Petroleum Geoscience最新文献

{"title":"Characterization of silicification and dissolution zones by integrating borehole image logs and core samples: A case study of a well from the Brazilian Pre-salt","authors":"M. Basso, G. Chinelatto, A. M. P. Belila, L. Mendes, J. P. Souza, D. Stefanelli, A. Vidal, J. F. Bueno","doi":"10.1144/petgeo2022-044","DOIUrl":"https://doi.org/10.1144/petgeo2022-044","url":null,"abstract":"Precise knowledge on the spatial distribution patterns of non-matrix porosity zones and the establishment of the geological factors controlling their evolution is crucial for building more accurate carbonate reservoir models and improve hydrocarbon production. The occurrence of intervals affected by significant carbonate dissolution may result in drilling fluid loss and time-consuming drawbacks during well construction. Vug or cave-rich reservoirs may exhibit excess permeability and extremely high initial flow rates. Similar situations have been reported in exploration activities in the Brazilian Pre-Salt plays, where evidence of dissolution and other burial diagenetic processes, such as severe silicification and dolomitization, are common. In this study, we investigate evidence of major post-depositional changes in the lacustrine carbonate reservoirs of the Barra Velha Formation, which comprises the most prolific hydrocarbon play in Brazil. Using a comprehensive database comprising both core samples and well-log data from a vertical well in the Santos Basin, we have characterized, at multiple scales, reservoir zones affected by silicification and carbonate dissolution. Additionally, we performed a petrophysical evaluation of the reservoir to understand the impact of such processes on porosity and permeability development. The results suggested an intimate relationship between silicification and dissolution processes, which can be associated to late fluid percolation under a deep burial flow regime. The occurrence of silicified and vuggy beds, associated with specific zones and lithofacies, indicates an important degree of stratigraphic control on fluid percolation and lateral migration. Furthermore, the presence of fractures at discrete stratigraphic levels have preferentially influenced the development of high-permeability zones, including metric scale fracture-related conduits. This study contributes to the general knowledge of carbonate reservoirs affected by silicification and dissolution while providing support for the recognition of such processes in partially- or non-cored wells.","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48463130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic stratigraphy of southern Eratosthenes High, eastern Mediterranean Sea: growth, demise and deformation of three superposed carbonate platforms (Mesozoic-Cenozoic)","authors":"T. Burchette, Gavrielle Groves-Gidney, K. Karcz","doi":"10.1144/petgeo2023-017","DOIUrl":"https://doi.org/10.1144/petgeo2023-017","url":null,"abstract":"Interpretation of seismic data over the south-eastern flank of the Eratosthenes High shows nine principal seismic stratigraphic units overlying probable faulted basement. Among these are three superposed carbonate platforms which build a stratigraphy exceeding 3000 m. Regional comparisons suggest these range in age from Jurassic to Miocene.\u0000 The Jurassic carbonate platform exhibits layered stratigraphy and aggradational deposition style over the whole study area. A Lower Cretaceous platform subsequently developed as a linear, aggrading bank and prograded as multiple high-frequency sequences for over 40 km into the Eratosthenes High interior, isolating an intrashelf basin which remained connected to the Levant Basin by a narrow seaway. The Jurassic platform margin was a fault-controlled, scalloped escarpment, while the mid-Cretaceous platform was strongly influenced by linear, northwest-southeast-orientated, fault-controlled sags.\u0000 The Miocene platform, a shoaling, “catch-up” neritic shelf, was established after a hiatus during which the flat top of the Cretaceous platform lay below the photic zone. The Miocene platform surface was subsequently incised by Messinian erosional channels which fed offlapping and down-stepping regressive carbonate or evaporitic shorelines that tracked Messinian sea-level fall. Updoming and segmentation of the Eratosthenes high occurred during the early Messinian prior to emplacement of Messinian salt onto its flanks.","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45656946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A numerical model and workflow for gas CO\u0000 2\u0000 injection and migration in a fault zone","authors":"V. Romano, S. Bigi, Heeho D. Park, A. Valocchi, J. Hyman, S. Karra, M. Nole, Glenn Hammond, G. Proietti, M. Battaglia","doi":"10.1144/petgeo2022-092","DOIUrl":"https://doi.org/10.1144/petgeo2022-092","url":null,"abstract":"\u0000 Understanding whether fractures and faults impact the CO\u0000 2\u0000 migration through the overburden is critical in the evaluation and monitoring of CO\u0000 2\u0000 geological storage sites. We present a numerical model and workflow to describe the hydraulic behaviour of