Marine and Petroleum Geology最新文献

{"title":"Sequence stratigraphic and reservoir modeling of KOC Field onshore Niger Delta Basin: implication for mature oilfield revitalization","authors":"Amoke Aniebonam Ignatius ,&nbsp;Ayonma Wilfred Mode ,&nbsp;Ikechukwu Onyema Njoku ,&nbsp;Eze Martins Okoro","doi":"10.1016/j.marpetgeo.2025.107553","DOIUrl":"10.1016/j.marpetgeo.2025.107553","url":null,"abstract":"<div><div>Recently, the exploration focus in the onshore areas of the Niger Delta Basin has been targeted towards extending the economic viability of “shallow hanging” producing reservoir units whilst searching wider and deeper for new oil and gas pools beyond known depths. The need therefore arises to deploy improved technologies for accurate mapping of prospect opportunities located at intermediate and deeper intervals within the basin. In this study, integrated sequence stratigraphic and reservoir modeling of the KOC Field onshore Niger Delta Basin was carried out using well logs, 3D seismic, and biostratigraphic data to assess the hydrocarbon potentials and also uncover the reservoir geometry, stratigraphic configuration, and structural framework of the study area. Logging and biofacies information from seven (7) wells, as well as key stratal surfaces including three (3) sequence boundaries (SB) and three (3) maximum flooding surfaces (MFS) provided in Well 001 and Well 039, formed the basis for chronostratigraphic correlation across the field. Two genetic sequences bounded at the top and base by maximum flooding surfaces were mapped and designated as Genetic Sequence 1 (G_SEQ1) and Genetic Sequence 2 (G_SEQ2). Three main stacking patterns (progradational, retrogradational and aggradational) interpreted as Lowstand Systems Tract (LST), Highstand Systems Tract (HST) and Transgressive Systems Tract (TST) were delineated from each of the identified genetic sequences. Lithological correlation of the wells revealed two hydrocarbon-bearing sand units with good reservoir quality characteristics. These reservoirs designated as R12 Sand and R15 Sand belonged to the LST and TST of G_SEQ2, and were interpreted to be basin floor fans and channel fill complexes, deposited within the neritic to bathyal environments. 3D geological modelling of the reservoirs showed good structural closures with thick sedimentary packages, suggesting that they are good locations for hydrocarbon accumulation. The major faults constitute good reservoir seals due to stratigraphic juxtapositions that may have prevailed in the cause of the dip slip movement.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107553"},"PeriodicalIF":3.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144662041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagenesis and burial history controls on Oligocene Huagang sandstones, southern Xihu Sag (East China Sea Basin): Implications for the formation of effective reservoirs","authors":"Hong-Liang Huo ,&nbsp;Cheng-Lin Liu ,&nbsp;Dao-Wu Huang ,&nbsp;An-Qi Tian ,&nbsp;Rizwan Sarwar Awan ,&nbsp;Hong-Yan Gao ,&nbsp;Chuang-Xin Liu ,&nbsp;Xue-Yong Chen ,&nbsp;Zi-Ye Tian ,&nbsp;Tao-Zheng Yang ,&nbsp;Bin-Bin Liu ,&nbsp;Chao-Jun Liang","doi":"10.1016/j.marpetgeo.2025.107592","DOIUrl":"10.1016/j.marpetgeo.2025.107592","url":null,"abstract":"<div><div>This study aims to reveal the diagenetic evolution sequence and controlling factors of Oligocene Huagang Formation (E₃h) sandstone reservoirs in the HY area, and predict high-quality reservoir distribution to guide hydrocarbon exploration. A comprehensive approach integrating core observation, thin-section petrography, geochemical analysis, and seismic-log interpretation was employed. By combining burial history simulation and diagenetic analysis, we systematically analyzed reservoir quality and diagenetic evolution and established evolution models for effective reservoir pore spaces. Results indicate that E₃h sandstones underwent intense diagenetic processes including compaction, cementation, and dissolution. Diagenesis plays a critical role in controlling reservoir quality: compaction is the primary factor that governs vertical variations in petrophysical properties, where shallower intervals typically exhibit better quality than deeper ones. In contrast, cementation and dissolution serve as secondary