driven the economic development and industrialization of Asia and even the world.Standing as the largest mineral producer worldwide,China ranked first in the production of 28 mineral commodities in the world in 2022.Besides,China exhibits the highest annual production value of minerals and the largest trade value of mineral products among all countries.Therefore,China's demand for global mineral products influences the global supply and demand patterns of minerals and the world economic situation.展开更多
The promotion of deep decarbonization in the cement industry is crucial for mitigating global climate change,a key component of which is carbon capture,utilization,and storage(CCUS)technology.Despite its importance,th...The promotion of deep decarbonization in the cement industry is crucial for mitigating global climate change,a key component of which is carbon capture,utilization,and storage(CCUS)technology.Despite its importance,there is a lack of empirical assessments of early opportunities for CCUS implementation in the cement sector.In this study,a comprehensive onshore and offshore source–sink matching optimization assessment framework for CCUS retrofitting in the cement industry,called the SSM-Cement framework,is proposed.The framework comprises four main modules:the cement plant suitability screening module,the storage site assessment module,the source–sink matching optimization model module,and the economic assessment module.By applying this framework to China,919 candidates are initially screened from 1132 existing cement plants.Further,603 CCUS-ready cement plants are identified,and are found to achieve a cumulative emission reduction of 18.5 Gt CO_(2) from 2030 to 2060 by meeting the CCUS feasibility conditions for constructing both onshore and offshore CO_(2) transportation routes.The levelized cost of cement(LCOC)is found to range from 30 to 96(mean 73)USD·(t cement)^(-1),while the levelized carbon avoidance cost(LCAC)ranges from^(-5) to 140(mean 88)USD·(t CO_(2))^(-1).The northeastern and northwestern regions of China are considered priority areas for CCUS implementation,with the LCAC concentrated in the range of 35 to 70 USD·(t CO_(2))^(-1).In addition to onshore storage of 15.8 Gt CO_(2) from 2030 to 2060,offshore storage would contribute 2.7 Gt of decarbonization for coastal cement plants,with comparable LCACs around 90 USD·(t CO_(2))^(-1).展开更多
The heat content(HC)of water masses on the Ross Sea continental shelf plays an important role in regulating the circulations and the basal melting of the Ross Ice Shelf(RIS).Yet,the evolution of the HC on the Ross Sea...The heat content(HC)of water masses on the Ross Sea continental shelf plays an important role in regulating the circulations and the basal melting of the Ross Ice Shelf(RIS).Yet,the evolution of the HC on the Ross Sea continental shelf is still not clear due to the sparsity of observations.By employing a coupled regional ocean-sea ice-ice shelf model for the Ross Sea,this study analyzes the heat budget of water masses over the continental shelf and in the RIS cavity.According to the topographic features and the HC density,the continental shelf region is divided into 17 subdomains.The heat budget of the middle layer for every subdomain is analyzed.In addition,the heat budget for the RIS cavity is assessed for the first time.Owing to Modified Circumpolar Deep Water intrusion,water masses over the eastern shelf are warmer than over the western shelf,with the coldest water identified in the southwestern inner shelf.The horizontal heat flux mainly provides heat to the continental shelf,while the atmospheric forcing tends to warm up the ocean during the ice-melting period and cool down the ocean during the ice-freezing period.The vertical heat flux is generally upward and transports heat from the deep layer to the upper layer.In the RIS cavity,the seasonal cycle of the HC is dominated by the horizontal flux across the RIS front rather than the basal thermal forcing of the RIS.展开更多
Medium-high maturity continental shale oil is one of the hydrocarbon resources with the most potential for successful development in China.Nevertheless,the unique geological conditions of a multi-lithologic superposit...Medium-high maturity continental shale oil is one of the hydrocarbon resources with the most potential for successful development in China.Nevertheless,the unique geological conditions of a multi-lithologic superposition shield the vertical propagation of hydraulic fractures and limit the longitudinal reconstruction in reservoirs,posing a great challenge for large-scale volumetric fracturing.Radial wellbore crosslayer fracturing,which transforms the interaction between the hydraulic fractures and lithologic interface into longitudinal multilayer competitive initiation,could provide a potential solution for this engineering challenge.To determine the longitudinal propagation behaviors of fractures guided by radial wellbores,true triaxial fracturing experiments were performed on multilayer shale-sandstone samples,with a focus on the injection pressure response,fracture morphology,and cross-layer pattern.The effects of the radial borehole length L,vertical stress difference K_(v),injection rate Q,and viscosity m of the fracturing fluid were analyzed.The results indicate that radial wellbores can greatly facilitate fracture initiation and cross-layer propagation.Unlike conventional hydraulic fracturing,there are two distinct fracture propagation patterns in radial wellbore fracturing:cross-layering and skip-layering.The fracture height guided by a radial wellbore is positively correlated with K_(v),Q,and m.Increasing these parameters causes a shift in the fracture initiation from a single root to an asynchronous root/toe end and can improve the cross-layer propagation capacity.Critical parameter thresholds exist for fracture propagation through and across interlayers under the guidance of radial boreholes.A parameter combination of critical cross-layering/skip-layering or alternating displacement/viscosity is recommended to simultaneously improve the fracture height and degree of lateral activation.The degree of correlation of different parameters with the vertical fracture height can be written as L>Q/m>K_(v).Increasing the radial wellbore length can effectively facilitate fracture cross-/skip-layer propagation and reduce the critical threshold of injection parameters,which is conducive to maximizing the stimulated reservoir volume.展开更多
To address the discrepancies between well and seismic data in stratigraphic correlation of the Triassic Yanchang Formation in the Ordos Basin,NW China,traditional stratigraphic classification schemes,the latest 3D sei...To address the discrepancies between well and seismic data in stratigraphic correlation of the Triassic Yanchang Formation in the Ordos Basin,NW China,traditional stratigraphic classification schemes,the latest 3D seismic and drilling data,and reservoir sections are thoroughly investigated.Guided by the theory of sequence stratigraphy,the progradational sequence stratigraphic framework of the Yanchang Formation is systematically constructed to elucidate new deposition mechanisms in the depressed lacustrine basin,and it has been successfully applied to the exploration and development practices in the Qingcheng Oilfield.Key findings are obtained in three aspects.First,the seismic progradational reflections,marker tuff beds,and condensed sections of flooding surfaces in the Yanchang Formation are consistent and isochronous.Using flooding surface markers as a reference,a progradational sequence stratigraphic architecture is reconstructed for the middle-upper part of Yanchang Formation,and divided into seven clinoform units(CF1-CF7).Second,progradation predominantly occurs in semi-deep to deep lake environments,with the depositional center not always coinciding with the thickest strata.The lacustrine basin underwent an evolution of“oscillatory regression-progradational infilling-multi-phase superimposition”.Third,the case study of Qingcheng Oilfield reveals that the major pay zones consist of“isochronous but heterochronous”gravity-flow sandstone complexes.Guided by the progradational sequence stratigraphic architecture,horizontal well oil-layer penetration rates remain above 82%.The progradational sequence stratigraphic architecture and associated geological insights are more consistent with the sedimentary infilling mechanisms of large-scale continental depressed lacustrine basins and actual drilling results.The research results provide crucial theoretical and technical support for subsequent refined exploration and development of the Yanchang Formation,and are expected to offer a reference for research and production practice in similar continental lacustrine basins.展开更多
