Coal measures are significant hydrocarbon source rocks and reservoirs in petroliferous basins.Many large gas fields and coalbed methane fields globally are originated from coal-measure source rocks or accumulated in c...Coal measures are significant hydrocarbon source rocks and reservoirs in petroliferous basins.Many large gas fields and coalbed methane fields globally are originated from coal-measure source rocks or accumulated in coal rocks.Inspired by the discovery of shale oil and gas,and guided by“the overall exploration concept of considering coal rock as reservoir”,breakthroughs in the exploration and development of coal-rock gas have been achieved in deep coal seams with favorable preservation conditions,thereby opening up a new development frontier for the unconventional gas in coal-rock reservoirs.Based on the data from exploration and development practices,a systematic study on the accumulation mechanism of coal-rock gas has been conducted.The mechanisms of“three fields”controlling coal-rock gas accumulation are revealed.It is confirmed that the coal-rock gas is different from CBM in accumulation process.The whole petroleum systems in the Carboniferous–Permian transitional facies coal measures of the eastern margin of the Ordos Basin and in the Jurassic continental facies coal measures of the Junggar Basin are characterized,and the key research directions for further developing the whole petroleum system theory of coal measures are proposed.Coal rocks,compared to shale,possess intense hydrocarbon generation potential,strong adsorption capacity,dual-medium reservoir properties,and partial or weak oil and gas self-sealing capacity.Additionally,unlike other unconventional gas such as shale gas and tight gas,coal-rock gas exhibits more complex accumulation characteristics,and its accumulation requires a certain coal-rock play form lithological and structural traps.Coal-rock gas also has the characteristics of conventional fractured gas reservoirs.Compared with the basic theory and model of the whole petroleum system established based on detrital rock formations,coal measures have distinct characteristics and differences in coal-rock reservoirs and source-reservoir coupling.The whole petroleum system of coal measures is composed of various types of coal-measure hydrocarbon plays with coal(and dark shale)in coal measures as source rock and reservoir,and with adjacent tight layers as reservoirs or cap or transport layers.Under the action of source-reservoir coupling,coal-rock gas is accumulated in coal-rock reservoirs with good preservation conditions,tight oil/gas is accumulated in tight layers,conventional oil/gas is accumulated in traps far away from sources,and coalbed methane is accumulated in coal-rock reservoirs damaged by later geological processes.The proposed whole petroleum system of coal measures represents a novel type of whole petroleum system.展开更多
Natural gas hydrate(NGH),as a widely recognized clean energy,has shown a significant resource potential.However,due to the lack of a unified evaluation methodology and the difficult determination of key parameters,the...Natural gas hydrate(NGH),as a widely recognized clean energy,has shown a significant resource potential.However,due to the lack of a unified evaluation methodology and the difficult determination of key parameters,the evaluation results of global NGH resource are greatly different.This paper establishes a quantitative relationship between NGH resource potential and conventional oil and gas resource and a NGH resource evaluation model based on the whole petroleum system(WPS)and through the analysis of dynamic field controlling hydrocarbon accumulation.The global NGH initially in-place and recoverable resources are inverted through the Monte Carlo simulation,and verified by using the volume analogy method based on drilling results and the trend analysis method of previous evaluation results.The proposed evaluation model considers two genetic mechanisms of natural gas(biological degradation and thermal degradation),surface volume conversion factor difference between conventional natural gas and NGH,and the impacts of differences in favorable distribution area and thickness and in other aspects on the results of NGH resource evaluation.The study shows that the global NGH initially in-place and recoverable resources are 99×10^(12) m^(3) and 30×10^(12) m3,with averages of 214×10^(12) m^(3) and 68×10^(12) m^(3),respectively,less than 5% of the total conventional oil and gas resources,and they can be used as a supplement for the future energy of the world.The proposed NGH resource evaluation model creates a new option of evaluation method and technology,and generates reliable data of NGH resource according to the reliability comprehensive analysis and test,providing a parameter basis for subsequent NGH exploration and development.展开更多
In the global wave of energy transition and low-carbon development,China Petroleum Enterprise Association,together with the University of International Business and Economics,China University of Petroleum-Beijing,Sout...In the global wave of energy transition and low-carbon development,China Petroleum Enterprise Association,together with the University of International Business and Economics,China University of Petroleum-Beijing,Southwest Petroleum University,and other institutions,released four significant blue books on April 17:Annual Operating Report of China’s Natural Gas Industry Blue Book(2024-2025),China Oil&Gas Industry Development Analysis and Outlook Blue Book(2024-2025),China Low-Carbon Economy Development Report Blue Book(2024-2025),and Refined Oil and New Energy Development Report Blue Book(2024-2025).This series of blue books provides a comprehensive and high-level analysis of the development,issues,and trends in the oil and gas industry,offering a detailed depiction of the China Oil&Gas industry and its progress towards low-carbon development.展开更多
As the national carbon emission trading system extends to high energy-consuming industries,the petroleum exploration&development and refining&chemical engineering sectors face the dual challenges of rigid carb...As the national carbon emission trading system extends to high energy-consuming industries,the petroleum exploration&development and refining&chemical engineering sectors face the dual challenges of rigid carbon constraints and energy structure restructuring.This study innovatively proposes the“dual inflection point theory”,which reveals that the transformation window requires the industry to overcome composite pressures including regional energy imbalances,international carbon tariff barriers,and technological substitution bottlenecks.This paper constructs a five-in-one governance framework encompassing“policy coordination,market circulation,intelligent regulation,energy substitution,energy efficiency innovation”.展开更多
Light oil and gas reservoirs are abundant in the Ordovician marine carbonate reservoir in Shunbei Oilfield,Tarim Basin.This presents a compelling geological puzzle,as ultra-deep reservoirs undergo intense alteration a...Light oil and gas reservoirs are abundant in the Ordovician marine carbonate reservoir in Shunbei Oilfield,Tarim Basin.This presents a compelling geological puzzle,as ultra-deep reservoirs undergo intense alteration and complex petroleum accumulation processes.A comprehensive suite of geochemical analyses,including molecular components,carbon isotope composition,homogenization temperature of saline inclusions,and burial-thermal history of single wells,was conducted to elucidate the genesis of these ancient reservoirs.Three petroleum filling events have been identified in the study area:Late Caledonian,Hercynian-Indosinian,and Himalayan,through analysis of homogenization temperatures of brine inclusions and burial-thermal histories.Additionally,the oil in the study area has undergone significant alteration processes such as biodegradation,thermal alteration,mixing,evaporative fractionation,and gas invasion.This study particularly emphasizes the influential role of Himalayan gas filling-induced evaporation fractionation and gas invasion in shaping the present petroleum phase distribution.Furthermore,analysis of light hydrocarbon and diamondoid parameters indicates the oil within the study area is at a high maturity stage,with equivalent vitrinite reflectance values ranging from 1.48%to 1.99%.Additionally,the analysis of light hydrocarbons,aromatics,and thiadiamondoids indicates that TSR should occur in reservoirs near the gypsum-salt layers in the Cambrian.The existence of the Cambrian petroleum system in the study area is strongly confirmed when considering the analysis results of natural gas type(oil cracking gas),evaporative fractionation,and gas invasion.Permian local thermal anomalies notably emerge as a significant factor contributing to the destruction of biomarkers in oil.For oil not subject to transient,abnormal thermal events,biomarker reliability extends to at least 190℃.In conclusion,examining the special formation mechanisms and conditions of various secondary processes can offer valuable insights for reconstructing the history of petroleum accumulation in ultradeep reservoirs.This research provides a scientific foundation for advancing our knowledge of petroleum systems and underscores the importance of hydrocarbon geochemistry in unraveling ultra-deep,complex geological phenomena.