controls, explaining property differences between Blocks A and B, with Block A reservoirs being superior. A three-stage relationship has been identified between burial history and diagenesis: (1) early gradual subsidence stage (GSS) with weak feldspar dissolution, early carbonate cementation, chlorite coating, and mechanical compaction; (2) intermediate tectonic activity stage (TAS) with massive feldspar dissolution, quartz overgrowth precipitation, and ferruginous cement formation; (3) late stable burial stage (SBS) featuring intensified compaction and clay mineral transformations. The spatial configuration of fault systems and sandstones, combined with compositional attributes, strongly controls diagenetic evolution. Favorable zones for dissolution development occur at intersections of fault zones and acidic fluid migration pathways, while quartz-feldspar-rich zones mitigate porosity loss via compaction resistance. Three effective reservoir development models were proposed: high dissolution-low cementation-low compaction, moderate dissolution-low cementation-low compaction, and low compaction-low cementation-low dissolution. This research provides a critical basis for predicting E₃h high-quality reservoirs in the study area. Furthermore, the comprehensive burial history-diagenesis analysis method presented here offers a valuable reference for studies on sandstone diagenetic evolution and hydrocarbon exploration in similar geological settings.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107592"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cenozoic sedimentary records from the eastern offshore of China reveal the Eocene birth of the Yangtze River","authors":"Qian Zhao ,&nbsp;Hongtao Zhu ,&nbsp;Tandis S. Bidgoli ,&nbsp;Yiming Jiang ,&nbsp;Yinshan Chang ,&nbsp;Qianghu Liu ,&nbsp;Wei Wang","doi":"10.1016/j.marpetgeo.2025.107558","DOIUrl":"10.1016/j.marpetgeo.2025.107558","url":null,"abstract":"<div><div>The Yangtze River, which links the Tibetan Plateau to the eastern offshore of China, is one of the most important sediment routing systems in East Asia. However, the timing of its establishment has remained controversial. This study examines new and published zircon U-Pb geochronology data from eastern offshore basins (the East China Sea Shelf Basin and South Yellow Sea Basin) and major rivers in East Asia, establishing new constraints on the timing of full integration of the Yangtze River. We report detrital zircon U-Pb ages (n = 664) from Paleogene strata in the East China Sea Shelf Basin, the primary sink for the river during the Cenozoic. Detrital zircons from the Eocene to early Oligocene Pinghu Formation range from 34.9 ± 0.7 to 2800 ± 42 Ma, with 100–250 Ma and 1700–2100 Ma age clusters, and small Paleozoic, Neoproterozoic, and Paleoproterozoic-Archean peaks. A similar age range (33 ± 0.4 to 2842 ± 43 Ma) and nearly identical peaks are documented for the Oligocene Huagang Formation. The maximum depositional age, based on the youngest single grains in our samples, is 34.9 ± 0.7 Ma for Pinghu Formation and 33 ± 0.4 Ma for Huagang Formation. Statistical comparison of the new U-Pb ages with published data from sands collected in major segments of the modern Yangtze River and its estuary demonstrate similar provenance, but with larger contributions of 700–1000 Ma and 1700–2100 Ma zircons, sourced from the Songpan-Garze terrane. Additionally, the new data suggest that both the East China Sea Shelf Basin and the South Yellow Sea Basin retain young (&lt;80 Ma) zircons, likely sourced from the Jinshajiang segment of the Yangtze River. The youngest of these zircons are ∼37-33 Ma and only occur in sands from the upper reaches of the modern river. The high degree of similarity between the eastern offshore samples and the modern Yangtze system suggests the river and source-to-sink system were established by the late Eocene, and may point to topographic adjustments in the Qiangtang portion of the Tibetan Plateau as a driver of drainage expansion and integration.