Petroleum Exploration and Development最新文献

{"title":"Tectonic differentiation of basins in the northern South China Sea and its control on hydrocarbon accumulation","authors":"Yuhong XIE ,&nbsp;Caiwei FAN ,&nbsp;Chuanxin TONG ,&nbsp;Junjun YOU ,&nbsp;Gang ZHOU","doi":"10.1016/S1876-3804(26)60692-1","DOIUrl":"10.1016/S1876-3804(26)60692-1","url":null,"abstract":"<div><div>Based on seismic data, well log data, and analyses of hydrocarbon accumulation elements in typical oil and gas fields, this study systematically investigates the tectonic differentiation and its control on hydrocarbon accumulation in four major Cenozoic petroliferous basins (Beibuwan, Pearl River Mouth, Qiongdongnan and Yinggehai) of the northern South China Sea. The results show that the tectonic evolution in the study area exhibits a significant differentiation characterized by “east-west staging and north-south zonation”, with major subsidence events occurred progressively later from west to east and from north to south, allowing the basins to be classified into two types: passive continental margin basins and transform continental margin basins. This tectonic differentiation governs hydrocarbon accumulation through a “triple-control” mechanism: subsidence-thermal evolution divergence controls source rock type and maturation; tectonic-depositional cycle coupling controls reservoir/trap type and reservoir-caprock assemblage; and structural configurations control hydrocarbon accumulation, preservation and enrichment patterns. Moderate heat flow on the northern shelf favors oil generation from the Paleogene lacustrine source rocks, while high geothermal gradients in the southern deep-water area promote late-stage rapid gas generation from coal measures, forming the resource distribution framework with “oil in the north and gas in the south”; Tectonic-depositional coupling regulates reservoir distribution and reservoir-caprock assemblage effectiveness, with the rift-stage faulting inducing isolated lacustrine delta reservoirs, the southward shift of subsidence during the rift-drift transition giving rise to extensive marine delta sandstones, the detachment faults in deep-water areas governing the development of canyon channels, and regional transgressive mudstones and overpressure mudstones serving as key caprocks; Structural styles dictate accumulation models, including primary oil reservoirs characterized by the association of weakly reworked traps and regional seals, deep-water gas reservoirs characterized by shelf-break controlled sand and high heat flow-driven gas migration, composite gas reservoirs characterized by transfer zone controlled reservoirs and overpressure mudstone sealing, and late-stage rapid hydrocarbon accumulation characterized by strike-slip stress transition and diapir conduit. Analysis of hydrocarbon accumulation in typical oil and gas fields validates these cognitions, revealing the comprehensive control of tectonic evolution on source rock maturation, reservoir distribution, trap types and preservation conditions. Based on these findings, it is recommended to differentiate exploration strategies by areas and layers, with focus on structural-lithological traps under high heat flow setting in deep-water areas and primary oil reservoirs with weak reworking in shallow-water areas.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 2","pages":"Pages 285-298"},"PeriodicalIF":8.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147754307","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":"Key technologies for efficient and stable production through intelligent zonal fine water injection in Qinghai Oilfield, NW China","authors":"Yongshu ZHANG ,&nbsp;Kunyu WU ,&nbsp;Quanbin WANG ,&nbsp;Yongwen YUAN ,&nbsp;Xiuyu ZHU ,&nbsp;Fuyong WANG ,&nbsp;Deli JIA","doi":"10.1016/S1876-3804(26)60704-5","DOIUrl":"10.1016/S1876-3804(26)60704-5","url":null,"abstract":"<div><div>In response to the unsatisfactory water injection performance in Qinghai Oilfield caused by complex reservoir geological conditions, the fourth-generation cable-controlled zonal water injection technology was innovatively upgraded. An integrated fine water injection technology system was established, integrating fine reservoir characterization, intelligent zonal water injection with precise monitoring, and remote dynamic regulation. Through the design of high-temperature-resistant measurement and control circuits and the development of low-flow downhole flow measurement technology, a small-diameter cable-controlled water distributor suitable