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 reservoired petroleum fluids in the deep Ordovician carbonates in the Tazhong area,Tarim Basin,exhibit diverse and intricate geochemical properties and petroleum phases.However,the study on the causal mechanisms f...The reservoired petroleum fluids in the deep Ordovician carbonates in the Tazhong area,Tarim Basin,exhibit diverse and intricate geochemical properties and petroleum phases.However,the study on the causal mechanisms for the genesis of co-existed complex petroleum phases and their distribution remains relatively limited.The quantitative assessment of changes in molecular compounds in petroleum pools influenced by secondary alteration to different degrees also needs further investigation.In this study,eight samples including condensate,volatile,and black oil from the Tazhong area were analyzed via GC×GC-TOFMS.The results reveal that condensate oil exhibits complete normal alkane distribution,with abundant diamantanes and organic sulfur compounds(OSCs),and features high density(>0.83 g/cm^(3)),elevated wax content(>20%),and remarkable gas washing loss.The condensate gas is characterized by highly mature oil-cracking gas with a heavy carbon isotope.Geological analysis indicates that the current Ordovician reservoir temperatures generally remain below 140℃,which is insufficient to induce in-situ oil cracking.Additionally,black oil pools are formed adjacent to the condensate gas pools,suggesting that the latter is not a result of in-situ oil cracking,but rather represents a secondary condensate gas pool formed through gas invasion of a pre-existed oil pool.Based on the loss of n-alkanes and variations in adamantanes(As)and diamantanes(Ds)content across different oil samples,the degree of gas invasion was assessed.We divided gas invasion intensity into strong(Q≥80%,As≥5000μg/g,Ds≥400μg/g),weak(20%≤Q<80%,3000μg/g≤As<5000μg/g,200μg/g≤Ds<400μg/g)and negligible(0≤Q<20%,As<3000μg/g,Ds<200μg/g).The multistage oil/gas charging events,specifically the sequence of“early oil and late gas”in the Ordovician from the Tazhong area,predominantly drives the phase evolution of reservoired petroleum.Furthermore,differential gas invasion alteration exacerbates the intricacy of petroleum phase distribution.Notably,gas washing processes significantly influence the disparate enrichment of diamondoids homologues in crude oil.Specifically,lower carbon number diamondoids are more abundant in condensate oil,while higher ones exhibit relatively increased abundance in black oil,potentially serving as a valuable quantitative assessment parameter.The findings in this study will provide guiding significance for the analysis and quantitative assessment of deep petroleum phase diversity.Additionally,this research will provide novel insights for comprehensively evaluating basins worldwide with complex petroleum phases distribution.展开更多
There are various types of natural gas resources in coal measures,making them major targets for natural gas exploration and development in China.In view of the particularity of the whole petroleum system of coal measu...There are various types of natural gas resources in coal measures,making them major targets for natural gas exploration and development in China.In view of the particularity of the whole petroleum system of coal measures and the reservoir-forming evolution of natural gas in coal,this study reveals the formation,enrichment characteristics and distribution laws of coal-rock gas by systematically reviewing the main types and geological characteristics of natural gas in the whole petroleum system of coal measures.First,natural gas in the whole petroleum system of coal measures is divided into two types,conventional gas and unconventional gas,according to its occurrence characteristics and accumulation mechanism,and into six types,distal detrital rock gas,special rock gas,distal/proximal tight sandstone gas,inner-source tight sandstone gas,shale gas,and coal-rock gas,according to its source and reservoir lithology.The natural gas present in coal-rock reservoirs is collectively referred to as coal-rock gas.Existing data indicate significant differences in the geological characteristics of coal-rock gas exploration and development between shallow and deep layers in the same area,with the transition depth boundary generally 1500-2000 m.Based on the current understanding of coal-rock gas and respecting the historical usage conventions of coalbed methane terminology,coal-rock gas can be divided into deep coal-rock gas and shallow coalbed methane according to burial depth.Second,according to the research concept of“full-process reservoir formation”in the theory of the whole petroleum system of coal measures,based on the formation and evolution of typical coal-rock gas reservoirs,coal-rock gas is further divided into four types:primary coal-rock gas,regenerated coal-rock gas,residual coal-rock gas,and bio coal-rock gas.The first two belong to deep coal-rock gas,while the latter two belong to shallow coal-rock gas.Third,research on the coal-rock gas reservoir formation and evolution shows that shallow coal-rock gas is mainly residual coal-rock gas or bio coal-rock gas formed after geological transformation of primary coal-rock gas,with the reservoir characteristics such as low reservoir pressure,low gas saturation,adsorbed gas in dominance,and gas production by drainage and depressurization,while deep coal-rock gas is mainly primary coal-rock gas and regenerated coal-rock gas,with the reservoir characteristics such as high reservoir pressure,high gas saturation,abundant free gas,and no or little water.In particular,the primary coal-rock gas is wide in distribution,large in resource quantity,and good in reservoir quality,making it the most favorable type of coal-rock gas for exploration and development.展开更多
Long-termpetroleum production forecasting is essential for the effective development andmanagement of oilfields.Due to its ability to extract complex patterns,deep learning has gained popularity for production forecas...Long-termpetroleum production forecasting is essential for the effective development andmanagement of oilfields.Due to its ability to extract complex patterns,deep learning has gained popularity for production forecasting.However,existing deep learning models frequently overlook the selective utilization of information from other production wells,resulting in suboptimal performance in long-term production forecasting across multiple wells.To achieve accurate long-term petroleum production forecast,we propose a spatial-geological perception graph convolutional neural network(SGP-GCN)that accounts for the temporal,spatial,and geological dependencies inherent in petroleum production.Utilizing the attention mechanism,the SGP-GCN effectively captures intricate correlations within production and geological data,forming the representations of each production well.Based on the spatial distances and geological feature correlations,we construct a spatial-geological matrix as the weight matrix to enable differential utilization of information from other wells.Additionally,a matrix sparsification algorithm based on production clustering(SPC)is also proposed to optimize the weight distribution within the spatial-geological matrix,thereby enhancing long-term forecasting performance.Empirical evaluations have shown that the SGP-GCN outperforms existing deep learning models,such as CNN-LSTM-SA,in long-term petroleum production forecasting.This demonstrates the potential of the SGP-GCN as a valuable tool for long-term petroleum production forecasting across multiple wells.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
Based on the investigation of sedimentary filling characteristics and pool-forming factors of the Mesozoic in the Ordos Basin,the whole petroleum system in the Mesozoic is divided,the migration&accumulation charac...Based on the investigation of sedimentary filling characteristics and pool-forming factors of the Mesozoic in the Ordos Basin,the whole petroleum system in the Mesozoic is divided,the migration&accumulation characteristics and main controlling factors of conventional-unconventional hydrocarbons are analyzed,and the whole petroleum system model is established.First,the whole petroleum system developed in the Mesozoic takes the high-quality source rocks of the 7th member of the Triassic Yanchang Formation as the core and mainly consists of low-permeability and unconventional oil and gas reservoirs.It can be divided into four hydrocarbon accumulation domains,including intra-source retained hydrocarbon accumulation domain,near-source tight hydrocarbon accumulation domain,far-source conventional hydrocarbon accumulation domain and transitional hydrocarbon accumulation domain,which together form a continuous,symbiotic,and orderly accumulation entity wherein unconventional resources significantly outweigh conventional ones in proportion.Second,the spatial core area of sedimentary filling is the oil-rich core of the whole petroleum system.From the core to the periphery,the reservoir type evolves as shale oil→tight oil→conventional oil,the accumulation power is dominated by overpressure→buoyancy or overpressure and capillary force,the accumulation scale changes from extensive hundreds of millions of tons to a isolated hundreds of thousands-million of tons,and the gas-oil ratio and methane content decrease.Third,the sedimentary filling system provides the material basis and spatial framework for the whole petroleum system,the superimposed sand body,fault and unconformity constitute the dominant migration pathway of hydrocarbons in the far-source conventional hydrocarbon accumulation domain and the transitional hydrocarbon accumulation domain,the high-quality source rocks provide a solid resource basis for shale oil,and the micro-nano pore throat-fracture network constitute unconventional accumulation space.The hydrocarbon migration and accumulation process is mainly controlled by intense expulsion of hydrocarbon under overpressure in the pool-forming stage and the in-situ re-enrichment controlled by underpressure in post-pool-forming stage.The oil-gas enrichment and long-term preservation depends on the coordination among three factors(stable geological structure,multi-cycle sedimentation,and dual self-sealing).Fourth,the whole petroleum system model is defined as four domains,overpressure+underpressure drive,and dual self-sealing.展开更多
