Petroleum Exploration and Development最新文献

{"title":"“Component flow” of shale oil and its significance for sweet spot evaluation in the Permian Lucaogou Formation, Jimsaer Sag, Junggar Basin, China","authors":"Wenzhi ZHAO,&nbsp;Shiju LIU,&nbsp;Congsheng BIAN,&nbsp;Yong SONG,&nbsp;Gang GAO,&nbsp;Wei LIU,&nbsp;Yongxin LI,&nbsp;Keting FAN,&nbsp;Jin DONG,&nbsp;Ming GUAN","doi":"10.1016/S1876-3804(26)60715-X","DOIUrl":"10.1016/S1876-3804(26)60715-X","url":null,"abstract":"<div><div>Considering the complex occurrence environment and significant compositional variation of continental shale oil, as well as the uncertainties in its mobility and producible amount, this study employs geochemical analysis and production monitoring to investigate the “component flow” phenomenon of shale oil during production from the Permian Lucaogou Formation in the Jimusar Sag, Junggar Basin. It is clarified that the miscibility of different hydrocarbon components and non-hydrocarbon substances improves the flowability of multi-component hydrocarbons and non-hydrocarbons, thereby effectively enhancing the production of shale oil. Research indicates that the “lower sweet spot” has a relatively high content of light and medium hydrocarbon components and strong formation energy compared to the “upper sweet spot” of Lucaogou Formation, resulting in higher density and viscosity of the produced crude oil, which can be regarded as evidence of “component flow” of retained hydrocarbons. The “upper sweet spot” exhibits two scenarios. In areas far from faults with good preservation conditions, the high content of light and medium components in retained hydrocarbons and a high formation pressure coefficient make component flow more likely to occur. Consequently, the produced crude oil has a higher density, and the estimated ultimate recovery (EUR) per well is also higher. In areas near faults with poor preservation conditions, although the produced crude oil has a light density, the EUR per well is relatively low, indicating that the conditions for component flow of retained hydrocarbons underground have deteriorated. The study also demonstrates that preservation conditions (preventing light hydrocarbon escape and maintaining formation energy) and production strategies (controlling production pressure differential and maintaining stable operations) are important factors in regulating the occurrence and continuity of “component flow” to maximize EUR per well. These new insights can be applied to the evaluation of economically productive “sweet spots” and provide guidance for achieving optimal EUR per well in shale oil production.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 3","pages":"Pages 322-334"},"PeriodicalIF":10.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148558557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research status and prospects of numerical simulation technology for hot dry rock geothermal development","authors":"Gensheng LI,&nbsp;Jiawei LI,&nbsp;Zhongwei HUANG,&nbsp;Xianzhi SONG,&nbsp;Gaosheng WANG,&nbsp;Xiaoguang WU,&nbsp;Tianyu WANG","doi":"10.1016/S1876-3804(26)60733-1","DOIUrl":"10.1016/S1876-3804(26)60733-1","url":null,"abstract":"<div><div>This paper systematically investigates the numerical simulation model construction and methods for hot dry rock geothermal resource development. It highlights the influence law and characterization differences of multi-physics field coupling mechanism across various stages of development and utilization. The technical features and applicable scenarios of typical numerical simulation methods, as well as the application potential and advantages of emerging technologies such as intelligent algorithms in numerical simulation for hot dry rock geothermal development, are comprehensively reviewed. In addition, the functional characteristics and engineering application cases of mainstream geothermal numerical simulation software in China and abroad are summarized. On this basis, the core challenges for existing techniques are identified, and future development directions are proposed. At present, numerical simulation for hot dry rock geothermal resource development still faces several challenges, including insufficient accuracy in characterizing complex reservoir structures, incomplete representation of multi-physics field coupling mechanisms, limited cross-scale simulation capability, inadequate adaptability of software to diverse scenarios, and insufficient support from field monitoring and fundamental data. In the future, numerical simulation technologies for hot dry rock geothermal resource development should advance theoretical and technical research in full-chain integrated modeling, refined characterization of multi-physics field coupling, deep integration of intelligent algorithms with numerical simulation, and establishment of an independent and controllable software ecosystem, thereby providing theoretical and technical support for the sustainable and efficient development of hot dry rock geothermal resources in China.