Ghana has four sedimentary basins,but attention has mostly been concentrated on the Tano Basin.This preference among potential investors is largely due to the fact that it has been extensively studied and also its est...Ghana has four sedimentary basins,but attention has mostly been concentrated on the Tano Basin.This preference among potential investors is largely due to the fact that it has been extensively studied and also its established oil and gas reserves,which have facilitated the discovery and development of major fields such as the Jubilee Field.In contrast,the Saltpond,Keta,and Voltaian basins have not undergone the same level of exploration and research,thereby making them less attractive to investors.A comparative analysis of the research conducted on the Tano Basin and the other basins is necessary to identify research opportunities that could enhance understanding of these less-explored basins and increase investor interests.The findings indicate that the Tano Basin requires minimal further exploration,while studies on the Saltpond,Keta,and Voltaian basins have primarily focused on sedimentological and geochemical analyses,offering valuable but limited insights into their petroleum systems and hydrocarbon potential.Unlocking Ghana's hydrocarbon potential demands tailored studies for each basin.In the Tano Basin,the key to sustaining and optimizing production lies in advanced seismic reprocessing,pre-stack depth migration,4D reservoir monitoring,and machine-learning-assisted reservoir characterization to address deepwater complexity and compartmentalization.Revitalizing the Saltpond Basin demands updated petroleum system evaluation through modern geochemical techniques,reprocessed 2D/3D seismic data,and comprehensive 1D–3D basin modeling to clarify trap integrity and overlooked plays.In the underexplored Accra–Keta Basin,high-resolution seismic imaging,sequence stratigraphic mapping,and full petroleum system modeling are essential to define reservoir intervals and assess charge potential.For the Voltaian Basin,a deep seismic profiling,integrated geological mapping,source-rock evaluation,and analog-based reservoir/seal studies are required to evaluate its hydrocarbon potential.These targeted efforts are key to de-risking and advancing exploration.An integrated approach is vital for gaining a deeper understanding of the petroleum system elements in these basins.This will not only expand scientific knowledge and inform decision-making at the highest levels but also provide a strong foundation for future exploration,development,and efficient exploitation of hydrocarbon resources.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
By investigating the evolution of shale gas generation,storage,adjustment and accumulation under different structural settings in superimposed basins,this study elucidates the differential accumulation mechanisms of s...By investigating the evolution of shale gas generation,storage,adjustment and accumulation under different structural settings in superimposed basins,this study elucidates the differential accumulation mechanisms of shale gas.An improved evaluation method of shale gas content evolution in superimposed basins is proposed.This method incorporates the coupling effect of key geological factors such as temperature,pressure,organic matter abundance,maturity,and pore characteristics on the content and occurrence state of shale gas,as well as the configuration relationship between shale gas generation and storage throughout geological history.Using this approach,the gas evolution histories of the Longmaxi Formation shales in wells N201 and PY1 are reconstructed under varying geological conditions.The Longmaxi Formation shales in these wells are dominated by typeⅠkerogen,with original total organic carbon(TOC_(o))contents of 6.20 wt% and 4.92 wt%,respectively,indicating differences in the initial material basis for gas generation.At the maximum burial depth of approximately 5000 m,the Longmaxi Formation shale in well N201 exhibits a formation pressure coefficient of 2.05,an organic matter maturity of 2.2%,and organic pores accounting for 68%of the total porosity.The gas generation quantity(Q_(g))reaches 19.24 m^(3)/t,while the gas storage capacity(Q_(s))is 4.30 m^(3)/t.The actual total gas content(Q_(a)),constrained by Q_(s),is 4.30 m^(3)/t,with free gas comprising 94%.Following relatively moderate tectonic uplift,the Q_(a) in well N201 decreases to 4.03 m^(3)/t,with free gas accounting for 63%.In contrast,the Longmaxi Formation shale in well PY1 reached a maximum burial depth of 6300 m,associated with a formation pressure coefficient of 1.62,organic matter maturity of 2.5%,and organic pore proportion of 67%.Here,Q_(g) is 16.87 m^(3)/t,and both Q_(s) and Q_(a) are 3.65 m^(3)/t,with free gas accounting for 98%.After intense tectonic uplift,Q_(a) declines to 2.72 m^(3)/t,and the proportion of free gas drops to51%.Finally,a four-stage differential accumulation model of shale gas is established:Slow gas generation and only adsorbed gas occur in stageⅠ,which is primarily controlled by TOC content;both adsorbed gas and free gas present in stageⅡ,with free gas becoming dominant;rapid gas generation and free gas predominance are controlled by temperature and porosity in stageⅢ;and gas adjustment and accumulation are primarily controlled by temperature and pressure in stageⅣ.展开更多
The hydrological system in Central Asia is highly sensitive to global climate change,significantly affecting water supply and energy production.In Tajikistan,the Vakhsh River—one of the main tributaries of the Amu Da...The hydrological system in Central Asia is highly sensitive to global climate change,significantly affecting water supply and energy production.In Tajikistan,the Vakhsh River—one of the main tributaries of the Amu Darya—plays a key role in the region’s hydropower and irrigation.However,research on long-term hydrological changes in its two top large basins—the Surkhob and Khingov river basins—remains limited.Therefore,this study analyzed long-term climate and hydrological changes in the Vakhsh River,including its main tributaries—the Surkhob and Khingov rivers—which are vital for the water resource management in Tajikistan and even in Central Asia.Using long-term hydrometeorological observations,the change trends of temperature(1933–2020),precipitation(1970–2020),and runoff(1940–2018)were examined to assess the impact of climate change on the regional water resources.The analysis revealed the occurrence of significant warming and a spatially uneven increase in precipitation.The temperature changes across three climatic periods(1933–1960,1960–1990,and 1990–2020)indicated that there was a transition from baseline level to accelerated warming.The precipitation showed a 2.99 mm/a increase in the Khingov River Basin and a 2.80 mm/a increase in the Surkhob River Basin during 1970–2020.Moreover,there was a gradual shift toward wetter conditions in recent decades.Despite the relatively stable annual mean runoff,seasonal redistribution occurred,with increased runoff in spring and reduced runoff in summer,due to the compensation of glacier melting.Moreover,this study forecasted runoff change during 2019–2040 using the exponential triple smoothing(ETS)method and revealed the occurrence of alternating wet and dry phases,emphasizing the sensitivity of the Vakhsh River Basin’s hydrological system to climate change and the necessity of adaptive water resource management in mountainous regions of Central Asia.Therefore,this study can provide evidence-based insights that are critical for future water resources planning,climate-resilient hydropower development,and regional adaptation strategies in climate-vulnerable basins in Central Asia.展开更多
The geothermal resources in China are primarily found in its sedimentary basins,particularly in the large basins located in eastern China,which hold significant potential for geothermal energy development.The Songliao...The geothermal resources in China are primarily found in its sedimentary basins,particularly in the large basins located in eastern China,which hold significant potential for geothermal energy development.The Songliao,North China,and Zhangzhou basins are of special interest due to their considerable exploration depths,extensive development history,and high levels of research activity.This study focuses on the three basins to analyze their thermal reservoir characteristics in eastern China.Between 2017 and 2023,the research team carried out a comprehensive analysis involving deep boreholes that exceeded 4000 m in depth within these three basins.They meticulously created detailed physical profiles that captured essential characteristics such as porosity,permeability,and thermal properties,reaching down to the basement of each basin.The findings indicated that variations in thermal conductivity within shallow geotechnical layers significantly influence the redistribution of deep thermal energy in the upper layers of the earth.Furthermore,differences in physical properties notably affect heat transport processes.The research proposes distinct heat models tailored for each basin:For the Songliao Basin,a low-permeability model with homogeneous thermal properties is constructed;for the North China Basin,high permeability and thermal conductivity layers are highlighted;and a fracture network controlling water and heat is presented in the Zhangzhou Basin.To elucidate the thermal structure of these basins,the Curie surface and Moho surface were analyzed.The shallow Curie surface indicates ongoing intense thermal activity stemming from crustal heat sources,while a shallow Moho surface signifies historical vigorous mantle thermal activity associated with mantle source heat production.Furthermore,the research evaluates the geothermal resources and the potential for carbon emission reduction in these basins.Total volume of exploitable geothermal fluid is estimated to be 76.9×10^(9) m^(3)/a,corresponding to an annual renewable geothermal energy 1.47×10^(16)k J.The implementation of geothermal energy could lead to a reduction in annual CO_(2)emissions by nearly 2×10^(9) t,which constitutes about 17.4%of China’s national carbon emissions in 2022.This estimation provides invaluable theoretical insights and data support for geothermal exploration and sustainable development in eastern China.展开更多