a fault located in the shallow part of the overburden. This helps to evaluate the sealing potential of the system in case of unwanted CO\u0000 2\u0000 migration toward the surface and to design an efficient monitoring plan. The model configuration is representative of several experiments performed at real sites under quite shallow conditions (50-500 m). The model results, applied to a selected fault outcropping in the Apennines (Italy), show that most of the gas migrates through the high, while some of the gas also migrates through the fault core in the hanging wall damage zone. A significant amount of gas then dissolves into the water, emphasizing the importance of accurate modelling to assess the hazard of CO\u0000 2\u0000 leakage into near-surface aquifers or to the surface. The occurrence of pressure buildup close to the fault core points out that detailed modelling of the migration conditions is required to predict gas path through a fault zone.\u0000 \u0000 \u0000 Thematic collection:\u0000 This article is part of the Fault and top seals 2022 collection available at:\u0000 https://www.lyellcollection.org/topic/collections/fault-and-top-seals-2022\u0000","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43458507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 role of organic carbon in the Southern Uplands-Down-Longford Terrane accretionary prism, Scotland and Ireland","authors":"J. Parnell, J. Armstrong, N. Blamey, A. Boyce, A. Schito, D. Muirhead","doi":"10.1144/petgeo2022-059","DOIUrl":"https://doi.org/10.1144/petgeo2022-059","url":null,"abstract":"Carbonaceous shales in the Southern Uplands-Down-Longford Terrane accretionary prism had extremely high potential for hydrocarbon generation in the Lower Paleozoic. Structural thickening in the prism enhanced the rapid generation of oil. Shale horizons are separated by thick turbidites composed of low-permeability greywackes, so oil under high fluid pressure either pooled along shale bedding surfaces or migrated into fractured greywackes. Pooled oil became solidified to bitumen, which locally formed deposits on a scale of tonnes, mined as coal. The carbon-rich shale also sequestered large amounts of sulfur from seawater, which precipitated as pyrite firstly during early diagenesis, then further during fluid flow through the shale beds. The oil was also sulfur-bearing. Deformation focused on the shale beds during the evolution of the accretionary prism would have been closely related to the fluid flow which precipitated bitumen and sulfides. The palaeo-fluids were also anomalously rich in methane and hydrogen, similar to fluids venting from modern accretionary prisms.\u0000 \u0000 Supplementary material:\u0000 details of localities searched for coal in Lower Palaeozoic, Southern Uplands-Down-Longford Terrane (locations shown in\u0000 Fig. 6\u0000 ) are available at\u0000 https://doi.org/10.6084/m9.figshare.c.6691597\u0000","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44725469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Utilization of chemostratigraphy to the subregional scale correlation of Permo-Carboniferous sediments, eastern Saudi Arabia","authors":"N. Craigie, C. Scheibe","doi":"10.1144/petgeo2023-007","DOIUrl":"https://doi.org/10.1144/petgeo2023-007","url":null,"abstract":"The following chemostratigraphy study was completed on the Permo-Carboniferous Unayzah Group in Eastern Saudi Arabia. The aim of the study was to determine whether the technique could be used to identify formation and member boundaries on a subregional scale, with the area extending for approximately 550 Km in a NW-SE direction and 350 Km NE-SW. A total of 30,375 core and cuttings samples were analyzed from 225 wells using ICP (inductively Coupled Plasma) and XRF (X-ray Fluorescence) instruments, with data acquired for 42-53 elements for each sample in the range Na-U in the periodic table. Of these, details of 14 wells are discussed in the present work.\u0000 Based on variations in Zr/Ti, Zr/U, Zr/Y, Y/U, U/Th, Gd/Zr, Nb/Yb and Nb/Th it is possible to identify a hierarchical order of one zone, fours subzones and five divisions, these chemozones being correlative on a subregional scale. By comparing geochemical, biostratigraphic, sedimentological and wireline log data in selected reference wells, it was possible to relate chemozones to particular members of the Unayzah Group. The differences in geochemistry between these chemozones/members is largely explained by changes in provenance, though depositional environment may have exerted at least some influence.","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41991490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterising along- and across-fault fluid flow properties for assessing flow rates and overburden fluid migration along faults - A case study from the North Sea","authors":"T. Bjørnarå, E. Skurtveit, E. Michie, Scott A. Smith","doi":"10.1144/petgeo2023-033","DOIUrl":"https://doi.org/10.1144/petgeo2023-033","url":null,"abstract":"\u0000 The article highlights the importance of understanding the permeability of fault zones as fluid migration pathways, with an example from the Vette Fault