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107558"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144828920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Marine flooding induced basinal brine mixing and carbonate cementation: An example from Cretaceous ultra-deep clastic reservoirs in the Kuqa Depression, western China","authors":"Shunyu Wang ,&nbsp;Jian Wang ,&nbsp;Keyu Liu ,&nbsp;Yong Li ,&nbsp;Zhenkun Li ,&nbsp;Meiyi Chen ,&nbsp;Leilei Yang","doi":"10.1016/j.marpetgeo.2025.107561","DOIUrl":"10.1016/j.marpetgeo.2025.107561","url":null,"abstract":"<div><div>Marine flooding can significantly change hydrochemical features of pore water and provide needed ions for reservoir diagenesis. Present basinal brines and contemporaneous cements may record the participation of paleo-marine flooding. The ultra-deep (&gt;6000 m) sandstone reservoirs of the Cretaceous Bashijiqike Formation (K_1bs) in the Kelasu thrust-fold belt, Kuqa Depression of western China, are featured by a CaCl₂-type brine and widespread eodiagenetic carbonate cementation. Through a study integrating petrographic characterization, cathodoluminescence imaging, hydrochemical feature comparison, geochemical indicators, carbon and oxygen isotopes and reactive transport simulations, we have concluded that late Cretaceous marine flooding events provided the essential ion source required for carbonate cementation and controlled major-ion compositions of the K_1bs brine. There appears to be a complementary spatial distribution of calcite and dolomite cements in K_1bs. Calcite cement occurs mainly in the northern paleo-high terrains, which was precipitated from alternating redox conditions due to periodic infiltration of meteoric water. Dolomite cement occurs mainly in the southern paleo-lows, being formed under stable reducing conditions caused by submerged seawater. Calcite precipitation, dolomitization and dissolution of K-feldspar further modified major ionic compositions of the late Cretaceous seawater during burial, leading to the formation of the present CaCl₂-type brines in K_1bs. Reactive transport modeling showed that high-flux meteoric water can promote calcite deposition, while low-flux meteoric water is beneficial to dolomite deposition. The late Cretaceous marine flooding significantly enhanced the major-ion contents, altered the hydrochemistry of the initial pore fluid and induced carbonate cementation within the terrestrial sandstone reservoirs in the seawater-meteoric water mixing zone.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107561"},"PeriodicalIF":3.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identifying source-rocks using trace-elements and garnet discrimination diagrams: Example from Potiguar Basin, equatorial margin, NE Brazil","authors":"Suyane Gonçalves de Campos ,&nbsp;Marcus Vinicius Dorneles Remus ,&nbsp;Bruno Rafael de Barros Pereira ,&nbsp;Cristiano de Carvalho Lana ,&nbsp;Marcia Boscato Gomes ,&nbsp;Susan Drago Martins ,&nbsp;Norberto Dani ,&nbsp;Emilson Fernandes Soares ,&nbsp;Diogo Andre Buck","doi":"10.1016/j.marpetgeo.2025.107608","DOIUrl":"10.1016/j.marpetgeo.2025.107608","url":null,"abstract":"<div><div>Sedimentary provenance analysis based on the major element composition of detrital garnet and tourmaline is a conventional and widely used method. However, overlapping compositional fields in standard garnet classification diagrams often hinder the accurate identification of source areas. To overcome such ambiguities, this study applies an integrated analytical approach. The methodology involved the compositional analysis of major and trace elements (Zn, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) in 1043 garnet grains, major elements in 1493 tourmaline grains, and multivariate statistical analysis to refine the provenance of sandstones from the Pendência, Alagamar and Açu formations (Potiguar Basin, NE Brazil). Initial classification using major elements suggested a significant contribution from felsic igneous sources (Bi-type). However, trace-element geochemistry revealed that a significant portion of these garnets (<span><math><mrow><mo>≈</mo><mn>79</mn><mtext>%</mtext></mrow></math></span> of the original Bi type) shows an affinity with amphibolite and granulite-facies metapelites. This reclassification is corroborated by the predominance of tourmalines derived from metapelites and by the statistical analysis of the major elements of the garnets in the investigated samples. Therefore, the results indicate that the sediment supply for the studied formations has a more significant