1 Introduction The Maritime Silk Road, once a historic network of trade routes that connected continents and facilitated centuries of cultural and economic exchange, has become a region of profound scientific importan...1 Introduction The Maritime Silk Road, once a historic network of trade routes that connected continents and facilitated centuries of cultural and economic exchange, has become a region of profound scientific importance. Stretching from East Asia to Europe and Africa, its marine environments are among the most complex and dynamic on Earth. This region encompasses diverse geological settings, including tectonically active zones, varied sedimentary basins, and extensive continental shelves. These features make it a unique natural laboratory for studying various geological and geophysical processes.展开更多
Guided by the fundamental principles of the whole petroleum system,the control of tectonism,sedimentation,and diagenesis on hydrocarbon accumulation in a rifted basin is studied using the data of petroleum geology and...Guided by the fundamental principles of the whole petroleum system,the control of tectonism,sedimentation,and diagenesis on hydrocarbon accumulation in a rifted basin is studied using the data of petroleum geology and exploration of the second member of the Paleogene Kongdian Formation(Kong-2 Member)in the Cangdong Sag,Bohai Bay Basin,China.It is clarified that the circle structure and circle effects are the marked features of a continental fault petroliferous basin,and they govern the orderly distribution of conventional and unconventional hydrocarbons in the whole petroleum systems of the rifted basin.Tectonic circle zones control sedimentary circle zones,while sedimentary circle zones and diagenetic circle zones control the spatial distribution of favorable reservoirs,thereby determining the orderly distribution of hydrocarbon accumulations in various circles.A model for the integrated,systematic accumulation of conventional and unconventional hydrocarbons under a multi-circle structure of the whole petroleum system of continental rifted basin has been developed.It reveals that each sag of the rifted basin is an independent whole petroleum system and circle system,which encompasses multiple orderly circles of conventional and unconventional hydrocarbons controlled by the same source kitchen.From the outer circle to the middle circle and then to the inner circle,there is an orderly transition from structural and stratigraphic reservoirs,to lithological and structural-lithological reservoirs,and finally to tight oil/gas and shale oil/gas enrichment zones.The significant feature of the whole petroleum system is the orderly control of hydrocarbons by multi-circle stratigraphic coupling,with the integrated,orderly distribution of conventional and unconventional reserves being the inevitable result of the multi-layered interaction within the whole petroleum system.This concept of multi-circle stratigraphic coupling for the orderly,integrated accumulation of conventional and unconventional hydrocarbons has guided significant breakthroughs in the overall,three-dimensional exploration and shale oil exploration in the Cangdong Sag.展开更多
The Pamir Plateau,located at the western syntaxis of the Himalayan-Tibetan orogenic belt,serves as a crucial natural laboratory for investigating ongoing continental collision and associated geodynamic processes(Schne...The Pamir Plateau,located at the western syntaxis of the Himalayan-Tibetan orogenic belt,serves as a crucial natural laboratory for investigating ongoing continental collision and associated geodynamic processes(Schneider et al.,2019;Kumar et al.,2022;Murodov et al.,2022;Bloch et al.,2023).As a primary convergence front between the Indian and Eurasian plates,this region exhibits extreme crustal shortening,significant uplift,and deep seismicity that extends to depths of~300 km beneath the Hindu Kush.Understanding the deep structure,dynamics,and crust-mantle interactions beneath the Pamir is essential for deciphering the tectonic evolution of the Asian continent and for assessing resource potential and geohazard mitigation.展开更多
The signing of the African Continental Free Trade Area(AfCFTA)in Kigali,Rwanda,on 21 March 2018 spurred a wave of optimism in street markets and corporate boardrooms alike.The 44 countries joining this single market p...The signing of the African Continental Free Trade Area(AfCFTA)in Kigali,Rwanda,on 21 March 2018 spurred a wave of optimism in street markets and corporate boardrooms alike.The 44 countries joining this single market pledged to remove tariffs on 90 percent of goods,knitting economies together in an unprecedented fashion.展开更多
Based on a set of high-resolution 3D seismic data from the northern continental margin of the South China Sea,the lithospheric structure,thinning mechanisms and related syn-rift tectonic deformation response processes...Based on a set of high-resolution 3D seismic data from the northern continental margin of the South China Sea,the lithospheric structure,thinning mechanisms and related syn-rift tectonic deformation response processes in the crustal necking zone in the deepwater area of the Pearl River Mouth Basin were systematically analyzed,and the petroleum geological significance was discussed.The necking zone investigated in the study is located in the Baiyun Sag and Kaiping Sag in the deepwater area of the Pearl River Mouth Basin.These areas show extreme crustal thinned geometries of central thinning and flank thickening,characterized by multi-level and multi-dipping detachment fault systems.The necking zone exhibits pronounced lateral heterogeneity in structural architectures,which can be classified into four types of thinned crustal architectures,i.e.the wedge-shaped extremely thinned crustal architecture in the Baiyun Main Sub-sag,dumbbell-shaped moderately thinned crustal architecture in the Baiyun West Sub-sag,box-shaped weakly thinned crustal architecture in eastern Baiyun Sag,and metamorphic core complex weakly thinned crustal architecture in the Kaiping Sag.This shows great variations in the degree and style of crustal thinning,types of detachment faults,distribution of syn-rift sedimentary sequences,and intensity of magmatism.The thinning of the necking zone is controlled by the heterogeneous rheological stratification of lithosphere,intensity of mantle-derived magmatism,and deformation modes of detachment faults.The syn-rift tectonic deformation of the necking zone evolved through three phases,i.e.uniform stretching during the early Wenchang Formation deposition period,necking during the late Wenchang Formation deposition period,and hyperextension during the Enping Formation deposition period.The crustal thinning extent and architectural differentiation in these phases were primarily controlled by three distinct mechanisms,i.e.the pure shear deformation activation of pre-existing thrust faults,the simple shear deformation of crust-mantle and inter-crust detachment faults,and differential coupling of lower crustal flow and ductile domes with main detachment faults.The hydrocarbon accumulation and enrichment in the necking zone exhibit marked spatial heterogeneity.Four distinct crustal thinned architecture-hydrocarbon accumulation models were identified in this study.The hydrocarbon accumulations in the shallow part exhibit significant correlations with their deep crustal thinned architectures.The unique lithospheric structure and deformation process predominantly control the favorable hydrocarbon accumulation zones with excellent source-fault-ridge-sand configurations,which is critical to reservoir-forming.The most promising exploration targets are mainly identified on the uplift zones and their seaward-dipping flanks associated with the middle and lower crustal domes.This research provides additional insights into lithospheric thinning-breakup process at intermediate continental margins of marine sedimentary basins,being significant for guiding the deepwater petroleum exploration in the Pearl River Mouth Basin.展开更多