Zone in the North Sea. The study characterizes the hydraulic properties of the fault zone by mixing host rock lithologies into the fault zone and deriving the fault width from empirical relationships. A parametric study with 1125 model realizations was conducted to understand the sensitivity related to uncertainties in overburden lithologies and fault width correlations. The study found that the fault zone significantly alters the flow-field compared to a model that only considers lithological juxtaposition. The most significant hydraulic communication in the Vette Fault Zone is downwards from the storage reservoir where sand is mixed into the fault zone. The models highlight the potential for downward hydraulic communication along the fault for brine and CO\u0000 2\u0000 capillary sealing towards the overburden.\u0000 \u0000 \u0000 Thematic collection:\u0000 This article is part of the Fault and top seals collection available at:\u0000 www.lyellcollection.org/topic/collections/fault-and-top-seals-2022\u0000","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44913099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 Rossano-San Nicola Fault Zone evolution impacts the burial and maturation histories of the Crotone Basin, Calabrian Arc, Italy","authors":"Giacomo Mangano, T. Alves, M. Zecchin, D. Civile, S. Critelli","doi":"10.1144/petgeo2022-085","DOIUrl":"https://doi.org/10.1144/petgeo2022-085","url":null,"abstract":"This work addresses the tectonic significance of a NW-SE strike-slip fault zone in the Calabrian Arc of Southern Italy, the Rossano-San Nicola Fault Zone (RSFZ). High-quality seismic reflection and 1D forward models of exploration boreholes and pseudo-wells show that the RSFZ experienced multiple Miocene phases of contractional/transpressional tectonics. These were followed by crustal extension during the Pliocene in association with the oceanisation of the Tyrrhenian Sea, Apennine orogenesis, and collision between the Calabrian Arc and adjacent tectonic plates. Such a setting had a profound influence on the Crotone Basin and its economic potential: 1) tectonic reactivation allowed reservoir units of the Crotone Basin to be charged by gas derived from Triassic/Lower Jurassic source rocks, and 2) source rocks reached their maximum depth and remained in the gas generation window after the emplacement of a large mass-transport complex in the Pliocene. In the surrounding areas, tectonic activity near the RSFZ contributed to source-rock maturation by enhancing local sedimentation rates, particularly during Langhian (Middle Miocene) and Zanclean (early Pliocene) tectonics. This work is important as it demonstrates the tectono-stratigraphic evolution of the Crotone Basin to be closely related to the structural evolution of the RSFZ. Crucially, the study area reveals the first example of a gas field fully sealed by a large mass-transport complex. As a corollary, we tie the Late Cenozoic geological history of the Crotone Basin to the geodynamic evolution of the central Mediterranean region, namely the Ionian and Tyrrhenian seas. We identify new prospects in the Crotone Basin and provide a time frame for gas generation and accumulation in Southern Italy.","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44256773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 insights into the stratigraphic evolution of southwest Britain: Implications for Triassic salt and hydrocarbon prospectivity","authors":"S. S. Husein, A. Fraser, G. Roberts, R. Bell","doi":"10.1144/petgeo2022-051","DOIUrl":"https://doi.org/10.1144/petgeo2022-051","url":null,"abstract":"The discovery of Wytch Farm field in the Wessex Basin, and Kinsale Head field in the North Celtic Sea Basin in the early 1970s, led to exploration interest offshore in the Western Approaches Trough. Despite this activity, little evidence for prospective hydrocarbon resources has been found. To better understand the failures and analyse remaining hydrocarbon potential in this region, we make use of a large collection of new seismic reflection and well data to map Carboniferous to Neogene stratigraphy. The improved seismic imaging has allowed a better interpretation of the hitherto poorly understood, salt-related structures in the South Melville and the Plymouth Bay basins. The implications of the new interpretations for Carnian (Late Triassic), and Carboniferous stratigraphic and geodynamic evolution are assessed and contextualised with regional salt deposition in the Wessex, Bristol, and South Celtic Sea basins. From a petroleum system perspective, the Lias and Carboniferous source rocks are evaluated and modelled to analyse the maturity and evolution of the petroleum systems. We conclude that the Lias is an ineffective petroleum system due to timing and source maturation risk. However, the Triassic salt and associated subcropping faults have produced several possible pre-salt hydrocarbon traps. The traps may be charged from sporadic Mid-Late Carboniferous coal-bearing post-orogenic basins, a petroleum system previously overlooked.