This paper expounds the basic principles and structures of the whole petroleum system to reveal the pattern of conventional oil/gas-tight oil/gas-shale oil/gas sequential accumulation and the hydrocarbon accumulation ...This paper expounds the basic principles and structures of the whole petroleum system to reveal the pattern of conventional oil/gas-tight oil/gas-shale oil/gas sequential accumulation and the hydrocarbon accumulation models and mechanisms of the whole petroleum system.It delineates the geological model,flow model,and production mechanism of shale and tight reservoirs,and proposes future research orientations.The main structure of the whole petroleum system includes three fluid dynamic fields,three types of oil and gas reservoirs/resources,and two types of reservoir-forming processes.Conventional oil/gas,tight oil/gas,and shale oil/gas are orderly in generation time and spatial distribution,and sequentially rational in genetic mechanism,showing the pattern of sequential accumulation.The whole petroleum system involves two categories of hydrocarbon accumulation models:hydrocarbon accumulation in the detrital basin and hydrocarbon accumulation in the carbonate basin/formation.The accumulation of unconventional oil/gas is self-containment,which is microscopically driven by the intermolecular force(van der Waals force).The unconventional oil/gas production has proved that the geological model,flow model,and production mechanism of shale and tight reservoirs represent a new and complex field that needs further study.Shale oil/gas must be the most important resource replacement for oil and gas resources of China.Future research efforts include:(1)the characteristics of the whole petroleum system in carbonate basins and the source-reservoir coupling patterns in the evolution of composite basins;(2)flow mechanisms in migration,accumulation,and production of shale oil/gas and tight oil/gas;(3)geological characteristics and enrichment of deep and ultra-deep shale oil/gas,tight oil/gas and coalbed methane;(4)resource evaluation and new generation of basin simulation technology of the whole petroleum system;(5)research on earth system-earth organic rock and fossil fuel system-whole petroleum system.展开更多
Significant exploration progress has been made in ultra-deep clastic rocks in the Kuqa Depression,Tarim Basin,over recent years.A new round of comprehensive geological research has formed four new understandings:(1)Es...Significant exploration progress has been made in ultra-deep clastic rocks in the Kuqa Depression,Tarim Basin,over recent years.A new round of comprehensive geological research has formed four new understandings:(1)Establish structural model consisting of multi-detachment composite,multi-stage structural superposition and multi-layer deformation.Multi-stage structural traps are overlapped vertically,and a series of structural traps are discovered in underlying ultra-deep layers.(2)Five sets of high-quality large-scale source rocks of three types of organic phases are developed in the Triassic and Jurassic systems,and forming a good combination of source-reservoir-cap rocks in ultra-deep layers with three sets of large-scale regional reservoir and cap rocks.(3)The formation of large oil and gas fields is controlled by four factors which are source,reservoir,cap rocks and fault.Based on the spatial configuration relationship of these four factors,a new three-dimensional reservoir formation model for ultra-deep clastic rocks in the Kuqa Depression has been established.(4)The next key exploration fields for ultra-deep clastic rocks in the Kuqa Depression include conventional and unconventional oil and gas.The conventional oil and gas fields include the deep multi-layer oil-gas accumulation zone in Kelasu,tight sandstone gas of Jurassic Ahe Formation in the northern structural zone,multi-target layer lithological oil and gas reservoirs in Zhongqiu–Dina structural zone,lithologic-stratigraphic and buried hill composite reservoirs in south slope and other favorable areas.Unconventional oil and gas fields include deep coal rock gas of Jurassic Kezilenuer and Yangxia formations,Triassic Tariqike Formation and Middle-Lower Jurassic and Upper Triassic continental shale gas.The achievements have important reference significance for enriching the theory of ultra-deep clastic rock oil and gas exploration and guiding the future oil and gas exploration deployment.展开更多
The ultra-deep(deeper than 8000 m)petroleum in the platform-basin zones of the Tarim Basin has been found mainly in the Lower Paleozoic reservoirs located to the east of the strike-slip fault F5 in the north depressio...The ultra-deep(deeper than 8000 m)petroleum in the platform-basin zones of the Tarim Basin has been found mainly in the Lower Paleozoic reservoirs located to the east of the strike-slip fault F5 in the north depression.However,the source and exploration potential of the ultra-deep petroleum in the Cambrian on the west of F5 are still unclear.Through the analysis of lithofacies and biomarkers,it is revealed that there are at least three kinds of isochronous source rocks(SRs)in the Cambrian Newfoundland Series in Tarim Basin,which were deposited in three sedimentary environments,i.e.sulfide slope,deep-water shelf and restricted bay.In 2024,Well XT-1 in the western part of northern Tarim Basin has yielded a high production of condensate from the Cambrian.In the produced oil,entire aryl-isoprenoid alkane biomarkers were detected,but triaromatic dinosterane was absent.This finding is well consistent with the geochemical characteristics of the Newfoundland sulfidized slope SRs represented by those in wells LT-1 and QT-1,suggesting that the Newfoundland SRs are the main source of the Cambrian petroleum discovered in Well XT-1.Cambrian crude oil of Well XT-1 also presents the predominance of C29 steranes and is rich in long-chain tricyclic terpanes(up to C39),which can be the indicators for effectively distinguishing lithofacies such as siliceous mudstone and carbonate rock.Combined with the analysis of hydrocarbon accumulation in respect of conduction systems including thrust fault and strike-slip fault,it is found that the area to the west of F5 is possible to receive effective supply of hydrocarbons from the Cambrian Newfoundland SRs in Manxi hydrocarbon-generation center.This finding suggests that the area to the west of F5 will be a new target of exploration in the Cambrian ultra-deep structural-lithologic reservoirs in the Tarim Basin,in addition to the Cambrian ultra-deep platform-margin facies-controlled reservoirs in the eastern part of the basin.展开更多
Overpressure prediction for exploratory drilling has become robust in most basins with increasing well control,high-quality seismic datasets,and proactive real-time overpressure monitoring while drilling.However,accur...Overpressure prediction for exploratory drilling has become robust in most basins with increasing well control,high-quality seismic datasets,and proactive real-time overpressure monitoring while drilling.However,accurate overpressure prediction remains challenging in offshore Northwest Borneo despite several decades of drilling experience.This paper focuses on two exploration wells drilled by Brunei Shell Petroleum 40 years apart that faced similar challenges with overpressure prediction and well control.An integrated lookback study is attempted using seismic and well-log data to explore the causes of the unsatisfactory Pore Pressure Prediction(PPP)outcome in pre-drill and real-time operation settings for thesewells.Our study indicates that the misprediction of overpressures is due to real differences in shale pressure(basis of pre-drill work and monitoring)and sand pressure(source of drill kick and well control chal-lenges)due to large-scale vertical leak or expulsion of deep-seated fluids into pre-compacted normally pressured overlying sediments in several regions through a mix of shear and tensile failure mechanisms.Such migrated fluids inflate the sand pressure in the normally compacted shallower sequences with the shale pressure remaining low.A predictive framework for upward fluid expulsion was attempted but found impracticable due to complex spatial and temporal variations in the horizontal stress field responsible for such leakage.As such,it is proposed that these migratory overpressures are essentially'unpredictable'from conventional PPP workflows viewed in the broad bucket of compaction disequi-librium(undercompaction)and fluid expansion(unloading)mechanisms.Further study is recommended to understand if such migrated overpressures in the sand can produce a discernible and predictable geophysical or petrophysical signature in the abutting normally compacted shales.The study highlights the possibility of large lateral variability in the sand overpressure within the same stratigraphic unit in regions with complex tectonostratigraphic evolution like Northwest Borneo.展开更多
