Articles de revues : « 3D Structural geological modelling »

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de Kemp, Eric A. « Spatial agents for geological surface modelling ». Geoscientific Model Development 14, n^o 11 (1 novembre 2021) : 6661–80. http://dx.doi.org/10.5194/gmd-14-6661-2021.

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Abstract. Increased availability and use of 3D-rendered geological models have provided society with predictive capabilities, supporting natural resource assessments, hazard awareness, and infrastructure development. The Geological Survey of Canada, along with other such institutions, has been trying to standardize and operationalize this modelling practice. Knowing what is in the subsurface, however, is not an easy exercise, especially when it is difficult or impossible to sample at greater depths. Existing approaches for creating 3D geological models involve developing surface components that represent spatial geological features, horizons, faults, and folds, and then assembling them into a framework model as context for downstream property modelling applications (e.g. geophysical inversions, thermo-mechanical simulations, and fracture density models). The current challenge is to develop geologically reasonable starting framework models from regions with sparser data when we have more complicated geology. This study explores the problem of geological data sparsity and presents a new approach that may be useful to open up the logjam in modelling the more challenging terrains using an agent-based approach. Semi-autonomous software entities called spatial agents can be programmed to perform spatial and property interrogation functions, estimations and construction operations for simple graphical objects, that may be usable in building 3D geological surfaces. These surfaces form the building blocks from which full geological and topological models are built and may be useful in sparse-data environments, where ancillary or a priori information is available. Critical in developing natural domain models is the use of gradient information. Increasing the density of spatial gradient information (fabric dips, fold plunges, and local or regional trends) from geologic feature orientations (planar and linear) is the key to more accurate geologic modelling and is core to the functions of spatial agents presented herein. This study, for the first time, examines the potential use of spatial agents to increase gradient constraints in the context of the Loop project (https://loop3d.github.io/, last access: 1 October 2021) in which new complementary methods are being developed for modelling complex geology for regional applications. The spatial agent codes presented may act to densify and supplement gradient as well as on-contact control points used in LoopStructural (https://www.github.com/Loop3d/LoopStructural, last access: 1 October 2021) and Map2Loop (https://doi.org/10.5281/zenodo.4288476, de Rose et al., 2020). Spatial agents are used to represent common geological data constraints, such as interface locations and gradient geometry, and simple but topologically consistent triangulated meshes. Spatial agents can potentially be used to develop surfaces that conform to reasonable geological patterns of interest, provided that they are embedded with behaviours that are reflective of the knowledge of their geological environment. Initially, this would involve detecting simple geological constraints: locations, trajectories, and trends of geological interfaces. Local and global eigenvectors enable spatial continuity estimates, which can reflect geological trends, with rotational bias, using a quaternion implementation. Spatial interpolation of structural geology orientation data with spatial agents employs a range of simple nearest-neighbour to inverse-distance-weighted (IDW) and quaternion-based spherical linear rotation interpolation (SLERP) schemes. This simulation environment implemented in NetLogo 3D is potentially useful for complex-geology–sparse-data environments where extension, projection, and propagation functions are needed to create more realistic geological forms.

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Thapa, Prem Bahadur. « An approach towards integrated modelling of 3D geology and landslide susceptibility in the Lesser Himalaya of central Nepal ». Journal of Nepal Geological Society 47, n^o 1 (30 juin 2014) : 65–76. http://dx.doi.org/10.3126/jngs.v47i1.23106.

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An approach towards integrated modelling of 3D geology and landslide susceptibility was performed with the application of GOCAD and GIS. Rock unit outcrops and orientation vectors were utilised in 3D geological modelling (geomodelling) whereas landslides and their causative variables were evaluated in the susceptibility model. Occurrence of landslides in the modelling site is the direct result of major rainstorms (extreme weather events) and their spatial localisation is greatly controlled by slope gradients, structural aspect of geological settings, and human interventions. The probability of future landslides was predicted through statistical algorithms (multivariate technique of logistic regression) and modelling result was validated by computing success rate in which AUC value is 93.78% indicating the model is valid with prediction accuracy of 0.5 to 1 (total area) and confirming the selected variables have positive influence on landslide susceptibility. Finally, 3D geological and landslide susceptibility models were integrated to illustrate virtual reality of the scenario.