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 3","pages":"Pages 597-609"},"PeriodicalIF":10.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148544573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase behavior and mass transfer mechanisms of CO2 multicomponent gas and crude oil system","authors":"Weifeng LYU,&nbsp;Yu ZHANG,&nbsp;Mingyuan WANG,&nbsp;Jiahao GAO,&nbsp;Ke ZHANG","doi":"10.1016/S1876-3804(26)60727-6","DOIUrl":"10.1016/S1876-3804(26)60727-6","url":null,"abstract":"<div><div>The large-scale deployment of carbon capture, utilization and storage (CCUS) technologies and the growing demand for low-cost gas sources provide new opportunities for the development of CO₂ multicomponent gas flooding. However, the interphase mass transfer mechanisms between CO₂ multicomponent gas and crude oil system remains unclear. In this work, non-equilibrium and equilibrium phase experiments, equation-of-state calculations, molecular dynamics simulations, and reservoir-scale numerical simulations were combined to investigate the phase behavior and mass transfer mechanisms of CO₂ multicomponent gas and crude oil system. The results show that non-equilibrium systems exhibit spatially heterogeneous local mass transfer. CO₂ demonstrates the strongest dynamic mass transfer capacity, while under the same conditions, the dynamic mass transfer effect of N₂ is extremely weak. The extraction effect of CO₂ multicomponent gas on hydrocarbon components in crude oil exhibits a nonlinear “critical response”. When the CO₂ mole fraction reaches a critical extraction threshold of approximately 70%, the overall extraction capacity of the system increases significantly, and heavy hydrocarbon components are more sensitive to changes in CO₂ concentration. As the crude oil becomes lighter, oil displacement efficiency exhibits weak dependence on the extraction of heavy components by the multicomponent gas. This study provides a theoretical basis for optimizing multicomponent gas composition and selecting low-cost gas sources, and offers a valuable guidance for the field application of CO₂ multicomponent gas flooding.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 3","pages":"Pages 514-526"},"PeriodicalIF":10.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148544570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aqueous two-phase high-viscosity friction reducer for deep reservoir fracturing and its mechanisms of temperature resistance and viscosity enhancement","authors":"Qing YOU,&nbsp;Xingxing DING,&nbsp;Hanzhou LI,&nbsp;Xiaokai HUANG,&nbsp;Zhirong JIN,&nbsp;Caili DAI,&nbsp;Jiaping TAO","doi":"10.1016/S1876-3804(26)60732-X","DOIUrl":"10.1016/S1876-3804(26)60732-X","url":null,"abstract":"<div><div>Given the stringent requirements for friction reducers in terms of long-distance friction reduction, efficient proppant transport, temperature resistance and viscosity enhancement in deep oil and gas reservoir fracturing development, an aqueous two-phase high-viscosity friction reducer ANSD-PADA suitable for deep reservoir fracturing was prepared by introducing nanomaterial ANSD and through the aqueous two-phase polymerization. Its mechanisms of temperature resistance, viscosity enhancement, and friction reduction were explored by means of fluorescence spectroscopy, microscopic morphology observation, nanomechanical testing and other analytical methods, and field tests were also carried out. The introduction of hydrophobic monomer N-(3-dimethylaminopropyl) methacrylamide enables PADA (a self-synthesized hydrophobic terpolymer) molecules to entangle, associate and self-assemble into a honeycomb-like network structure under the combined effects of van der Waals forces, electrostatic repulsion and hydrophobic interaction. This structure further increases the hydrodynamic volume, thereby significantly improving the viscosity-enhancing performance of the product. ANSD fills the pores of the polymer network structure, effectively strengthening the network skeleton and association junctions, and remarkably improving the temperature resistance of the system. The friction reducer retains a friction reduction rate of 73.36% at 130 °C, with a temperature resistance up to 150 °C, and it has demonstrated encouraging results in the pilot site at Well XX-HF targeting deep shale oil reservoirs on the northern slope zone of the Gaoyou Sag, Subei Basin, China.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 3","pages":"Pages 585-596"},"PeriodicalIF":10.