Thiadiamondoids(TDs)have recently attracted increasing attention as molecular proxies for thermochemical sulfate reduction(TSR)reactions in reservoirs.However,their formation mechanisms,as well as the generation and e...Thiadiamondoids(TDs)have recently attracted increasing attention as molecular proxies for thermochemical sulfate reduction(TSR)reactions in reservoirs.However,their formation mechanisms,as well as the generation and evolution processes,remain poorly understood.In this study,simulation experiments with a duration of 160 h were conducted on the model compound 1,3-dimethyladamantane(1,3-DMA)using the CaSO_(4),MgSO_(4),and elemental S systems,with measurements at the 10th,20th,40th,80th and 160th hours during the simulation process being presented.The results indicate that at the end of simulation,the MgSO_(4) system exhibited the lowest residual amounts of 1,3-DMA,suggesting the highest degree of TSR.Four types of non-hydrocarbon compounds with adamantane structures were detected in the liquid products in the three experiment systems:adamantanones,adamantanols,adamantanethiols(ATs),and thiaadamantanes(TAs).Among these,adamantanones exhibited the highest concentrations in the three simulation systems.In addition,TAs were dominated by C_(3)-TAs in the CaSO_(4) and MgSO_(4) systems and by C_(2)-TAs in the elemental S system.The simulation experiments revealed a strong correlation between the concentrations of TAs and adamantanones,suggesting that adamantanones might be the intermediates for TAs.Combined with the synthesis mechanism of TAs from thiaadamamantane-4,8-dione,TDs might have two different genetic mechanisms:(a)low temperature cationic carbon ion rearrangement from diagenesis to early catagenesis stage,and(b)a free sulfur radical mechanism in high-temperature TSR process during middle-late catagenesis.TAs exhibited different generation and evolution processes across different experiment systems.Notably,the MgSO_(4) system revealed that TAs undergo generation,accumulation,and destruction process,corresponding to Easy%Ro values of 0.89%-0.98%,0.98%-1.21%,and>1.21%,respectively.Among these three simulation systems,dibenzothiophenes(DBTs)concentrations consistently trended upwards,indicating TAs have lower thermal stability than DBTs.展开更多
Based on the oil and gas exploration in the Sichuan Basin,combined with data such as seismic,logging and geochemistry,the basic geological conditions,hydrocarbon types,hydrocarbon distribution characteristics,source-r...Based on the oil and gas exploration in the Sichuan Basin,combined with data such as seismic,logging and geochemistry,the basic geological conditions,hydrocarbon types,hydrocarbon distribution characteristics,source-reservoir relationship and accumulation model of the Upper Triassic–Jurassic continental whole petroleum system in the basin are systematically analyzed.The continental whole petroleum system in the Sichuan Basin develops multiple sets of gas-bearing strata,forming a whole petroleum system centered on the Triassic Xujiahe Formation source rocks.The thick and high-quality source rocks in the Upper Triassic Xujiahe Formation provide sufficient gas source basis for the continental whole petroleum system in the basin.The development of conventional-unconventional reservoirs provides favorable space for hydrocarbon accumulation.The coupling of faults and sandbodies provides a high-quality transport system for gas migration.Source rocks and reservoirs are overlapped vertically,and there are obvious differences in sedimentary environment,reservoir lithology and physical properties,which lead to the orderly development of inner-source shale gas,near-source tight gas,and far-source tight–conventional gas in the Upper Triassic–Jurassic,from bottom to top.The orderly change of geological conditions such as burial depth,reservoir physical properties,formation pressure and hydrocarbon generation intensity in zones controlled the formation of the whole petroleum system consisting of structural gas reservoir in thrust zone,shale gas-tight gas reservoir in depression zone,tight gas reservoir in slope zone,and tight gas–conventional gas reservoir in uplift zone on the plane.Based on the theory and concept of the whole petroleum system,the continental shale gas and tight gas resources in the Sichuan Basin have great potential,especially in the central and western parts with abundant unconventional resources.展开更多
Taking the Paleozoic of the Sichuan and Tarim basins in China as example,the controlling effects of the Earth system evolution and multi-spherical interactions on the formation and enrichment of marine ultra-deep petr...Taking the Paleozoic of the Sichuan and Tarim basins in China as example,the controlling effects of the Earth system evolution and multi-spherical interactions on the formation and enrichment of marine ultra-deep petroleum in China have been elaborated.By discussing the development of“source-reservoir-seal”controlled by the breakup and assembly of supercontinents and regional tectonic movements,and the mechanisms of petroleum generation and accumulation controlled by temperature-pressure system and fault conduit system,Both the South China and Tarim blocks passed through the intertropical convergence zone(ITCZ)of the low-latitude Hadley Cell twice during their drifts,and formed hydrocarbon source rocks with high quality.It is proposed that deep tectonic activities and surface climate evolution jointly controlled the types and stratigraphic positions of ultra-deep hydrocarbon source rocks,reservoirs,and seals in the Sichuan and Tarim basins,forming multiple petroleum systems in the Ediacaran-Cambrian,Cambrian-Ordovician,Cambrian-Permian and Permian-Triassic strata.The matching degree of source-reservoir-seal,the type of organic matter in source rocks,the deep thermal regime of basin,and the burial-uplift process across tectonic periods collectively control the entire process from the generation to the accumulation of oil and gas.Three types of oil and gas enrichment models are formed,including near-source accumulation in platform marginal zones,distant-source accumulation in high-energy beaches through faults,and three-dimensional accumulation in strike-slip fault zones,which ultimately result in the multi-layered natural gas enrichment in ultra-deep layers of the Sichuan Basin and co-enrichment of oil and gas in the ultra-deep layers of the Tarim Basin.展开更多
According to the complex differential accumulation history of deep marine oil and gas in superimposed basins,the Lower Paleozoic petroleum system in Tahe Oilfield of Tarim Basin is selected as a typical case,and the p...According to the complex differential accumulation history of deep marine oil and gas in superimposed basins,the Lower Paleozoic petroleum system in Tahe Oilfield of Tarim Basin is selected as a typical case,and the process of hydrocarbon generation and expulsion,migration and accumulation,adjustment and transformation of deep oil and gas is restored by means of reservoine-forming dynamics simulation.The thermal evolution history of the Lower Cambrian source rocks in Tahe Oilfield reflects the obvious differences in hydrocarbon generation and expulsion process and intensity in different tectonic zones,which is the main reason controlling the differences in deep oil and gas phases.The complex transport system composed of strike-slip fault and unconformity,etc.controlled early migration and accumulation and late adjustment of deep oil and gas,while the Middle Cambrian gypsum-salt rock in inner carbonate platform prevented vertical migration and accumulation of deep oil and gas,resulting in an obvious"fault-controlled"feature of deep oil and gas,in which the low potential area superimposed by the NE-strike-slip fault zone and deep oil and gas migration was conducive to accumulation,and it is mainly beaded along the strike-slip fault zone in the northeast direction.The dynamic simulation of reservoir formation reveals that the spatio-temporal configuration of"source-fault-fracture-gypsum-preservation"controls the differential accumulation of deep oil and gas in Tahe Oilfield.The Ordovician has experienced the accumulation history of multiple periods of charging,vertical migration and accumulation,and lateral adjustment and transformation,and deep oil and gas have always been in the dynamic equilibrium of migration,accumulation and escape.The statistics of residual oil and gas show that the deep stratum of Tahe Oilfield still has exploration and development potential in the Ordovician Yingshan Formation and Penglaiba Formation,and the Middle and Upper Cambrian ultra-deep stratum has a certain oil and gas resource prospect.This study provides a reference for the dynamic quantitative evaluation of deep oil and gas in the Tarim Basin,and also provides a reference for the study of reservoir formation and evolution in carbonate reservoir of paleo-craton basin.展开更多