metasedimentary contribution than suggested by conventional methods alone. The integrated data point to the Seridó Terrane and the Caicó Complex, within the Borborema Province, as the most likely source areas, with a predominance of amphibolite-facies and, secondarily, granulite-facies metasedimentary rocks. The participation of igneous sources was more evident in the pre-rift phase due to precursor and contemporaneous Cretaceous magmatic activity. A mixed supply, with an expressive contribution from igneous and metamorphic basement sources, characterized the rift phase (Pendência Formation). The post-rift (Alagamar Formation) and drift (Açu Formation) phases maintained this mixed pattern, with a predominance of metasedimentary sources from the basement, but with the addition of new magmatic pulses and the reworking of preexisting volcaniclastic materials during the drift phase.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107608"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145265000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New data on the identification of magnesium-rich carbonate phases using Fourier Transform Infrared Spectroscopy","authors":"Katarzyna Stanienda-Pilecki ,&nbsp;Dariusz Łukowiec","doi":"10.1016/j.marpetgeo.2025.107585","DOIUrl":"10.1016/j.marpetgeo.2025.107585","url":null,"abstract":"<div><div>This paper presents the theory behind the importance and applicability of Fourier infrared spectroscopy in identifying carbonate phases with varying magnesium content. It presents the results of studies of Triassic limestone and dolomite samples taken from the Polish part of the Germanic Basin, which were analysed using this method. The scientific significance of the FTIR method lies in its ability to identify carbonate phases with varying magnesium content, even at low levels. FTIR is one of the few methods that offer such possibilities.</div><div>The following phases were analysed: low-Mg calcite, high-Mg calcite, dolomite and huntite. These carbonate phases were identified based on wave numbers occurring in the infrared absorption spectra. Low-Mg calcite is the dominant phase in the limestones. Some samples also contain a small amount of high-Mg calcite. Dolomite and huntite were also identified. High-Mg calcite and dolomite are prevalent in dolomites and dolomitic limestones. The research results indicate that the rocks of the Gogolin Unit (Lower Muschelkalk) and Diplopor Unit (Middle Muschelkalk) exhibit the least differentiation in carbonate phase content with varying magnesium contents, whereas the rocks of the Tarnowice and Boruszowice Units (Upper Muschelkalk) exhibit the most. The results suggest that the rocks of the Lower Muschelkalk (Gogolin Unit) and Middle Muschelkalk (Diplopor Unit) are quartz- and kaolinite-rich limestones. In contrast, the rocks of the Upper Muschelkalk (Tarnowice and Boruszowice units) are dolomites and dolomitic limestones. The results of the study demonstrate that Fourier infrared spectroscopy is one of the most effective methods for identifying carbonate phases with varying magnesium content, including those with magnesium substitution, due to its ease of use and high level of accuracy.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107585"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas-in-place (GIP) model and resource potential of the ultra-deep Lower Cambrian gas-rich shales in the southern Sichuan Basin, China","authors":"Haitao Gao ,&nbsp;Peng Cheng ,&nbsp;Wei Wu ,&nbsp;Chao Luo ,&nbsp;Haifeng Gai ,&nbsp;Liang Xu ,&nbsp;Tengfei Li ,&nbsp;Shangli Liu ,&nbsp;Hui Tian","doi":"10.1016/j.marpetgeo.2025.107606","DOIUrl":"10.1016/j.marpetgeo.2025.107606","url":null,"abstract":"<div><div>The deep and ultra-deep Lower Cambrian Qiongzhusi (DUDQ) shales have abundant gas resources. However, the strong heterogeneity of the DUDQ shale makes it complex to accurately predict the gas-in-place (GIP) content and resource potential. The first high-yield DUDQ shale well Z201 in the southern Sichuan Basin, offering a crucial opportunity to investigate their gas-bearing characteristics. This study focuses on the Qiongzhusi Formation Q1₂ submember (Q1₂) of well Z201, analyzes their geological characteristics, and measures its adsorption parameters through high-temperatures (60−150 °C) and high-pressures (0.01−35 MPa) methane adsorption experiments, and a geological GIP model is established to predict the shale gas resources of the DUDQ shales. The maximum absolute adsorption gas content (n₀) and adsorbed phase methane density (ρ_ads) of the DUDQ shales range from 1.90 to 4.91 cm³/g and 0.28−0.47 g/cm³, respectively. Both n₀ and ρ_ads are positively correlated with total organic carbon (TOC) content and geopressures, but negatively correlated with temperature. The average adsorption capacity of inorganic matter (IM) in the DUDQ shales is 1.99 cm³/g, which, together with high TOC content, are the main important factors contributing to the high GIP contents. With increasing burial depth, the formation temperature and pressure gradually increase. Meanwhile, the adsorbed gas content (n_ads) and total gas content (n_tot) initially tend to increase followed by a subsequent decrease, whereas the free gas content (n_free) tends to increase. Moreover, n_tot is also affected by the TOC content and effective porosity. The most promising areas for the DUDQ shale gas exploration and development are the central area of the intracratonic sag and the surrounding regions of the Weiyuan anticline, with estimated shale gas resources exceeding 2.52 × 10¹² m³.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107606"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of extensional and strike-slip composite tectonic activity on the development of fine-grained sedimentary rocks and the enrichment of organic matter in lacustrine rift basin: Insights from the Paleogene of the Shanan Sag, Bohai Offshore Basin","authors":"Yujie Ning ,&nbsp;Hao Liu ,&nbsp;Carlos Zavala ,&nbsp;Hehe Chen ,&nbsp;Wenlong Shi ,&nbsp;Xiaodong Lan ,&nbsp;Liang Zhou","doi":"10.1016/j.marpetgeo.2025.107574","DOIUrl":"10.1016/j.marpetgeo.2025.107574","url":null,"abstract":"<div><div>Fine-grained sedimentary rocks (FGSRs), are critical hydrocarbon source and reservoir units. In lacustrine rift basins, the development of FGSRs is constrained by factors such as paleoclimate, but predominantly governed by tectonics in terms of their spatio-temporal distribution. Although the paleoclimatic impacts are studied, the tectonic control mechanisms remain poorly understood, especially in extensional and strike-slip composite settings. By integrating 3D seismic data with well-logs, petrology, and geochemistry, we investigate how differential basin structural evolution influences fine-grained sedimentation and organic matter (OM) enrichment. In our study, three lithofacies associations (FA1, FA2, and FA3) were identified, corresponding to deep lake, semi-deep lake, and shallow lake environments, respectively. We suggest that, the sag's multi-phase, complex tectonics controlled the spatio-temporal evolution of FGSRs and their OM enrichment via architecture modification. (1) During the rifting stage (Es₃^L), the intense activity of the NW-trending faults formed a north-faulted south-onlapping half-graben, with thick OM-rich, semi-deep to deep lacustrine deposits. (2) During the strike-slip reversal stage (Es₃^m-u), NNE-trending faults underwent sinistral-to-dextral inversion, inducing local transpressional belts, uplifting early sedimentary areas, forming multi-sag patterns that altered the distribution of FGSRs and OM enrichment. (3) During the tectonic quiescence stage (Es_1-2), relatively mild extension favored the widespread deposition of shallow to semi-deep lacustrine sediments with enhanced OM preservation. (4) During the transtensional stage (Ed Formation), intense extension drove the deposition of thick-layers FGSRs in depocenters, while transcurrent motion controlled depocenter migration along the principal displacement zone. Our study provides insight into predicting characteristics of FGSRs in analogous lacustrine rift basins.