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148544572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design framework for polymer gel treatments from a database of field projects","authors":"Baojun BAI,&nbsp;Munqith ALDHAHERI,&nbsp;Mingzhen WEI","doi":"10.1016/S1876-3804(26)60728-8","DOIUrl":"10.1016/S1876-3804(26)60728-8","url":null,"abstract":"<div><div>This study compiles and analyzes data from over 125 published field projects around the world, covering nearly 900 treated wells. Building on those detailed studies, this paper distills the most important findings into a concise, practical, and actionable framework to guide where in-situ gel treatments should be applied, how they should be designed, and how their outcomes can be evaluated. The proposed workflow guides engineers through five integrated stages: screening appropriate gel types, designing formulation and injection strategies, predicting field response, evaluating treatment performance, and conducting iterative refinement with feedback loops to adjust designs based on observed outcomes. The framework integrates empirical selection rules, statistical design ranges, tapering strategies, and machine-learning tools, to support informed decision-making. While derived from retrospective analysis of mostly successful treatments, the structured methodology offers actionable guidance for future applications and helps bridge the gap between field observations and systematic design logic. By providing a data-informed workflow supported by field evidence, this study aims to enhance the reliability, consistency, and economic value of polymer gel treatments in complex reservoir conditions.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 3","pages":"Pages 527-541"},"PeriodicalIF":10.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148544574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-agent collaborative framework with human-in-the-loop for well log interpretation and applications","authors":"Zhangxing CHEN,&nbsp;Ruichen DING,&nbsp;Yang MENG,&nbsp;Yizheng LI,&nbsp;Junwei ZHANG,&nbsp;Liu CAO,&nbsp;Jian LI,&nbsp;Wenqi FAN,&nbsp;Yiyuan ZHANG,&nbsp;Liqiu WANG,&nbsp;Dongxiao ZHANG,&nbsp;Yuntian CHEN","doi":"10.1016/S1876-3804(26)60734-3","DOIUrl":"10.1016/S1876-3804(26)60734-3","url":null,"abstract":"<div><div>This paper proposes a multi-agent system centered on large language models to address the issues that traditional well log interpretation relies on expert experience and poses great difficulty in multi-disciplinary collaboration and constructs a digital twin architecture across three dimensions of agents, tools and environment. At the agent level, a role-based architecture is established to decompose the complex log interpretation workflow into independent subtasks, enabling structured transfer of expert knowledge. At the tool level, petrophysical formulas and machine learning algorithms are encapsulated to form a physics-data dual-path hybrid reasoning mechanism; at the environment level, a standardized digital twin space is established based on the Model Context Protocol to achieve closed-loop control of the entire workflow. Engineers can drive the system through natural language commands to complete the full log interpretation process from data loading and parameter calculation to reservoir classification, realizing end-to-end automation from raw data to interpretation conclusions. In tests on 100 field wells, the system generates key interpretation parameters that are highly consistent with expert results, exhibiting stable recognition capability for complex reservoir types. This study demonstrates that this human-machine collaborative working mode significantly enhances the standardization and efficiency of well log interpretation, providing technical reference for intelligent transformation of highly specialized industrial processes.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 3","pages":"Pages 610-624"},"PeriodicalIF":10.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148545315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Innovation and practice of the whole petroleum system theory: A new paradigm for “all strata, all types, all domains” petroleum exploration","authors":"Dongming ZHI,&nbsp;Deyu GONG,&nbsp;Zhijun QIN,&nbsp;An XIE,&nbsp;Wenjun HE","doi":"10.1016/S1876-3804(26)60719-7","DOIUrl":"10.1016/S1876-3804(26)60719-7","url":null,"abstract":"<div><div>The whole petroleum system (WPS) theory represents a significant innovation proposed to address the limitations of the classical petroleum system theory. The successful application of this theory has propelled the oil and gas exploration in China toward a new paradigm characterized by “all stratigraphic sequences, all resource types, and all exploration domains”. Based on a review of the fundamental principles of this theory, this study provides a comprehensive analysis of 25 relevant cases from 12 basins in China. It is indicated that there exists an orderly distribution of three fluid dynamic fields in a whole