for complex conditions characterized by high temperature, high pressure, and high salinity was developed. In addition, a remote monitoring and management system for zonal water injection was established, enabling real-time monitoring of production parameters and dynamic regulation of injection rates throughout the entire layered water injection process. The technology system has been applied in the Huatugou and Yingdong demonstration areas. The intelligent zonal water injection can effectively improve the injection profile, enhance waterflood sweep efficiency, control the natural production decline rate of well groups, increase the qualification rate of zonal water injection, and slow down the rise of water cut. Economic evaluation results show that, compared with conventional zonal water injection technology, the proposed intelligent zonal fine water injection method demonstrates significant advantages in reducing operational costs and improving development efficiency. The results indicate that the upgraded fourth-generation cable-controlled zonal water injection technology can significantly improve waterflood performance and provides a replicable and scalable engineering solution for fine water injection and efficient, stable production in complex fault-block reservoirs.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 2","pages":"Pages 460-472"},"PeriodicalIF":8.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147754290","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":"Hydrocarbon accumulation characteristics and exploration progress of the Triassic Jiucaiyuan Formation in the eastern Fukang Sag, Junggar Basin, NW China","authors":"Jilun KANG ,&nbsp;Shilin LI ,&nbsp;Lilong WANG ,&nbsp;Gang GAO ,&nbsp;Wei ZHANG ,&nbsp;Qiang MA ,&nbsp;Guoqiang JIA ,&nbsp;Haiyue YU ,&nbsp;Qi ZHANG ,&nbsp;Xiaohua YU ,&nbsp;Guobin FU ,&nbsp;Zhong QING","doi":"10.1016/S1876-3804(26)60697-0","DOIUrl":"10.1016/S1876-3804(26)60697-0","url":null,"abstract":"<div><div>Based on data from drilling, logging, seismic surveys and tests, a systematic study was conducted on the petroleum geological characteristics and hydrocarbon accumulation features/models of the Triassic Jiucaiyuan Formation in the eastern Fukang Sag of the Junggar Basin. The favorable exploration targets were identified. First, the highly mature, high-quality saline lacustrine source rocks developed in the Permian Lucaogou Formation in the eastern Fukang Sag are characterized by continuous and efficient hydrocarbon expulsion over multiple stages, providing a critical material foundation for large-scale hydrocarbon accumulation in the Jiucaiyuan Formation. Second, the Jiucaiyuan Formation, a dual source—sink system, represents a distal, large-scale braided river delta sand bodies originated from the Karamaili Mountain, with well-preserved intergranular pores and fractures, providing good reservoir conditions. Third, the middle and upper parts of the Jiucaiyuan Formation contain thick, high-quality mudstone caprocks. Source-connected faults and associated fracture systems serve as effective pathways for hydrocarbon migration and accumulation. The continuous hydrocarbon generation and pressurization conditions are favorable for the formation of ultra-high-pressure oil and gas reservoirs. Fourth, the effective spatial configuration of various accumulation elements constitutes a hydrocarbon accumulation model characterized by “lower generation, upper accumulation, fault transportation, sandbody-fracture storage, and overpressure-driven enrichment”, resulting in the current structural-lithologic reservoirs within the Jiucaiyuan Formation. Fifth, the most favorable exploration targets in Fudong are areas adjacent to the hydrocarbon generation center of the Lucaogou Formation, with superior structural settings and superimposed development of faults and sandbodies, corresponding to the prospective trap area of 263 km² and the possible resources amounting to 1.68×10⁸ t. Sixth, the zones with efficient coupling of five elements (source, fault, sandbody, fracture and pressure) are recommended as preferential targets for seeking additional large-scale petroleum discoveries in the Jiucaiyuan Formation. The renewed major breakthrough in the Triassic petroleum exploration in the Fukang Sag, represented by a high oil flow rate of 56.16 m³/d at Well Fukang-2 during test, has underscored its significant potential and promising prospects for large-scale exploration. The research findings on hydrocarbon accumulation are expected to promote a multi-layer three-dimensional exploration pattern in the eastern part of the Junggar Basin and have an important strategic significance for oil and gas exploration in the Triassic across the basin.