In a re-examination of the Neogene stratigraphy of the Uşak,Güre,and Selendi basins of western Anatolia,western Turkey,the stratigraphic position of the previously definedİnay Group is revised,which was previousl...In a re-examination of the Neogene stratigraphy of the Uşak,Güre,and Selendi basins of western Anatolia,western Turkey,the stratigraphic position of the previously definedİnay Group is revised,which was previously considered to be of the Middle Miocene age.Based on mammalian biochronology and stratigraphic relationships,two sequences are identified,separated by conformable/transitional contacts within the former group:the Middle Miocene Güre Group is composed of the FakılıFormation,characterized by alluvial fan deposits,and the lacustrine Derbent Formation.Radiometric dating of alkaline volcanics laterally associated with Güre Group sediments in the Uşak and Güre basins,and mammalian fossils re-evaluated into the MN5-6 biozones in the Selendi Basin,indicate early Middle Miocene.Considering the stratigraphic relationship with the overlying early Late Mioceneİnay Group as redefined,we estimate that the Güre Group was deposited in the Middle Miocene.Theİnay Group is characterized by a lateral-vertical transition from alluvial deposits of the Ahmetler Formation to the overlying lacustrine Ulubey Formation.An MN9-10 fauna,containing deinotheres,was found within the latter formation.展开更多
The development of sedimentary layers in offshore salt-bearing basins in the central segment of west Africa is closely linked to elements such as faults,igneous rocks and crustal thickness.To investigate their spatial...The development of sedimentary layers in offshore salt-bearing basins in the central segment of west Africa is closely linked to elements such as faults,igneous rocks and crustal thickness.To investigate their spatial relationships,we analyzed gravity and magnetic data in the oceanic areas,and employed edge detection,correlation analysis,and inversion techniques to study the characteristics of these geological elements.Our findings revealed numerous faults and igneous rocks in the crust underlying these non-volcanic continental margins,and these faults and igneous rocks continued to indirectly influence basin sedimentation since the rift period.On the basis of the thickness of the crust and sedimentary layers,we classified the offshore basins into four types of secondary structural units.Combined with the characteristics of faults and igneous rocks,we concluded that the exhumed bulges within the Western Uplift Zone are favorable for oil and gas exploration.展开更多
This study examines the molecular and isotopic composition of 193 gas samples collected from oil and gas fields across Colombia's onshore basins with active hydrocarbon production.Comparative analyses were conduct...This study examines the molecular and isotopic composition of 193 gas samples collected from oil and gas fields across Colombia's onshore basins with active hydrocarbon production.Comparative analyses were conducted on both isotopic and molecular compositions across the Lower Magdalena Basin(LMB),Middle Magdalena Basin(MMB),Upper Magdalena Basin(UMB),Putumayo Cagu an Basin(PUTCAB),Catatumbo Basin(CATB),Eastern Llanos Basin(LLAB),and Eastern Cordillera Basin(ECB).The primary objectives were to classify the gases produced,characterize their origins,assess transformation processes such as biodegradation and migration,and analyze the statistical distribution patterns of their components.This geochemical characterization aims to support the discovery of new reserves for both natural gas(NG)and liquefied petroleum gas(LPG),given Colombia's potential risk of diminished energy selfsufficiency in gas resources.The basins under study produce dry gas,wet gas,and liquefied petroleum gas(LPG/C_(3+)),all associated with oil and gas fields of commercial hydrocarbon production.Notably,the LLAB contains the highest proportions of heavy isotopic carbon and C_(3+)(LPG)concentrations,whereas LMB is characterized by isotopically lighter methane,indicative of dry gas predominance.Results suggest a predominantly thermogenic origin for the gases studied,generated within the oil and gas windows,with several samples originating from secondary oil cracking,while some samples from LMB display a likely biogenic origin.Additionally,evidence of gas migration and biodegradation was observed in a significant subset of samples.The analysis of statistical distributions and compositional trends reveals a prevalent high methane content,with substantial C_(2)-C_(5)(C_(2+))gas concentrations across all basins studied.This composition underscores the potential for both natural gas(NG)and LPG production.The C_(3+)(LPG)content varies between 1%and 92%,with 35%of the samples containing less than 5%LPG.High original gas-in-place(OGIP)volumes and substantial LPG content in the Eastern Llanos foothills,encompassing fields such as Cusiana and Cupiagua,highlight the prospective potential of this region.Near-field exploration could further add reserves of both NG and LPG.展开更多
Scientific understanding of the trade-offs between services is crucial for the scientific management and protection of ecosystems and the formulation of resource management policies.This study integrated meteorologica...Scientific understanding of the trade-offs between services is crucial for the scientific management and protection of ecosystems and the formulation of resource management policies.This study integrated meteorological,land use,and soil data to assess the ecosystem services,namely,water yield(WY),soil erosion(SE),and carbon sinks(CS),in peak-cluster depression basins on the Sino-Vietnamese border in China during 2000-2020.It analyzed the trade-offs and synergistic relationships among the three ecosystem services and their time-lag effects and driving mechanisms with the help of pixel-by-pixel time-lag intercorrelation and geographical de-tector methods.Results show that:1)from 2000 to 2020,the key ecosystem service indicators in the peak-cluster depression basins on the Sino-Vietnamese border in China demonstrated a significant and synergistic trend of positive change.The WY increased at a rate of 11.99 mm/yr,CS increased at a rate of 2.44 g C/(m^(2)∙yr),and SE decreased at a rate of 0.06 t/(ha∙yr).2)Most areas showed a synergistic relationship across the three ecosystem services,and the areas with a trade-off relationship were mostly concentrated in Baise City and the southwest of Chongzuo City,Guangxi.3)The time-lag effect between SE and WY was mostly concentrated in 0 yr,that between SE and CS was mostly concentrated in 5 yr,and that between CS and WY was mostly concentrated in 1 yr.4)Population density was the controlling factor between SE and WY.Vegetation coverage factor is the main controlling factor between SE and CS.The lithologic factor is the main controlling factor between CS and WY.Studying the trade-off relationship of ecosystem services at spatial and tem-poral scales on the Sino-Vietnamese border in China karst areas can provide a basis for regional ecological construction and develop-ment strategies,and it is conducive to meeting regional interest needs,maximizing comprehensive benefits,balancing the ecological en-vironment,and achieving regional sustainable development.展开更多
The Ross Sea basins,shaped by Late Cretaceous and Cenozoic extension within the crust of the Ross Sea,represent key regions for understanding continental rifting processes.However,the dynamic mechanisms driving the tr...The Ross Sea basins,shaped by Late Cretaceous and Cenozoic extension within the crust of the Ross Sea,represent key regions for understanding continental rifting processes.However,the dynamic mechanisms driving the transition from diffuse extension to focused extension in these basins remain poorly understood.Here,we provide a comprehensive model of crustal extension in the Ross Sea basins,detailing the kinematic and dynamic evolution from 100 Ma to the present on the basis of published finite rotation poles.Our model illuminates the complex relative motions between the West Antarctic and East Antarctic Plates and quantifies the crustal strain rates associated with their relative movements.We show that West Antarctica began to move away slowly from the East Antarctic and rotated clockwise at approximately 53 Ma,and the motion progressively decreased until it ceased at approximately 11 Ma.This kinematic shift temporally coincided with the onset of focused rifting,indicating a transition from broadly distributed extension in the eastern Ross Sea to localized deformation in the western basin.Time-resolved strain rate fields further reveal several hundred kilometers of total crustal extension,suggesting a primary influence of evolving plate motions over passive lithospheric weakening.These findings refine the tectonic history of the Ross Sea and provide a reproducible framework linking rift basin evolution to global plate motion.展开更多
