Fine-grained sediments are widely distributed and constitute the most abundant component in sedi-mentary systems,thus the research on their genesis and distribution is of great significance.In recent years,fine-graine...Fine-grained sediments are widely distributed and constitute the most abundant component in sedi-mentary systems,thus the research on their genesis and distribution is of great significance.In recent years,fine-grained sediment gravity-flows(FGSGF)have been recognized as an important transportation and depositional mechanism for accumulating thick successions of fine-grained sediments.Through a comprehensive review and synthesis of global research on FGSGF deposition,the characteristics,depositional mechanisms,and distribution patterns of fine-grained sediment gravity-flow deposits(FGSGFD)are discussed,and future research prospects are clarified.In addition to the traditionally recognized low-density turbidity current and muddy debris flow,wave-enhanced gravity flow,low-density muddy hyperpycnal flow,and hypopycnal plumes can all form widely distributed FGSGFD.At the same time,the evolution of FGSGF during transportation can result in transitional and hybrid gravity-flow deposits.The combination of multiple triggering mechanisms promotes the widespread develop-ment of FGSGFD,without temporal and spatial limitations.Different types and concentrations of clay minerals,organic matters,and organo-clay complexes are the keys to controlling the flow transformation of FGSGF from low-concentration turbidity currents to high-concentration muddy debris flows.Further study is needed on the interaction mechanism of FGSGF caused by different initiations,the evolution of FGSGF with the effect of organic-inorganic synergy,and the controlling factors of the distribution pat-terns of FGSGFD.The study of FGSGFD can shed some new light on the formation of widely developed thin-bedded siltstones within shales.At the same time,these insights may broaden the exploration scope of shale oil and gas,which have important geological significances for unconventional shale oil and gas.展开更多
Key technologies that make productivity increase are revealed through analyzing the best practices and production data in major shale basins of North America.Trends of the key technologies and optimization designs for...Key technologies that make productivity increase are revealed through analyzing the best practices and production data in major shale basins of North America.Trends of the key technologies and optimization designs for shale oil and gas development are summarized and analyzed based on drilling and completion operations and well data.These technologies mainly include:(1)Optimizing well design and hydraulic fracturing design,including reducing cluster spacing,increasing proppant and fracturing fluid volumes,optimizing horizontal well lateral length and fracture stage length.The most effective method is to reduce cluster spacing to an optimized length.The second most effective method is to optimally increase proppant volumes.(2)Placing horizontal wells in the sweet spots and drilling the wells parallel or close to the minimum horizontal stress direction.(3)Using cube development with optimized well spacing to maximize resource recovery and reduce well interferences.Plus,in-situ stress impacts on hydraulic fracture propagation and hydrocarbon production are addressed.Determination of formation breakdown pressure is studied by considering the impacts of in-situ stresses,drilling and perforation directions.Whether or not the hydraulic fracturing can generate orthogonal fracture networks is also discussed.The key technologies and optimization design parameters proposed in this paper can be applied to guide new well placement,drilling and completion designs,and hydraulic fracture operations to increase productivity.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
In July 2025,Claudio Descalzi,CEO of Italian oil company Eni,stated in an interview with the Financial Times that Eni’s low-carbon business operating profits would equal those of its oil and gas business by 2035 and ...In July 2025,Claudio Descalzi,CEO of Italian oil company Eni,stated in an interview with the Financial Times that Eni’s low-carbon business operating profits would equal those of its oil and gas business by 2035 and exceed oil and gas business profits by 2040.Meanwhile,British oil company bp is scaling back its low-carbon business under shareholder pressure,returning to traditional oil and gas operations,and plans to gradually dispose of USD 20 billion worth of low-carbon business assets such as onshore wind farms,aiming to increase oil and gas production to 2.3−2.5 million boe per day by 2030.Two European oil companies are heading in completely different strategic directions.In the future,whether Eni can achieve its expected goals of making renewable energy business a key core business,as well as what development strategies oil and gas companies should implement and adhere to,are questions worthy of deep consideration.展开更多
The Jurassic tight sandstone oil and gas exploration and development in the eastern Yangxia Sag is a new field.To elucidate the origin,accumulation process and potential of tight oil and gas,the authors have conducted...The Jurassic tight sandstone oil and gas exploration and development in the eastern Yangxia Sag is a new field.To elucidate the origin,accumulation process and potential of tight oil and gas,the authors have conducted comprehensive analyses employing methodologies encompassing source rocks,oil geochemistry,and fluid inclusions.The results show that the abundance of organic matter of Jurassic source rocks is high,and the type of organic matter is ofⅡ-Ⅲand in mature evolution stage.The main source rocks of oil and gas are Huangshanjie Formation and Jurassic coal-bearing source rocks.Ahe Formation developed two stages of hydrocarbon charging,and the period is later than the reservoir densification time.Yangxia Formation oil charged before the reservoir densified,and the late gas charged after the reservoir densified.Hydrocarbon generation intensity of Jurassic source rocks has reached the basic conditions for the formation of tight gas reservoirs.Controlled by the difference of source rocks distribution and accumulation process,tight sandstone oil and gas accumulation conditions are better in the depression direction than in the southeast margin area.This study is of practical importance for expanding the exploration field and selecting favorable areas in the eastern Yangxia sag.展开更多
Represented by CNPC,Chinese national oil companies go overseas conducting international oil and gas collaboration.Q4:To address domestic energy supply shortages,fully utilize international oil and gas resources,and st...Represented by CNPC,Chinese national oil companies go overseas conducting international oil and gas collaboration.Q4:To address domestic energy supply shortages,fully utilize international oil and gas resources,and strengthen international oil and gas cooperation while further enhancing core competitiveness,China’s petroleum enterprises proposed the strategic concept of effectively leveraging both domestic and international resources and markets,literally the strategy of“two resources and two markets”as early as the 1990s and resolutely took the first step in the great endeavor of“going overseas”.Through international cooperation and operations,state-owned oil enterprises represented by CNPC have not only ensured national energy security and enhanced corporate competitiveness,but also made significant contributions to global energy cooperation and advancement of Belt and Road Initiative.Could you please discuss the situation of Chinese petroleum enterprises’international oil and gas cooperation and their achievements in the field of petroleum exploration and development?展开更多