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Kassymkanova, Khaini Kamal, Sara Istekova, Kanay Rysbekov, Bakytzhan Amralinova, Guldana Kyrgizbayeva, Saule Soltabayeva et Gulnara Dossetova. « Improving a geophysical method to determine the boundaries of ore-bearing rocks considering certain tectonic disturbances ». Mining of Mineral Deposits 17, n^o 1 (30 mars 2023) : 17–27. http://dx.doi.org/10.33271/mining17.01.017.

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Purpose is to improve a geophysical method of determining the boundaries of ore-bearing rocks and tectonic disturbances under complex mining and geological conditions while developing 3D geological models. Methods. 3D geological models of natural objects were developed on the basis of complex structural, geological-geophysical, and lithological facies analysis with the wide use of modern 3D seismic exploration technologies taking into consideration the parameters for prediction and selection of optimal factors for ore deposit development. Findings. The scientifically substantiated result is represented by the increased reliability and efficiency of seismic exploration for singling out the ore horizons and ore bodies as well as tectonic disturbances at different depths by specifying geological structures of the prospective areas and sites under study. Originality. Basing on the carried out studies, methods of the development of 3D geological models to study depth geological inhomogeneities of the ore-bearing complexes under complex mining and geological conditions were improved. Practical implications. The obtained results of 3D modelling of geological media basing on the applied 3D seismic exploration will help increase a confidence factor of scientifically substantiated prediction of ore deposits, provide optimal development of complex ore objects, reduce risks, and increase economic efficiency of solid deposit development under complex mining and geological conditions.

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Alvarado-Neves, Fernanda, Laurent Ailleres, Lachlan Grose, Alexander R. Cruden et Robin Armit. « Three-dimensional geological modelling of igneous intrusions in LoopStructural v1.5.10 ». Geoscientific Model Development 17, n^o 5 (5 mars 2024) : 1975–93. http://dx.doi.org/10.5194/gmd-17-1975-2024.

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Abstract. Over the last 2 decades, there have been significant advances in the 3D modelling of geological structures via the incorporation of geological knowledge into the model algorithms. These methods take advantage of different structural data types and do not require manual processing, making them robust and objective. Igneous intrusions have received little attention in 3D modelling workflows, and there is no current method that ensures the reproduction of intrusion shapes comparable to those mapped in the field or in geophysical imagery. Intrusions are usually partly or totally covered, making the generation of realistic 3D models challenging without the modeller's intervention. In this contribution, we present a method to model igneous intrusions in 3D considering geometric constraints consistent with emplacement mechanisms. Contact data and inflation and propagation direction are used to constrain the geometry of the intrusion. Conceptual models of the intrusion contact are fitted to the data, providing a characterisation of the intrusion thickness and width. The method is tested using synthetic and real-world case studies, and the results indicate that the method can reproduce expected geometries without manual processing and with restricted datasets. A comparison with radial basis function (RBF) interpolation shows that our method can better reproduce complex geometries, such as saucer-shaped sill complexes.

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Calcagno, Philippe, Joëlle Lazarre, Gabriel Courrioux et Patrick Ledru. « 3D geometric modelling of an external orogenic domain : a case history from the western Alps (massif de Morges, Pelvoux) ». Bulletin de la Société Géologique de France 178, n^o 4 (1 juillet 2007) : 263–74. http://dx.doi.org/10.2113/gssgfbull.178.4.263.

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Abstract Describing the 3D geometry of geological surfaces is a fundamental step to infer their structural history, especially when they have recorded successive deformation phases. This study aims at testing the contribution of 3D modelling to the understanding of orogenic domains. It focuses on the cover/basement contact of an External Crystalline Massif of the French Alps considered as a marker of the finite deformation at orogen scale. This contact is observable in outliers of Mesozoic cover in the test area located in the Massif de Morges (Pelvoux Massif). A 3D geometric model has been built from map and cross-section data derived from field structural and kinematic observations using STRIM software (Matra Datavision). 3D modelling ensures geometric consistency of geological interpretation. Moreover, the model has been unfolded to restore surfaces and to quantify shortening. Together with field analyses, those results show that two sub-perpendicular phases of deformation related to the Alpine cycle have occurred. The first and main one consisted of the NNE-SSW inversion of previous extensional paleo-faults that controlled the geometry of the Tethyan margin. The second one was an E-W compression of post-Early Oligocene age.