The distribution of igneous rocks is closely related to hydrocarbon resources.This study utilized high-precision gravity,magnetic,and rock physical property data,employing gravity-magnetic field fusion technology and ...The distribution of igneous rocks is closely related to hydrocarbon resources.This study utilized high-precision gravity,magnetic,and rock physical property data,employing gravity-magnetic field fusion technology and Euler deconvolution technology.The objective was to identify the distribution of igneous rocks in the China Seas and neighboring regions and investigate their relationships with petroliferous basins.Our results reveal that igneous rocks are widely scattered throughout the China Seas and neighboring regions,with the highest concentration in the northwest(NW)and the second highest concentration in the east-northeast(ENE).The largest-scale igneous rocks are those with a north-south(N-S)orientation,followed by those with northeast(NE),NW,and ENE orientations.The depths of igneous rocks within petroliferous basins typically range from 3 km to 9 km and are associated with hydrocarbon resource distributions characterized by deep oil and shallow gas.The proportions of igneous rocks in different types of basins exhibit varying correlations with the total hydrocarbon resources.In particular,the proportion of igneous rocks in rift-type basins in the China Seas exhibits a strong linear correlation with the total hydrocarbon resources.These research findings provide valuable guidance for studying the relationship between igneous rock distribution and petroliferous basins,offering insights that can inform future hydrocarbon exploration endeavors.展开更多
It is an important standard to judge the flood disaster in the basin whether the rainfall at the flood-inducing interface is reached.In this paper,the Xin'anjiang model,Topmodel model and SCS model were selected t...It is an important standard to judge the flood disaster in the basin whether the rainfall at the flood-inducing interface is reached.In this paper,the Xin'anjiang model,Topmodel model and SCS model were selected to calculate and compare the rainfall at the flood-inducing interface in the Zhanghe Reservoir basin in Hubei Province.The results showed that average relative error and average absolute error of Xin'anjiang model were-3.36%and-21.46×10^(5)m^(3),which were the minimum,followed by Topmodel model with 5.72%and 26.22×10^(5)m^(3),SCS model with 11.33%and 58.13×10^(5)m^(3).The minimum absolute error of the three hydrological models in calculating the rainfall at the critical interface was 3.26 mm,while the maximum was 49.24 mm.When the initial water level exceeded 120 m,the difference among the three models in calculating the rainfall at the critical interface became more and more obvious.When the reservoir water level was lower than 120 m,it mainly referred to the calculation results of Xin'anjiang model.When the reservoir water level was higher than 120 m,it mainly referred to the calculation results of Topmodel model.The research conclusion can provide reference for small and medium-sized basins selecting hydrological model to calculate the rainfall at the flood-inducing interface.展开更多
Offshore carbon dioxide(CO_(2))geological storage is a promising strategy for reducing carbon emissions and supporting sustainable development in coastal regions within a carbon neutrality framework.However,only a few...Offshore carbon dioxide(CO_(2))geological storage is a promising strategy for reducing carbon emissions and supporting sustainable development in coastal regions within a carbon neutrality framework.However,only a few works have focused on offshore basins in China.To address this gap,this study established a dual indicator system that comprises necessary and critical indices and is integrated with the analytic hierarchy process.A coupled analysis was then performed to evaluate the suitability of 10 offshore sedimentary basins in China for CO_(2)geological storage.The necessary indicator system focuses on storage potential,geological conditions,and engineering feasibility.Meanwhile,the critical indicator system emphasizes the safety of storage projects and the viability of drilling operations.Evaluation results revealed that China's offshore basins have undergone two geological evolution stages,namely,the rifting and post-rifting phases,leading to the formation of a dual-layer structure characterized by faulted lower layers and sagged upper layers.These basins have thick and widespread Cenozoic strata,generally low seismic activity,and medium-to-low geothermal gradients.They form five reservoir-caprock systems with favorable geological conditions for CO_(2)storage.The Pearl River Mouth,East China Sea Shelf,and Bohai Basins emerged as primary candidates that offer substantial storage potential to support carbon neutrality goals in the Bohai Rim Economic Zone,Yangtze River Delta Economic Zone,and Guangdong-Hong Kong-Macao Greater Bay Area.The Beibu Gulf and South Yellow Sea Basins were identified as secondary candidates,and the Qiongdongnan and Yinggehai Basins were considered potential alternatives.展开更多
Conventional borehole image log interpretation of linear fractures on volcanic rocks,represented as sinusoids on unwrapped cylinder projections,is relatively straight-forward,however,interpreting non-linear rock struc...Conventional borehole image log interpretation of linear fractures on volcanic rocks,represented as sinusoids on unwrapped cylinder projections,is relatively straight-forward,however,interpreting non-linear rock structures and complex facies geometries can be more challenging.To characterize diverse volcanic paleoenvironments related to the formation of the South American continent,this study presents a new methodology based on image logs,petrography,seismic data,and outcrop analogues.The presented methodology used pseudo-boreholes images generated from outcrop photographs with typical igneous rock features worldwide simulating 2D unwrapped cylinder projections of a 31 cm(12.25 in)diameter well.These synthetic images and standard outcrop photographs were used to define morphological patterns of igneous structures and facies for comparison with wireline borehole image logs from subsurface volcanic and subvolcanic units,providing a“visual scale”for geological evaluation of volcanic facies,significantly enhancing the identification efficiency and reliability of complex geological structures.Our analysis focused on various scales of columnar jointing and pillow lava lobes with additional examples including pahoehoe lava,ignimbrite,hyaloclastite,and various intrusive features in Campos,Santos,and Parnaíba basins in Brazil.This approach increases confidence in the interpretation of subvolcanic,subaerial,and subaqueous deposits.The image log interpretation combined with regional geological knowledge has enabled paleoenvironmental insights into the rift magmatism system related to the breakup of Gondwana with associated implications for hydrocarbon exploration.展开更多
The Bikaner-Nagaur and Barmer Basins(Rajasthan)are the most important petroliferous sedimentary basins in India.For over a decade,the exploration and extraction of hydrocarbons in these basins.Paleocene-Eocene age roc...The Bikaner-Nagaur and Barmer Basins(Rajasthan)are the most important petroliferous sedimentary basins in India.For over a decade,the exploration and extraction of hydrocarbons in these basins.Paleocene-Eocene age rocks bear organic-rich sediments in these basins,including lignite and carbonaceous shale deposits.The present research investigates the source rock properties,petroleum potential and thermal maturity of the carbonaceous shale partings from the lignite mines of Gurha(Bikaner-Nagaur Basin)and Kapurdi(Barmer Basin)using petrographical and geochemical tools.The carbonaceous shales have high organic matter(OM),with considerable total organic carbon(TOC)contents ranging from 13%to 39%.Furthermore,they contain hydrogen-rich kerogen,including types II and II/III,as evidenced by the Rock-Eval and elemental analysis results.The existence of these kerogen types indicates the abundance of reactive(vitrinite and liptinite)macerals.However,the carbonaceous shales from the Bikaner–Nagaur Basin have oil generation potentials,with a high hydrogen index(up to 516 mg HC/g TOC)and a H/C ratio(up to 1.5)along with a significant presence of oil-prone liptinitic macerals.Apart from the geochemical and petrological results,the studied shales have low huminite reflectance(0.31%–0.48%),maximum temperature(S_(2) peak;Tmax)between 419℃ and 429℃,and low production index values(PI:0.01–0.03).These results indicate that these carbonaceous shales contain immature OM,and thereby,they cannot yet release commercial amount of oil.This immaturity level in the studied outcrop section is due to the shallow burial depth.Geochemical proxies further indicate the presence of both oil and gas-prone source rocks.展开更多