Petroleum asphalt,an important by-product of the petrochemical industry,has diverse applications but often suffers from low industrial added value.Because of its low cost,high carbon content,and high polycyclic aromat...Petroleum asphalt,an important by-product of the petrochemical industry,has diverse applications but often suffers from low industrial added value.Because of its low cost,high carbon content,and high polycyclic aromatic hydrocarbon content,appropriate modification can increase its value and expand its energy storage applications.Current research progress on the common preparation methods of petroleum asphalt-based carbon materials,including template-assisted pyrolysis,molten salt treatment,activation,heteroatom doping,and pre-oxidation is reviewed,and its use in supercapacitors and alkali metal ion batteries,is also elaborated.Feasible solutions for the current problems with petroleum asphalt are proposed,with the aim of providing insights into its high value-added utilization.展开更多
基金Supported by the PetroChina Basic Project(2024DJ23)CNPC Science Research and Technology Development Project(2021DJ0101)。
文摘Coal measures are significant hydrocarbon source rocks and reservoirs in petroliferous basins.Many large gas fields and coalbed methane fields globally are originated from coal-measure source rocks or accumulated in coal rocks.Inspired by the discovery of shale oil and gas,and guided by“the overall exploration concept of considering coal rock as reservoir”,breakthroughs in the exploration and development of coal-rock gas have been achieved in deep coal seams with favorable preservation conditions,thereby opening up a new development frontier for the unconventional gas in coal-rock reservoirs.Based on the data from exploration and development practices,a systematic study on the accumulation mechanism of coal-rock gas has been conducted.The mechanisms of“three fields”controlling coal-rock gas accumulation are revealed.It is confirmed that the coal-rock gas is different from CBM in accumulation process.The whole petroleum systems in the Carboniferous–Permian transitional facies coal measures of the eastern margin of the Ordos Basin and in the Jurassic continental facies coal measures of the Junggar Basin are characterized,and the key research directions for further developing the whole petroleum system theory of coal measures are proposed.Coal rocks,compared to shale,possess intense hydrocarbon generation potential,strong adsorption capacity,dual-medium reservoir properties,and partial or weak oil and gas self-sealing capacity.Additionally,unlike other unconventional gas such as shale gas and tight gas,coal-rock gas exhibits more complex accumulation characteristics,and its accumulation requires a certain coal-rock play form lithological and structural traps.Coal-rock gas also has the characteristics of conventional fractured gas reservoirs.Compared with the basic theory and model of the whole petroleum system established based on detrital rock formations,coal measures have distinct characteristics and differences in coal-rock reservoirs and source-reservoir coupling.The whole petroleum system of coal measures is composed of various types of coal-measure hydrocarbon plays with coal(and dark shale)in coal measures as source rock and reservoir,and with adjacent tight layers as reservoirs or cap or transport layers.Under the action of source-reservoir coupling,coal-rock gas is accumulated in coal-rock reservoirs with good preservation conditions,tight oil/gas is accumulated in tight layers,conventional oil/gas is accumulated in traps far away from sources,and coalbed methane is accumulated in coal-rock reservoirs damaged by later geological processes.The proposed whole petroleum system of coal measures represents a novel type of whole petroleum system.
基金Supported by the Major Consultation Project of the Chinese Academy of Sciences(2019-ZW11-Z-035)Technology Development Project of PetroChina Research Institute of Petroleum Exploration&Development(2021DJ0101)。
文摘Natural gas hydrate(NGH),as a widely recognized clean energy,has shown a significant resource potential.However,due to the lack of a unified evaluation methodology and the difficult determination of key parameters,the evaluation results of global NGH resource are greatly different.This paper establishes a quantitative relationship between NGH resource potential and conventional oil and gas resource and a NGH resource evaluation model based on the whole petroleum system(WPS)and through the analysis of dynamic field controlling hydrocarbon accumulation.The global NGH initially in-place and recoverable resources are inverted through the Monte Carlo simulation,and verified by using the volume analogy method based on drilling results and the trend analysis method of previous evaluation results.The proposed evaluation model considers two genetic mechanisms of natural gas(biological degradation and thermal degradation),surface volume conversion factor difference between conventional natural gas and NGH,and the impacts of differences in favorable distribution area and thickness and in other aspects on the results of NGH resource evaluation.The study shows that the global NGH initially in-place and recoverable resources are 99×10^(12) m^(3) and 30×10^(12) m3,with averages of 214×10^(12) m^(3) and 68×10^(12) m^(3),respectively,less than 5% of the total conventional oil and gas resources,and they can be used as a supplement for the future energy of the world.The proposed NGH resource evaluation model creates a new option of evaluation method and technology,and generates reliable data of NGH resource according to the reliability comprehensive analysis and test,providing a parameter basis for subsequent NGH exploration and development.
文摘In the global wave of energy transition and low-carbon development,China Petroleum Enterprise Association,together with the University of International Business and Economics,China University of Petroleum-Beijing,Southwest Petroleum University,and other institutions,released four significant blue books on April 17:Annual Operating Report of China’s Natural Gas Industry Blue Book(2024-2025),China Oil&Gas Industry Development Analysis and Outlook Blue Book(2024-2025),China Low-Carbon Economy Development Report Blue Book(2024-2025),and Refined Oil and New Energy Development Report Blue Book(2024-2025).This series of blue books provides a comprehensive and high-level analysis of the development,issues,and trends in the oil and gas industry,offering a detailed depiction of the China Oil&Gas industry and its progress towards low-carbon development.
文摘As the national carbon emission trading system extends to high energy-consuming industries,the petroleum exploration&development and refining&chemical engineering sectors face the dual challenges of rigid carbon constraints and energy structure restructuring.This study innovatively proposes the“dual inflection point theory”,which reveals that the transformation window requires the industry to overcome composite pressures including regional energy imbalances,international carbon tariff barriers,and technological substitution bottlenecks.This paper constructs a five-in-one governance framework encompassing“policy coordination,market circulation,intelligent regulation,energy substitution,energy efficiency innovation”.
基金funded by the National Natural Science Foundations of China(Grant No.42173054)。
文摘Light oil and gas reservoirs are abundant in the Ordovician marine carbonate reservoir in Shunbei Oilfield,Tarim Basin.This presents a compelling geological puzzle,as ultra-deep reservoirs undergo intense alteration and complex petroleum accumulation processes.A comprehensive suite of geochemical analyses,including molecular components,carbon isotope composition,homogenization temperature of saline inclusions,and burial-thermal history of single wells,was conducted to elucidate the genesis of these ancient reservoirs.Three petroleum filling events have been identified in the study area:Late Caledonian,Hercynian-Indosinian,and Himalayan,through analysis of homogenization temperatures of brine inclusions and burial-thermal histories.Additionally,the oil in the study area has undergone significant alteration processes such as biodegradation,thermal alteration,mixing,evaporative fractionation,and gas invasion.This study particularly emphasizes the influential role of Himalayan gas filling-induced evaporation fractionation and gas invasion in shaping the present petroleum phase distribution.Furthermore,analysis of light hydrocarbon and diamondoid parameters indicates the oil within the study area is at a high maturity stage,with equivalent vitrinite reflectance values ranging from 1.48%to 1.99%.Additionally,the analysis of light hydrocarbons,aromatics,and thiadiamondoids indicates that TSR should occur in reservoirs near the gypsum-salt layers in the Cambrian.The existence of the Cambrian petroleum system in the study area is strongly confirmed when considering the analysis results of natural gas type(oil cracking gas),evaporative fractionation,and gas invasion.Permian local thermal anomalies notably emerge as a significant factor contributing to the destruction of biomarkers in oil.For oil not subject to transient,abnormal thermal events,biomarker reliability extends to at least 190℃.In conclusion,examining the special formation mechanisms and conditions of various secondary processes can offer valuable insights for reconstructing the history of petroleum accumulation in ultradeep reservoirs.This research provides a scientific foundation for advancing our knowledge of petroleum systems and underscores the importance of hydrocarbon geochemistry in unraveling ultra-deep,complex geological phenomena.
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.