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 2","pages":"Pages 359-371"},"PeriodicalIF":8.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147754149","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":"Perforation optimization of Gulong shale oil reservoirs based on near-wellbore fracture morphology control, Songliao Basin, NE China","authors":"Siwei MENG ,&nbsp;Jinbo LI ,&nbsp;Suling WANG ,&nbsp;Jiaping TAO ,&nbsp;Kangxing DONG ,&nbsp;Qiuyu LU","doi":"10.1016/S1876-3804(26)60709-4","DOIUrl":"10.1016/S1876-3804(26)60709-4","url":null,"abstract":"<div><div>In response to the problems such as complex near-wellbore fractures, difficult far-wellbore fracture propagation, and limited stimulated reservoir volume (SRV) caused by the “thousand-layer thin pancakes” configuration of the Guolong shale oil reservoir in the Songliao Basin, China, triaxial mechanical and fracture visualization experiments were conducted on shale samples. Combined with digital image correlation technology and laser pulse ultrafast resolution technology, the micro-scale deformation and supersonic-scale fracture expansion characteristics of the Guolong shale were captured in real time. A constitutive model reflecting the flexible deformation and anisotropy of the Guolong shale and a mechanical model considering competitive fracture initiation-propagation from multiple perforation holes under the coupling of stress interference and flow distribution were established to reveal the control mechanisms of pore density, pore number, and pore distribution on fracture propagation. The results show that by reducing the number of holes and increasing the perforation density, the stress interference between multiple perforation holes can be effectively mitigated, and combined with the extreme limited entry (ELE), the fracturing fluid can be evenly distributed. Compared with the high-density perforation (8 holes per cluster), the low-density perforation (6 holes per cluster) yields an increased opening rate by approximately 45 percentage points. Compared with spiral perforation, the 30° phase angle conjugate directional perforation enables both stress interference reduction and enhanced longitudinal/transverse reservoir connectivity, and it can easily form vertical energy concentration, as indicated by stress field, to drive fracture expansion across layers. The directional perforation + ELE fracturing mode has been verified through field practice. After changing the perforation method from 60°–180° phase angle spiral perforation to 30° phase angle conjugate directional perforation, and reducing the number of perforations from 12–16 holes per cluster to 5–7 holes per cluster, the SRV increased by 17.4% and 48.9%, respectively.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 2","pages":"Pages 534-548"},"PeriodicalIF":8.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147754289","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":"Concept, technology generation classification and field practices of enhanced gas recovery","authors":"Yunsheng WEI,&nbsp;Haijun YAN,&nbsp;Jianlin GUO,&nbsp;Junlei WANG,&nbsp;Haifa TANG,&nbsp;Zhi GUO,&nbsp;Yadong QI,&nbsp;Hanqing ZHU,&nbsp;Zhongnan WANG,&nbsp;Yanling GAO","doi":"10.1016/S1876-3804(26)60705-7","DOIUrl":"10.1016/S1876-3804(26)60705-7","url":null,"abstract":"<div><div>Starting from the first principle thinking, this study systematically reviews the development mechanisms of gas reservoirs and proposes the development concept of “full life cycle enhanced gas recovery (EGR)”. Following the principles of scientificity, practicality and comparability, a generational classification system for EGR technologies is established. The research indicates that the properties of natural gas dictate a development mechanism primarily driven by pressure depletion to release the elastic expansion energy of gas. This leads to a development model centered on primary depletion, supplemented by limited adjustments in late stages. Early development essentially lies in well pattern optimization and risk pre-control, while late development focuses on targeted local adjustments and integrated collaborative control. Primary gas recovery, relying on natural energy depletion, achieves a recovery factor of 25%–55%. Secondary gas recovery, through active regulation of the reservoir pressure field via techniques