In contrast to well-studied rift basins in NE China,the Hailar Basin has received relatively less attention regarding the combined patterns of different types of grabens and half-grabens.This study aims to explore whe...In contrast to well-studied rift basins in NE China,the Hailar Basin has received relatively less attention regarding the combined patterns of different types of grabens and half-grabens.This study aims to explore whether the combined patterns of grabens in the Hailar Basin exhibit similar characteristics to those in other NE China rift basins and to identify the underlying causes.To achieve this,a comprehensive analysis of the major fault systems and the combined patterns of faulted sub-depressions,as well as their controlling mechanisms,was conducted.This analysis utilized the latest 3D seismic data that cover nearly the entire Beier Depression.Three groups of pre-existing fault systems were observed in the basement of the Beier Depression,and they are the NEE-EW-trending fault systems,the NE-trending fault systems,and the NW-trending fault systems.The NEE-EW-trending fault systems were distributed in the central part of the Beier Depression and primarily controlled the sedimentary filling of the Tongbomiao and the Lower Nantun Formations.The NE-trending fault systems were distributed in the southwestern part of the Beier Depression and primarily controlled the sedimentary filling of the Upper Nantun Formations.The NW-trending fault systems were distributed rarely in the Beier Depression.Five kinds of combined patterns of the sub-depressions were developed in the Beier Depression,and they are the parallel,en echelon,face-to-face,back-to-back,and S-shaped combined patterns.They were controlled by the NEE-EW-trending and the NE-trending fault systems with different orientations,arrangements,and activation sequences.展开更多
The Triassic Xujiahe Formation in the slope zone of the Sichuan foreland basin is a new field of continental tight gas exploration in recent years.The fourth member of the Xujiahe Formation(Xu4 Member),the major inter...The Triassic Xujiahe Formation in the slope zone of the Sichuan foreland basin is a new field of continental tight gas exploration in recent years.The fourth member of the Xujiahe Formation(Xu4 Member),the major interval in the Jianyang Block of the Tianfu gas field in the basin,is characterized by considerable buried depth,tight reservoirs,and strong heterogeneity.By using cast thin section,X-ray diffraction(XRD),scanning electron microscopy(SEM),fluid inclusion thermometry,and core analysis,the reservoir rock types,dominant diageneses,diagenetic history,and controls on high-graded reservoirs were investigated.It is found that the Xu4 Member in Jianyang mainly consists of lithic feldspar sandstones and feldspar lithic sandstones,followed by lithic quartz sandstones.High-energy hydrodynamic conditions in the microfacies of underwater distributary channels and mouth bars are beneficial to the preservation of primary pores and the occurrence of secondary pores,and there are no significant differences in petrophysical properties between these two microfacies.Compaction and calcareous cementation are the dominant controls on reservoir porosity decrease in the Xujiahe Formation;corrosion is the major contributor to porosity increase by generating secondary dissolved pores,e.g.intragranular dissolved pores and intergranular dissolved pores,as major reservoir space in the study area.Fracture zones around the faults inside the Xujiahe Formation(fourth‒order faults)are favorable for proximal tight gas accumulation,preservation,and production.The research findings have been successfully applied to explore the Xujiahe Formation in the slope zone of the Sichuan foreland basin.They can be referential for other similar tight sandstone gas accumulations.展开更多
Dynamical systems often exhibit multiple attractors representing significantly different functioning conditions.A global map of attraction basins can offer valuable guidance for stabilizing or transitioning system sta...Dynamical systems often exhibit multiple attractors representing significantly different functioning conditions.A global map of attraction basins can offer valuable guidance for stabilizing or transitioning system states.Such a map can be constructed without prior system knowledge by identifying attractors across a sufficient number of points in the state space.However,determining the attractor for each initial state can be a laborious task.Here,we tackle the challenge of reconstructing attraction basins using as few initial points as possible.In each iteration of our approach,informative points are selected through random seeding and are driven along the current classification boundary,promoting the eventual selection of points that are both diverse and enlightening.The results across various experimental dynamical systems demonstrate that our approach requires fewer points than baseline methods while achieving comparable mapping accuracy.Additionally,the reconstructed map allows us to accurately estimate the minimum escape distance required to transition the system state to a target basin.展开更多
Restoration of denudation thickness is of great significance to understanding tectonic evolution,hydrocarbon migration and accumulation history in petroliferous basins.How to accurately restore and distinguish denudat...Restoration of denudation thickness is of great significance to understanding tectonic evolution,hydrocarbon migration and accumulation history in petroliferous basins.How to accurately restore and distinguish denudation thicknesses in different periods,however,is difficult.With measurements of vitrinite reflectance(Ro)and interval transit time,along with stratigraphic profile comparison,we restored the total denudation thickness of the Cretaceous in the central Sichuan Basin at a depth range of1100-3300 m.The apatite fission track analysis(AFTA)was employed to identify the denudation periods,namely,the Late Yanshanian,Early Himalayan and the Late Himalayan orogenic epochs,and the ratio of their denudation intensity is about 3.8:1:3.9.The denudation thicknesses at different periods provide an important basis for tectonic evolution and hydrocarbon migration and accumulation.Affected by the diverse denudation intensities,the paleo-structures in the study area feature high in the south and low in the north at the Late Jurassic,high in the north and low in the south at the late Early Cretaceous,high in the southeast and low in the northwest at present in succession.EW-and NE-trending folds and faults are the products of inherited development,which have a controlling effect on hydrocarbon migration and accumulation.展开更多
文摘Ghana has four sedimentary basins,but attention has mostly been concentrated on the Tano Basin.This preference among potential investors is largely due to the fact that it has been extensively studied and also its established oil and gas reserves,which have facilitated the discovery and development of major fields such as the Jubilee Field.In contrast,the Saltpond,Keta,and Voltaian basins have not undergone the same level of exploration and research,thereby making them less attractive to investors.A comparative analysis of the research conducted on the Tano Basin and the other basins is necessary to identify research opportunities that could enhance understanding of these less-explored basins and increase investor interests.The findings indicate that the Tano Basin requires minimal further exploration,while studies on the Saltpond,Keta,and Voltaian basins have primarily focused on sedimentological and geochemical analyses,offering valuable but limited insights into their petroleum systems and hydrocarbon potential.Unlocking Ghana's hydrocarbon potential demands tailored studies for each basin.In the Tano Basin,the key to sustaining and optimizing production lies in advanced seismic reprocessing,pre-stack depth migration,4D reservoir monitoring,and machine-learning-assisted reservoir characterization to address deepwater complexity and compartmentalization.Revitalizing the Saltpond Basin demands updated petroleum system evaluation through modern geochemical techniques,reprocessed 2D/3D seismic data,and comprehensive 1D–3D basin modeling to clarify trap integrity and overlooked plays.In the underexplored Accra–Keta Basin,high-resolution seismic imaging,sequence stratigraphic mapping,and full petroleum system modeling are essential to define reservoir intervals and assess charge potential.For the Voltaian Basin,a deep seismic profiling,integrated geological mapping,source-rock evaluation,and analog-based reservoir/seal studies are required to evaluate its hydrocarbon potential.These targeted efforts are key to de-risking and advancing exploration.An integrated approach is vital for gaining a deeper understanding of the petroleum system elements in these basins.This will not only expand scientific knowledge and inform decision-making at the highest levels but also provide a strong foundation for future exploration,development,and efficient exploitation of hydrocarbon resources.
