Petroleum Exploration and Development最新文献

{"title":"Identification indexes and diagrams for natural gas origin: Connotation, significance and application","authors":"Ping’an PENG ,&nbsp;Dujie HOU ,&nbsp;TENGER ,&nbsp;Yunyan NI ,&nbsp;Deyu GONG ,&nbsp;Xiaoqi WU ,&nbsp;Ziqi FENG ,&nbsp;Guoyi HU ,&nbsp;Shipeng HUANG ,&nbsp;Cong YU ,&nbsp;Fengrong LIAO","doi":"10.1016/S1876-3804(25)60589-1","DOIUrl":"10.1016/S1876-3804(25)60589-1","url":null,"abstract":"<div><div>Accurate identification of natural gas origin is fundamental to the theoretical research on natural gas geosciences and the exploration deployment and resource potential assessment of oil and gas. Since the 1970s, Academician Dai Jinxing has developed a comprehensive system for natural gas origin determination, grounded in geochemical theory and practice, and based on the integrated analysis of stable isotopic compositions, molecular composition, light hydrocarbon fingerprints, and geological context. This paper systematically reviews the core framework established by him and his team according to related references and application results, focusing on the conceptual design and technical pathways of key diagnostic diagrams such as δ¹³C₁–C₁/(C₂+C₃), δ¹³C₁–δ¹³C₂–δ¹³C₃, δ¹³C_CO2 versus CO₂ content, and the C₇ light hydrocarbon ternary plot. We evaluate the applicability and innovation of these tools in distinguishing between oil-type gas, coal-derived gas, microbial gas, and abiogenic gas, as well as in identifying mixed-source gases and multi-stage charging systems. The findings suggest that this identification system has significantly advanced natural gas geochemical interpretation in China, shifting from single-indicator analyses to multi-parameter integration and from qualitative assessments to systematic graphical identification, and has also exerted considerable influence on international research in natural gas geochemistry. The structured overview of the development trajectory of natural gas origin discrimination methodologies provides a technical support for natural gas geological theory and practice and offer a scientific foundation for the academic evaluation and application of related achievements.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"52 3","pages":"Pages 573-586"},"PeriodicalIF":7.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theory and practice of energy-focused fracturing development technology","authors":"Qingzhong ZHU ,&nbsp;Wei XIONG ,&nbsp;Dingwei WENG ,&nbsp;Shuai LI ,&nbsp;Wei GUO ,&nbsp;Xueying ZHANG ,&nbsp;Yuhang XIAO ,&nbsp;Yutian LUO ,&nbsp;Meng FAN","doi":"10.1016/S1876-3804(25)60600-8","DOIUrl":"10.1016/S1876-3804(25)60600-8","url":null,"abstract":"<div><div>Currently, unconventional reservoirs are characterized by low single well-controlled reserves, high initial production but fast production decline. This paper sorts out the problems of energy dispersion and limited length and height of main hydraulic fractures induced in staged multi-cluster fracturing, and proposes an innovative concept of “energy-focused fracturing development”. The technical connotation, theoretical model, and core techniques of energy-focused fracturing development are systematically examined, and the implementation path of this technology is determined. The energy-focused fracturing development technology incorporates the techniques such as geology-engineering integrated design, perforation optimization design, fracturing process design, and drainage engineering control. It transforms the numerous, short and dense hydraulic fractures to limited, long and sparse fractures. It focuses on fracturing energy, and aims to improve the fracture length, height and lateral width, and the proppant long-distance transportation capacity, thus enhancing the single well-controlled reserves and development effect. The energy-focused fracturing development technology has been successfully applied in the carbonate reservoirs in buried hill, shallow coalbed methane reservoirs, and coal-rock gas reservoirs in China, demonstrating the technology’s promising application. It is concluded that the energy-focused fracturing development technology can significantly increase the single well production and estimated ultimate recovery (EUR), and will be helpful for efficiently developing low-permeability, unconventional and low-grade resources in China.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"52 3","pages":"Pages 746-758"},"PeriodicalIF":7.