petroleum system, i.e., free dynamic field, restricted dynamic field and confined dynamic field. Hydrocarbon accumulation in a restricted dynamic field primarily relies on capillary force and viscous force; however, long-term effectiveness still depends on sealing capacity and regional boundary conditions. The superposition of hydrocarbon generation from source rocks with different kerogen types or lithologies results in a broader hydrocarbon generation window, and earlier and longer hydrocarbon generation, than the traditional Tissot model, demonstrating a whole-process hydrocarbon generation across all kerogen types. The distribution and physical properties of reservoirs are generally controlled by sedimentary facies and diagenesis. From basin margin to sag center, sediment grains generally present reservoir-forming features of all facies belts and all grain-size grades from coarse to fine. A typical whole petroleum system generally follows a full-sequence, three-dimensional accumulation pattern described as “three zones laterally, three layers vertically”. Laterally, along the basin margin → slope area → sag area, conventional oil and gas reservoirs, tight oil and gas reservoirs, and shale oil and gas reservoirs develop sequentially, corresponding to the intervals of major source rocks. Vertically, in addition to shale/coal-rock oil and gas reservoirs within these intervals, tight/conventional reservoirs are also found above and below the source beds. Within the accumulation framework of the whole petroleum system, underexplored areas that have not yet achieved breakthroughs represent important potential domains for future oil and gas discoveries.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 3","pages":"Pages 384-401"},"PeriodicalIF":10.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148544634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research progress, challenges, and prospects of continental shale oil","authors":"Rukai ZHU,&nbsp;Zhongyi ZHANG,&nbsp;Chun FENG,&nbsp;Ming SHAO,&nbsp;Xue MIAO,&nbsp;Dan ZHANG,&nbsp;Yanbo LIANG","doi":"10.1016/S1876-3804(26)60721-5","DOIUrl":"10.1016/S1876-3804(26)60721-5","url":null,"abstract":"<div><div>Through systematic comparison of the geological characteristics, resource distribution, and exploration and development status of global marine and continental shale oil, this paper deeply analyzes the key theoretical and technical issues that restrict the development of continental shale oil in China. It points out that the basic theoretical research areas, such as the enrichment and accumulation mechanisms of shale oil with different lithological combinations, and the multi-scale and multiphase flow mechanisms in nanoscale confined spaces, are relatively underdeveloped; the accuracy of sweet spot prediction cannot effectively guide the selection of target layers and the positioning of horizontal well trajectories, and geology-engineering integration practices remain insufficient. All these factors severely restrict the large-scale utilization of shale oil resources. Focusing on the progress in the study of continental shale oil in the Songliao Basin, Ordos Basin, Junggar Basin and Bohai Bay Basin of China, this paper systematically analyzes six bottleneck issues (genetic models of fine-grained sedimentary rocks, types and distribution of hydrocarbon-generating organic matter, hydrocarbon generation-expulsion models and potential, types and performance of reservoir spaces, parameter selection and evaluation techniques for sweet spots, and productivity laws and enhanced oil recovery), summarizes progress in theoretical and technological research, and discusses examples and directions for tackling key issues. It identifies six major challenges on geological theory and engineering technology confronting the shale oil revolution in China: hydrocarbon accumulation mechanisms, sweet spot identification, seepage law, fracturing modification, drainage and production technology and recovery enhancement. To address these, the study proposes to establish a shale oil classification scheme based on source-reservoir configuration, to promote the refined development model of “geology-engineering-geology spiral integration”, and build an efficient shale oil development technology system tailored to the continental geological conditions in China, providing theoretical and technical support for achieving large-scale and beneficial development.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 3","pages":"Pages 418-432"},"PeriodicalIF":10.