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funded by the Sinopec Science and Technology Project(No.P23132)the AAPG Foundation Grants-inAid Program(No.18644937)。
文摘By investigating the evolution of shale gas generation,storage,adjustment and accumulation under different structural settings in superimposed basins,this study elucidates the differential accumulation mechanisms of shale gas.An improved evaluation method of shale gas content evolution in superimposed basins is proposed.This method incorporates the coupling effect of key geological factors such as temperature,pressure,organic matter abundance,maturity,and pore characteristics on the content and occurrence state of shale gas,as well as the configuration relationship between shale gas generation and storage throughout geological history.Using this approach,the gas evolution histories of the Longmaxi Formation shales in wells N201 and PY1 are reconstructed under varying geological conditions.The Longmaxi Formation shales in these wells are dominated by typeⅠkerogen,with original total organic carbon(TOC_(o))contents of 6.20 wt% and 4.92 wt%,respectively,indicating differences in the initial material basis for gas generation.At the maximum burial depth of approximately 5000 m,the Longmaxi Formation shale in well N201 exhibits a formation pressure coefficient of 2.05,an organic matter maturity of 2.2%,and organic pores accounting for 68%of the total porosity.The gas generation quantity(Q_(g))reaches 19.24 m^(3)/t,while the gas storage capacity(Q_(s))is 4.30 m^(3)/t.The actual total gas content(Q_(a)),constrained by Q_(s),is 4.30 m^(3)/t,with free gas comprising 94%.Following relatively moderate tectonic uplift,the Q_(a) in well N201 decreases to 4.03 m^(3)/t,with free gas accounting for 63%.In contrast,the Longmaxi Formation shale in well PY1 reached a maximum burial depth of 6300 m,associated with a formation pressure coefficient of 1.62,organic matter maturity of 2.5%,and organic pore proportion of 67%.Here,Q_(g) is 16.87 m^(3)/t,and both Q_(s) and Q_(a) are 3.65 m^(3)/t,with free gas accounting for 98%.After intense tectonic uplift,Q_(a) declines to 2.72 m^(3)/t,and the proportion of free gas drops to51%.Finally,a four-stage differential accumulation model of shale gas is established:Slow gas generation and only adsorbed gas occur in stageⅠ,which is primarily controlled by TOC content;both adsorbed gas and free gas present in stageⅡ,with free gas becoming dominant;rapid gas generation and free gas predominance are controlled by temperature and porosity in stageⅢ;and gas adjustment and accumulation are primarily controlled by temperature and pressure in stageⅣ.
基金supported by the National Natural Science Foundation of China(W2412135).
文摘The hydrological system in Central Asia is highly sensitive to global climate change,significantly affecting water supply and energy production.In Tajikistan,the Vakhsh River—one of the main tributaries of the Amu Darya—plays a key role in the region’s hydropower and irrigation.However,research on long-term hydrological changes in its two top large basins—the Surkhob and Khingov river basins—remains limited.Therefore,this study analyzed long-term climate and hydrological changes in the Vakhsh River,including its main tributaries—the Surkhob and Khingov rivers—which are vital for the water resource management in Tajikistan and even in Central Asia.Using long-term hydrometeorological observations,the change trends of temperature(1933–2020),precipitation(1970–2020),and runoff(1940–2018)were examined to assess the impact of climate change on the regional water resources.The analysis revealed the occurrence of significant warming and a spatially uneven increase in precipitation.The temperature changes across three climatic periods(1933–1960,1960–1990,and 1990–2020)indicated that there was a transition from baseline level to accelerated warming.The precipitation showed a 2.99 mm/a increase in the Khingov River Basin and a 2.80 mm/a increase in the Surkhob River Basin during 1970–2020.Moreover,there was a gradual shift toward wetter conditions in recent decades.Despite the relatively stable annual mean runoff,seasonal redistribution occurred,with increased runoff in spring and reduced runoff in summer,due to the compensation of glacier melting.Moreover,this study forecasted runoff change during 2019–2040 using the exponential triple smoothing(ETS)method and revealed the occurrence of alternating wet and dry phases,emphasizing the sensitivity of the Vakhsh River Basin’s hydrological system to climate change and the necessity of adaptive water resource management in mountainous regions of Central Asia.Therefore,this study can provide evidence-based insights that are critical for future water resources planning,climate-resilient hydropower development,and regional adaptation strategies in climate-vulnerable basins in Central Asia.