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TROCMÉ, VINCENT, EMILY ALBOUY, JEAN-PAUL CALLOT, JEAN LETOUZEY, NICOLAS ROLLAND, HASSAN GOODARZI et SALMAN JAHANI. « 3D structural modelling of the southern Zagros fold-and-thrust belt diapiric province ». Geological Magazine 148, n^o 5-6 (5 août 2011) : 879–900. http://dx.doi.org/10.1017/s0016756811000446.

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Abstract3D modelling of geological structures is a key method to improve the understanding of the geological history of an area, and to serve as a drive for exploration. Geomodelling has been performed on a large 60000 km2 area of the Zagros fold-and-thrust belt of Iran, to reconcile a vast but heterogeneous dataset. Topography, geological surface data and dips, outcrop surveys, and well and seismic data were integrated into the model. The method was to construct a key surface maximizing the hard data constraints. The Oligo-Miocene Top Asmari layer was chosen, as this formation was regionally deposited before the main Zagros collision phase and because the numerous outcrops allow proper control of the bed geometry in the fold cores. Interpreted seismic data have been integrated to interpolate the surfaces at depth within the synclines. Several conceptual models of fold geometry have been applied to estimate the best way to convert seismic time signal to depth. Several deeper horizons down to Palaeozoic strata were deduced from this key horizon by applying palaeo-thickness maps. During the construction, the 3D interpolated surfaces could be reconverted to time, using a velocity model, and compared with previous seismic interpretations. This exercise obliged us to revise some early interpretations of seismic lines that were badly tied to wells. The 3D modelling therefore clearly improves regional interpretation. In addition, the 3D model is the only tool that allows drawing consistent cross-sections in areas where there are no seismic lines. Emerging Hormuz salt diapirs were added to the model. Dimensions and shapes of the individual diapirs were modelled using a statistical survey on the cropping out Hormuz structures. Modelling reliably demonstrated that the diapirs, when piercing, show a constant mushroom shape whose diameter depends on the stratigraphic depth of observation. This observation allowed us to exemplify relations between the pre-existing diapirs and the anticlines of the area, and to highlight the morphological changes from the inner onshore areas to the coastal and offshore areas. In addition, one of the surprising results of this study was the observation of the increasing diameter of the diapirs at the time of the Zagros collision and folding event, with growth strata and overhangs on the flanks of the diapirs.

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Volanis, George, Demitrios Galanakis, Nikolaos Bolanakis, Emmanuel Maravelakis, Ruben Paul Borg et Georgios E. Stavroulakis. « Modelling and Stability Assessment of the Rock Cliffs and Xrobb l-Ġħaġin Neolithic Structure in Malta ». Heritage 7, n^o 6 (3 juin 2024) : 2944–58. http://dx.doi.org/10.3390/heritage7060138.

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The stability of rock cliffs is a longstanding issue and is of practical significance. This case study demonstrates the application and use of advanced 3D modeling techniques, concentrating on the geological formations of the Xrobb l-Ġħaġin peninsula on the south-east coast of Malta, where the Xrobb l-Ġħaġin Neolithic site is located. In order to utilize a static and dynamic analysis of the investigated scenario, a 3D finite element model (FEM) of the geological formation in which the monument is set had to be created. To this end, 3D scanning, unmanned aerial vehicles (UAVs), and oblique photogrammetry were first used with state-of-the-art commercial packages for mesh reconstruction. As a result, a geometric and finite element model (FEM) was created, suitable for both static and dynamic analysis. In the second stage, a parametric investigation of the material properties of the structural system of the geological substrate was sought. The structural response of the system was evaluated for different loading scenarios assuming nonlinear finite element analysis. Collapse case scenarios were investigated for standard and weakened materials, predicting which components would collapse first and under which case of weakened materials the collapse occurs. Among other aspects, the main novelty of this paper lies in the integrated approach and multidisciplinary paradigm that supplement the available historical knowledge for this specific cultural heritage Neolithic site towards its conservation.

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Wang, Shuqin, Minghui Liu, Bing Bo, Hongfei Ma, Tianyu Zheng et Yujie Gao. « MODELING of Water Saturation in Shallow Sandstone Oilfield ». Journal of Physics : Conference Series 2706, n^o 1 (1 février 2024) : 012083. http://dx.doi.org/10.1088/1742-6596/2706/1/012083.