Since 2011,America has maintained its position as the world’s largest natural gas producer.Since 2017,America has consistently experienced a surplus in natural gas supply,becoming a net exporter of natural gas.Americ...Since 2011,America has maintained its position as the world’s largest natural gas producer.Since 2017,America has consistently experienced a surplus in natural gas supply,becoming a net exporter of natural gas.America’s“natural gas independence”has reshaped the global natural gas market,creating a new pattern of“supply shifting westward and consumption shifting eastward”.展开更多
The potential of the vertical-horizontal well hybrid SAGD technique for developing shallow heavy oil reservoirs is gradually being realized.However,challenges remain in terms of low thermal efficiency and high carbon ...The potential of the vertical-horizontal well hybrid SAGD technique for developing shallow heavy oil reservoirs is gradually being realized.However,challenges remain in terms of low thermal efficiency and high carbon emissions in reservoirs with interlayers.Currently,there is limited research on the low-carbon strategy of coupling exhaust gas from steam boilers with the VH-SAGD technique.Herein,considering heterogeneity,a series of flue gas-assisted VH-SAGD experiments were conducted employing a high-performance 2D visualization model.The mechanism of enhanced recovery of flue gas in VH-SAGD and the effect of its injection methods were studied,with a focus on steam chamber development and oil saturation distribution.Crucially,the interlayer length was optimized to enhance oil recovery,providing a new perspective for well location design in heavy oil reservoirs with interlayers.The results showed that flue gas,as an additive,could fully exploit the well-type advantage of VH-SAGD.By supplementing energy at the reservoir top,flue gas effectively promoted steam chamber development,expanded the oil drainage area of VH-SAGD,and increased the oil recovery from 58.9%to 71.7%.The flow channels formed by pre-injection flue gas accelerated the early-stage expansion of the steam chamber while also inducing lateral migration of steam,slowing steam rise,and consequently increasing the heating range within the low-permeability layer.When the distance between the vertical and horizontal wells was set to twice the interlayer length,the negative effects of the interlayer were more effectively turned into advantages.Because when the lateral development distance of the steam chamber in the low-permeability layer slightly exceeds the interlayer,enhanced heating of the lower part of the reservoir occurred through vertical convection of rising steam and returning condensate.The research results contribute to reducing carbon emissions from steam-based heavy oil extraction while advancing the maturity of VH-SAGD.展开更多
This paper analyses the impact of oil and gas pipelines on the environment and settlements from the perspective of environmental justice,using a case study of the oil-producing communities in the Niger Delta region of...This paper analyses the impact of oil and gas pipelines on the environment and settlements from the perspective of environmental justice,using a case study of the oil-producing communities in the Niger Delta region of Nigeria.The paper mobilises theories of environmental justice to support an in-depth empirical analysis of the development and management of oil and gas pipelines in the region.The empirical evidence equally suggests that the lack of community involvement and appropriate recognition of some groups of stakeholders in the management of the oil and gas pipeline project is strongly related to the incidence of pipeline impacts on the communities[1].The paper advocates a new approach,based on the core principles of environmental justice that promotes inclusion of the necessary stakeholders,including the physical planners,and would incorporate local knowledge and experience into the environmental management of the region in a way to protect the environment and people from the impacts of the pipeline[2].展开更多
With the development of offshore oil and gas resources,hydrates pose a significant challenge to flow assurance.Hydrates can form,accumulate,and settle in pipelines,causing blockages,reducing transport capacity,and lea...With the development of offshore oil and gas resources,hydrates pose a significant challenge to flow assurance.Hydrates can form,accumulate,and settle in pipelines,causing blockages,reducing transport capacity,and leading to significant economic losses and fatalities.As oil and gas exploration moves deeper into the ocean,the issue of hydrate blockages has become more severe.It is essential to take adequate measures promptly to mitigate the hazards of hydrate blockages after they form.However,a prerequisite for effective mitigation is accurately detecting the location and amount of hydrate formation.This article summarizes the temperature–pressure,acoustic,electrical,instrumental–response,and flow characteristics of hydrate formation and blocking under various conditions.It also analyzes the principles,limitations,and applicability of various blockage detection methods,including acoustic,transient,and fiber-optic-based methods.Finally,it lists the results of field experiments and commercially used products.Given their advantages of accuracy and a wide detection range,acoustic pulse reflectometry and transient-based methods are considered effective for detecting hydrate blockages in future underwater pipelines.Using strict backpressure warnings combined with accurate detection via acoustic pulse reflectometry or transient-based methods,efficient and timely diagnosis of hydrate blockages can be achieved.The use of a hydrate model combined with fiber optics could prove to be an effective method for detecting blockages in newly laid pipelines in the future.展开更多
Pressure-preserving controllers(PPCs)are crucial components of in situ pressure-preserving coring(IPP-Coring)devices for deep oil and gas extraction,and their ultimate pressure-bearing(UPB)capability determines the up...Pressure-preserving controllers(PPCs)are crucial components of in situ pressure-preserving coring(IPP-Coring)devices for deep oil and gas extraction,and their ultimate pressure-bearing(UPB)capability determines the upper limit of their ability to acquire oil and gas reserves.However,due to the UPB-capability and sealing challenges,the working pressure typically does not exceed 70 MPa.In this study,the optimal design of a PPC using a self-developed IPP-Coring test platform is presented,and its seal failure mechanism is revealed.Experimental results demonstrate that the designed saddle-shaped PPC achieves a minimal UPB-capability of 140 MPa,which is twice the highest value reported in literature.A numerical simulation method was developed to predict the UPB-capability of the PPC,and its reliability was validated in comparison with experimental results.The simulation results indicate that the sealing failure of the PPC is attributed to a progressive escalation in seal clearance between valve cover and seat,which causes an O-ring extrusion.Under ambient temperature and ultrahigh pressure,the critical threshold for seal clearance in PPC seal failure is approximately 0.2 mm.These results provide significant insights into enhancing deep resource acquisition capabilities.展开更多
As industrialization and informatization in China deeply integrate and the Internet of Things rapidly develops,industrial control systems are facing increasingly severe information security challenges.The industrial c...As industrialization and informatization in China deeply integrate and the Internet of Things rapidly develops,industrial control systems are facing increasingly severe information security challenges.The industrial control system of the gas extraction plant is characterized by numerous points and centralized operations,with a strong reliance on the system and stringent real-time requirements.展开更多