基金funded by the Basic Scientific Research of China Geological Academy(YK202305)National Key R&D Program of China(2019YFB1504101)+1 种基金National Natural Science Foundation of China(41602271)China Geological Survey(DD20160207 and DD20189112)。
文摘The geothermal resources in China are primarily found in its sedimentary basins,particularly in the large basins located in eastern China,which hold significant potential for geothermal energy development.The Songliao,North China,and Zhangzhou basins are of special interest due to their considerable exploration depths,extensive development history,and high levels of research activity.This study focuses on the three basins to analyze their thermal reservoir characteristics in eastern China.Between 2017 and 2023,the research team carried out a comprehensive analysis involving deep boreholes that exceeded 4000 m in depth within these three basins.They meticulously created detailed physical profiles that captured essential characteristics such as porosity,permeability,and thermal properties,reaching down to the basement of each basin.The findings indicated that variations in thermal conductivity within shallow geotechnical layers significantly influence the redistribution of deep thermal energy in the upper layers of the earth.Furthermore,differences in physical properties notably affect heat transport processes.The research proposes distinct heat models tailored for each basin:For the Songliao Basin,a low-permeability model with homogeneous thermal properties is constructed;for the North China Basin,high permeability and thermal conductivity layers are highlighted;and a fracture network controlling water and heat is presented in the Zhangzhou Basin.To elucidate the thermal structure of these basins,the Curie surface and Moho surface were analyzed.The shallow Curie surface indicates ongoing intense thermal activity stemming from crustal heat sources,while a shallow Moho surface signifies historical vigorous mantle thermal activity associated with mantle source heat production.Furthermore,the research evaluates the geothermal resources and the potential for carbon emission reduction in these basins.Total volume of exploitable geothermal fluid is estimated to be 76.9×10^(9) m^(3)/a,corresponding to an annual renewable geothermal energy 1.47×10^(16)k J.The implementation of geothermal energy could lead to a reduction in annual CO_(2)emissions by nearly 2×10^(9) t,which constitutes about 17.4%of China’s national carbon emissions in 2022.This estimation provides invaluable theoretical insights and data support for geothermal exploration and sustainable development in eastern China.
基金the framework of projects coded 97-20A and 9815 by the General Directorate of Mineral Research and Exploration (Ankara, Türkiye)
文摘In a re-examination of the Neogene stratigraphy of the Uşak,Güre,and Selendi basins of western Anatolia,western Turkey,the stratigraphic position of the previously definedİnay Group is revised,which was previously considered to be of the Middle Miocene age.Based on mammalian biochronology and stratigraphic relationships,two sequences are identified,separated by conformable/transitional contacts within the former group:the Middle Miocene Güre Group is composed of the FakılıFormation,characterized by alluvial fan deposits,and the lacustrine Derbent Formation.Radiometric dating of alkaline volcanics laterally associated with Güre Group sediments in the Uşak and Güre basins,and mammalian fossils re-evaluated into the MN5-6 biozones in the Selendi Basin,indicate early Middle Miocene.Considering the stratigraphic relationship with the overlying early Late Mioceneİnay Group as redefined,we estimate that the Güre Group was deposited in the Middle Miocene.Theİnay Group is characterized by a lateral-vertical transition from alluvial deposits of the Ahmetler Formation to the overlying lacustrine Ulubey Formation.An MN9-10 fauna,containing deinotheres,was found within the latter formation.
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 development of sedimentary layers in offshore salt-bearing basins in the central segment of west Africa is closely linked to elements such as faults,igneous rocks and crustal thickness.To investigate their spatial relationships,we analyzed gravity and magnetic data in the oceanic areas,and employed edge detection,correlation analysis,and inversion techniques to study the characteristics of these geological elements.Our findings revealed numerous faults and igneous rocks in the crust underlying these non-volcanic continental margins,and these faults and igneous rocks continued to indirectly influence basin sedimentation since the rift period.On the basis of the thickness of the crust and sedimentary layers,we classified the offshore basins into four types of secondary structural units.Combined with the characteristics of faults and igneous rocks,we concluded that the exhumed bulges within the Western Uplift Zone are favorable for oil and gas exploration.
文摘This study examines the molecular and isotopic composition of 193 gas samples collected from oil and gas fields across Colombia's onshore basins with active hydrocarbon production.Comparative analyses were conducted on both isotopic and molecular compositions across the Lower Magdalena Basin(LMB),Middle Magdalena Basin(MMB),Upper Magdalena Basin(UMB),Putumayo Cagu an Basin(PUTCAB),Catatumbo Basin(CATB),Eastern Llanos Basin(LLAB),and Eastern Cordillera Basin(ECB).The primary objectives were to classify the gases produced,characterize their origins,assess transformation processes such as biodegradation and migration,and analyze the statistical distribution patterns of their components.This geochemical characterization aims to support the discovery of new reserves for both natural gas(NG)and liquefied petroleum gas(LPG),given Colombia's potential risk of diminished energy selfsufficiency in gas resources.The basins under study produce dry gas,wet gas,and liquefied petroleum gas(LPG/C_(3+)),all associated with oil and gas fields of commercial hydrocarbon production.Notably,the LLAB contains the highest proportions of heavy isotopic carbon and C_(3+)(LPG)concentrations,whereas LMB is characterized by isotopically lighter methane,indicative of dry gas predominance.Results suggest a predominantly thermogenic origin for the gases studied,generated within the oil and gas windows,with several samples originating from secondary oil cracking,while some samples from LMB display a likely biogenic origin.Additionally,evidence of gas migration and biodegradation was observed in a significant subset of samples.The analysis of statistical distributions and compositional trends reveals a prevalent high methane content,with substantial C_(2)-C_(5)(C_(2+))gas concentrations across all basins studied.This composition underscores the potential for both natural gas(NG)and LPG production.The C_(3+)(LPG)content varies between 1%and 92%,with 35%of the samples containing less than 5%LPG.High original gas-in-place(OGIP)volumes and substantial LPG content in the Eastern Llanos foothills,encompassing fields such as Cusiana and Cupiagua,highlight the prospective potential of this region.Near-field exploration could further add reserves of both NG and LPG.
基金Under the auspices of National Natural Science Foundation of China(No.42061020)Natural Science Foundation of Guangxi Zhuang Autonomous Region(No.2018JJA150135)+2 种基金Guangxi Key Research and Development Program(No.AA18118038)Science and Technology Department of Guangxi Zhuang Autonomous Region(No.2019AC20088)High Level Talent Introduction Project of Beibu Gulf University(No.2019KYQD28)。
文摘Scientific understanding of the trade-offs between services is crucial for the scientific management and protection of ecosystems and the formulation of resource management policies.This study integrated meteorological,land use,and soil data to assess the ecosystem services,namely,water yield(WY),soil erosion(SE),and carbon sinks(CS),in peak-cluster depression basins on the Sino-Vietnamese border in China during 2000-2020.It analyzed the trade-offs and synergistic relationships among the three ecosystem services and their time-lag effects and driving mechanisms with the help of pixel-by-pixel time-lag intercorrelation and geographical de-tector methods.Results show that:1)from 2000 to 2020,the key ecosystem service indicators in the peak-cluster depression basins on the Sino-Vietnamese border in China demonstrated a significant and synergistic trend of positive change.The WY increased at a rate of 11.99 mm/yr,CS increased at a rate of 2.44 g C/(m^(2)∙yr),and SE decreased at a rate of 0.06 t/(ha∙yr).2)Most areas showed a synergistic relationship across the three ecosystem services,and the areas with a trade-off relationship were mostly concentrated in Baise City and the southwest of Chongzuo City,Guangxi.3)The time-lag effect between SE and WY was mostly concentrated in 0 yr,that between SE and CS was mostly concentrated in 5 yr,and that between CS and WY was mostly concentrated in 1 yr.4)Population density was the controlling factor between SE and WY.Vegetation coverage factor is the main controlling factor between SE and CS.The lithologic factor is the main controlling factor between CS and WY.Studying the trade-off relationship of ecosystem services at spatial and tem-poral scales on the Sino-Vietnamese border in China karst areas can provide a basis for regional ecological construction and develop-ment strategies,and it is conducive to meeting regional interest needs,maximizing comprehensive benefits,balancing the ecological en-vironment,and achieving regional sustainable development.