East Asian continental tectonics challenges the plate tectonics paradigm with its diffuse intraplate deformation,magmatism,and earthquakes.Despite extensive studies,fundamental questions persist.This review examines t...East Asian continental tectonics challenges the plate tectonics paradigm with its diffuse intraplate deformation,magmatism,and earthquakes.Despite extensive studies,fundamental questions persist.This review examines ten critical questions of East Asian tectonics,including the thickness of the continental lithosphere,the origin of the North–South Gravity Lineament,and the northern extent of the Indian plate beneath the Tibetan Plateau.Additional questions address the Tibetan Plateau's lateral growth,the Tianshan mountain building,the mantle flow in response to the Indo-Asian collision,and the formation of the Shanxi Rift.The review also explores the subduction along the eastern margins of the East Asian Continent and the origins of the Changbaishan volcanic field,the destruction of the North China Craton,and the development of the Mesozoic Large Granitic Province in South China.Originally presented at the DEEP2024 workshop to stimulate discussion of how SinoProbe-II research initiatives could advance our understanding of Asian tectonics,this review provides context for each question,summarizes current knowledge,and identifies promising research directions.展开更多
Two new free-living marine nematode species belonging to the genus Tricoma Cobb,1894(Desmoscolecidae)are identi-fied from the continental shelf region of the Bay of Bengal.Tricoma ajmalia sp.nov.is characterized by th...Two new free-living marine nematode species belonging to the genus Tricoma Cobb,1894(Desmoscolecidae)are identi-fied from the continental shelf region of the Bay of Bengal.Tricoma ajmalia sp.nov.is characterized by the number of main rings(84 male and 85 female),the arrangement of somatic setae,the head shape with broadly truncated end,the relatively long cephalic setae(69%-73%of corresponding head diameter),the amphids extending up to second main ring,slender spicules slightly curved and gu-berbaculum with dorsocaudally directed apophyses.The second new species,Tricoma sampadansis sp.nov.is characterized by the number of rings(64),the arrangement of somatic setae(14-13 subdorsal,16 subvenral),the head shape with broadly truncated end,the relatively long cephalic setae(75%corresponding head diameter),the amphidial fovea extending over first main ring,anterioirly bent spicules and gubernaculum with hooked proximal end.An updated valid species list of Tricoma is also presented.展开更多
Mobility is a crucial metric for assessing sweet spots of continental shale oil.However,due to the complexity of shale oil reservoirs characteristics and the lack of systematic analyses of factors influencing mobility...Mobility is a crucial metric for assessing sweet spots of continental shale oil.However,due to the complexity of shale oil reservoirs characteristics and the lack of systematic analyses of factors influencing mobility,the difference in shale oil mobility under multiple lithofacies control remains unclear,causing significant challenges for mobility evaluation and sweet spot prediction.This study examines continental shales of the Fengcheng Formation in the Mahu Sag,employing scanning electron microscopy(SEM),nitrogen adsorption(NA),nuclear magnetic resonance(NMR),spontaneous imbibition(SI),and contact angle measurements(CAM)to investigate the pore structure,connectivity,and wettability properties of different lithofacies shale.Quantitative analyses of shale movable oil content and saturation were conducted using multistep temperature pyrolysis(MTP)and NMR centrifugation techniques.Furthermore,the influence of reservoir characteristics,geochemical characteristics,and lamination development on shale oil mobility were discussed.Results indicate that larger pore diameter,higher imbibition slopes,and lower fractal dimensions of movable fluid pores(D2)correspond to higher movable oil saturation.Organic matter exerts a dual effect on shale movable oil content.When the TOC is below a threshold,the movable oil content gradually increases with TOC.Laminations exhibit favorable reservoir properties and light oil enrichment,enhancing shale oil mobility.Massive siltstone(MS)develops interconnected intergranular pores with the best pore structure and connectivity,the lowest D2 values,and the highest shale oil mobility.Laminated felsic shale(LFS)and laminated calcareous shale(LCS)exhibit moderate mobility,where the development of microfractures enhances fluid flow by connecting isolated pores into pore-fracture networks.In contrast,massive felsic shale(MFS)and bedded felsic shale(BFS)primarily develop intragranular dissolution pores with more complex structures and poorer connectivity,resulting in weaker mobility.A more accurate approach for assessing shale oil mobility has been presented,taking into account both total oil content and movable oil saturation.More importantly,this study establishes a comprehensive conceptual model illustrating the potential relationships among shale lithofacies,reservoir characteristics,and movable oil flow space in the study area.This research not only provides a systematic approach for assessing shale oil mobility but also deepens the understanding of flow mechanisms of continental shale oil,offering theoretical guidance for optimizing sweet spots in the Fengcheng Formation shale oil reservoirs of the Mahu Sag.展开更多
Large-scale Danian-age(post-K/Pg boundary)Deccan magmatism is well known from the Mumbai metropolitan area,located in the structurally complex Panvel flexure zone along the western Indian rifted continental margin.Thi...Large-scale Danian-age(post-K/Pg boundary)Deccan magmatism is well known from the Mumbai metropolitan area,located in the structurally complex Panvel flexure zone along the western Indian rifted continental margin.This compositionally diverse late-Deccan magmatic suite contains subaerial tholeiitic lavas and dykes typical of the main Deccan province,with many features atypical of the Deccan,such as spilitic pillow lavas,“intertrappean”sediments(often containing considerable volcanic ash),rhyolitic lavas and tuffs,gabbro-granophyre intrusions,and trachyte intrusions containing alkali basalt enclaves.Most of these units,previously dated at 62.5 Ma to 61 Ma,are contemporaneous with or slightly postdate the 62.5 Ma India-Seychelles continental breakup and Panvel flexure formation.In the Dongri-Uttan area,two samples of a>50-m-thick,columnar-jointed rhyolite from the Darkhan Quarry and from a section behind the current Uttan Sagari Police Station have previously been dated at 62.6±0.6 Ma and 62.9±0.2 Ma(^(40)Ar/^(39)Ar,2r errors).New exposures reveal that these two statistically indistinguishable 40 Ar/39 Ar ages correspond to two distinct rhyolite units,separated by well-bedded silicic ash.The columnar rhyolites are microcrystalline,composed of quartz and alkali feldspar,with rare small(1–2 mm),altered feldspar phenocrysts,and no recognisable relict vitroclasts.Given the westerly structural dip,most of their lateral extent is submerged under the Arabian Sea,and we consider them to be possible flood rhyolite lavas.We interpret the ash beds,composed of pumice clasts and glass shards,as a low-grade(nonwelded)vitric ash,derived from a possibly distal Plinian eruption and deposited by fallout.The lavas and ash are peraluminous rhyolites.The lavas are Sr-Ba-poor and Rb-Zr-Nb-rich,and show“seagull-shaped”rare earth element patterns with deep negative europium anomalies.These crystal-poor lavas are“hot-dry-reduced”rhyolites typical of intraplate,continental rift and rifted margin settings.The very different high-field strength element contents of the lavas and the ash indicate compositionally distinct magma batches.The 62.5 Ma Dongri-Uttan sequence provides clear evidence for rapid silicic eruptions of effusive and explosive nature,alternating with each other and sourced from distinct magma chambers and eruptive vents.A newly identified,highly feldspar-phyric trachyte intrusion marks the last phase of magmatic activity in the area,corresponding with late-stage trachyte-syenite intrusions exposed in coastal western India and the Seychelles,and shows that the Mumbai rhyolites and trachytes form a compositional continuum.展开更多
基金funding for this research comes fromHubei Provincial Natural Science Foundation(2022CFB690)the Open Foundation(UOG2024-03)of Cooperative Innovation Center of Unconventional Oil+1 种基金Gas,Yangtze University(Ministry of Education&Hubei Province)and the Open Foundation(YQZC202302)of Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering(Yangtze University)the National Natural Science Foundation of China(Grant no.U23B20156).