In recent years,large language models(LLMs)have demonstrated immense potential in practical applications to enhance work efficiency and decision-making capabilities.However,specialized LLMs in the oil and gas engineer...In recent years,large language models(LLMs)have demonstrated immense potential in practical applications to enhance work efficiency and decision-making capabilities.However,specialized LLMs in the oil and gas engineering area are rarely developed.To aid in exploring and developing deep and ultra-deep unconventional reservoirs,there is a call for a personalized LLM on oil-and gas-related rock mechanics,which may handle complex professional data and make intelligent predictions and decisions.To that end,herein,we overview general and industry-specific LLMs.Then,a systematic workflow is proposed for building this domain-specific LLM for oil and gas engineering,including data collection and processing,model construction and training,model validation,and implementation in the specific domain.Moreover,three application scenarios are investigated:knowledge extraction from textural resources,field operation with multidisciplinary integration,and intelligent decision assistance.Finally,several challenges in developing this domain-specific LLM are highlighted.Our key findings are that geological surveys,laboratory experiments,field tests,and numerical simulations form the four original sources of rock mechanics data.Those data must flow through collection,storage,processing,and governance before being fed into LLM training.This domain-specific LLM can be trained by fine-tuning a general open-source LLM with professional data and constraints such as rock mechanics datasets and principles.The LLM can then follow the commonly used training and validation processes before being implemented in the oil and gas field.However,there are three primary challenges in building this domain-specific LLM:data standardization,data security and access,and striking a compromise between physics and data when building the model structure.Some of these challenges are administrative rather than technical,and overcoming those requires close collaboration between the different interested parties and various professional practitioners.展开更多
The importance of organic geochemistry and basin modeling is widely recognized and used to understand the source rock potential and hydrocarbon generation history of the Mangahewa Formation,and thereby given the found...The importance of organic geochemistry and basin modeling is widely recognized and used to understand the source rock potential and hydrocarbon generation history of the Mangahewa Formation,and thereby given the foundational role in the petroleum exploration.This study utilized the total organic carbon(TOC)content and hydrogen index(HI)to investigate the dominant kerogen type and hydrogen richness for the significance of petroleum generative potential.The Mangahewa coals and carbonaceous shales exhibit an excellent source rocks,with high total organic content(TOC)of more than 22%.The coals and carbonaceous shales were also characterised by Type Ⅱ‒Ⅲ kerogen with Type Ⅲ kerogen,promising oiland gas-prones.The Mangahewa Formation reached the main oil generation,with vitrinite reflectances between 0.53%and 1.01%.Vitrinite reflectance was also used in developing themal models and reveal the transformation(TR)of 10‒50%kerogen to oil during the Late Miocene.The models also showed that the Mangahewa source rock has a significant oil generation and little expulsion competency,with a TR of up to 54%.These findings support the substantial oil-generating potential in the Taranaki Basin's southern graben and can be used as a guide when developing strategies for an oil exploration program.展开更多
The BZ oilfield in the Bohai Sea is a rare,highly volatile reservoir with fractures in the metamorphic rocks of buried hills.Clarifying the mechanism of gas injection for improving oil recovery and determining the opt...The BZ oilfield in the Bohai Sea is a rare,highly volatile reservoir with fractures in the metamorphic rocks of buried hills.Clarifying the mechanism of gas injection for improving oil recovery and determining the optimal way to deploy injection-production well networks are critical issues that must be urgently addressed for efficient oilfield development.Experimental research on the mixed-phase displacement mechanism through gas injection into indoor formation fluids was conducted to guide the efficient development of gas injection in oil fields.We established a model of dual-medium reservoir composition and researched the deployment strategy for a three-dimensional well network for gas injection development.The coupling relationship between key influencing factors of the well network and fracture development was also quantitatively analyzed.The results show that the solubility of the associated gas and strong volatile oil system injected into the BZ oilfield is high.This high solubility demonstrates a mixed-phase displacement mechanism involving intermediate hydrocarbons,dissolution and condensation of medium components,and coexistence of extraction processes.Injecting gas and crude oil can achieve a favorable mixing effect when the local formation pressure is greater than 35.79 MPa.Associated gas reinjection is recommended to supplement energy for developing the highly volatile oil reservoirs in the fractured buried hills of the BZ oilfield.This recommendation involves fully utilizing the structural position and gravity-assisted oil displacement mechanism to deploy an injection-production well network.Gas injection points should be constructed at the top of high areas,and oil production points should be placed at the middle and lower parts of low areas.This approach forms a spatial threedimensional well network.By adopting high inclination well development,the oil production well forms a 45°angle with the fracture direction,which increases the drainage area and enhances single-well production capacity.The optimal injection-production well spacing along the fracture direction is approximately 1000 m,while the reasonable well spacing in the vertical fracture direction is approximately 800 m.The research results were applied to the development practice of the buried hills in the BZ oilfield,which achieved favorable development results.These outcomes provide a valuable reference for the formulation of development plans and efficient gas injection development in similar oil and gas fields in buried hills.展开更多
China’s energy resource endowment is characterized by being“poor in oil,scarce in gas,and rich in coal”,a fundamental national condition that determines the uniqueness of China’s energy strategy.At the beginning o...China’s energy resource endowment is characterized by being“poor in oil,scarce in gas,and rich in coal”,a fundamental national condition that determines the uniqueness of China’s energy strategy.At the beginning of the 20th century,foreign experts and scholars generally concluded and claimed that China was an“oil-poor country”lacking the geological conditions for hydrocarbon formation.展开更多
A novel temperature-preserved core chamber designed for depths exceeding 5000 m has been developed to enhance the scientific understanding of deep oil and gas reservoirs.This temperature-preserved core chamber employs...A novel temperature-preserved core chamber designed for depths exceeding 5000 m has been developed to enhance the scientific understanding of deep oil and gas reservoirs.This temperature-preserved core chamber employs an innovative vacuum layer for temperature preservation and is compatible with a temperature-pressure preserved coring system.The design principles and key parameters of the temperature-preserved core chamber were determined through static analysis.Numerical simulations assessed the mechanical properties of 70,85,and 100 MPa core chambers under conditions of 120-150℃.The results demonstrate that the temperature-preserved core chambers withstand the applied stresses without plastic deformation,and the vacuum layer maintains its integrity under these conditions.A 70 MPa class core chamber prototype was manufactured,and system integration tests were performed on a self-developed in-situ coring platform.The system demonstrated stable operation at 70 MPa for 120 min,with pressure fluctuations within 5%.Additionally,the integrated system operated without interference,enabling the successful extraction of cores with a 50 mm diameter.These findings provide valuable theoretical guidance and design recommendations for advancing oil and gas in-situ temperature-pressure preserved coring technologies in high-temperature and high-pressure environments.展开更多