like blockage removal, and injection-production optimization, can enhance the recovery factor by 10–15 percentage points. Tertiary gas recovery, employing multiple mechanisms to alter the reservoir’s physical and chemical fields synergistically, offers a potential further increase of 5–10 percentage points. Currently, primary recovery technologies are mature and well-established. Synergistic optimization of well patterns and fracture networks enables effective production from gas-drive reservoirs, while optimized development strategies facilitate orderly production from water-drive gas reservoirs. Secondary recovery technologies, in the field pilot stage currently, adopt active measures like enhanced water drainage, water shutoff, and gas injection to effectively control water influx and release trapped gas. Tertiary recovery remains largely in the laboratory or pilot test stage. Future efforts should focus on cross-generational technologies, such as “primary + secondary” and “primary + tertiary” combinations, to continuously improve recovery factors throughout the full lifecycle of gas reservoirs.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 2","pages":"Pages 473-488"},"PeriodicalIF":8.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147754291","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":"A prediction method for proppant embedment depth in artificial fractures of hydrate reservoirs","authors":"Nengyou WU ,&nbsp;Yongchao ZHANG ,&nbsp;Jiawei ZHANG ,&nbsp;Jing’an LU ,&nbsp;Yanlong LI ,&nbsp;Kaixiang SHEN ,&nbsp;Yunkai JI ,&nbsp;Qiang CHEN","doi":"10.1016/S1876-3804(26)60710-0","DOIUrl":"10.1016/S1876-3804(26)60710-0","url":null,"abstract":"<div><div>Given the absence of a prediction method for proppant embedment depth in artificial fractures of hydrate reservoirs, this study employs a hypoplastic constitutive model to quantitatively evaluate the impact of hydrate saturation on the mechanical parameters of the sediments. By integrating the load distribution at the proppant-sediment interface with their respective deformation characteristics, a computational model is developed to determine the proppant embedment depth across three distinct stages: elastic, elastoplastic and fully plastic. Based on the established model, the influences of hydrate saturation, proppant particle size, proppant arrangement pattern, and closure pressure on the proppant embedment depth are analyzed. The results demonstrate that the proppant embedment depth in fractures of hydrate reservoirs increases with greater closure pressure and larger proppant particle sizes, while it decreases with higher hydrate saturation and increased proppant areal packing density. At a constant closure pressure, the proppant embedment depth exhibits a nonlinear relationship with hydrate saturation, proppant particle size, and proppant areal packing density, with this nonlinearity becoming more pronounced at elevated closure pressures.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 2","pages":"Pages 549-560"},"PeriodicalIF":8.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147754293","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":"Internal architecture characterization of carbonate reservoirs and its geological significance for reservoir development: A case study of Cretaceous Main Mishrif Formation in H oilfield, the Middle East","authors":"Zhanfeng QIAO ,&nbsp;Guangya ZHU ,&nbsp;Guanming SHAO ,&nbsp;Zifei FAN ,&nbsp;Xiaowei SUN ,&nbsp;Yu ZHANG ,&nbsp;Chaozhong NING","doi":"10.1016/S1876-3804(26)60696-9","DOIUrl":"10.1016/S1876-3804(26)60696-9","url":null,"abstract":"<div><div>This study investigates the strong heterogeneity and complex internal architecture of carbonate reservoirs, using the Cretaceous Main Mishrif Formation in the Middle East as an example. A multi-scale characterization of sedimentary architecture is conducted based on reservoir genetic analysis. Quantitative calibration of well logs with core thin sections enables semi-quantitative evaluation of dissolution intensity in non-cored intervals. Within a coupled depositional-diagenetic framework, reservoir classification is established with depositional-diagenetic facies as the linking framework, allowing delineation of their spatial distribution and connectivity. The results show that three types of architectural units are developed in the Main Mishrif Formation, including tidal channels, bioclastic shoals, and tidal bioclastic deltas, which exhibit fining-upward, coarsening-upward, and coarsening-upward–fining-upward