基金jointly supported by the National Natural Science Foundation of China(Grant Nos.42002178 and 42472203)“CUG Scholar”Scientific Research Funds at China University of Geosciences(Grant No.2022193)China National Petroleum Corporation(CNPC)Scientific Research and Technology Development Projects(Grant Nos.2019B-04 and 2021DJ05)。
文摘The reservoired petroleum fluids in the deep Ordovician carbonates in the Tazhong area,Tarim Basin,exhibit diverse and intricate geochemical properties and petroleum phases.However,the study on the causal mechanisms for the genesis of co-existed complex petroleum phases and their distribution remains relatively limited.The quantitative assessment of changes in molecular compounds in petroleum pools influenced by secondary alteration to different degrees also needs further investigation.In this study,eight samples including condensate,volatile,and black oil from the Tazhong area were analyzed via GC×GC-TOFMS.The results reveal that condensate oil exhibits complete normal alkane distribution,with abundant diamantanes and organic sulfur compounds(OSCs),and features high density(>0.83 g/cm^(3)),elevated wax content(>20%),and remarkable gas washing loss.The condensate gas is characterized by highly mature oil-cracking gas with a heavy carbon isotope.Geological analysis indicates that the current Ordovician reservoir temperatures generally remain below 140℃,which is insufficient to induce in-situ oil cracking.Additionally,black oil pools are formed adjacent to the condensate gas pools,suggesting that the latter is not a result of in-situ oil cracking,but rather represents a secondary condensate gas pool formed through gas invasion of a pre-existed oil pool.Based on the loss of n-alkanes and variations in adamantanes(As)and diamantanes(Ds)content across different oil samples,the degree of gas invasion was assessed.We divided gas invasion intensity into strong(Q≥80%,As≥5000μg/g,Ds≥400μg/g),weak(20%≤Q<80%,3000μg/g≤As<5000μg/g,200μg/g≤Ds<400μg/g)and negligible(0≤Q<20%,As<3000μg/g,Ds<200μg/g).The multistage oil/gas charging events,specifically the sequence of“early oil and late gas”in the Ordovician from the Tazhong area,predominantly drives the phase evolution of reservoired petroleum.Furthermore,differential gas invasion alteration exacerbates the intricacy of petroleum phase distribution.Notably,gas washing processes significantly influence the disparate enrichment of diamondoids homologues in crude oil.Specifically,lower carbon number diamondoids are more abundant in condensate oil,while higher ones exhibit relatively increased abundance in black oil,potentially serving as a valuable quantitative assessment parameter.The findings in this study will provide guiding significance for the analysis and quantitative assessment of deep petroleum phase diversity.Additionally,this research will provide novel insights for comprehensively evaluating basins worldwide with complex petroleum phases distribution.
基金Supported by the National Science and Technology Major Project for New Oil and Gas Exploration and Development(2025ZD1404200)Forward-looking and Fundamental Project of PetroChina Company Limited(2024DJ23)Scientific Research and Technology Development Project of PetroChina Research Institute of Petroleum Exploration&Development(2024vzz).
文摘There are various types of natural gas resources in coal measures,making them major targets for natural gas exploration and development in China.In view of the particularity of the whole petroleum system of coal measures and the reservoir-forming evolution of natural gas in coal,this study reveals the formation,enrichment characteristics and distribution laws of coal-rock gas by systematically reviewing the main types and geological characteristics of natural gas in the whole petroleum system of coal measures.First,natural gas in the whole petroleum system of coal measures is divided into two types,conventional gas and unconventional gas,according to its occurrence characteristics and accumulation mechanism,and into six types,distal detrital rock gas,special rock gas,distal/proximal tight sandstone gas,inner-source tight sandstone gas,shale gas,and coal-rock gas,according to its source and reservoir lithology.The natural gas present in coal-rock reservoirs is collectively referred to as coal-rock gas.Existing data indicate significant differences in the geological characteristics of coal-rock gas exploration and development between shallow and deep layers in the same area,with the transition depth boundary generally 1500-2000 m.Based on the current understanding of coal-rock gas and respecting the historical usage conventions of coalbed methane terminology,coal-rock gas can be divided into deep coal-rock gas and shallow coalbed methane according to burial depth.Second,according to the research concept of“full-process reservoir formation”in the theory of the whole petroleum system of coal measures,based on the formation and evolution of typical coal-rock gas reservoirs,coal-rock gas is further divided into four types:primary coal-rock gas,regenerated coal-rock gas,residual coal-rock gas,and bio coal-rock gas.The first two belong to deep coal-rock gas,while the latter two belong to shallow coal-rock gas.Third,research on the coal-rock gas reservoir formation and evolution shows that shallow coal-rock gas is mainly residual coal-rock gas or bio coal-rock gas formed after geological transformation of primary coal-rock gas,with the reservoir characteristics such as low reservoir pressure,low gas saturation,adsorbed gas in dominance,and gas production by drainage and depressurization,while deep coal-rock gas is mainly primary coal-rock gas and regenerated coal-rock gas,with the reservoir characteristics such as high reservoir pressure,high gas saturation,abundant free gas,and no or little water.In particular,the primary coal-rock gas is wide in distribution,large in resource quantity,and good in reservoir quality,making it the most favorable type of coal-rock gas for exploration and development.
基金funded by National Natural Science Foundation of China,grant number 62071491.
文摘Long-termpetroleum production forecasting is essential for the effective development andmanagement of oilfields.Due to its ability to extract complex patterns,deep learning has gained popularity for production forecasting.However,existing deep learning models frequently overlook the selective utilization of information from other production wells,resulting in suboptimal performance in long-term production forecasting across multiple wells.To achieve accurate long-term petroleum production forecast,we propose a spatial-geological perception graph convolutional neural network(SGP-GCN)that accounts for the temporal,spatial,and geological dependencies inherent in petroleum production.Utilizing the attention mechanism,the SGP-GCN effectively captures intricate correlations within production and geological data,forming the representations of each production well.Based on the spatial distances and geological feature correlations,we construct a spatial-geological matrix as the weight matrix to enable differential utilization of information from other wells.Additionally,a matrix sparsification algorithm based on production clustering(SPC)is also proposed to optimize the weight distribution within the spatial-geological matrix,thereby enhancing long-term forecasting performance.Empirical evaluations have shown that the SGP-GCN outperforms existing deep learning models,such as CNN-LSTM-SA,in long-term petroleum production forecasting.This demonstrates the potential of the SGP-GCN as a valuable tool for long-term petroleum production forecasting across multiple wells.
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Supported by CNPC Basic Technology Research and Development Project(2021DJ2203)National Science and Technology Major Project for New Oil and Gas Exploration and Development(2025ZD1400200).
文摘Based on the investigation of sedimentary filling characteristics and pool-forming factors of the Mesozoic in the Ordos Basin,the whole petroleum system in the Mesozoic is divided,the migration&accumulation characteristics and main controlling factors of conventional-unconventional hydrocarbons are analyzed,and the whole petroleum system model is established.First,the whole petroleum system developed in the Mesozoic takes the high-quality source rocks of the 7th member of the Triassic Yanchang Formation as the core and mainly consists of low-permeability and unconventional oil and gas reservoirs.It can be divided into four hydrocarbon accumulation domains,including intra-source retained hydrocarbon accumulation domain,near-source tight hydrocarbon accumulation domain,far-source conventional hydrocarbon accumulation domain and transitional hydrocarbon accumulation domain,which together form a continuous,symbiotic,and orderly accumulation entity wherein unconventional resources significantly outweigh conventional ones in proportion.Second,the spatial core area of sedimentary filling is the oil-rich core of the whole petroleum system.From the core to the periphery,the reservoir type evolves as shale oil→tight oil→conventional oil,the accumulation power is dominated by overpressure→buoyancy or overpressure and capillary force,the accumulation scale changes from extensive hundreds of millions of tons to a isolated hundreds of thousands-million of tons,and the gas-oil ratio and methane content decrease.Third,the sedimentary filling system provides the material basis and spatial framework for the whole petroleum system,the superimposed sand body,fault and unconformity constitute the dominant migration pathway of hydrocarbons in the far-source conventional hydrocarbon accumulation domain and the transitional hydrocarbon accumulation domain,the high-quality source rocks provide a solid resource basis for shale oil,and the micro-nano pore throat-fracture network constitute unconventional accumulation space.The hydrocarbon migration and accumulation process is mainly controlled by intense expulsion of hydrocarbon under overpressure in the pool-forming stage and the in-situ re-enrichment controlled by underpressure in post-pool-forming stage.The oil-gas enrichment and long-term preservation depends on the coordination among three factors(stable geological structure,multi-cycle sedimentation,and dual self-sealing).Fourth,the whole petroleum system model is defined as four domains,overpressure+underpressure drive,and dual self-sealing.