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Abstract 3D geological modeling technology has achieved visualization of underground reservoirs in oil and gas fields, and has been widely applied in oil and gas field development. 3D geological modeling includes structural modeling and attribute modeling, and strata and faults can be completed based on data from oil and gas field exploration and development. The porosity and permeability in the geological attribute model can be established based on logging interpretation conclusions and other relevant data, The establishment of a saturation model has always been a difficulty in 3D geological modelling. As the water saturation, is different from porosity and permeability of an oil field. Saturation is distributed under the control of factors such as gravity and capillary force, and cannot be established through spatial simulation interpolation. Instead, the influence of factors such as gravity and capillary force should be considered. This article takes the shallow sandstone M oilfield in Kazakhstan as an example, and establishes the J function of the oilfield by combining the capillary pressure experiment of the core well, in order to establish an oilfield saturation model.

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Cudrigh-Maislinger, Susanna. « 3D geological modelling - Through the example of Karawanken Tunnel project, northern section ». Geomechanics and Tunnelling 11, n^o 5 (octobre 2018) : 530–36. http://dx.doi.org/10.1002/geot.201800025.

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ΜΑΝΟΥΤΣΟΓΛΟΥ, Ε., Ε. ΣΠΥΡΙΔΩΝΟΣ, Α. SOUJON et V. JACOBSHAGEN. « Revision of the geological map and 3D modelling of the geological structure of the Samaria Gorge Region, W. Crete ». Bulletin of the Geological Society of Greece 34, n^o 1 (1 janvier 2001) : 29. http://dx.doi.org/10.12681/bgsg.16940.

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The island of Crete is situated near the front of an active plate margin. Therefore, it is of great interest in the framework of the International Continental Drilling Project (I.C.D.P.). A short review of the digital modelling methods, their applications in the geosciences and the associated advantages is also presented. The digital 3-dimensional geometric model of the geological structure of the Samaria Gorge region is based on the study of the stratigraphy and the tectonic evolution of the metamorphic rocks of the Plattenkalk group in SW Crete. Data from the geological map of Greece (Vatolakkos sheet, 1:50.000) and from the literature have been supplemented by geological mapping and structural analyses. In our study we applied interactive 3D CAD methods implemented in the integrated software package SURPAC2000. The surface geology has been draped over a digital elevation model of the topography in order to model the geometry of the subsurface structures. Two hypotheses about the geological structure of the region are examined: a) the one given by the existing geological map, which proposes a syncline structure and b) the one resulting from the combination of existing data, corrections carried out through repeated 3D simulations and new field observations. After distinguishing in the S of the study area the Trypali union, overthrusted on the Plattenkalk group, we propose an anticline structure with a NNE/SSW striking axis dipping to the NE.

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Guo, Yinling, Suping Peng, Wenfeng Du et Dong Li. « Fault and horizon automatic interpretation by CNN : a case study of coalfield ». Journal of Geophysics and Engineering 17, n^o 6 (décembre 2020) : 1016–25. http://dx.doi.org/10.1093/jge/gxaa060.

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Abstract A convolutional neural network (CNN) is a powerful tool used for seismic interpretation. It does not require manual intervention and can automatically detect geological structures using the pattern features of the original seismic data. In this study, we presented the development history of seismic interpretation and the application of CNN in seismic exploration. We proposed a set of CNN prediction methods and processes for coalfield seismic interpretation and realised automatic interpretation of faults and horizons based on the relationship between faults and horizons. We defined a CNN model training method based on structural geological modelling, which allowed rapid and accurate establishment of fault and horizon labels by using structural modelling. We used two examples to verify the accuracy of the algorithm, one to test for synthetic 3D seismic data and one to test for real coalfield seismic data. The results showed that CNNs can effectively predict both faults and horizons at the same time and has high accuracy. Thus, CNNs are potentially novel interpretation tools for coalfield seismic interpretation.

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Jian, F. X. « 3D STOCHASTIC RESERVOIR MODELLING AND FIELD DEVELOPMENT PLANNING ». APPEA Journal 39, n^o 1 (1999) : 537. http://dx.doi.org/10.1071/aj98034.

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3D stochastic reservoir modelling is an emerging new technology for the oil and gas industry and is increasingly used by oil and gas companies as a tool to support major business decisions in field development planning, and the acquisition and management of petroleum assets. However, the potential benefit that 3D stochastic reservoir modelling can offer is still overlooked by many asset teams. Conventional methods are often still applied for field development planning and reserve estimation, where over-simplified geological models are used and reservoir uncertainties are substantially under-estimated. This is one reason why the oil and gas industry does not have a good track record in estimating reserves and field development planning.3D stochastic reservoir modelling methods that incorporate the structural-stratigraphic framework, facies and petrophyscial properties can ensure that the reservoir models fully describe reservoir heterogeneity. This in turn lays a sound foundation for field development planning. The 3D stochastic reservoir modelling methods also quantify and reduce uncertainties in various aspects of the reservoir. This allows a field development plan to be more robust yet flexible enough to take the advantage of upside reserve potential and to be economically sound if the downside case occurs. Based on quantification of uncertainties, optimal well positions and well paths can be designed to maximise oil and gas recovery.