successions, respectively. These units form two composite stacking patterns, namely the “encapsulated” pattern and the “upper-lower” pattern. A dissolution intensity index is defined based on thin-section analysis, and a log-based prediction model is developed using principal component analysis and multivariate regression. Dissolution in the MB2 sub-member is controlled by third-order sequence boundaries, with strong dissolution occurring from MC1-1 to MB2-1, forming high-permeability zones across architectural units. In contrast, dissolution in the MB1 sub-member is controlled by high-frequency sequences, with stronger dissolution in the upper intervals, favoring the development of high-permeability zones. By combining depositional and dissolution characteristics, a total of 21 depositional-diagenetic facies are identified, and the distributions of high-permeability zones, high-quality, moderate, and poor reservoirs, as well as interlayers are systematically characterized. These findings provide a geological basis for stratified reservoir development, well pattern optimization, and remaining oil recovery in carbonate reservoirs, and are promising for the characterization of giant thick carbonate reservoirs in the Middle East and Central Asia.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 2","pages":"Pages 343-358"},"PeriodicalIF":8.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147754314","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 classification of Ordovician paleokarst conduits and intelligent quantitative prediction of filling degree in Tahe Oilfield, NW China","authors":"Jiyuan GAO ,&nbsp;Nuoyu WANG ,&nbsp;Yuyang LI ,&nbsp;Zhongxian CAI ,&nbsp;Heng ZHANG ,&nbsp;Lin JIANG ,&nbsp;Yan WANG ,&nbsp;Shilin WANG","doi":"10.1016/S1876-3804(26)60702-1","DOIUrl":"10.1016/S1876-3804(26)60702-1","url":null,"abstract":"<div><div>Based on 3D seismic, logging, and core data from the Tahe Oilfield, Tarim Basin, this study carried out logging-based identification of cave filling facies in drilled Ordovician paleokarst conduits and quantitative calculation of filling degree, and analyzed the internal structure of paleokarst conduits. On this basis, a quantitative prediction of the filling degree of conduit networks in plan view was achieved by constructing a nonlinear relationship model. The results show that, according to differences in petrophysical fabric, filling facies in drilled caves can be classified into fractured host-rock facies, sandy-muddy cemented conglomeratic clastic facies, transported sandstone facies, chemical sedimentary filling facies and unfilled cave facies. Using a convolutional neural network algorithm, the filling degree of 156 drilled caves in the study area was quantitatively calculated, among which caves with a filling degree greater than 80% account for 39.7%, whereas those with a filling degree less than 20% account for only 16.0%. The genetic types of paleokarst conduits were divided into 7 categories: main-stream conduits, tributary conduits, outflow conduits, along-stream conduits, turnaround conduits, sinking-river conduits and labyrinthine conduits; and six conduit morphologies were identified: sinkholes, hall-shaped chambers, underflow loops, horizontal underflow passages, corridor passages and medium-dip connecting passages. Furthermore, a quantitative prediction method for conduit filling degree was established based on a backpropagation neural network, with geological controlling factors as input variables. The prediction results indicate that the filling within paleokarst conduits shows obvious spatial differentiation: the probability of filling is relatively high in underflow loop segments, zones of increased potential energy, and medium-dip passage segments, whereas the spaces above hall-shaped chambers, the upper parts of medium-dip connecting passages, and downstream outlets of conduits have relatively low filling probabilities. The latter should therefore be regarded as key potential targets for future fine-scale development of paleokarst conduit reservoirs.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 2","pages":"Pages 427-443"},"PeriodicalIF":8.