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107574"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144863179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can compaction modeling and pore pressure prediction be simplified by the definition of effective stress?","authors":"Matt R. Hauser,&nbsp;Brent A. Couzens-Schultz","doi":"10.1016/j.marpetgeo.2025.107563","DOIUrl":"10.1016/j.marpetgeo.2025.107563","url":null,"abstract":"<div><div>Disequilibrium compaction is a significant source of overpressures in sedimentary basins, and for decades relationships between effective stress and compaction state have been used in such settings to model compaction and to predict pore pressure. These relationships have proved to be robust when calibrated and applied in formations with similar geologic history, lithologies, and pressure controls. However, they are also found to break down in many cases and these failures often lead workers to invoke a variety of complicating processes which may or may not be supported by geologic analyses; in other cases, to match data, workers may simply invoke <em>ad hoc</em> piecewise adjustments. A consistent thread through almost all such studies is the definition of effective stress as the difference between total stress and pore pressure, as defined by Terzaghi. Given persistent cases where typical models break down, though, it may be fair to ask if we have been using the best approach. An alternative definition of effective stress proposed by Biot is investigated here with a large field dataset and shown to give simpler compaction trends which are also much more consistent from region to region than those obtained with a Terzaghi definition. While the processes often invoked to explain departures from Terzaghi effective stress trends are likely present in many areas, this work suggests that their prevalence and significance may be less than often thought, and that a simple change of effective stress definition may provide substantially improved models with less need to invoke other geologic explanations.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107563"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144863177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-scale characterization and control factors of bedding-parallel fractures in continental shale reservoirs: Insights from the Qingshankou Formation, Songliao Basin, China","authors":"Xiaocen Su ,&nbsp;Rukai Zhu ,&nbsp;Jingya Zhang ,&nbsp;Chang Liu ,&nbsp;Lei Gong ,&nbsp;Xiaohua Jiang ,&nbsp;Xiaofei Fu ,&nbsp;Mehdi Ostadhassan","doi":"10.1016/j.marpetgeo.2025.107580","DOIUrl":"10.1016/j.marpetgeo.2025.107580","url":null,"abstract":"<div><div>Bedding-parallel fractures play a critical role in enhancing storage capacity and horizontal permeability in tight shale reservoirs, significantly influencing the enrichment and productivity of shale oil. This study focuses on the continental shale of the Qingshankou Formation in the Songliao Basin, China, and systematically investigates the development characteristics and controlling factors of bedding-parallel fractures using a multi-scale dataset including core observations, image logs, scanning electron microscopy (SEM), and optical microscopy. Results show that bedding-parallel fractures are extensively developed across nano-to macro-scales, with nano-scale fractures reaching densities of up to 10⁵ fractures/m. Fracture density is negatively correlated with both fracture scale and aperture. These fractures are generally sub-parallel to bedding or exhibit low-angle orientations (mostly &lt;10°), and are typically discontinuous with limited lateral connectivity. Quantitative analyses indicate that fracture density is positively correlated with the contents of clay minerals, pyrite, and carbonate minerals, while showing weak or negative correlations with brittle minerals such as quartz and feldspar. Higher fracture densities are also observed in shales with elevated TOC content and higher thermal maturity. Furthermore, the type, thickness, and density of lamination significantly influence fracture development. At micro- and nano-scales, bedding-parallel fractures primarily act as hydrocarbon storage spaces and micro-flow conduits, whereas at the macro-scale, they mainly serve as horizontal flow pathways. These findings elucidate the multi-scale development mechanisms of bedding-parallel fractures in continental shale and underscore their dominant role in improving reservoir performance.</div></div>","PeriodicalId":18189,"journal":{"name":"Marine and Petroleum Geology","volume":"182 ","pages":"Article 107580"},"PeriodicalIF":3.6,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144826897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}