文摘To investigate the long-term fracture conductivity behavior of propped fractures under the high-temperature and high-pressure conditions of deep shale gas reservoirs in the Sichuan Basin,this study systematically analyzed the effects of closure stress,proppant concentration,formation temperature,and proppant size combination.Conductivity experiments were conducted using the HXDL-2C long-term proppant conductivity evaluation system under simulated reservoir conditions to determine the time-dependent evolution of fracture conductivity.The results showed that the 50-h conductivity retention of the rock-plate experiments ranged from 22%to 28%.With increasing closure stress,fracture conductivity exhibited a rapid decline.Under a formation temperature of 120℃ and a proppant concentration of 5 kg·m^(-2),the short-term conductivity of 70/140 mesh quartz-sand-propped fractures was 2.37μm^(2)·cm,which decreased to 0.66μm^(2)·cm after long-term testing.When the closure stress increased to 80 MPa,the short-term and long-term conductivities further declined to 1.36μm^(2)·cm and 0.39μm^(2)·cm,respectively.Increasing the proppant concentration from 5 to 7.5 kg·m^(-2)at 120℃ and 80 MPa improved both short-term and long-term conductivities by enlarging the effective fracture width;however,the conductivity decay rate accelerated,and the 50-h retention dropped from 27.2%to 22.8%.Raising the temperature from 120℃ to 140℃ promoted proppant crushing and compaction,intensified shale creep,and accelerated fracture closure,reducing long-term conductivity from 0.37 to 0.30μm^(2)·cm.Under identical conditions,40/70 mesh ceramic proppants maintained significantly higher conductivities than 70/140 mesh quartz sand,with short-term and long-term values of 8.71 and 2.19μm^(2)·cm,respectively,at 120℃,80 MPa,and 5 kg·m^(-2).Pure quartz-sand systems failed to maintain effective conductivity under high-temperature and high-stress conditions,whereas adding 20%40/70 mesh ceramic proppant and thoroughly mixing it,the long-term conductivity has increased by 2.3 times,improving fracture stability while reducing overall cost.A predictive equation was derived from the experimental results to capture the dynamic decay characteristics of fracture conductivity.These outcomes provide a valuable experimental basis and technical support for optimizing fracturing fluid design,proppant selection,and operation parameters in deep shale formations.
基金financially supported by the National Key R&D Program of China(2023YFD1902802)the Science Fund for Distinguished Young Scholars in Hunan,China(2024JJ2052)+3 种基金the Natural Science Foundation of Fujian Province,China(2022J05263)the Nanping City Science and Technology Plan Project,China(NP2021KTS02)the Talent Introduction Project of Wuyi University,China(YJ202117)the Open Foundation of State Key Laboratory of Microbial Technology in Shandong University,China(M2022-05)。
文摘Microorganisms carrying cbbL,pmoA and coxL genes play crucial roles in regulating soil-atmosphere exchanges of carbon trace gases(CO_(2),CH_(4),and CO).However,the geographical distribution patterns of these functional genes in agricultural ecosystems and their environmental drivers remain poorly understood.Here,we surveyed agricultural soils across four climate zones(tropical,subtropical,warm temperate,and mid-temperate)in eastern China to quantify the abundances of CO_(2)-assimilating bacteria(cbbL gene),methanotrophs(pmoA gene),and CO-oxidizing bacteria(coxL gene).We found significant ecosystem-specific patterns:the cbbL gene was more abundant in upland soils(averaging 9.46×10^(9)copies g^(–1))than in paddy soils(6.44×10^(9) copies g^(–1)).In contrast,methanotrophs abundance was 1 to 3 orders of magnitude higher in paddy(averaging 1.17×10^(8) copies g^(–1))than in upland(5.78×10^(6)copies g^(–1))soils.The coxL gene maintained similar abundance levels across both soil types(averaging 6.12×10^(8) vs.5.91×10^(8) copies g^(–1)).Structural equation models revealed that spatial factors primarily shaped cbbL and pmoA in uplands,whereas total bacterial abundance was the dominant predictor for all three genes in paddy soils.These results highlight distinct ecological controls on microbial functional groups and provide a predictive framework for how land use and climate change may regulate microbial mediation of carbon gas fluxes across a continental-scale transect in eastern China.
基金supported by the National Natural Science Foundation of China(Grant No.42405029).
文摘Based on reanalysis data and CMIP6 simulations,this study investigates the distinct responses of the cross-equatorial flows(CEFs)over the Maritime Continent(MC)under the simultaneous summer condition of two types of ENSO:central Pacific(CP)and eastern Pacific(EP).Results indicate that CP ENSO tends to exert stronger impacts on CEF.In CP ENSO years,significant lower-level southerly anomalies can be observed across all CEF branches adjacent to MC,accompanied by broader and deeper upper-level northerly anomalies,indicating a well-organized strengthening of both upper-and lowerlevel CEFs.In contrast,CEF anomalies in EP ENSO years tend to be weaker,with significant meridional wind anomalies confined to the east of MC.The disparities in the CEF responses can be elucidated from the perspective of convection over MC,a crucial factor in triggering CEF.In CP ENSO years,westward-leaning sea surface temperature(SST)anomalies result in a distinct cooling in MC and suppressed convection above,driving pronounced CEF anomalies.Conversely,the absence of such organized SST cooling during EP ENSO results in weaker convective forcing and subdued CEF responses.Furthermore,historical simulations from 48 CMIP6 models are utilized to validate the observational findings.Results show that model simulations can successfully reproduce the stronger impacts of CP ENSO,with a remarkable intermodel consistency.This research contributes toward a comprehensive understanding of the diversity in the relationship between CEF and ENSO types,and has implications for seasonal forecasting of CEF variability.
基金Supported by the China National Science and Technology Major Project(2024ZD1405103)SINOPEC Science and Technology Major Project(P25184)。
文摘Centering on the critical bottlenecks in the development of shale oil in the Jiyang Depression of Shengli Oilfield,key scientific and engineering issues are proposed in aspects such as the storage space and occurrence state of shale oil,the formation mechanisms of multi-scale flow spaces,the mobilization mechanisms of crude oil in pores and fractures,and the enhanced oil recovery(EOR)mechanisms during the late stage of elastic development.The research progress and mechanistic insights in recent years are reviewed with respect to experimental techniques,characteristics of pore-fracture structure and fluid occurrence,fracture evolution mechanisms,shale oil flow mechanisms and EOR techniques.Through improving the experimental methods,optimizing the testing conditions,and developing new technologies,we deeply understand the occurrence state,storage space and flow pattern of shale oil,and reveal the distribution pattern of“oil-bearing in all pore sizes and oil-rich in large pores”and the differences in fluid phase states under the confinement effect of nano-scale pores in the shales of the Jiyang Depression;depict the characteristics of“restricted vertical expansion and complex fracture networks”of induced fractures and the dynamic evolution of fracture networks during the fracturing-soaking-production process;establish a“easy flow-slow flow-stagnant flow”three-zone model and the elastic drive+imbibition drive synergistic energy replenishment mechanism;and carry out high-pressure injection to further enhance the mass transfer and diffusion capacity of CO_(2)within the shale pore-fracture system,and compete for the desorption of alkanes to improve the mobilization degree of shale oil.The research achievements provide crucial support for the formation of the theory of continental shale oil development and the construction of the technical system.The future research efforts will focus on mine-scale multi-field coupling physical simulation equipment,microscopic to macroscopic multi-scale experimental methods,pore/fracture fine characterization and post-fracturing core fracture description technologies,multi-media fluid-structure coupling numerical simulation algorithms,and low-cost EOR and low-quality shale oil in-situ upgrading technologies,in order to promote the large-scale and profitable development of shale oil in the Jiyang Depression.