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Bar, N., A. McQuillan, T. Ma, D. Wai, R. Hammah, B. Corkum, T. Yacoub, JC Cobián et B. Mojica. « A geotechnical evaluation of the Cumba Pit Slope Failure, Dominican Republic ». IOP Conference Series : Earth and Environmental Science 1124, n^o 1 (1 janvier 2023) : 012009. http://dx.doi.org/10.1088/1755-1315/1124/1/012009.

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Abstract The combined availability of topographical, geological, structural, hydrogeological and monitoring data is rapidly increasing. Technology and software advances allow the real time incorporation of this data across various software platforms. This paper describes the back-analysis of a 70 m high, pit slope failure of an open pit gold mine in the Dominican Republic, using data from aerial photogrammetry, ground-based synthetic aperture radar and 3D limit equilibrium and finite element modelling. This back-analysis process is considered leading practice with the latest technology. The (northern) side of the Cumba pit slumped along a non-daylighting plane that was identified after the failure event. Remedial investigations included review of geological data, major structures, rock mass constitutive models and groundwater conditions. Topographical and structural data acquired from aerial photogrammetry, pre- and post-failure event, was input into 3D models to replicate observed ground movement. 3D models of pit progression were compared with displacements recorded by ground-based synthetic aperture radar to calibrate model inputs and increase reliability of forward predictions. Such a technical review was completed in less than one week, and the review process implemented for the Cumba pit slope failure now forms the baseline approach for all future geotechnical analysis at the operating mine.

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Phillips, Thomas B., John B. Naliboff, Ken J. W. McCaffrey, Sophie Pan, Jeroen van Hunen et Malte Froemchen. « The influence of crustal strength on rift geometry and development – insights from 3D numerical modelling ». Solid Earth 14, n^o 4 (5 avril 2023) : 369–88. http://dx.doi.org/10.5194/se-14-369-2023.

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Abstract. The lateral distribution of strength within the crust is non-uniform, dictated by crustal lithology and the presence and distribution of heterogeneities within it. During continental extension, areas of crust with distinct lithological and rheological properties manifest strain differently, influencing the structural style, geometry, and evolution of the developing rift system. Here, we use 3D thermo-mechanical models of continental extension to explore how pre-rift upper-crustal strength variations influence rift physiography. We model a 500×500×100 km volume containing 125 km wide domains of mechanically “strong” and “weak” upper crust along with two reference domains, based upon geological observations of the Great South Basin, New Zealand, where extension occurs parallel to the boundaries between distinct geological terranes. Crustal strength is represented by varying the initial strength of 5 km3 blocks. Extension is oriented parallel to the domain boundaries such that each domain is subject to the same 5 mm yr−1 extension rate. Our modelling results show that strain initially localises in the weak domain, with faults initially following the distribution of initial plastic strain before reorganising to produce a well-established network, all occurring in the initial 100 kyr. In contrast, little to no localisation occurs in the strong domain, which is characterised by uniform strain. We find that although faults in the weak domain are initially inhibited at the terrane boundaries, they eventually propagate through and “seed” faults in the relatively strong adjacent domains. We show characteristic structural styles associated with strong and weak crust and relate our observations to rift systems developed across laterally heterogeneous crust worldwide, such as the Great South Basin, New Zealand, and the Tanganyika Rift, East Africa.

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Breunig, M., A. Borrmann, E. Rank, S. Hinz, T. Kolbe, M. Schilcher, R. P. Mundani et al. « COLLABORATIVE MULTI-SCALE 3D CITY AND INFRASTRUCTURE MODELING AND SIMULATION ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W4 (27 septembre 2017) : 341–52. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w4-341-2017.