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148544635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Progress in shale gas accumulation theory and exploration of the Cambrian Qiongzhusi Formation in the Sichuan Basin, China","authors":"Tonglou GUO,&nbsp;Hucheng DENG,&nbsp;Zhengxiang LYU,&nbsp;Hua ZHOU,&nbsp;Yong ZHAO,&nbsp;Yong WANG,&nbsp;Susu WANG,&nbsp;Cheng XIE","doi":"10.1016/S1876-3804(26)60720-3","DOIUrl":"10.1016/S1876-3804(26)60720-3","url":null,"abstract":"<div><div>Taking the Cambrian Qiongzhusi Formation in the Ziyang–Jingyan area of the southwestern Sichuan Basin as the research object, this study investigates the reservoir characteristics, enrichment mechanism and accumulation model of new-type shale gas by comprehensively using core and thin section observation, geochemical testing, and production dynamic analysis. Two types of shales, organic-rich shale and organic-lean shale, are developed in the study area. The organic-lean shale can receive gas supply from source rock cracking in adjacent areas, possessing the foundation of multi-source hydrocarbon generation and gas supply. Multiple sets of tuffaceous shale were developed in the Qiongzhusi Formation of southern Sichuan Basin. Multi-stage volcanic-hydrothermal activities promoted the development of inorganic pores, microfractures and reservoir space. The reservoirs are characterized by high inorganic pore content, high brittle mineral content and high free gas proportion, and the ultra-deep shale presents favorable reservoir fracturing property and gas-bearing potential. Breaking the traditional understanding that shale gas only migrates over a short distance and accumulates in-situ merely in organic-rich shale, a new mixed-source enrichment model of in-situ generation + external migration charging for organic-lean shale is established. It is clarified that natural gas in the central Sichuan Basin follows a composite accumulation evolution path of “source rock cracking – in-situ generation – migration replenishment”. Three types of gas reservoirs are formed successively, including the early in-situ cracked conventional gas in the Cambrian Longwangmiao Formation of the Gaoshiti – Moxi area, the middle-stage in-situ enriched shale gas in the Qiongzhusi Formation of the Ziyang area, and the mixed-source shale gas formed by in-situ generation superimposed with late migration replenishment in the Qiongzhusi Formation of the Jingyan area.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 3","pages":"Pages 402-417"},"PeriodicalIF":10.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148544568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research advances and exploration breakthrough directions of the Jurassic coal-measure whole petroleum system in the Junggar Basin, China","authors":"Xinjun MAO,&nbsp;Weijiang YAO,&nbsp;Zhichao PANG,&nbsp;Zhengzhou HU,&nbsp;Jing LI,&nbsp;Ming CHENG,&nbsp;Haowei ZHANG","doi":"10.1016/S1876-3804(26)60723-9","DOIUrl":"10.1016/S1876-3804(26)60723-9","url":null,"abstract":"<div><div>Under the guidance of the whole petroleum system (WPS) concept, the Jurassic coal-measure source rocks, source-reservoir- caprock conditions, and configurations of various hydrocarbon accumulations in the Junggar Basin were systematically investigated to reveal the hydrocarbon accumulation characteristics and exploration targets of the Jurassic coal-measure WPS. The following research insights are obtained. First, the coal rocks of the Jurassic Badaowan and Xishanyao formations, together with the mudstones of the Sangonghe Formation, constitute a unified source kitchen characterized by large thickness, high thermal evolution degree and sustained gas-generation capability. This kitchen provides an ample source for the orderly accumulation of conventional oil and gas, coal-rock gas and tight sandstone gas. Second, multi-phase fluvial–deltaic sedimentation has developed thick conventional sandstones, tight sandstones, and coal rocks as diverse types of reservoirs in the basin, offering various storage spaces for hydrocarbon accumulation, while regionally extensive thick mudstones ensure effective sealing of deep gas reservoirs. Third, within the unified petroleum accumulation, system, multi-phase detachment and superimposed structures control hydrocarbon migration pathways and accumulation units, resulting in a orderly distribution of reservoirs from structural highs to deep sags. Specifically, at the southern margin, deep conventional natural gas and deep coal-rock gas are endowed in the central segment, while oil and gas coexist in the eastern and western segments; in the basin hinterland, coal-rock gas generated from old strata and stored in young strata is confirmed in the Dinan–Baijiahai area, while coal-rock gas generated and stored in the same set of strata is discovered in the Qigu area; in the slope and structurally complex zones, tight sandstone gas of the Badaowan Formation is found.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 3","pages":"Pages 451-466"},"PeriodicalIF":10.7,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148544567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}