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147754148","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":"Reworking and reservoir-forming effects of grain shoals in a carbonate platform affected by multi-phase storm events: A case study of Middle–Upper Cambrian Xixiangchi Group in central–southern Sichuan Basin, SW China","authors":"Wenliang SHANG ,&nbsp;Shuyuan SHI ,&nbsp;Wei YANG ,&nbsp;Gang ZHOU ,&nbsp;Zhuangzhuang BAI ,&nbsp;Jiabin WU","doi":"10.1016/S1876-3804(26)60701-X","DOIUrl":"10.1016/S1876-3804(26)60701-X","url":null,"abstract":"<div><div>Taking the Middle–Upper Cambrian Xixiangchi Group in the central–southern Sichuan Basin as an example, this study investigates the sedimentary characteristics and evolutionary history of tempestites using field outcrop, core, thin-section and logging data, and elucidates the patterns and processes by which storms have reworked grain shoal reservoirs in carbonate platforms, thereby identifying the zones with favorable reservoirs. The results indicate that: (1) The Xixiangchi Group develops massive storm deposits, with five intervals occurred in a complete storm sedimentary sequence; Xixiangchi Group exhibits six typical storm depositional sequences, with storm-related grain shoals developed in settings such as mixed tidal flats, intra-platform depressions, and margins of the intra-platform depressions. (2) During the deposition of the Xixiangchi Group, storm activities were mainly in the southeastern, central and southwestern parts of the Sichuan Basin. Overall, storm action showed an initial increase followed by a decrease. (3) The impact of storms on the reworking of grain shoal reservoirs varies across different facies zones. The intra-platform depression margins, influenced by storm centers, experienced strong reworking, leading to the vertical stacking of storm-related grain shoals and normal grain shoals, which expands the scale of the shoal complex. Furthermore, storms enhance the penecontemporaneous dissolution, favoring the development of large-scale high-quality reservoirs. The intra-platform depressions and mixed tidal flats, controlled by the storm centers, were weakly modified, possibly inducing scattered storm-related grain shoals under low-energy conditions. The degree of karst modification is generally low, and local conditions are favorable for reservoir development. (4) The Dazu-Hechuan-Guang’an area, strongly reworked by storm activities, exhibits a large scale of storm-related grain shoals with good physical properties, providing favorable conditions for the development of contiguous, high-quality grain shoal reservoirs, so it can be regarded as a key target for subsequent exploration of the Xixiangchi Group.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 2","pages":"Pages 414-426"},"PeriodicalIF":8.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147754147","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":"Phased array electromagnetic wellbore detection technology","authors":"Yongqiang FU ,&nbsp;Deli JIA ,&nbsp;Bo DANG ,&nbsp;Zhi WANG ,&nbsp;Zheng TONG ,&nbsp;Ran WEI","doi":"10.1016/S1876-3804(26)60707-0","DOIUrl":"10.1016/S1876-3804(26)60707-0","url":null,"abstract":"<div><div>Traditional wellbore detection technologies face limitations such as low detection efficiency, poor accuracy, unsuitability for unconventional oil/gas well fracturing operations, and incomplete coverage of wellbore damage as well as integrity assessment. This paper introduces a phased array electromagnetic wellbore detection technology. The theoretical principles, instrument design, and technical connotation of this technology are systematically elaborated. Field applications, including casing damage and corrosion detection in old wells in Xinjiang Oilfield, China, and fracturing-induced casing deformation detection in platform wells targeting deep shale gas in Southwest Oil &amp; Gas Field and deep shale oil in Dagang Oilfield, China, are analyzed to evaluate the proposed technology’s performance in inspecting metal casing strings. Results demonstrate that the phased array electromagnetic wellbore detection technology provides high measurement accuracy, broad applicability, ease of operation and high scalability. The technology achieves a resolution of 10 mm for non-penetrating damage detection, 0.5 mm for inner diameter measurement of oil casing, and 0.3 mm for wall thickness assessment. It maintains stable performance in high-temperature (no more than 175 °C) and high-pressure (no more than 140 MPa) environments, and effectively addresses current exploration and production requirements by providing comprehensive and accurate wellbore integrity data for downhole operations.</div></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"53 2","pages":"Pages 501-511"},"PeriodicalIF":8.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147754153","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}