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Computer-aided collaborative and multi-scale 3D planning are challenges for complex railway and subway track infrastructure projects in the built environment. Many legal, economic, environmental, and structural requirements have to be taken into account. The stringent use of 3D models in the different phases of the planning process facilitates communication and collaboration between the stake holders such as civil engineers, geological engineers, and decision makers. This paper presents concepts, developments, and experiences gained by an interdisciplinary research group coming from civil engineering informatics and geo-informatics banding together skills of both, the Building Information Modeling and the 3D GIS world. New approaches including the development of a collaborative platform and 3D multi-scale modelling are proposed for collaborative planning and simulation to improve the digital 3D planning of subway tracks and other infrastructures. Experiences during this research and lessons learned are presented as well as an outlook on future research focusing on Building Information Modeling and 3D GIS applications for cities of the future.

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Preziosi, Elisabetta, Nicolas Guyennon, Anna Bruna Petrangeli, Emanuele Romano et Cristina Di Salvo. « A Stepwise Modelling Approach to Identifying Structural Features That Control Groundwater Flow in a Folded Carbonate Aquifer System ». Water 14, n^o 16 (11 août 2022) : 2475. http://dx.doi.org/10.3390/w14162475.

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This paper concerns a stepwise modelling procedure for groundwater flow simulation in a folded and faulted, multilayer carbonate aquifer, which constitutes a source of good quality water for human consumption in the Apennine Range in Central Italy. A perennial river acts as the main natural drain for groundwater while sustaining valuable water-related ecosystems. The spatial distribution of recharge was estimated using the Thornthwaite–Mather method on 60 years of climate data. The system was conceptualized as three main aquifers separated by two locally discontinuous aquitards. Three numerical models were implemented by gradually adding complexity to the model grid: single layer (2D), three layers (quasi-3D) and five layers (fully 3D), using an equivalent porous medium approach, in order to find the best solution with a parsimonious model setting. To overcome dry-cell problems in the fully 3D model, the Newton–Raphson formulation for MODFLOW-2005 was invoked. The calibration results show that a fully 3D model was required to match the observed distribution of aquifer outflow to the river baseflow. The numerical model demonstrated the major impact of folded and faulted geological structures on controlling the flow dynamics in terms of flow direction, water heads and the spatial distribution of the outflows to the river and springs.

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Boothby, Peter G., Ratih Puspitasari, Sanjay Thakur, Zachariah John Pallikathekathil et Chris Walton. « Integrating multi-disciplinary data for building fit-for-purpose 3D mechanical earth model ». APPEA Journal 59, n^o 2 (2019) : 856. http://dx.doi.org/10.1071/aj18153.

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Understanding the influence of geomechanics early in the field development phase facilitates reservoir management planning. To capture complex geology and associated field development, a 3D mechanical earth model (3D MEM) with finite element method (FEM) approach was selected to analyse the geomechanical-related risks associated with two fields in the North West Shelf, Australia. The 3D MEMs were constructed using geological static models, and seismic-derived horizons and faults. The 3D properties were propagated based on core-calibrated 1D properties and controlled by stratigraphy, 3D facies and seismic inversion volumes. The FEM was used to calculate the equilibrium of stresses and strains within the 3D MEMs. The 3D properties and pre-production stresses were validated in blind test wells before forward modelling. The 3D MEMs were linked to the dynamic reservoir models to capture the pressure evolution throughout the field lifecycle. The results were used to analyse the risks associated with compaction, subsidence, fault instability, completion integrity and drilling stability of infill wells through depleted reservoirs. The results provided insight in managing the risk early in field development stage. The study’s largest challenge was integrating a large volume of data to ensure that the structural complexity and rock heterogeneity were captured and consistent with the geological understanding of the field. A multi-disciplinary team of earth scientists and reservoir and geomechanics engineers worked together, and the value of data integration, good communication and teamwork were key success factors. Lessons learned and best practices were captured throughout the study and provided valuable feedback for future works.

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Cunningham, Jennifer E., Nestor Cardozo, Chris Townsend et Richard H. T. Callow. « The impact of seismic interpretation methods on the analysis of faults : a case study from the Snøhvit field, Barents Sea ». Solid Earth 12, n^o 3 (30 mars 2021) : 741–64. http://dx.doi.org/10.5194/se-12-741-2021.