基金Supported by the National Natural Science Foundation of China(U22B6002)PetroChina Science Research and Technology Development Project(2021DJ0101)。
文摘This paper expounds the basic principles and structures of the whole petroleum system to reveal the pattern of conventional oil/gas-tight oil/gas-shale oil/gas sequential accumulation and the hydrocarbon accumulation models and mechanisms of the whole petroleum system.It delineates the geological model,flow model,and production mechanism of shale and tight reservoirs,and proposes future research orientations.The main structure of the whole petroleum system includes three fluid dynamic fields,three types of oil and gas reservoirs/resources,and two types of reservoir-forming processes.Conventional oil/gas,tight oil/gas,and shale oil/gas are orderly in generation time and spatial distribution,and sequentially rational in genetic mechanism,showing the pattern of sequential accumulation.The whole petroleum system involves two categories of hydrocarbon accumulation models:hydrocarbon accumulation in the detrital basin and hydrocarbon accumulation in the carbonate basin/formation.The accumulation of unconventional oil/gas is self-containment,which is microscopically driven by the intermolecular force(van der Waals force).The unconventional oil/gas production has proved that the geological model,flow model,and production mechanism of shale and tight reservoirs represent a new and complex field that needs further study.Shale oil/gas must be the most important resource replacement for oil and gas resources of China.Future research efforts include:(1)the characteristics of the whole petroleum system in carbonate basins and the source-reservoir coupling patterns in the evolution of composite basins;(2)flow mechanisms in migration,accumulation,and production of shale oil/gas and tight oil/gas;(3)geological characteristics and enrichment of deep and ultra-deep shale oil/gas,tight oil/gas and coalbed methane;(4)resource evaluation and new generation of basin simulation technology of the whole petroleum system;(5)research on earth system-earth organic rock and fossil fuel system-whole petroleum system.
基金Supported by the National Natural Science Foundation of China(U22B6002)PetroChina Science and Technology Project(2023ZZ14).
文摘Significant exploration progress has been made in ultra-deep clastic rocks in the Kuqa Depression,Tarim Basin,over recent years.A new round of comprehensive geological research has formed four new understandings:(1)Establish structural model consisting of multi-detachment composite,multi-stage structural superposition and multi-layer deformation.Multi-stage structural traps are overlapped vertically,and a series of structural traps are discovered in underlying ultra-deep layers.(2)Five sets of high-quality large-scale source rocks of three types of organic phases are developed in the Triassic and Jurassic systems,and forming a good combination of source-reservoir-cap rocks in ultra-deep layers with three sets of large-scale regional reservoir and cap rocks.(3)The formation of large oil and gas fields is controlled by four factors which are source,reservoir,cap rocks and fault.Based on the spatial configuration relationship of these four factors,a new three-dimensional reservoir formation model for ultra-deep clastic rocks in the Kuqa Depression has been established.(4)The next key exploration fields for ultra-deep clastic rocks in the Kuqa Depression include conventional and unconventional oil and gas.The conventional oil and gas fields include the deep multi-layer oil-gas accumulation zone in Kelasu,tight sandstone gas of Jurassic Ahe Formation in the northern structural zone,multi-target layer lithological oil and gas reservoirs in Zhongqiu–Dina structural zone,lithologic-stratigraphic and buried hill composite reservoirs in south slope and other favorable areas.Unconventional oil and gas fields include deep coal rock gas of Jurassic Kezilenuer and Yangxia formations,Triassic Tariqike Formation and Middle-Lower Jurassic and Upper Triassic continental shale gas.The achievements have important reference significance for enriching the theory of ultra-deep clastic rock oil and gas exploration and guiding the future oil and gas exploration deployment.
基金Supported by the CNPC Science and Technology Project(2024ZZ0203)。
文摘The ultra-deep(deeper than 8000 m)petroleum in the platform-basin zones of the Tarim Basin has been found mainly in the Lower Paleozoic reservoirs located to the east of the strike-slip fault F5 in the north depression.However,the source and exploration potential of the ultra-deep petroleum in the Cambrian on the west of F5 are still unclear.Through the analysis of lithofacies and biomarkers,it is revealed that there are at least three kinds of isochronous source rocks(SRs)in the Cambrian Newfoundland Series in Tarim Basin,which were deposited in three sedimentary environments,i.e.sulfide slope,deep-water shelf and restricted bay.In 2024,Well XT-1 in the western part of northern Tarim Basin has yielded a high production of condensate from the Cambrian.In the produced oil,entire aryl-isoprenoid alkane biomarkers were detected,but triaromatic dinosterane was absent.This finding is well consistent with the geochemical characteristics of the Newfoundland sulfidized slope SRs represented by those in wells LT-1 and QT-1,suggesting that the Newfoundland SRs are the main source of the Cambrian petroleum discovered in Well XT-1.Cambrian crude oil of Well XT-1 also presents the predominance of C29 steranes and is rich in long-chain tricyclic terpanes(up to C39),which can be the indicators for effectively distinguishing lithofacies such as siliceous mudstone and carbonate rock.Combined with the analysis of hydrocarbon accumulation in respect of conduction systems including thrust fault and strike-slip fault,it is found that the area to the west of F5 is possible to receive effective supply of hydrocarbons from the Cambrian Newfoundland SRs in Manxi hydrocarbon-generation center.This finding suggests that the area to the west of F5 will be a new target of exploration in the Cambrian ultra-deep structural-lithologic reservoirs in the Tarim Basin,in addition to the Cambrian ultra-deep platform-margin facies-controlled reservoirs in the eastern part of the basin.
文摘Overpressure prediction for exploratory drilling has become robust in most basins with increasing well control,high-quality seismic datasets,and proactive real-time overpressure monitoring while drilling.However,accurate overpressure prediction remains challenging in offshore Northwest Borneo despite several decades of drilling experience.This paper focuses on two exploration wells drilled by Brunei Shell Petroleum 40 years apart that faced similar challenges with overpressure prediction and well control.An integrated lookback study is attempted using seismic and well-log data to explore the causes of the unsatisfactory Pore Pressure Prediction(PPP)outcome in pre-drill and real-time operation settings for thesewells.Our study indicates that the misprediction of overpressures is due to real differences in shale pressure(basis of pre-drill work and monitoring)and sand pressure(source of drill kick and well control chal-lenges)due to large-scale vertical leak or expulsion of deep-seated fluids into pre-compacted normally pressured overlying sediments in several regions through a mix of shear and tensile failure mechanisms.Such migrated fluids inflate the sand pressure in the normally compacted shallower sequences with the shale pressure remaining low.A predictive framework for upward fluid expulsion was attempted but found impracticable due to complex spatial and temporal variations in the horizontal stress field responsible for such leakage.As such,it is proposed that these migratory overpressures are essentially'unpredictable'from conventional PPP workflows viewed in the broad bucket of compaction disequi-librium(undercompaction)and fluid expansion(unloading)mechanisms.Further study is recommended to understand if such migrated overpressures in the sand can produce a discernible and predictable geophysical or petrophysical signature in the abutting normally compacted shales.The study highlights the possibility of large lateral variability in the sand overpressure within the same stratigraphic unit in regions with complex tectonostratigraphic evolution like Northwest Borneo.
基金funded by the Natural Science Foundation of China(Grants Nos.42272167,U24B6001,and 41772153)Science&Technology Project of Sinopec(Grant Nos.P23167 and P24173).