The development of gas condensate reservoirs with a large gas cap,thin oil rim,strong bottom water,and natural barriers faces numerous challenges,including reservoir heterogeneity,coning effects,phase changes,and mult...The development of gas condensate reservoirs with a large gas cap,thin oil rim,strong bottom water,and natural barriers faces numerous challenges,including reservoir heterogeneity,coning effects,phase changes,and multiphase flow dynamics.The influx of gas and water may lead to a low recovery of the oil rim,while reservoir heterogeneity and natural barriers further exacerbate the uneven distribution of reservoir fluid,complicating development strategies.This paper aims to investigate innovative and effective development strategies for this type of reservoir.A detailed,proportionally scaled numerical simulation is performed based on the experimental results of an artificial sand-filled model,providing novel insights into the dynamic behavior of these reservoirs.By understanding the phase behavior and fluid flow characteristics of the reservoir,the study simulates various strategies for the rational and efficient development of the gas condensate reservoir.These strategies include well patterns and completions,the decision to develop the oil rim or gas cap,depletion rates,the bottom water control,and gas injection.The results show that horizontal wells or highly deviated wells are more suitable for the development of the oil rim,as they provide larger control ranges.The presence of strong bottom water is advantageous for displacement energy supply and pressure maintenance,but it intensifies water coning effects,leading to an earlier breakthrough and a sharp production decline.Therefore,it is preferable to apply highly deviated wells at the oil-gas contact,developing the oil rim at lower rates and smaller pressure gradients,followed by developing the gas cap.This approach can reduce water coning effects and improve recovery,with oil and gas recovery reaching 24.4%and 67.95%,respectively,which is an increase of 16.74%and 17.84%compared to direct depletion development of the gas cap.Due to the strong water bottom,continuous gas injection at the top of the reservoir becomes challenging.This study introduces gas assisted gravity drainage with water control technology,a novel and highly effective approach that addresses the impact of bottom water coning effects on the oil and gas zones and overcomes the limitations of gas flooding in reservoirs with strong bottom water.This method can significantly improve oil and gas recovery,achieving recovery of 39.74%and 84.50%,respectively.Compared to the conventional depletion strategy of sequential oil rim and gas cap development,this method achieves additional improvements of 15.33%and 16.55%in oil and gas recovery,respectively.展开更多
The total replacement of old fossil fuels poses obstacles,making the production of efficient biogasoline vital.Despite its potential as an environmentally friendly fossil fuel substitute,the life cycle assessment(LCA)...The total replacement of old fossil fuels poses obstacles,making the production of efficient biogasoline vital.Despite its potential as an environmentally friendly fossil fuel substitute,the life cycle assessment(LCA)of palm oil-derived biogasoline remains underexplored.This study investigated the production of biogasoline fromcrude palm oil(CPO)based biorefinery using catalytic cracking over mesoporousγ-Al_(2)O_(3) catalyst and LCA analysis.High selectivity of converting CPO into biogasoline was achieved by optimizing catalytic cracking parameters,including catalyst dose,temperature,and contact time.γ-Al_(2)O_(3) and CPO were characterized by several methods to study the physical and chemical properties.The physical properties of biogasoline,such as density,calorific value,viscosity,and flash point,were investigated.An overall yield of 60.11%was achieved after catalytic cracking produced several C5-C11 short-chain hydrocarbons.Additionally,this research proposes innovative emission reduction strategies,including waste-to-biogasoline conversion and the use of biodegradable feedstocks that enhance the sustainability of biogasoline production.LCA ofγ-Al_(2)O_(3)’s energy and environmental implications reveals minor effects on global warming(0.0068%)and freshwater ecotoxicity(0.187%).LCAs show a 0.085%impact in the energy sector.This focus on both ecological impacts and practical mitigation strategies deepens the understanding of biogasoline production.展开更多
Carbon dioxide Enhanced Oil Recovery(CO_(2)-EOR)technology guarantees substantial underground CO_(2) sequestration while simultaneously boosting the production capacity of subsurface hydrocarbons(oil and gas).However,...Carbon dioxide Enhanced Oil Recovery(CO_(2)-EOR)technology guarantees substantial underground CO_(2) sequestration while simultaneously boosting the production capacity of subsurface hydrocarbons(oil and gas).However,unreasonable CO_(2)-EOR strategies,encompassing well placement and well control parameters,will lead to premature gas channeling in production wells,resulting in large amounts of CO_(2) escape without any beneficial effect.Due to the lack of prediction and optimization tools that integrate complex geological and engineering information for the widely used CO_(2)-EOR technology in promising industries,it is imperative to conduct thorough process simulations and optimization evaluations of CO_(2)-EOR technology.In this paper,a novel optimization workflow that couples the AST-GraphTrans-based proxy model(Attention-based Spatio-temporal Graph Transformer)and multi-objective optimization algorithm MOPSO(Multi-objective Particle Swarm Optimization)is established to optimize CO_(2)-EOR strategies.The workflow consists of two outstanding components.The AST-GraphTrans-based proxy model is utilized to forecast the dynamics of CO_(2) flooding and sequestration,which includes cumulative oil production,CO_(2) sequestration volume,and CO_(2) plume front.And the MOPSO algorithm is employed for achieving maximum oil production and maximum sequestration volume by coordinating well placement and well control parameters with the containment of gas channeling.By the collaborative coordination of the two aforementioned components,the AST-GraphTrans proxy-assisted optimization workflow overcomes the limitations of rapid optimization in CO_(2)-EOR technology,which cannot consider high-dimensional spatio-temporal information.The effectiveness of the proposed workflow is validated on a 2D synthetic model and a 3D field-scale reservoir model.The proposed workflow yields optimizations that lead to a significant increase in cumulative oil production by 87%and 49%,and CO_(2) sequestration volume enhancement by 78%and 50%across various reservoirs.These findings underscore the superior stability and generalization capabilities of the AST-GraphTrans proxy-assisted framework.The contribution of this study is to provide a more efficient prediction and optimization tool that maximizes CO_(2) sequestration and oil recovery while mitigating CO_(2) gas channeling,thereby ensuring cleaner oil production.展开更多
基金supported by National Natural Science Foundation of China(Grant Nos.42072126,42372139)the Natural Science Foundation of Sichuan Province(Grant Nos.2022NSFSC0990).