\u0000 \u0000 Supplementary material\u0000 : [Appendix showing seismic, well data and petroleum systems boundary conditions. Burial history plots of the petroleum systems modelling scenarios used to generate source rock transformation ratio plots shown in Figs 9 & 10. [Item 1: Spreadsheet with seismic and well data used in the study, and petroleum system modelling input data. Item 2: Raw decompacted burial history plot, and burial history plots of the 3 Lias petroleum systems scenarios]\u0000 https://doi.org/10.6084/m9.figshare.c.6486999\u0000 \u0000 \u0000 Thematic collection:\u0000 This article is part of the UKCS Atlantic Margin collection available at:\u0000 https://www.lyellcollection.org/topic/collections/new-learning-from-exploration-and-development-in-the-ukcs-atlantic-margin\u0000","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46491601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shear velocity estimation based on rock physics modeling of limestone gas reservoir in the Pannonian basin","authors":"D. Vukadin","doi":"10.1144/petgeo2022-070","DOIUrl":"https://doi.org/10.1144/petgeo2022-070","url":null,"abstract":"In the Pannonian Basin, especially in Croatia, there are a small number of wells with acquired shear velocities. Often, quantitative interpretation must rely only on compressional velocity data, and shear velocity must be modelled. Shear wave velocity estimation in combination with other petrophysical data is essential for detailed reservoir characterization. Compressional and shear wave velocity allow the seismic modelling of different saturation states in a reservoir. This paper demonstrates a workflow for S-wave velocity estimation where shear velocity data is absent in the gas field and neighboring fields with the same lithology, based on the Kuster-Toksöz and Xu-Payne models applied to the Pannonian basin limestone reservoir. The results are calibrated with the P-wave velocity obtained from borehole data and the VSP S-wave interval velocity. Although rock physics models are idealized analogues of real rocks, a very good correlation was obtained between the modelled and measured P-wave velocity, as well as between the modelled S-wave velocity and the VSP interval velocity. The study also illustrates the problem of defining the pore aspect ratio in zones of increasing shale content. Due to the limited research on the limestones of the Pannonian Basin, these results enable a better understanding of the seismic parameters of the Pannonian Basin limestones. The results indicate that the proposed workflow gives an adequate estimation of S-wave velocities.","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48220930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 importance of facies, grain size, and clay content in controlling fluvial reservoir quality – An example from the Triassic Skagerrak Formation, Central North Sea, UK","authors":"Oluwafemi E. Aro, S. Jones, N. Meadows, J. Gluyas, Dimitrios Charlaftis","doi":"10.1144/petgeo2022-043","DOIUrl":"https://doi.org/10.1144/petgeo2022-043","url":null,"abstract":"Clay-coated grains play an important role in preserving reservoir quality in high-pressure high-temperature (HPHT) sandstone reservoirs. Previous studies have shown that the completeness of coverage of clay coats effectively inhibits quartz cementation. However, the main factors controlling the extent of coverage remain controversial. This research sheds light on the influence of different depositional processes and hydrodynamics on clay coat coverage and reservoir quality evolution. Detailed petrographic analysis of core samples from the Triassic fluvial Skagerrak Formation, Central North Sea, identified that channel facies offer the best reservoir quality; however, this varies as a function of depositional energy, grain size and clay content. Due to their coarser grain size and lower clay content, high energy channel sandstones have higher permeabilities (100-1150 mD) than low energy channel sandstones (<100 mD). Porosity is preserved due to grain-coating clays, with clay coat coverage correlating with grain size, clay coat volume and quartz cement. Higher coverage (70-98%) occurs in finer-grained, low energy channel sandstones. In contrast, lower coverage (<50%) occurs in coarser-grained, high energy channel sandstones. Quartz cement modelling showed a clear correlation between available quartz surface area and quartz cement volume. Although high energy channel sandstones have better reservoir quality, they present moderate quartz overgrowths due to lesser coat coverage, thus prone to allowing further quartz cementation and porosity loss in ultra-deep HPHT settings. Conversely, low energy channel sandstones containing moderate amounts of clay occurring as clay coats are more likely to preserve porosity in ultra-deep HPHT settings and form viable reservoirs for exploration.\u0000 \u0000 Supplementary material:\u0000 of data and technique used in this study are available at\u0000 https://doi.org/10.6084/m9.figshare.c.6438450.v1\u0000","PeriodicalId":49704,"journal":{"name":"Petroleum Geoscience","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2023-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45696107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}