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploration breakthrough and hydrocarbon accumulation conditions of Mesozoic volcanic rocks in Bodong Low Uplift, Bohai Bay Basin, China","authors":"Changgui XU ,&nbsp;Haifeng YANG ,&nbsp;Lei CHEN ,&nbsp;Yanfei GAO ,&nbsp;Shaofeng BU ,&nbsp;Qi LI","doi":"10.1016/S1876-3804(25)60591-X","DOIUrl":"10.1016/S1876-3804(25)60591-X","url":null,"abstract":"<div><div>The Mesozoic volcanic rocks of the Bodong Low Uplift in the Bohai Bay Basin have been studied and explored for years. In 2024, the LK7-A well drilled in this region tested high-yield oil and gas flows from volcanic weathered crust. These volcanic rocks need to be further investigated in terms of distribution patterns, conditions for forming high-quality reservoirs, and main factors controlling hydrocarbon accumulation. Based on the logging, geochemical and mineralogical data from wells newly drilled to the Mesozoic volcanic rocks in the basin, and high-resolution 3D seismic data, a comprehensive study was conducted for this area. The research findings are as follows. First, the volcanic rocks in the LK7-A structure are adakites with a large source area depth, and the deep and large faults have provided channels for the emplacement of intermediate-acidic volcanic rocks. Second, volcanic rock reservoirs are mainly distributed in tectonic breccias and intermediate-acidic lavas, and they are dominantly fractured-porous reservoirs, with high-porosity and low-permeability or medium-porosity and low-permeability. Third, the dominant lithologies/lithofacies is the basic condition for forming large-scale volcanic rock reservoirs. Structural fractures and late-stage strong weathering are crucial mechanisms for the formation scale of reservoirs in the Mesozoic volcanic rocks. Fourth, the Bodong Low Uplift exhibits strong hydrocarbon charging by two sags and overpressure mudstone capping, which are favorable for forming high-abundance oil and gas reservoirs. The Mesozoic volcanic buried hills in the study area reflect good trap geometry, providing favorable conditions for large-scale reservoir formation, and also excellent migration and accumulation conditions. Areas with long-term exposure of intermediate-acidic volcanic rocks, particularly in active structural regions, are the key targets for future exploration.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"52 3","pages":"Pages 600-615"},"PeriodicalIF":7.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Artificial intelligence large model for logging curve reconstruction","authors":"Zhangxing CHEN ,&nbsp;Yongan ZHANG ,&nbsp;Jian LI ,&nbsp;Gang HUI ,&nbsp;Youzhuang SUN ,&nbsp;Yizheng LI ,&nbsp;Yuntian CHEN ,&nbsp;Dongxiao ZHANG","doi":"10.1016/S1876-3804(25)60607-0","DOIUrl":"10.1016/S1876-3804(25)60607-0","url":null,"abstract":"<div><div>To improve the accuracy and generalization of well logging curve reconstruction, this paper proposes an artificial intelligence large language model – “Gaia” and conducts model evaluation experiments. By fine-tuning the pre-trained large language model, the Gaia significantly improved its ability in extracting sequential patterns and spatial features from well-log curves. Leveraging the adapter method for fine-tuning, this model required training only about 1/70 of its original parameters, greatly improving training efficiency. Comparative experiments, ablation experiments, and generalization experiments were designed and conducted using well-log data from 250 wells. In the comparative experiment, the Gaia model was benchmarked against cutting-edge small deep learning models and conventional large language models, demonstrating that the Gaia model reduced the mean absolute error (MAE) by at least 20%. In the ablation experiments, the synergistic effect of the Gaia model’s multiple components was validated, with its MAE being at least 30% lower than that of single-component models. In the generalization experiments, the superior performance of the Gaia model in blind-well predictions was further confirmed. Compared to traditional models, the Gaia model is significantly superior in accuracy and generalization for logging curve reconstruction, fully showcasing the potential of large language models in the field of well-logging. This provides a new approach for future intelligent logging data processing.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"52 3","pages":"Pages 842-854"},"PeriodicalIF":7.