基金Supported by the China National Science and Technology Major Project(2025ZD400801)CNPC Science and Technology Major Project(2023ZZ07-01)。
文摘Based on the plate tectonics theory,the sedimentary environment of paleotectonics along the passive continental margins on both sides of the South Atlantic Ocean was reconstructed using the paleomagnetic,regional geological,and seismic data,and the intrinsic relationships of hydrocarbon distribution in the passive continental margin basins and the differential hydrocarbon accumulation patterns were analyzed.Results show that basins on both sides of the South Atlantic experienced two major extensional phases—rift and depression—and four evolutionary stages:the Early Cretaceous Berriasian-Barremian intracontinental rift stage,the Early Cretaceous Aptian-Albian intercontinental rift to initial drift transition stage,the Late Cretaceous-Paleogene drift-related marine transgressive depression stage,and the Neogene-Quaternary drift-related marine regressive depression stage.According to basin architecture and superposition style,the passive-margin basins are classified into two principal types:rift-continental marginal depression composite and continental marginal depression-dominated.The basins in the study area were further divided into six types based on the development degree of salt tectonics and the type of dominant sand bodies,i.e.salt-free rift-continental marginal gravity-flow composite type,salt-free rift-continental marginal delta composite type,salt-bearing rift-continental marginal gravity flow composite type,delta-dominated salt-bearing rift-continental marginal delta composite type,gravity-flow-dominated continental marginal depression type,and delta-dominated continental marginal depression type.The salt-free rift-continental marginal gravity flow and delta composite basins are mainly distributed in the southern segment.The salt-bearing rift-continental marginal gravity flow and delta composite basins are mainly distributed in the central segment.The gravity-flow-dominated continental marginal depression basins are mainy distributed in the northern segment.The delta-dominated passive-margin depression basins are distributed in three segments from north to south.In different types of basins,distinctive depositional systems and source-reservoir-caprock assemblages were formed in each upper/lower structure layer.The superimposition and evolution of multi-phase prototype basins result in the orderly hydrocarbon accumulation vertically and laterally,which are“segmented along-strike,zoned across-strike,and layered vertically”.
基金supported by the National Natural Science Foundation of China(42372250,42102262 and 41972235)National Key Research and Development Program Project(2023YFF0803701)+1 种基金Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP206)the program of China Scholarship Council。
文摘The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a subduction setting,the distinct investigation reveals the necessity for reassessment.To address this,the authors employ integrated methods encompassing petrological,zircon U-Pb geochronological,Lu-Hf isotopic and geochemical methods for sedimentary rocks from the upper Shenshan subgroup and Banxi Group.The geochemical results indicate that they were formed through the recycling deposition of intermediate-acidic igneous source material and experienced moderate chemical weathering.Additionally,both sedimentary sequences exhibit characteristics consistent with those formed in an intracontinental extensional rift setting since ca.810 Ma.The provenance analysis indicates that the upper Shenshan subgroup primarily originates from the Yangtze Domain,while the Banxi Group from both the Yangtze and Cathaysia domains.Synthesizing with previous studies,the Shenshan Group should be subdivided into the lower and upper subgroups which represent distinct tectonic backgrounds.The lower subgroup is inferred to have formed in an Early Neoproterozoic fore-arc setting,akin to the Zhoutan group.The upper subgroup corresponds to the Banxi Group,representing the Middle Neoproterozoic postorogenic rift setting,responding to the breakup of Rodinia.
基金funded by geological survey project of China Geological Survey(DD20211404)。
文摘Mineral resources in Asia continent and its mining industry play a significant role in the economic growth and industrialization of both Asia and the world.Asia continent boasts the most comprehensive kinds of minerals,with reserves of at least 38 of over 80 widely used minerals worldwide accounting for more than30%of the global total reserves.Asia continent experienced three main tectonic evolution and mineralization stages:The Precambrian,the Paleozoic,and the Mesozoic to Cenozoic.The abundant mineral resources in this continent can be divided into seven first-order metallogenic belts(metallogenic domains),18 second-order metallogenic belts(metallogenic provinces),61 third-order metallogenic belts(metallogenic zones),and nine main minerogenetic series.Asia continent exhibits the most significant metallogenic specialization among all continents.Specifically,granite belts of Asia continent manifest pronounced metallogenic specialization of tin,rare metals,and porphyry Cu-Au-Mo deposits.Its maficultramafic rock belts and ophiolite belts display notable metallogenic specialization of lateritic nickel deposits and magmatic type chromite deposits,while its Mesozoic to Cenozoic basalt belts show remarkable metallogenic specialization of lateritic bauxite deposits.Consequently,many giant metallogenic belts were formed,including the Southeast Asian tin belt,the Qinghai-Xizang Plateau rare metal metallogenic belt,the Tethyan porphyry Cu-Au-Mo metallogenic belt,the circum-Pacific porphyry Cu-Au-Mo metallogenic belt,the Southeast Asian lateritic bauxite metallogenic belt,the Deccan Plateau lateritic bauxite metallogenic belt in India,the Southeast Asian lateritic nickel metallogenic belt,and the Tethyan magmatic type chromite metallogenic belt—all of which are significant metallogenic belts in Asia continent.Future mineral exploration in Asia should focus primarily on the Precambrian mineralization of ancient cratons,the Paleozoic mineralization of the Central Asian-Mongolian orogenic belt,and the Mesozoic to Cenozoic mineralization of the Tethyan and circum-Pacific mobile belts.Asia's mining industry not only underpins its own economic growth but also propels global economic development and industrialization,contributing significantly to the world economy.Asia boasts the highest production value of minerals,the largest annual production of minerals,and the greatest trade value of mineral products among all the continents,having emerged as the trade center of global mineral products and the center of the mining industry economy.China is identified as one of the few countries that possess the most comprehensive kinds of minerals,and its mining industry has supported and driven the economic development and industrialization of Asia and even the world.Standing as the largest mineral producer worldwide,China ranked first in the production of 28 mineral commodities in the world in 2022.Besides,China exhibits the highest annual production value of minerals and the largest trade value of mineral products among all countries.Therefore,China's demand for global mineral products influences the global supply and demand patterns of minerals and the world economic situation.