基金The National Natural Science Foundation of China under contract Nos 42176067,41576069,47906197 and 42206066the National Key R&D Program of China under contract No.2024YFF0506701the Project of Impact and Response of Antarctic Seas to Climate Change under contract No.IRASCC01-03-01.
文摘The Ross Sea basins,shaped by Late Cretaceous and Cenozoic extension within the crust of the Ross Sea,represent key regions for understanding continental rifting processes.However,the dynamic mechanisms driving the transition from diffuse extension to focused extension in these basins remain poorly understood.Here,we provide a comprehensive model of crustal extension in the Ross Sea basins,detailing the kinematic and dynamic evolution from 100 Ma to the present on the basis of published finite rotation poles.Our model illuminates the complex relative motions between the West Antarctic and East Antarctic Plates and quantifies the crustal strain rates associated with their relative movements.We show that West Antarctica began to move away slowly from the East Antarctic and rotated clockwise at approximately 53 Ma,and the motion progressively decreased until it ceased at approximately 11 Ma.This kinematic shift temporally coincided with the onset of focused rifting,indicating a transition from broadly distributed extension in the eastern Ross Sea to localized deformation in the western basin.Time-resolved strain rate fields further reveal several hundred kilometers of total crustal extension,suggesting a primary influence of evolving plate motions over passive lithospheric weakening.These findings refine the tectonic history of the Ross Sea and provide a reproducible framework linking rift basin evolution to global plate motion.
基金The National Key Research and Development Program of China under contract No.2017YFC0602202.
文摘The distribution of igneous rocks is closely related to hydrocarbon resources.This study utilized high-precision gravity,magnetic,and rock physical property data,employing gravity-magnetic field fusion technology and Euler deconvolution technology.The objective was to identify the distribution of igneous rocks in the China Seas and neighboring regions and investigate their relationships with petroliferous basins.Our results reveal that igneous rocks are widely scattered throughout the China Seas and neighboring regions,with the highest concentration in the northwest(NW)and the second highest concentration in the east-northeast(ENE).The largest-scale igneous rocks are those with a north-south(N-S)orientation,followed by those with northeast(NE),NW,and ENE orientations.The depths of igneous rocks within petroliferous basins typically range from 3 km to 9 km and are associated with hydrocarbon resource distributions characterized by deep oil and shallow gas.The proportions of igneous rocks in different types of basins exhibit varying correlations with the total hydrocarbon resources.In particular,the proportion of igneous rocks in rift-type basins in the China Seas exhibits a strong linear correlation with the total hydrocarbon resources.These research findings provide valuable guidance for studying the relationship between igneous rock distribution and petroliferous basins,offering insights that can inform future hydrocarbon exploration endeavors.
基金Supported by Open Project Fund of China Meteorological Administration Basin Heavy Rainfall Key Laboratory(2023BHR-Y26)Innovation Project Fund of Wuhan Metropolitan Area Meteorological Joint Science and Technology(WHCSQY202305)+1 种基金Innovation and Development Special Project of China Meteorological Administration(CXFZ2022J019)Project of Huanggang Meteorological Bureau's Scientific Research(2022Y02).
文摘It is an important standard to judge the flood disaster in the basin whether the rainfall at the flood-inducing interface is reached.In this paper,the Xin'anjiang model,Topmodel model and SCS model were selected to calculate and compare the rainfall at the flood-inducing interface in the Zhanghe Reservoir basin in Hubei Province.The results showed that average relative error and average absolute error of Xin'anjiang model were-3.36%and-21.46×10^(5)m^(3),which were the minimum,followed by Topmodel model with 5.72%and 26.22×10^(5)m^(3),SCS model with 11.33%and 58.13×10^(5)m^(3).The minimum absolute error of the three hydrological models in calculating the rainfall at the critical interface was 3.26 mm,while the maximum was 49.24 mm.When the initial water level exceeded 120 m,the difference among the three models in calculating the rainfall at the critical interface became more and more obvious.When the reservoir water level was lower than 120 m,it mainly referred to the calculation results of Xin'anjiang model.When the reservoir water level was higher than 120 m,it mainly referred to the calculation results of Topmodel model.The research conclusion can provide reference for small and medium-sized basins selecting hydrological model to calculate the rainfall at the flood-inducing interface.
基金the National Natural Science Foundation of China(Nos.42206234,42476228,42076220)the Key R&D Project of Shandong Province(No.2024SFGC0302)+2 种基金the Project of Laoshan Laboratory(No.LSKJ202203404)the Project of China Geology Survey(Nos.DD202503023,DD20230401)support from the Ocean Negative Carbon Emissions(ONCE)Program。
文摘Offshore carbon dioxide(CO_(2))geological storage is a promising strategy for reducing carbon emissions and supporting sustainable development in coastal regions within a carbon neutrality framework.However,only a few works have focused on offshore basins in China.To address this gap,this study established a dual indicator system that comprises necessary and critical indices and is integrated with the analytic hierarchy process.A coupled analysis was then performed to evaluate the suitability of 10 offshore sedimentary basins in China for CO_(2)geological storage.The necessary indicator system focuses on storage potential,geological conditions,and engineering feasibility.Meanwhile,the critical indicator system emphasizes the safety of storage projects and the viability of drilling operations.Evaluation results revealed that China's offshore basins have undergone two geological evolution stages,namely,the rifting and post-rifting phases,leading to the formation of a dual-layer structure characterized by faulted lower layers and sagged upper layers.These basins have thick and widespread Cenozoic strata,generally low seismic activity,and medium-to-low geothermal gradients.They form five reservoir-caprock systems with favorable geological conditions for CO_(2)storage.The Pearl River Mouth,East China Sea Shelf,and Bohai Basins emerged as primary candidates that offer substantial storage potential to support carbon neutrality goals in the Bohai Rim Economic Zone,Yangtze River Delta Economic Zone,and Guangdong-Hong Kong-Macao Greater Bay Area.The Beibu Gulf and South Yellow Sea Basins were identified as secondary candidates,and the Qiongdongnan and Yinggehai Basins were considered potential alternatives.
文摘Conventional borehole image log interpretation of linear fractures on volcanic rocks,represented as sinusoids on unwrapped cylinder projections,is relatively straight-forward,however,interpreting non-linear rock structures and complex facies geometries can be more challenging.To characterize diverse volcanic paleoenvironments related to the formation of the South American continent,this study presents a new methodology based on image logs,petrography,seismic data,and outcrop analogues.The presented methodology used pseudo-boreholes images generated from outcrop photographs with typical igneous rock features worldwide simulating 2D unwrapped cylinder projections of a 31 cm(12.25 in)diameter well.These synthetic images and standard outcrop photographs were used to define morphological patterns of igneous structures and facies for comparison with wireline borehole image logs from subsurface volcanic and subvolcanic units,providing a“visual scale”for geological evaluation of volcanic facies,significantly enhancing the identification efficiency and reliability of complex geological structures.Our analysis focused on various scales of columnar jointing and pillow lava lobes with additional examples including pahoehoe lava,ignimbrite,hyaloclastite,and various intrusive features in Campos,Santos,and Parnaíba basins in Brazil.This approach increases confidence in the interpretation of subvolcanic,subaerial,and subaqueous deposits.The image log interpretation combined with regional geological knowledge has enabled paleoenvironmental insights into the rift magmatism system related to the breakup of Gondwana with associated implications for hydrocarbon exploration.