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144492138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal bit selection for large-diameter wellbore drilling in an ultra-deep well","authors":"Lili CHEN ,&nbsp;Wenzhe LI ,&nbsp;Jianhua GUO ,&nbsp;Ke LI ,&nbsp;Zhixiang CAI ,&nbsp;Jie WU ,&nbsp;Weining XU ,&nbsp;Xiaohua ZHU","doi":"10.1016/S1876-3804(25)60604-5","DOIUrl":"10.1016/S1876-3804(25)60604-5","url":null,"abstract":"<div><div>To optimize the bit selection for large-diameter wellbore in the upper section of an ultra-deep well S-1, a full-well dynamic model integrating drill string vibration and bit rock-breaking was established and then verified using measured vibration data of drilling tools and actual rate of penetration (ROP) from Well HT-1 in northern Sichuan Basin. This model was employed to calculate and analyze drill string dynamic characteristics during large-diameter wellbore drilling in the Jurassic Penglaizhen Formation of Well S-1, followed by bit optimization. Research results show that during the drilling in Penglaizhen Formation of Well S-1, considering both the ROP of six candidate bits and the lateral/axial/torsional vibration characteristics of downhole tools, the six-blade dual-row cutter bit with the fastest ROP (average 7.12 m/h) was optimally selected. When using this bit, the downhole tool vibration levels remained at medium-low values. Field data showed over 90% consistency between actual ROP data and dynamic model calculation results after bit placement, demonstrating that the model can be used for bit program screening.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"52 3","pages":"Pages 807-816"},"PeriodicalIF":7.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144492135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment and exploration prospects of the oldest marine shale oil in North China","authors":"Xiaomei WANG ,&nbsp;Zhichao YU ,&nbsp;Kun HE ,&nbsp;Xiu HUANG ,&nbsp;Mingze YE ,&nbsp;Modi GUAN ,&nbsp;Shuichang ZHANG","doi":"10.1016/S1876-3804(25)60593-3","DOIUrl":"10.1016/S1876-3804(25)60593-3","url":null,"abstract":"<div><div>Based on large-field rock thin section scanning, high-resolution field emission-scanning electron microscopy (FE-SEM), fluorescence spectroscopy, and rock pyrolysis experiments of the Mesoproterozoic Jixianian Hongshuizhuang Formation shale samples from the Yanliao Basin in northern China, combined with sedimentary forward modeling, a systematic petrological and organic geochemical study was conducted on the reservoir quality, oil-bearing potential, distribution, and resource potential of the Hongshuizhuang Formation shale in Well Yuanji-2. The results indicate that: (1) The original organic carbon content of the Hongshuizhuang Formation shale averages up to 6.24%, and the original hydrocarbon generation potential is as high as 44.09 mg/g, demonstrating a strong oil generation potential. (2) The rock type is primarily siliceous shale containing low clay mineral content, characterized by the development of shale bedding fractures and organic shrinkage fractures, resulting in good compressibility and reservoir quality. (3) The fifth and fourth members of the Hongshuizhuang Formation serve as shale oil sweet spots, contributing more than 60% of shale oil production with their total thickness as only 40% of the target formation. (4) The Kuancheng-Laozhuanghu area is the most prospective shale oil exploration option in the Yanliao Basin and covers approximately 7 200 km². Its original total hydrocarbon generation potential reaches about 74.11 billion tons, with current estimated retained shale oil resources exceeding 1.148 billion tons (lower limit) – comparable to the geological resources of the Permian Lucaogou Formation shale oil in the Jimsar Sag of the Junggar Basin. These findings demonstrate the robust exploration potential of the Hongshuizhuang Formation shale oil in the Yanliao Basin.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"52 3","pages":"Pages 630-648"},"PeriodicalIF":7.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geological characteristics and hydrocarbon accumulation model of the whole petroleum system in Paleogene of Jiyang Depression, Bohai Bay Basin, China","authors":"Yang GAO ,&nbsp;Huimin LIU","doi":"10.1016/S1876-3804(25)60592-1","DOIUrl":"10.1016/S1876-3804(25)60592-1","url":null,"abstract":"<div><div>Based on a large amount of basic research and experimental analysis data from Shengli Oilfield, Bohai Bay Basin, guided by the theory of whole petroleum system, the distribution of sedimentary systems, the distribution and hydrocarbon generation and expulsion process of source rocks, the variation of reservoir properties, and the control of fracture systems on hydrocarbon accumulation in the Paleogene of the Jiyang Depression, Boahai Bay Basin, were systematically analyzed, and the geological characteristics of the whole petroleum system in the rift basin were identified. Taking the Dongying Sag as an example, combined with the distribution of discovered conventional, tight, and shale oil/gas, a hydrocarbon accumulation model of the fault-controlled