基金financial support of National Natural Science Foundation of China(72174196 and 71874193)the Open Fund of State Key Laboratory of Coal Resources and Safe Mining(SKLCRSM21KFA05)National Program for Support of Top-Notch Young Professionals.
文摘The promotion of deep decarbonization in the cement industry is crucial for mitigating global climate change,a key component of which is carbon capture,utilization,and storage(CCUS)technology.Despite its importance,there is a lack of empirical assessments of early opportunities for CCUS implementation in the cement sector.In this study,a comprehensive onshore and offshore source–sink matching optimization assessment framework for CCUS retrofitting in the cement industry,called the SSM-Cement framework,is proposed.The framework comprises four main modules:the cement plant suitability screening module,the storage site assessment module,the source–sink matching optimization model module,and the economic assessment module.By applying this framework to China,919 candidates are initially screened from 1132 existing cement plants.Further,603 CCUS-ready cement plants are identified,and are found to achieve a cumulative emission reduction of 18.5 Gt CO_(2) from 2030 to 2060 by meeting the CCUS feasibility conditions for constructing both onshore and offshore CO_(2) transportation routes.The levelized cost of cement(LCOC)is found to range from 30 to 96(mean 73)USD·(t cement)^(-1),while the levelized carbon avoidance cost(LCAC)ranges from^(-5) to 140(mean 88)USD·(t CO_(2))^(-1).The northeastern and northwestern regions of China are considered priority areas for CCUS implementation,with the LCAC concentrated in the range of 35 to 70 USD·(t CO_(2))^(-1).In addition to onshore storage of 15.8 Gt CO_(2) from 2030 to 2060,offshore storage would contribute 2.7 Gt of decarbonization for coastal cement plants,with comparable LCACs around 90 USD·(t CO_(2))^(-1).
基金supported by the National Key R&D Program of China (Grant No. 2024YFF0506603)the Independent Research Foundation of the Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) (Grant Nos. SML2023SP201 and SML2021SP306)+2 种基金the Natural Science Foundation of Guangdong Province, China (Grant No. 2024A1515012717)the Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) (Grant Nos. 313021004, 313022009 and 313022001)the Program of Innovation 2030 on Smart Ocean, Zhejiang University
文摘The heat content(HC)of water masses on the Ross Sea continental shelf plays an important role in regulating the circulations and the basal melting of the Ross Ice Shelf(RIS).Yet,the evolution of the HC on the Ross Sea continental shelf is still not clear due to the sparsity of observations.By employing a coupled regional ocean-sea ice-ice shelf model for the Ross Sea,this study analyzes the heat budget of water masses over the continental shelf and in the RIS cavity.According to the topographic features and the HC density,the continental shelf region is divided into 17 subdomains.The heat budget of the middle layer for every subdomain is analyzed.In addition,the heat budget for the RIS cavity is assessed for the first time.Owing to Modified Circumpolar Deep Water intrusion,water masses over the eastern shelf are warmer than over the western shelf,with the coldest water identified in the southwestern inner shelf.The horizontal heat flux mainly provides heat to the continental shelf,while the atmospheric forcing tends to warm up the ocean during the ice-melting period and cool down the ocean during the ice-freezing period.The vertical heat flux is generally upward and transports heat from the deep layer to the upper layer.In the RIS cavity,the seasonal cycle of the HC is dominated by the horizontal flux across the RIS front rather than the basal thermal forcing of the RIS.
基金supported by the National Natural Science Foun-dation of China(52421002,U24B6001,52204019,and 52192624)the Open Foundation of the Shanxi Key Laboratory of Carbon Dioxide Sequestration and Enhanced Oil Recovery。
文摘Medium-high maturity continental shale oil is one of the hydrocarbon resources with the most potential for successful development in China.Nevertheless,the unique geological conditions of a multi-lithologic superposition shield the vertical propagation of hydraulic fractures and limit the longitudinal reconstruction in reservoirs,posing a great challenge for large-scale volumetric fracturing.Radial wellbore crosslayer fracturing,which transforms the interaction between the hydraulic fractures and lithologic interface into longitudinal multilayer competitive initiation,could provide a potential solution for this engineering challenge.To determine the longitudinal propagation behaviors of fractures guided by radial wellbores,true triaxial fracturing experiments were performed on multilayer shale-sandstone samples,with a focus on the injection pressure response,fracture morphology,and cross-layer pattern.The effects of the radial borehole length L,vertical stress difference K_(v),injection rate Q,and viscosity m of the fracturing fluid were analyzed.The results indicate that radial wellbores can greatly facilitate fracture initiation and cross-layer propagation.Unlike conventional hydraulic fracturing,there are two distinct fracture propagation patterns in radial wellbore fracturing:cross-layering and skip-layering.The fracture height guided by a radial wellbore is positively correlated with K_(v),Q,and m.Increasing these parameters causes a shift in the fracture initiation from a single root to an asynchronous root/toe end and can improve the cross-layer propagation capacity.Critical parameter thresholds exist for fracture propagation through and across interlayers under the guidance of radial boreholes.A parameter combination of critical cross-layering/skip-layering or alternating displacement/viscosity is recommended to simultaneously improve the fracture height and degree of lateral activation.The degree of correlation of different parameters with the vertical fracture height can be written as L>Q/m>K_(v).Increasing the radial wellbore length can effectively facilitate fracture cross-/skip-layer propagation and reduce the critical threshold of injection parameters,which is conducive to maximizing the stimulated reservoir volume.
基金Supported by the National Science and Technology Major Project(2017ZX05001)CNPC Technology Project(2023YQX20111).
文摘To address the discrepancies between well and seismic data in stratigraphic correlation of the Triassic Yanchang Formation in the Ordos Basin,NW China,traditional stratigraphic classification schemes,the latest 3D seismic and drilling data,and reservoir sections are thoroughly investigated.Guided by the theory of sequence stratigraphy,the progradational sequence stratigraphic framework of the Yanchang Formation is systematically constructed to elucidate new deposition mechanisms in the depressed lacustrine basin,and it has been successfully applied to the exploration and development practices in the Qingcheng Oilfield.Key findings are obtained in three aspects.First,the seismic progradational reflections,marker tuff beds,and condensed sections of flooding surfaces in the Yanchang Formation are consistent and isochronous.Using flooding surface markers as a reference,a progradational sequence stratigraphic architecture is reconstructed for the middle-upper part of Yanchang Formation,and divided into seven clinoform units(CF1-CF7).Second,progradation predominantly occurs in semi-deep to deep lake environments,with the depositional center not always coinciding with the thickest strata.The lacustrine basin underwent an evolution of“oscillatory regression-progradational infilling-multi-phase superimposition”.Third,the case study of Qingcheng Oilfield reveals that the major pay zones consist of“isochronous but heterochronous”gravity-flow sandstone complexes.Guided by the progradational sequence stratigraphic architecture,horizontal well oil-layer penetration rates remain above 82%.The progradational sequence stratigraphic architecture and associated geological insights are more consistent with the sedimentary infilling mechanisms of large-scale continental depressed lacustrine basins and actual drilling results.The research results provide crucial theoretical and technical support for subsequent refined exploration and development of the Yanchang Formation,and are expected to offer a reference for research and production practice in similar continental lacustrine basins.