文摘Fine-grained sediments are widely distributed and constitute the most abundant component in sedi-mentary systems,thus the research on their genesis and distribution is of great significance.In recent years,fine-grained sediment gravity-flows(FGSGF)have been recognized as an important transportation and depositional mechanism for accumulating thick successions of fine-grained sediments.Through a comprehensive review and synthesis of global research on FGSGF deposition,the characteristics,depositional mechanisms,and distribution patterns of fine-grained sediment gravity-flow deposits(FGSGFD)are discussed,and future research prospects are clarified.In addition to the traditionally recognized low-density turbidity current and muddy debris flow,wave-enhanced gravity flow,low-density muddy hyperpycnal flow,and hypopycnal plumes can all form widely distributed FGSGFD.At the same time,the evolution of FGSGF during transportation can result in transitional and hybrid gravity-flow deposits.The combination of multiple triggering mechanisms promotes the widespread develop-ment of FGSGFD,without temporal and spatial limitations.Different types and concentrations of clay minerals,organic matters,and organo-clay complexes are the keys to controlling the flow transformation of FGSGF from low-concentration turbidity currents to high-concentration muddy debris flows.Further study is needed on the interaction mechanism of FGSGF caused by different initiations,the evolution of FGSGF with the effect of organic-inorganic synergy,and the controlling factors of the distribution pat-terns of FGSGFD.The study of FGSGFD can shed some new light on the formation of widely developed thin-bedded siltstones within shales.At the same time,these insights may broaden the exploration scope of shale oil and gas,which have important geological significances for unconventional shale oil and gas.
文摘Key technologies that make productivity increase are revealed through analyzing the best practices and production data in major shale basins of North America.Trends of the key technologies and optimization designs for shale oil and gas development are summarized and analyzed based on drilling and completion operations and well data.These technologies mainly include:(1)Optimizing well design and hydraulic fracturing design,including reducing cluster spacing,increasing proppant and fracturing fluid volumes,optimizing horizontal well lateral length and fracture stage length.The most effective method is to reduce cluster spacing to an optimized length.The second most effective method is to optimally increase proppant volumes.(2)Placing horizontal wells in the sweet spots and drilling the wells parallel or close to the minimum horizontal stress direction.(3)Using cube development with optimized well spacing to maximize resource recovery and reduce well interferences.Plus,in-situ stress impacts on hydraulic fracture propagation and hydrocarbon production are addressed.Determination of formation breakdown pressure is studied by considering the impacts of in-situ stresses,drilling and perforation directions.Whether or not the hydraulic fracturing can generate orthogonal fracture networks is also discussed.The key technologies and optimization design parameters proposed in this paper can be applied to guide new well placement,drilling and completion designs,and hydraulic fracture operations to increase productivity.
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In July 2025,Claudio Descalzi,CEO of Italian oil company Eni,stated in an interview with the Financial Times that Eni’s low-carbon business operating profits would equal those of its oil and gas business by 2035 and exceed oil and gas business profits by 2040.Meanwhile,British oil company bp is scaling back its low-carbon business under shareholder pressure,returning to traditional oil and gas operations,and plans to gradually dispose of USD 20 billion worth of low-carbon business assets such as onshore wind farms,aiming to increase oil and gas production to 2.3−2.5 million boe per day by 2030.Two European oil companies are heading in completely different strategic directions.In the future,whether Eni can achieve its expected goals of making renewable energy business a key core business,as well as what development strategies oil and gas companies should implement and adhere to,are questions worthy of deep consideration.
基金supported by Joint Fund Project of National Natural Science Foundation(No.U22B6002)CNPC Scientific Research and Technology Development Project(No.2023ZZ14YJ02).
文摘The Jurassic tight sandstone oil and gas exploration and development in the eastern Yangxia Sag is a new field.To elucidate the origin,accumulation process and potential of tight oil and gas,the authors have conducted comprehensive analyses employing methodologies encompassing source rocks,oil geochemistry,and fluid inclusions.The results show that the abundance of organic matter of Jurassic source rocks is high,and the type of organic matter is ofⅡ-Ⅲand in mature evolution stage.The main source rocks of oil and gas are Huangshanjie Formation and Jurassic coal-bearing source rocks.Ahe Formation developed two stages of hydrocarbon charging,and the period is later than the reservoir densification time.Yangxia Formation oil charged before the reservoir densified,and the late gas charged after the reservoir densified.Hydrocarbon generation intensity of Jurassic source rocks has reached the basic conditions for the formation of tight gas reservoirs.Controlled by the difference of source rocks distribution and accumulation process,tight sandstone oil and gas accumulation conditions are better in the depression direction than in the southeast margin area.This study is of practical importance for expanding the exploration field and selecting favorable areas in the eastern Yangxia sag.