whole petroleum system in rift basin was proposed, and the distribution patterns of conventional and unconventional oil and gas reservoirs in large geological bodies horizontally and vertically were clarified. The research results show that paleoclimate and tectonic cycles control the orderly distribution of the Paleogene sedimentary system in the Jiyang Depression, the multi-stage source rocks provide sufficient material basis for in-situ shale oil/gas accumulation and other hydrocarbon migration and accumulation, the changes in reservoir properties control the dynamic threshold of hydrocarbon accumulation, and the combination of faults and fractures at different stages controls hydrocarbon migration and accumulation, and in-situ retention and accumulation of shale oil/gas, making the whole petroleum system in the rift basin associated, segmented and abrupt. The above elements are configured to form a composite whole petroleum system controlled by faults in the Paleogene of the Jiyang Depression. Moreover, under the control of hydrocarbon accumulaiton dynamics, a whole petroleum system can be divided into conventional subsystem and unconventional subsystem, with shale oil, tight oil and conventional oil in an orderly distribution in horizontal and vertical directions. This systematic understanding is referential for ananlyzing the whole petroleum system in continental rift basins in eastern China.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"52 3","pages":"Pages 616-629"},"PeriodicalIF":7.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of hydration on the mechanical properties of deep shale under true triaxial stress: A case study of Fuling shale gas in Sichuan Basin, SW China","authors":"Jinzhou ZHAO ,&nbsp;Zhihao YU ,&nbsp;Lan REN ,&nbsp;Ran LIN ,&nbsp;Jianfa WU ,&nbsp;Yi SONG ,&nbsp;Cheng SHEN ,&nbsp;Ying SUN","doi":"10.1016/S1876-3804(25)60603-3","DOIUrl":"10.1016/S1876-3804(25)60603-3","url":null,"abstract":"<div><div>This study takes shale samples from the Jiaoshiba block in the Fuling shale gas field of the Sichuan Basin, and uses the true triaxial testing system to conduct a series of mechanical experiments under deep shale reservoir conditions after shale hydration. Stress-strain data and mechanical parameters of shale after hydration under high temperature and high pressure were obtained to investigate the effects of reservoir temperature, hydration time and horizontal stress difference on the mechanical strength of shale after hydration. By using nonlinear regression and interpolation methods, a prediction model for the mechanical strength of shale after hydration was constructed, and the mechanical strength chart of deep shale under high stress difference was plotted. First, higher hydration temperature, longer hydration reaction time, and greater horizontal stress difference cause shale to enter the yield stage earlier during the compression process after hydration and to exhibit more prominent plastic characteristics, lower peak strength, peak strain, residual strength and elastic modulus, and higher Poisson’s ratio. Second, the longer the hydration time, the smaller the impact of hydration temperature on the mechanical strength of deep shale. As the horizontal stress difference increases, the peak strength and residual strength weaken intensely, and the peak strain, elastic modulus and Poisson’s ratio deteriorate slowly. Third, the mechanical strength of shale decreases significantly in the first 5 days of hydration, but gradually stabilizes as the hydration time increases. Fourth, the visual mechanical strength chart helps to understand the post-fracturing dynamics in deep shale gas reservoir fracturing site and adjust the drainage and production plan in time.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"52 3","pages":"Pages 795-806"},"PeriodicalIF":7.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144492134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural characteristics of faults in Wangfu fault depression and their control on coal-rock gas enrichment, Songliao Basin, NE China","authors":"Yonghe SUN ,&nbsp;Yumin LIU ,&nbsp;Wenguang TIAN","doi":"10.1016/S1876-3804(25)60594-5","DOIUrl":"10.1016/S1876-3804(25)60594-5","url":null,"abstract":"<div><div>Taking the Wangfu fault depression in the Songliao Basin as an example, on the basis of seismic interpretation and drilling data analysis, the distribution of the basement faults was clarified, the fault activity periods of the coal-bearing formations were determined, and the fault systems were divided. Combined with the coal seam thickness and actual gas indication in logging, the controls of fault systems in the rift basin