文摘1 Introduction The Maritime Silk Road, once a historic network of trade routes that connected continents and facilitated centuries of cultural and economic exchange, has become a region of profound scientific importance. Stretching from East Asia to Europe and Africa, its marine environments are among the most complex and dynamic on Earth. This region encompasses diverse geological settings, including tectonically active zones, varied sedimentary basins, and extensive continental shelves. These features make it a unique natural laboratory for studying various geological and geophysical processes.
基金Supported by the National Science and Technology Major Project of China(2024ZD1400101)China National Key Research and Development Project(2022YFF0801204)Major Science and Technology Project of CNPC(2023ZZ15YJ01,2021DJ0702)。
文摘Guided by the fundamental principles of the whole petroleum system,the control of tectonism,sedimentation,and diagenesis on hydrocarbon accumulation in a rifted basin is studied using the data of petroleum geology and exploration of the second member of the Paleogene Kongdian Formation(Kong-2 Member)in the Cangdong Sag,Bohai Bay Basin,China.It is clarified that the circle structure and circle effects are the marked features of a continental fault petroliferous basin,and they govern the orderly distribution of conventional and unconventional hydrocarbons in the whole petroleum systems of the rifted basin.Tectonic circle zones control sedimentary circle zones,while sedimentary circle zones and diagenetic circle zones control the spatial distribution of favorable reservoirs,thereby determining the orderly distribution of hydrocarbon accumulations in various circles.A model for the integrated,systematic accumulation of conventional and unconventional hydrocarbons under a multi-circle structure of the whole petroleum system of continental rifted basin has been developed.It reveals that each sag of the rifted basin is an independent whole petroleum system and circle system,which encompasses multiple orderly circles of conventional and unconventional hydrocarbons controlled by the same source kitchen.From the outer circle to the middle circle and then to the inner circle,there is an orderly transition from structural and stratigraphic reservoirs,to lithological and structural-lithological reservoirs,and finally to tight oil/gas and shale oil/gas enrichment zones.The significant feature of the whole petroleum system is the orderly control of hydrocarbons by multi-circle stratigraphic coupling,with the integrated,orderly distribution of conventional and unconventional reserves being the inevitable result of the multi-layered interaction within the whole petroleum system.This concept of multi-circle stratigraphic coupling for the orderly,integrated accumulation of conventional and unconventional hydrocarbons has guided significant breakthroughs in the overall,three-dimensional exploration and shale oil exploration in the Cangdong Sag.
文摘The Pamir Plateau,located at the western syntaxis of the Himalayan-Tibetan orogenic belt,serves as a crucial natural laboratory for investigating ongoing continental collision and associated geodynamic processes(Schneider et al.,2019;Kumar et al.,2022;Murodov et al.,2022;Bloch et al.,2023).As a primary convergence front between the Indian and Eurasian plates,this region exhibits extreme crustal shortening,significant uplift,and deep seismicity that extends to depths of~300 km beneath the Hindu Kush.Understanding the deep structure,dynamics,and crust-mantle interactions beneath the Pamir is essential for deciphering the tectonic evolution of the Asian continent and for assessing resource potential and geohazard mitigation.
文摘The signing of the African Continental Free Trade Area(AfCFTA)in Kigali,Rwanda,on 21 March 2018 spurred a wave of optimism in street markets and corporate boardrooms alike.The 44 countries joining this single market pledged to remove tariffs on 90 percent of goods,knitting economies together in an unprecedented fashion.
基金Supported by the Prospective Basic Research Project of CNOOC China Limited(KJQZ-2023-2001)Major Science and Technology Project of CNOOC(KJGG2022-0103-03).
文摘Based on a set of high-resolution 3D seismic data from the northern continental margin of the South China Sea,the lithospheric structure,thinning mechanisms and related syn-rift tectonic deformation response processes in the crustal necking zone in the deepwater area of the Pearl River Mouth Basin were systematically analyzed,and the petroleum geological significance was discussed.The necking zone investigated in the study is located in the Baiyun Sag and Kaiping Sag in the deepwater area of the Pearl River Mouth Basin.These areas show extreme crustal thinned geometries of central thinning and flank thickening,characterized by multi-level and multi-dipping detachment fault systems.The necking zone exhibits pronounced lateral heterogeneity in structural architectures,which can be classified into four types of thinned crustal architectures,i.e.the wedge-shaped extremely thinned crustal architecture in the Baiyun Main Sub-sag,dumbbell-shaped moderately thinned crustal architecture in the Baiyun West Sub-sag,box-shaped weakly thinned crustal architecture in eastern Baiyun Sag,and metamorphic core complex weakly thinned crustal architecture in the Kaiping Sag.This shows great variations in the degree and style of crustal thinning,types of detachment faults,distribution of syn-rift sedimentary sequences,and intensity of magmatism.The thinning of the necking zone is controlled by the heterogeneous rheological stratification of lithosphere,intensity of mantle-derived magmatism,and deformation modes of detachment faults.The syn-rift tectonic deformation of the necking zone evolved through three phases,i.e.uniform stretching during the early Wenchang Formation deposition period,necking during the late Wenchang Formation deposition period,and hyperextension during the Enping Formation deposition period.The crustal thinning extent and architectural differentiation in these phases were primarily controlled by three distinct mechanisms,i.e.the pure shear deformation activation of pre-existing thrust faults,the simple shear deformation of crust-mantle and inter-crust detachment faults,and differential coupling of lower crustal flow and ductile domes with main detachment faults.The hydrocarbon accumulation and enrichment in the necking zone exhibit marked spatial heterogeneity.Four distinct crustal thinned architecture-hydrocarbon accumulation models were identified in this study.The hydrocarbon accumulations in the shallow part exhibit significant correlations with their deep crustal thinned architectures.The unique lithospheric structure and deformation process predominantly control the favorable hydrocarbon accumulation zones with excellent source-fault-ridge-sand configurations,which is critical to reservoir-forming.The most promising exploration targets are mainly identified on the uplift zones and their seaward-dipping flanks associated with the middle and lower crustal domes.This research provides additional insights into lithospheric thinning-breakup process at intermediate continental margins of marine sedimentary basins,being significant for guiding the deepwater petroleum exploration in the Pearl River Mouth Basin.
基金supported by grants from the National Science Foundation of the USA.
文摘East Asian continental tectonics challenges the plate tectonics paradigm with its diffuse intraplate deformation,magmatism,and earthquakes.Despite extensive studies,fundamental questions persist.This review examines ten critical questions of East Asian tectonics,including the thickness of the continental lithosphere,the origin of the North–South Gravity Lineament,and the northern extent of the Indian plate beneath the Tibetan Plateau.Additional questions address the Tibetan Plateau's lateral growth,the Tianshan mountain building,the mantle flow in response to the Indo-Asian collision,and the formation of the Shanxi Rift.The review also explores the subduction along the eastern margins of the East Asian Continent and the origins of the Changbaishan volcanic field,the destruction of the North China Craton,and the development of the Mesozoic Large Granitic Province in South China.Originally presented at the DEEP2024 workshop to stimulate discussion of how SinoProbe-II research initiatives could advance our understanding of Asian tectonics,this review provides context for each question,summarizes current knowledge,and identifies promising research directions.