文摘Represented by CNPC,Chinese national oil companies go overseas conducting international oil and gas collaboration.Q4:To address domestic energy supply shortages,fully utilize international oil and gas resources,and strengthen international oil and gas cooperation while further enhancing core competitiveness,China’s petroleum enterprises proposed the strategic concept of effectively leveraging both domestic and international resources and markets,literally the strategy of“two resources and two markets”as early as the 1990s and resolutely took the first step in the great endeavor of“going overseas”.Through international cooperation and operations,state-owned oil enterprises represented by CNPC have not only ensured national energy security and enhanced corporate competitiveness,but also made significant contributions to global energy cooperation and advancement of Belt and Road Initiative.Could you please discuss the situation of Chinese petroleum enterprises’international oil and gas cooperation and their achievements in the field of petroleum exploration and development?
文摘Since 2011,America has maintained its position as the world’s largest natural gas producer.Since 2017,America has consistently experienced a surplus in natural gas supply,becoming a net exporter of natural gas.America’s“natural gas independence”has reshaped the global natural gas market,creating a new pattern of“supply shifting westward and consumption shifting eastward”.
基金support for this work is received from the National Natural Science Foundation of China(Grant No.U22B20144).
文摘The potential of the vertical-horizontal well hybrid SAGD technique for developing shallow heavy oil reservoirs is gradually being realized.However,challenges remain in terms of low thermal efficiency and high carbon emissions in reservoirs with interlayers.Currently,there is limited research on the low-carbon strategy of coupling exhaust gas from steam boilers with the VH-SAGD technique.Herein,considering heterogeneity,a series of flue gas-assisted VH-SAGD experiments were conducted employing a high-performance 2D visualization model.The mechanism of enhanced recovery of flue gas in VH-SAGD and the effect of its injection methods were studied,with a focus on steam chamber development and oil saturation distribution.Crucially,the interlayer length was optimized to enhance oil recovery,providing a new perspective for well location design in heavy oil reservoirs with interlayers.The results showed that flue gas,as an additive,could fully exploit the well-type advantage of VH-SAGD.By supplementing energy at the reservoir top,flue gas effectively promoted steam chamber development,expanded the oil drainage area of VH-SAGD,and increased the oil recovery from 58.9%to 71.7%.The flow channels formed by pre-injection flue gas accelerated the early-stage expansion of the steam chamber while also inducing lateral migration of steam,slowing steam rise,and consequently increasing the heating range within the low-permeability layer.When the distance between the vertical and horizontal wells was set to twice the interlayer length,the negative effects of the interlayer were more effectively turned into advantages.Because when the lateral development distance of the steam chamber in the low-permeability layer slightly exceeds the interlayer,enhanced heating of the lower part of the reservoir occurred through vertical convection of rising steam and returning condensate.The research results contribute to reducing carbon emissions from steam-based heavy oil extraction while advancing the maturity of VH-SAGD.
文摘This paper analyses the impact of oil and gas pipelines on the environment and settlements from the perspective of environmental justice,using a case study of the oil-producing communities in the Niger Delta region of Nigeria.The paper mobilises theories of environmental justice to support an in-depth empirical analysis of the development and management of oil and gas pipelines in the region.The empirical evidence equally suggests that the lack of community involvement and appropriate recognition of some groups of stakeholders in the management of the oil and gas pipeline project is strongly related to the incidence of pipeline impacts on the communities[1].The paper advocates a new approach,based on the core principles of environmental justice that promotes inclusion of the necessary stakeholders,including the physical planners,and would incorporate local knowledge and experience into the environmental management of the region in a way to protect the environment and people from the impacts of the pipeline[2].
基金supported by the National Natural Science Foundation of China(52476058,U21B2065,52006024,and 52306188)the National Key Research and Development(2022YFC2806200).
文摘With the development of offshore oil and gas resources,hydrates pose a significant challenge to flow assurance.Hydrates can form,accumulate,and settle in pipelines,causing blockages,reducing transport capacity,and leading to significant economic losses and fatalities.As oil and gas exploration moves deeper into the ocean,the issue of hydrate blockages has become more severe.It is essential to take adequate measures promptly to mitigate the hazards of hydrate blockages after they form.However,a prerequisite for effective mitigation is accurately detecting the location and amount of hydrate formation.This article summarizes the temperature–pressure,acoustic,electrical,instrumental–response,and flow characteristics of hydrate formation and blocking under various conditions.It also analyzes the principles,limitations,and applicability of various blockage detection methods,including acoustic,transient,and fiber-optic-based methods.Finally,it lists the results of field experiments and commercially used products.Given their advantages of accuracy and a wide detection range,acoustic pulse reflectometry and transient-based methods are considered effective for detecting hydrate blockages in future underwater pipelines.Using strict backpressure warnings combined with accurate detection via acoustic pulse reflectometry or transient-based methods,efficient and timely diagnosis of hydrate blockages can be achieved.The use of a hydrate model combined with fiber optics could prove to be an effective method for detecting blockages in newly laid pipelines in the future.
基金support from National Natural Science Foundation of China(Grant Nos.52304146 and 52225403)the China Postdoctoral Science Foundation(Grant No.2023M742460).
文摘Pressure-preserving controllers(PPCs)are crucial components of in situ pressure-preserving coring(IPP-Coring)devices for deep oil and gas extraction,and their ultimate pressure-bearing(UPB)capability determines the upper limit of their ability to acquire oil and gas reserves.However,due to the UPB-capability and sealing challenges,the working pressure typically does not exceed 70 MPa.In this study,the optimal design of a PPC using a self-developed IPP-Coring test platform is presented,and its seal failure mechanism is revealed.Experimental results demonstrate that the designed saddle-shaped PPC achieves a minimal UPB-capability of 140 MPa,which is twice the highest value reported in literature.A numerical simulation method was developed to predict the UPB-capability of the PPC,and its reliability was validated in comparison with experimental results.The simulation results indicate that the sealing failure of the PPC is attributed to a progressive escalation in seal clearance between valve cover and seat,which causes an O-ring extrusion.Under ambient temperature and ultrahigh pressure,the critical threshold for seal clearance in PPC seal failure is approximately 0.2 mm.These results provide significant insights into enhancing deep resource acquisition capabilities.
文摘As industrialization and informatization in China deeply integrate and the Internet of Things rapidly develops,industrial control systems are facing increasingly severe information security challenges.The industrial control system of the gas extraction plant is characterized by numerous points and centralized operations,with a strong reliance on the system and stringent real-time requirements.