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Abstract. Five seismic interpretation experiments were conducted on an area of interest containing a fault relay in the Snøhvit field, Barents Sea, Norway, to understand how the interpretation method impacts the analysis of fault and horizon morphologies, fault lengths, and throw. The resulting horizon and fault interpretations from the least and most successful interpretation methods were further analysed to understand their impact on geological modelling and hydrocarbon volume calculation. Generally, the least dense manual interpretation method of horizons (32 inlines and 32 crosslines; 32 ILs × 32 XLs, 400 m) and faults (32 ILs, 400 m) resulted in inaccurate fault and horizon interpretations and underdeveloped relay morphologies and throw, which are inadequate for any detailed geological analysis. The densest fault interpretations (4 ILs, 50 m) and 3D auto-tracked horizons (all ILs and XLs spaced 12.5 m) provided the most detailed interpretations, most developed relay and fault morphologies, and geologically realistic throw distributions. Sparse interpretation grids generate significant issues in the model itself, which make it geologically inaccurate and lead to misunderstanding of the structural evolution of the relay. Despite significant differences between the two models, the calculated in-place petroleum reserves are broadly similar in the least and most dense experiments. However, when considered at field scale, the differences in volumes that are generated by the contrasting interpretation methodologies clearly demonstrate the importance of applying accurate interpretation strategies.

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Török, Ákos, Gyula Bögöly, Árpád Somogyi et Tamás Lovas. « Application of UAV in Topographic Modelling and Structural Geological Mapping of Quarries and Their Surroundings—Delineation of Fault-Bordered Raw Material Reserves ». Sensors 20, n^o 2 (15 janvier 2020) : 489. http://dx.doi.org/10.3390/s20020489.

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A 3D surface model of an active limestone quarry and a vegetation-covered plateau was created using unmanned aerial vehicle (UAV) technique in combination with terrestrial laser scanning (TLS). The aim of the research was to identify major fault zones that dissect the inaccessible quarry faces and to prepare a model that shows the location of these fault zones at the entire study area. An additional purpose was to calculate reserves of the four identified lithological units. It was only possible to measure faults at the lowermost two meters of the quarry faces. At the upper parts of the quarry and on the vegetation-covered plateau where no field geological information was available, remote sensing was used. Former logs of core drillings were obtained for the modelling of the spatial distribution of four lithological units representing cover beds and various quality of limestone reserves. With the comparison of core data, field measurements and remote sensing, it was possible to depict major faults. Waste material volumes and limestone reserves were calculated for five blocks that are surrounded by these faults. The paper demonstrates that, with remote sensing and with localised control field measurements, it is possible: (a) to provide all geometric data of faults and (b) to create a 3D model with fault planes even at no exposure or at hardly accessible areas. The surface model with detected faults serves as a basis for calculating geological reserves.

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Pertiwi, Tiaraningtias Bagus, Yunus Daud et Fikri Fahmi. « Investigation of Geological Structure Using Magnetotelluric and Gravity Data Optimization on Non Volcanic Geothermal, Bora, Centre of Sulawesi ». Journal of Geoscience, Engineering, Environment, and Technology 8, n^o 02-2 (31 juillet 2023) : 13–17. http://dx.doi.org/10.25299/jgeet.2023.8.02-2.13876.

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The existence of geological structures is one of the important parameters in determining the permeability zone in a geothermal system. This research was conducted in a non-volcanic geothermal field, Bora, located in the province of Central Sulawesi, aiming to identify the subsurface features, especially geological structures related to permeability zones by optimizing geophysical data. Magnetotelluric (MT) 3D inversion modelling is some of the latest methods to identify geological structural patterns in geothermal systems. The results of the MT model and analysis its parameters can find variations in the distribution of subsurface resistivity, orientation of the direction of the prospect area, and indications of geological structure zones. The type and geometry of the geological structure associated with the high permeability zone can be complemented by determining the contrast of gravity values and analysis of the maximum First Horizontal Derivative (FHD) and zero of the Second Vertical Derivative (SVD). Based on the analysis of geophysical data, it is possible to identify the permeability zone associated with the main structure, namely the Palu-Koro fault, delineate the geothermal reservoir at a depth of 1500-2000 meters and determine the location of well drilling. To visualize the geothermal system comprehensively, a conceptual model is developed by integrating the geophysical model with geological and geochemical data that are correlated with each other, therefore it can assist in determining the location of production well development.

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Ramli, Nadia, Hamzah Hussin, Muhammad Afiq Abdul Kahar et Mohd Amir Asyraf Sulaiman. « The Utilisation of Electrical Resistivity Imaging (ERI) for Geological Structures Mapping in Rock Mass : A Review ». IOP Conference Series : Earth and Environmental Science 1102, n^o 1 (1 novembre 2022) : 012089. http://dx.doi.org/10.1088/1755-1315/1102/1/012089.