基金The University of Malaya's postdoctoral fellowship program has been acknowledged by the first author and is associated with grant number IF064-2019the Department of Science and Technology (Project No. SB/S4/ES-681/2013), Government of India, for their supportthe Researchers Supporting Project number (RSPD2024R546) at King Saud University in Riyadh, Saudi Arabia
文摘The Bikaner-Nagaur and Barmer Basins(Rajasthan)are the most important petroliferous sedimentary basins in India.For over a decade,the exploration and extraction of hydrocarbons in these basins.Paleocene-Eocene age rocks bear organic-rich sediments in these basins,including lignite and carbonaceous shale deposits.The present research investigates the source rock properties,petroleum potential and thermal maturity of the carbonaceous shale partings from the lignite mines of Gurha(Bikaner-Nagaur Basin)and Kapurdi(Barmer Basin)using petrographical and geochemical tools.The carbonaceous shales have high organic matter(OM),with considerable total organic carbon(TOC)contents ranging from 13%to 39%.Furthermore,they contain hydrogen-rich kerogen,including types II and II/III,as evidenced by the Rock-Eval and elemental analysis results.The existence of these kerogen types indicates the abundance of reactive(vitrinite and liptinite)macerals.However,the carbonaceous shales from the Bikaner–Nagaur Basin have oil generation potentials,with a high hydrogen index(up to 516 mg HC/g TOC)and a H/C ratio(up to 1.5)along with a significant presence of oil-prone liptinitic macerals.Apart from the geochemical and petrological results,the studied shales have low huminite reflectance(0.31%–0.48%),maximum temperature(S_(2) peak;Tmax)between 419℃ and 429℃,and low production index values(PI:0.01–0.03).These results indicate that these carbonaceous shales contain immature OM,and thereby,they cannot yet release commercial amount of oil.This immaturity level in the studied outcrop section is due to the shallow burial depth.Geochemical proxies further indicate the presence of both oil and gas-prone source rocks.
基金supported by the Major National Science and Technology Programs of China(No.2016E-0202,No.QGYQZYPJ2022-1).
文摘In contrast to well-studied rift basins in NE China,the Hailar Basin has received relatively less attention regarding the combined patterns of different types of grabens and half-grabens.This study aims to explore whether the combined patterns of grabens in the Hailar Basin exhibit similar characteristics to those in other NE China rift basins and to identify the underlying causes.To achieve this,a comprehensive analysis of the major fault systems and the combined patterns of faulted sub-depressions,as well as their controlling mechanisms,was conducted.This analysis utilized the latest 3D seismic data that cover nearly the entire Beier Depression.Three groups of pre-existing fault systems were observed in the basement of the Beier Depression,and they are the NEE-EW-trending fault systems,the NE-trending fault systems,and the NW-trending fault systems.The NEE-EW-trending fault systems were distributed in the central part of the Beier Depression and primarily controlled the sedimentary filling of the Tongbomiao and the Lower Nantun Formations.The NE-trending fault systems were distributed in the southwestern part of the Beier Depression and primarily controlled the sedimentary filling of the Upper Nantun Formations.The NW-trending fault systems were distributed rarely in the Beier Depression.Five kinds of combined patterns of the sub-depressions were developed in the Beier Depression,and they are the parallel,en echelon,face-to-face,back-to-back,and S-shaped combined patterns.They were controlled by the NEE-EW-trending and the NE-trending fault systems with different orientations,arrangements,and activation sequences.
基金supported by the China National Petroleum Corporation Science and Technology Project(Study on genesis mechanism and distribution law of high quality reservoir of the fourth Member of Xujiahe Formation in middle and west Sichuan area,20230301-23)。
文摘The Triassic Xujiahe Formation in the slope zone of the Sichuan foreland basin is a new field of continental tight gas exploration in recent years.The fourth member of the Xujiahe Formation(Xu4 Member),the major interval in the Jianyang Block of the Tianfu gas field in the basin,is characterized by considerable buried depth,tight reservoirs,and strong heterogeneity.By using cast thin section,X-ray diffraction(XRD),scanning electron microscopy(SEM),fluid inclusion thermometry,and core analysis,the reservoir rock types,dominant diageneses,diagenetic history,and controls on high-graded reservoirs were investigated.It is found that the Xu4 Member in Jianyang mainly consists of lithic feldspar sandstones and feldspar lithic sandstones,followed by lithic quartz sandstones.High-energy hydrodynamic conditions in the microfacies of underwater distributary channels and mouth bars are beneficial to the preservation of primary pores and the occurrence of secondary pores,and there are no significant differences in petrophysical properties between these two microfacies.Compaction and calcareous cementation are the dominant controls on reservoir porosity decrease in the Xujiahe Formation;corrosion is the major contributor to porosity increase by generating secondary dissolved pores,e.g.intragranular dissolved pores and intergranular dissolved pores,as major reservoir space in the study area.Fracture zones around the faults inside the Xujiahe Formation(fourth‒order faults)are favorable for proximal tight gas accumulation,preservation,and production.The research findings have been successfully applied to explore the Xujiahe Formation in the slope zone of the Sichuan foreland basin.They can be referential for other similar tight sandstone gas accumulations.
基金supported by the National Natural Science Foundation of China(Grant Nos.T2225022,12350710786,62088101,and 12161141016)Shuguang Program of Shanghai Education Development Foundation(Grant No.22SG21)Shanghai Municipal Education Commission,and the Fundamental Research Funds for the Central Universities。
文摘Dynamical systems often exhibit multiple attractors representing significantly different functioning conditions.A global map of attraction basins can offer valuable guidance for stabilizing or transitioning system states.Such a map can be constructed without prior system knowledge by identifying attractors across a sufficient number of points in the state space.However,determining the attractor for each initial state can be a laborious task.Here,we tackle the challenge of reconstructing attraction basins using as few initial points as possible.In each iteration of our approach,informative points are selected through random seeding and are driven along the current classification boundary,promoting the eventual selection of points that are both diverse and enlightening.The results across various experimental dynamical systems demonstrate that our approach requires fewer points than baseline methods while achieving comparable mapping accuracy.Additionally,the reconstructed map allows us to accurately estimate the minimum escape distance required to transition the system state to a target basin.
基金financially supported by the National Natural Science Foundation of China(42272151)。
文摘Restoration of denudation thickness is of great significance to understanding tectonic evolution,hydrocarbon migration and accumulation history in petroliferous basins.How to accurately restore and distinguish denudation thicknesses in different periods,however,is difficult.With measurements of vitrinite reflectance(Ro)and interval transit time,along with stratigraphic profile comparison,we restored the total denudation thickness of the Cretaceous in the central Sichuan Basin at a depth range of1100-3300 m.The apatite fission track analysis(AFTA)was employed to identify the denudation periods,namely,the Late Yanshanian,Early Himalayan and the Late Himalayan orogenic epochs,and the ratio of their denudation intensity is about 3.8:1:3.9.The denudation thicknesses at different periods provide an important basis for tectonic evolution and hydrocarbon migration and accumulation.Affected by the diverse denudation intensities,the paleo-structures in the study area feature high in the south and low in the north at the Late Jurassic,high in the north and low in the south at the late Early Cretaceous,high in the southeast and low in the northwest at present in succession.EW-and NE-trending folds and faults are the products of inherited development,which have a controlling effect on hydrocarbon migration and accumulation.