基金supported by the National Natural Science Foundation of China(no.42277122)the Science Foun-dation of the China University of Petroleum,Beijing(No.2462024BJRC013).
文摘In recent years,large language models(LLMs)have demonstrated immense potential in practical applications to enhance work efficiency and decision-making capabilities.However,specialized LLMs in the oil and gas engineering area are rarely developed.To aid in exploring and developing deep and ultra-deep unconventional reservoirs,there is a call for a personalized LLM on oil-and gas-related rock mechanics,which may handle complex professional data and make intelligent predictions and decisions.To that end,herein,we overview general and industry-specific LLMs.Then,a systematic workflow is proposed for building this domain-specific LLM for oil and gas engineering,including data collection and processing,model construction and training,model validation,and implementation in the specific domain.Moreover,three application scenarios are investigated:knowledge extraction from textural resources,field operation with multidisciplinary integration,and intelligent decision assistance.Finally,several challenges in developing this domain-specific LLM are highlighted.Our key findings are that geological surveys,laboratory experiments,field tests,and numerical simulations form the four original sources of rock mechanics data.Those data must flow through collection,storage,processing,and governance before being fed into LLM training.This domain-specific LLM can be trained by fine-tuning a general open-source LLM with professional data and constraints such as rock mechanics datasets and principles.The LLM can then follow the commonly used training and validation processes before being implemented in the oil and gas field.However,there are three primary challenges in building this domain-specific LLM:data standardization,data security and access,and striking a compromise between physics and data when building the model structure.Some of these challenges are administrative rather than technical,and overcoming those requires close collaboration between the different interested parties and various professional practitioners.
基金Supporting Project number(RSP2025R92)at King Saud University,Riyadh,Saudi Arabia,for their support.
文摘The importance of organic geochemistry and basin modeling is widely recognized and used to understand the source rock potential and hydrocarbon generation history of the Mangahewa Formation,and thereby given the foundational role in the petroleum exploration.This study utilized the total organic carbon(TOC)content and hydrogen index(HI)to investigate the dominant kerogen type and hydrogen richness for the significance of petroleum generative potential.The Mangahewa coals and carbonaceous shales exhibit an excellent source rocks,with high total organic content(TOC)of more than 22%.The coals and carbonaceous shales were also characterised by Type Ⅱ‒Ⅲ kerogen with Type Ⅲ kerogen,promising oiland gas-prones.The Mangahewa Formation reached the main oil generation,with vitrinite reflectances between 0.53%and 1.01%.Vitrinite reflectance was also used in developing themal models and reveal the transformation(TR)of 10‒50%kerogen to oil during the Late Miocene.The models also showed that the Mangahewa source rock has a significant oil generation and little expulsion competency,with a TR of up to 54%.These findings support the substantial oil-generating potential in the Taranaki Basin's southern graben and can be used as a guide when developing strategies for an oil exploration program.
文摘The BZ oilfield in the Bohai Sea is a rare,highly volatile reservoir with fractures in the metamorphic rocks of buried hills.Clarifying the mechanism of gas injection for improving oil recovery and determining the optimal way to deploy injection-production well networks are critical issues that must be urgently addressed for efficient oilfield development.Experimental research on the mixed-phase displacement mechanism through gas injection into indoor formation fluids was conducted to guide the efficient development of gas injection in oil fields.We established a model of dual-medium reservoir composition and researched the deployment strategy for a three-dimensional well network for gas injection development.The coupling relationship between key influencing factors of the well network and fracture development was also quantitatively analyzed.The results show that the solubility of the associated gas and strong volatile oil system injected into the BZ oilfield is high.This high solubility demonstrates a mixed-phase displacement mechanism involving intermediate hydrocarbons,dissolution and condensation of medium components,and coexistence of extraction processes.Injecting gas and crude oil can achieve a favorable mixing effect when the local formation pressure is greater than 35.79 MPa.Associated gas reinjection is recommended to supplement energy for developing the highly volatile oil reservoirs in the fractured buried hills of the BZ oilfield.This recommendation involves fully utilizing the structural position and gravity-assisted oil displacement mechanism to deploy an injection-production well network.Gas injection points should be constructed at the top of high areas,and oil production points should be placed at the middle and lower parts of low areas.This approach forms a spatial threedimensional well network.By adopting high inclination well development,the oil production well forms a 45°angle with the fracture direction,which increases the drainage area and enhances single-well production capacity.The optimal injection-production well spacing along the fracture direction is approximately 1000 m,while the reasonable well spacing in the vertical fracture direction is approximately 800 m.The research results were applied to the development practice of the buried hills in the BZ oilfield,which achieved favorable development results.These outcomes provide a valuable reference for the formulation of development plans and efficient gas injection development in similar oil and gas fields in buried hills.
文摘China’s energy resource endowment is characterized by being“poor in oil,scarce in gas,and rich in coal”,a fundamental national condition that determines the uniqueness of China’s energy strategy.At the beginning of the 20th century,foreign experts and scholars generally concluded and claimed that China was an“oil-poor country”lacking the geological conditions for hydrocarbon formation.
基金the financial support from the National Key R&D Program of China(No.2022YFB3706604)the National Natural Science Foundation of China(52304033)+2 种基金the National Natural Science Foundation of China(No.51827901)Sichuan Science and Technology Program(2023NSFSC0790)China Postdoctoral Science Foundation(No.2023M742446)。
文摘A novel temperature-preserved core chamber designed for depths exceeding 5000 m has been developed to enhance the scientific understanding of deep oil and gas reservoirs.This temperature-preserved core chamber employs an innovative vacuum layer for temperature preservation and is compatible with a temperature-pressure preserved coring system.The design principles and key parameters of the temperature-preserved core chamber were determined through static analysis.Numerical simulations assessed the mechanical properties of 70,85,and 100 MPa core chambers under conditions of 120-150℃.The results demonstrate that the temperature-preserved core chambers withstand the applied stresses without plastic deformation,and the vacuum layer maintains its integrity under these conditions.A 70 MPa class core chamber prototype was manufactured,and system integration tests were performed on a self-developed in-situ coring platform.The system demonstrated stable operation at 70 MPa for 120 min,with pressure fluctuations within 5%.Additionally,the integrated system operated without interference,enabling the successful extraction of cores with a 50 mm diameter.These findings provide valuable theoretical guidance and design recommendations for advancing oil and gas in-situ temperature-pressure preserved coring technologies in high-temperature and high-pressure environments.