文摘Thiadiamondoids(TDs)have recently attracted increasing attention as molecular proxies for thermochemical sulfate reduction(TSR)reactions in reservoirs.However,their formation mechanisms,as well as the generation and evolution processes,remain poorly understood.In this study,simulation experiments with a duration of 160 h were conducted on the model compound 1,3-dimethyladamantane(1,3-DMA)using the CaSO_(4),MgSO_(4),and elemental S systems,with measurements at the 10th,20th,40th,80th and 160th hours during the simulation process being presented.The results indicate that at the end of simulation,the MgSO_(4) system exhibited the lowest residual amounts of 1,3-DMA,suggesting the highest degree of TSR.Four types of non-hydrocarbon compounds with adamantane structures were detected in the liquid products in the three experiment systems:adamantanones,adamantanols,adamantanethiols(ATs),and thiaadamantanes(TAs).Among these,adamantanones exhibited the highest concentrations in the three simulation systems.In addition,TAs were dominated by C_(3)-TAs in the CaSO_(4) and MgSO_(4) systems and by C_(2)-TAs in the elemental S system.The simulation experiments revealed a strong correlation between the concentrations of TAs and adamantanones,suggesting that adamantanones might be the intermediates for TAs.Combined with the synthesis mechanism of TAs from thiaadamamantane-4,8-dione,TDs might have two different genetic mechanisms:(a)low temperature cationic carbon ion rearrangement from diagenesis to early catagenesis stage,and(b)a free sulfur radical mechanism in high-temperature TSR process during middle-late catagenesis.TAs exhibited different generation and evolution processes across different experiment systems.Notably,the MgSO_(4) system revealed that TAs undergo generation,accumulation,and destruction process,corresponding to Easy%Ro values of 0.89%-0.98%,0.98%-1.21%,and>1.21%,respectively.Among these three simulation systems,dibenzothiophenes(DBTs)concentrations consistently trended upwards,indicating TAs have lower thermal stability than DBTs.
基金Supported by the Scientific and Technological Project of the Southwest Oil and Gas Field Company of PetroChina(20230301-23)。
文摘Based on the oil and gas exploration in the Sichuan Basin,combined with data such as seismic,logging and geochemistry,the basic geological conditions,hydrocarbon types,hydrocarbon distribution characteristics,source-reservoir relationship and accumulation model of the Upper Triassic–Jurassic continental whole petroleum system in the basin are systematically analyzed.The continental whole petroleum system in the Sichuan Basin develops multiple sets of gas-bearing strata,forming a whole petroleum system centered on the Triassic Xujiahe Formation source rocks.The thick and high-quality source rocks in the Upper Triassic Xujiahe Formation provide sufficient gas source basis for the continental whole petroleum system in the basin.The development of conventional-unconventional reservoirs provides favorable space for hydrocarbon accumulation.The coupling of faults and sandbodies provides a high-quality transport system for gas migration.Source rocks and reservoirs are overlapped vertically,and there are obvious differences in sedimentary environment,reservoir lithology and physical properties,which lead to the orderly development of inner-source shale gas,near-source tight gas,and far-source tight–conventional gas in the Upper Triassic–Jurassic,from bottom to top.The orderly change of geological conditions such as burial depth,reservoir physical properties,formation pressure and hydrocarbon generation intensity in zones controlled the formation of the whole petroleum system consisting of structural gas reservoir in thrust zone,shale gas-tight gas reservoir in depression zone,tight gas reservoir in slope zone,and tight gas–conventional gas reservoir in uplift zone on the plane.Based on the theory and concept of the whole petroleum system,the continental shale gas and tight gas resources in the Sichuan Basin have great potential,especially in the central and western parts with abundant unconventional resources.
基金Supported by National Key Research and Development Program of China(2017YFC0603101)National Natural Science Foundation of China(42225303,42372162,42102146)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(XDA14010101)Basic and Forward-Looking Major Technology Project of China National Petroleum Corporation(2023ZZ0203)。
文摘Taking the Paleozoic of the Sichuan and Tarim basins in China as example,the controlling effects of the Earth system evolution and multi-spherical interactions on the formation and enrichment of marine ultra-deep petroleum in China have been elaborated.By discussing the development of“source-reservoir-seal”controlled by the breakup and assembly of supercontinents and regional tectonic movements,and the mechanisms of petroleum generation and accumulation controlled by temperature-pressure system and fault conduit system,Both the South China and Tarim blocks passed through the intertropical convergence zone(ITCZ)of the low-latitude Hadley Cell twice during their drifts,and formed hydrocarbon source rocks with high quality.It is proposed that deep tectonic activities and surface climate evolution jointly controlled the types and stratigraphic positions of ultra-deep hydrocarbon source rocks,reservoirs,and seals in the Sichuan and Tarim basins,forming multiple petroleum systems in the Ediacaran-Cambrian,Cambrian-Ordovician,Cambrian-Permian and Permian-Triassic strata.The matching degree of source-reservoir-seal,the type of organic matter in source rocks,the deep thermal regime of basin,and the burial-uplift process across tectonic periods collectively control the entire process from the generation to the accumulation of oil and gas.Three types of oil and gas enrichment models are formed,including near-source accumulation in platform marginal zones,distant-source accumulation in high-energy beaches through faults,and three-dimensional accumulation in strike-slip fault zones,which ultimately result in the multi-layered natural gas enrichment in ultra-deep layers of the Sichuan Basin and co-enrichment of oil and gas in the ultra-deep layers of the Tarim Basin.
基金Supported by the Sichuan Province Regional Innovation Cooperation Project(21QYCX0048)Sinopec Science and Technology Department Project(P21048-3)。
文摘According to the complex differential accumulation history of deep marine oil and gas in superimposed basins,the Lower Paleozoic petroleum system in Tahe Oilfield of Tarim Basin is selected as a typical case,and the process of hydrocarbon generation and expulsion,migration and accumulation,adjustment and transformation of deep oil and gas is restored by means of reservoine-forming dynamics simulation.The thermal evolution history of the Lower Cambrian source rocks in Tahe Oilfield reflects the obvious differences in hydrocarbon generation and expulsion process and intensity in different tectonic zones,which is the main reason controlling the differences in deep oil and gas phases.The complex transport system composed of strike-slip fault and unconformity,etc.controlled early migration and accumulation and late adjustment of deep oil and gas,while the Middle Cambrian gypsum-salt rock in inner carbonate platform prevented vertical migration and accumulation of deep oil and gas,resulting in an obvious"fault-controlled"feature of deep oil and gas,in which the low potential area superimposed by the NE-strike-slip fault zone and deep oil and gas migration was conducive to accumulation,and it is mainly beaded along the strike-slip fault zone in the northeast direction.The dynamic simulation of reservoir formation reveals that the spatio-temporal configuration of"source-fault-fracture-gypsum-preservation"controls the differential accumulation of deep oil and gas in Tahe Oilfield.The Ordovician has experienced the accumulation history of multiple periods of charging,vertical migration and accumulation,and lateral adjustment and transformation,and deep oil and gas have always been in the dynamic equilibrium of migration,accumulation and escape.The statistics of residual oil and gas show that the deep stratum of Tahe Oilfield still has exploration and development potential in the Ordovician Yingshan Formation and Penglaiba Formation,and the Middle and Upper Cambrian ultra-deep stratum has a certain oil and gas resource prospect.This study provides a reference for the dynamic quantitative evaluation of deep oil and gas in the Tarim Basin,and also provides a reference for the study of reservoir formation and evolution in carbonate reservoir of paleo-craton basin.
文摘Petroleum asphalt,an important by-product of the petrochemical industry,has diverse applications but often suffers from low industrial added value.Because of its low cost,high carbon content,and high polycyclic aromatic hydrocarbon content,appropriate modification can increase its value and expand its energy storage applications.Current research progress on the common preparation methods of petroleum asphalt-based carbon materials,including template-assisted pyrolysis,molten salt treatment,activation,heteroatom doping,and pre-oxidation is reviewed,and its use in supercapacitors and alkali metal ion batteries,is also elaborated.Feasible solutions for the current problems with petroleum asphalt are proposed,with the aim of providing insights into its high value-added utilization.