on the spatial distribution of coal and the occurrence of coal-rock gas were identified. The results show that the Wangfu fault depression is an asymmetrical graben formed under the control of basement reactivated strike-slip T-rupture, and contains coal-bearing formations and five sub-types of fault systems under three types. The horizontal extension strength, vertical activity strength and tectono-sedimentary filling difference of basement faults control vertical stratigraphic sequences, accumulation intensity, and accumulation frequency of coal seam in rift basin. The structural transfer zone formed during the segmented reactivation and growth of the basement faults controls the injection location of steep slope exogenous clasts. The filling effect induced by igneous intrusion accelerates the sediment filling process in the rift lacustrine area. The structural transfer zone and igneous intrusion together determine the preferential accumulation location of coal seams in the plane. The faults reactivated at the basement and newly formed during the rifting phase serve as pathways connecting to the gas source, affecting the enrichment degree of coal-rock gas. The vertical sealing of the faults was evaluated by using shale smear factor (SSF), and the evaluation criteria was established. It is indicated that the SSF is below 1.1 in major coal areas, indicating favorable preservation conditions for coal-rock gas. Based on the influence factors such as fault activity, segmentation and sealing, the coal-rock gas accumulation model of rift basin was established.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"52 3","pages":"Pages 649-662"},"PeriodicalIF":7.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-detachment-controlled thrust structures and deep hydrocarbon exploration targets in southern margin of Junggar Basin, NW China","authors":"Baoli YU ,&nbsp;Chengzao JIA ,&nbsp;Keyu LIU ,&nbsp;Yong DENG ,&nbsp;Wei WANG ,&nbsp;Peng CHEN ,&nbsp;Chao LI ,&nbsp;Jia CHEN ,&nbsp;Boyang GUO","doi":"10.1016/S1876-3804(25)60595-7","DOIUrl":"10.1016/S1876-3804(25)60595-7","url":null,"abstract":"<div><div>For deep prospects in the foreland thrust belt, southern Junggar Basin, NW China, there are uncertainties in factors controlling the structural deformation, distribution of paleo-structures and detachment layers, and distribution of major hydrocarbon source rocks. Based on the latest 3D seismic, gravity-magnetic, and drilling data, together with the results of previous structural physical simulation and discrete element numerical simulation experiments, the spatial distribution of pre-existing paleo-structures and detachment layers in deep strata of southern Junggar Basin were systematically characterized, the structural deformation characteristics and formation mechanisms were analyzed, the distribution patterns of multiple hydrocarbon source rock suites were clarified, and hydrocarbon accumulation features in key zones were reassessed. The exploration targets in deep lower assemblages with possibility of breakthrough were expected. Key results are obtained in three aspects. First, structural deformation is controlled by two-stage paleo-structures and three detachment layers with distinct lateral variations: the Jurassic layer (moderate thickness, wide distribution), the Cretaceous layer (thickest but weak detachment), and the Paleogene layer (thin but long-distance lateral thrusting). Accordingly, a four-layer composite deformation sequence was identified, and the structural genetic model with paleo-bulge controlling zonation by segments laterally and multiple detachment layers controlling sequence vertically. Second, the Permian source rocks show a distribution pattern with narrow trough (west), multiple sags (central), and broad basin (east), which is depicted by combining high-precision gravity-magnetic data and time-frequency electromagnetic data for the first time, and the Jurassic source rocks feature thicker mudstones in the west and rich coals in the east according to the reassessment. Third, two petroleum systems and a four-layer composite hydrocarbon accumulation model are established depending on the structural deformation strength, trap effectiveness and source-trap configuration. The southern Junggar Basin is divided into three segments with ten zones, and a hierarchical exploration strategy is proposed for deep lower assemblages in this region, that is, focusing on five priority zones, expanding to three potential areas, and challenging two high-risk targets.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"52 3","pages":"Pages 663-679"},"PeriodicalIF":7.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}