基金the Centre for Marine Living Resources and Ecology (CMLRE),Ministry of Earth Sciences (MoES), Kochi, Government of India, for the support of crew ‘FORV Sagar Sampada’Funding was provided by the Centre for Marine Living Resources and Ecology (CMLRE), Ministry of Earth Sciences (MoES), Kochi, Government of India
文摘Two new free-living marine nematode species belonging to the genus Tricoma Cobb,1894(Desmoscolecidae)are identi-fied from the continental shelf region of the Bay of Bengal.Tricoma ajmalia sp.nov.is characterized by the number of main rings(84 male and 85 female),the arrangement of somatic setae,the head shape with broadly truncated end,the relatively long cephalic setae(69%-73%of corresponding head diameter),the amphids extending up to second main ring,slender spicules slightly curved and gu-berbaculum with dorsocaudally directed apophyses.The second new species,Tricoma sampadansis sp.nov.is characterized by the number of rings(64),the arrangement of somatic setae(14-13 subdorsal,16 subvenral),the head shape with broadly truncated end,the relatively long cephalic setae(75%corresponding head diameter),the amphidial fovea extending over first main ring,anterioirly bent spicules and gubernaculum with hooked proximal end.An updated valid species list of Tricoma is also presented.
基金supported by National Natural Science Foundation of China(42272137 and U24A20592)the Strategic Cooperation Technology Projecti of CNPC and CUPB(ZLZX2020-01-05)AAPG Foundation Grants-in-Aid.
文摘Mobility is a crucial metric for assessing sweet spots of continental shale oil.However,due to the complexity of shale oil reservoirs characteristics and the lack of systematic analyses of factors influencing mobility,the difference in shale oil mobility under multiple lithofacies control remains unclear,causing significant challenges for mobility evaluation and sweet spot prediction.This study examines continental shales of the Fengcheng Formation in the Mahu Sag,employing scanning electron microscopy(SEM),nitrogen adsorption(NA),nuclear magnetic resonance(NMR),spontaneous imbibition(SI),and contact angle measurements(CAM)to investigate the pore structure,connectivity,and wettability properties of different lithofacies shale.Quantitative analyses of shale movable oil content and saturation were conducted using multistep temperature pyrolysis(MTP)and NMR centrifugation techniques.Furthermore,the influence of reservoir characteristics,geochemical characteristics,and lamination development on shale oil mobility were discussed.Results indicate that larger pore diameter,higher imbibition slopes,and lower fractal dimensions of movable fluid pores(D2)correspond to higher movable oil saturation.Organic matter exerts a dual effect on shale movable oil content.When the TOC is below a threshold,the movable oil content gradually increases with TOC.Laminations exhibit favorable reservoir properties and light oil enrichment,enhancing shale oil mobility.Massive siltstone(MS)develops interconnected intergranular pores with the best pore structure and connectivity,the lowest D2 values,and the highest shale oil mobility.Laminated felsic shale(LFS)and laminated calcareous shale(LCS)exhibit moderate mobility,where the development of microfractures enhances fluid flow by connecting isolated pores into pore-fracture networks.In contrast,massive felsic shale(MFS)and bedded felsic shale(BFS)primarily develop intragranular dissolution pores with more complex structures and poorer connectivity,resulting in weaker mobility.A more accurate approach for assessing shale oil mobility has been presented,taking into account both total oil content and movable oil saturation.More importantly,this study establishes a comprehensive conceptual model illustrating the potential relationships among shale lithofacies,reservoir characteristics,and movable oil flow space in the study area.This research not only provides a systematic approach for assessing shale oil mobility but also deepens the understanding of flow mechanisms of continental shale oil,offering theoretical guidance for optimizing sweet spots in the Fengcheng Formation shale oil reservoirs of the Mahu Sag.
基金supported by the research award project RI/0220-10000618-001 to Sheth from the Industrial Research and Consultancy Centre(IRCC)IIT Bombay.Shekhar and Astha were supported by Prime Minister’s Research Fellowships(PMRF,File Nos.1303100 and 1303103,respectively)+4 种基金Naik was initially supported by an IIT Bombay Institute Post-Doctoral Fellowship(File No.HR-1(HRM-1)/Rect/33/2022/20003002)subsequently by a Goa State Research Foundation Post-doctoral Fellowship(File No.PDF2024003)We express our sincere gratitude to Prof.N.Prabhakar for kindly granting us access to the WD-XRF spectrometry facility(SIP ProjectWBS Code:IN/22-1111039E-01)the ICP-MS facility,and the SERB-funded EPMA National Facility(IRPHA Grant No.IR/S4/ESF-16/2009(G))in the Department of Earth Sciences,IIT Bombay.
文摘Large-scale Danian-age(post-K/Pg boundary)Deccan magmatism is well known from the Mumbai metropolitan area,located in the structurally complex Panvel flexure zone along the western Indian rifted continental margin.This compositionally diverse late-Deccan magmatic suite contains subaerial tholeiitic lavas and dykes typical of the main Deccan province,with many features atypical of the Deccan,such as spilitic pillow lavas,“intertrappean”sediments(often containing considerable volcanic ash),rhyolitic lavas and tuffs,gabbro-granophyre intrusions,and trachyte intrusions containing alkali basalt enclaves.Most of these units,previously dated at 62.5 Ma to 61 Ma,are contemporaneous with or slightly postdate the 62.5 Ma India-Seychelles continental breakup and Panvel flexure formation.In the Dongri-Uttan area,two samples of a>50-m-thick,columnar-jointed rhyolite from the Darkhan Quarry and from a section behind the current Uttan Sagari Police Station have previously been dated at 62.6±0.6 Ma and 62.9±0.2 Ma(^(40)Ar/^(39)Ar,2r errors).New exposures reveal that these two statistically indistinguishable 40 Ar/39 Ar ages correspond to two distinct rhyolite units,separated by well-bedded silicic ash.The columnar rhyolites are microcrystalline,composed of quartz and alkali feldspar,with rare small(1–2 mm),altered feldspar phenocrysts,and no recognisable relict vitroclasts.Given the westerly structural dip,most of their lateral extent is submerged under the Arabian Sea,and we consider them to be possible flood rhyolite lavas.We interpret the ash beds,composed of pumice clasts and glass shards,as a low-grade(nonwelded)vitric ash,derived from a possibly distal Plinian eruption and deposited by fallout.The lavas and ash are peraluminous rhyolites.The lavas are Sr-Ba-poor and Rb-Zr-Nb-rich,and show“seagull-shaped”rare earth element patterns with deep negative europium anomalies.These crystal-poor lavas are“hot-dry-reduced”rhyolites typical of intraplate,continental rift and rifted margin settings.The very different high-field strength element contents of the lavas and the ash indicate compositionally distinct magma batches.The 62.5 Ma Dongri-Uttan sequence provides clear evidence for rapid silicic eruptions of effusive and explosive nature,alternating with each other and sourced from distinct magma chambers and eruptive vents.A newly identified,highly feldspar-phyric trachyte intrusion marks the last phase of magmatic activity in the area,corresponding with late-stage trachyte-syenite intrusions exposed in coastal western India and the Seychelles,and shows that the Mumbai rhyolites and trachytes form a compositional continuum.