基金the support from the National Natural Science Foundation of China(NSFC Grant No.:52004032)。
文摘The development of gas condensate reservoirs with a large gas cap,thin oil rim,strong bottom water,and natural barriers faces numerous challenges,including reservoir heterogeneity,coning effects,phase changes,and multiphase flow dynamics.The influx of gas and water may lead to a low recovery of the oil rim,while reservoir heterogeneity and natural barriers further exacerbate the uneven distribution of reservoir fluid,complicating development strategies.This paper aims to investigate innovative and effective development strategies for this type of reservoir.A detailed,proportionally scaled numerical simulation is performed based on the experimental results of an artificial sand-filled model,providing novel insights into the dynamic behavior of these reservoirs.By understanding the phase behavior and fluid flow characteristics of the reservoir,the study simulates various strategies for the rational and efficient development of the gas condensate reservoir.These strategies include well patterns and completions,the decision to develop the oil rim or gas cap,depletion rates,the bottom water control,and gas injection.The results show that horizontal wells or highly deviated wells are more suitable for the development of the oil rim,as they provide larger control ranges.The presence of strong bottom water is advantageous for displacement energy supply and pressure maintenance,but it intensifies water coning effects,leading to an earlier breakthrough and a sharp production decline.Therefore,it is preferable to apply highly deviated wells at the oil-gas contact,developing the oil rim at lower rates and smaller pressure gradients,followed by developing the gas cap.This approach can reduce water coning effects and improve recovery,with oil and gas recovery reaching 24.4%and 67.95%,respectively,which is an increase of 16.74%and 17.84%compared to direct depletion development of the gas cap.Due to the strong water bottom,continuous gas injection at the top of the reservoir becomes challenging.This study introduces gas assisted gravity drainage with water control technology,a novel and highly effective approach that addresses the impact of bottom water coning effects on the oil and gas zones and overcomes the limitations of gas flooding in reservoirs with strong bottom water.This method can significantly improve oil and gas recovery,achieving recovery of 39.74%and 84.50%,respectively.Compared to the conventional depletion strategy of sequential oil rim and gas cap development,this method achieves additional improvements of 15.33%and 16.55%in oil and gas recovery,respectively.
基金The contract No.PRJ-395/DPKS/2022 or 2383/PKS/ITS/2022 on 14 November 2022.
文摘The total replacement of old fossil fuels poses obstacles,making the production of efficient biogasoline vital.Despite its potential as an environmentally friendly fossil fuel substitute,the life cycle assessment(LCA)of palm oil-derived biogasoline remains underexplored.This study investigated the production of biogasoline fromcrude palm oil(CPO)based biorefinery using catalytic cracking over mesoporousγ-Al_(2)O_(3) catalyst and LCA analysis.High selectivity of converting CPO into biogasoline was achieved by optimizing catalytic cracking parameters,including catalyst dose,temperature,and contact time.γ-Al_(2)O_(3) and CPO were characterized by several methods to study the physical and chemical properties.The physical properties of biogasoline,such as density,calorific value,viscosity,and flash point,were investigated.An overall yield of 60.11%was achieved after catalytic cracking produced several C5-C11 short-chain hydrocarbons.Additionally,this research proposes innovative emission reduction strategies,including waste-to-biogasoline conversion and the use of biodegradable feedstocks that enhance the sustainability of biogasoline production.LCA ofγ-Al_(2)O_(3)’s energy and environmental implications reveals minor effects on global warming(0.0068%)and freshwater ecotoxicity(0.187%).LCAs show a 0.085%impact in the energy sector.This focus on both ecological impacts and practical mitigation strategies deepens the understanding of biogasoline production.
基金supported by the National Natural Science Foundation of China(Nos.52374064,52274056)China Scholarship Council(No.202406450086).
文摘Carbon dioxide Enhanced Oil Recovery(CO_(2)-EOR)technology guarantees substantial underground CO_(2) sequestration while simultaneously boosting the production capacity of subsurface hydrocarbons(oil and gas).However,unreasonable CO_(2)-EOR strategies,encompassing well placement and well control parameters,will lead to premature gas channeling in production wells,resulting in large amounts of CO_(2) escape without any beneficial effect.Due to the lack of prediction and optimization tools that integrate complex geological and engineering information for the widely used CO_(2)-EOR technology in promising industries,it is imperative to conduct thorough process simulations and optimization evaluations of CO_(2)-EOR technology.In this paper,a novel optimization workflow that couples the AST-GraphTrans-based proxy model(Attention-based Spatio-temporal Graph Transformer)and multi-objective optimization algorithm MOPSO(Multi-objective Particle Swarm Optimization)is established to optimize CO_(2)-EOR strategies.The workflow consists of two outstanding components.The AST-GraphTrans-based proxy model is utilized to forecast the dynamics of CO_(2) flooding and sequestration,which includes cumulative oil production,CO_(2) sequestration volume,and CO_(2) plume front.And the MOPSO algorithm is employed for achieving maximum oil production and maximum sequestration volume by coordinating well placement and well control parameters with the containment of gas channeling.By the collaborative coordination of the two aforementioned components,the AST-GraphTrans proxy-assisted optimization workflow overcomes the limitations of rapid optimization in CO_(2)-EOR technology,which cannot consider high-dimensional spatio-temporal information.The effectiveness of the proposed workflow is validated on a 2D synthetic model and a 3D field-scale reservoir model.The proposed workflow yields optimizations that lead to a significant increase in cumulative oil production by 87%and 49%,and CO_(2) sequestration volume enhancement by 78%and 50%across various reservoirs.These findings underscore the superior stability and generalization capabilities of the AST-GraphTrans proxy-assisted framework.The contribution of this study is to provide a more efficient prediction and optimization tool that maximizes CO_(2) sequestration and oil recovery while mitigating CO_(2) gas channeling,thereby ensuring cleaner oil production.