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Electrical Resistivity Imaging (ERI) is an in-situ geophysical method widely used in environmental, engineering and hydrogeological explorations due to cost, time, and data coverage efficiency. Traditionally, geotechnical parameters such as discontinuities properties are obtained from rock samples acquired from a borehole. However, it only provides a single information point, costly and time-consuming. Thus, an approach using electrical resistivity to detect the presence of geological structure in a rock mass is an alternative method that can be applied. Discontinuities in rock mass include joints, bedding planes, blasting cracks, fractures, faults, and folds. This paper aims to present the utilisation of geoelectrical resistivity imaging for geological structures mapping in rock mass based on the review from previous research. The Electrical Resistivity Imaging (ERI) method is an effective tool to obtain structural differentiation of geological medium by interpreting 2D and even 3D electrical resistivity models. Electrical Resistivity Imaging (ERI) is an automated data acquisition system, inversion codes, non-invasive and user-friendly. The raw data received from data acquisition was analysed using Res2DINV software. The data inversion was done by applying the robust method and finite element grid to accommodate the steep topography. The data interpretation included numerical modelling to assess the suitability of all used electrode arrays in relation to the geological setting.

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Somba, Bunga Elim, Saiful Darman, Rachmat Zainuddin et Raihanda Dwimart Mangawe. « GEOLOGICAL MODELLING OF LITHOSEQUENT BASED ON DEM AND FINITE ELEMENT METHOD INVERSION OF VES DATA ». AGROLAND The Agricultural Sciences Journal (e-Journal) 9, n^o 2 (1 décembre 2022) : 98–106. http://dx.doi.org/10.22487/agroland.v9i2.1476.

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The aims of this study are to develop interpretation of structural geology in lithosequent using DEM and finite elemen method based on VES data. This research was conducted on June 2021 untill January 2022 at Pasang District, North Toraja. Four main point location were selected and recorded in google earth. Those points were processed using software QGIS for developing 3D model, Saga-GIS for interpolated DEM and VES for generating 1D and 2D geoelectrical modelling. Data were interpolated using Universal Kriging method and analysed using IP2WIN software. The results of these research shows that Geostatistical Universal Kriging can be used for interpolating DEM in lithosequent Pasang Village, by using as the variogram equation and yield 95,12% determinations; VES method in geoelectrical resistivity can be configure into 2D and produce clearer modeling of pseudo-section; The synthetics data can be generated from field measurement data and interpretation of 2D VES; Result of synthetic block on geoelectrical data can be inverted using Finite Element Method and generated clearer data; By using these methods, the thickness of weathering layer in lithosequent Pasang Village can be estimated and modelling.

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Piskarev, A. L., A. A. Kireev, G. I. Ovanesyan, V. A. Poselov, V. A. Savin, O. E. Smirnov et S. N. Tabyrtsa. « Structural Connection of the Chukchi Borderland and the Chukchi Sea Shelf : 3D Geophysical Modelling of the Earth Crust ». Geotektonika, n^o 5 (12 décembre 2024) : 28–45. https://doi.org/10.31857/s0016853x24050024.

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A 3D model of the crustal structure of the region, which includes the Chukchi Borderland with the adjacent ocean and the Chukotka‒Alaska Shelf, has been compiled and calculated. The peculiarity of the crustal structure is the three-sided isolation of the Chukchi Borderland and presence of a transitional area from the south connecting the Chukchi Borderland with the Chukotka‒Alaska Shelf. The connection between the Chukchi Borderland and the Wrangel Rise of the Chukchi Shelf is traced through the North Chukchi Rise located between the North Chukchi Trough and the Hanna Trough. A clockwise rotation of the Chukchi Borderland began in the Early Cretaceous, because basalts at the bottom of the sedimentary strata sections along the eastern and southern boundaries of the Chukchi Basin have a reversed magnetization, i.e., their outpouring occurred before the beginning of the Cretaceous superchron, earlier than 121 Ma. Near the upper boundary of the Neocomian, there was a large-scale shear displacement of crustal blocks along the eastern boundary of the Chukchi Rise, which had a thrust pattern before that. The 3D model demonstrates that the Chukchi Borderland and the Chukchi Basin are the natural components of the continental margin, as they have a strong geological connection with the continental masses of the Chukchi Shelf.

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Othman, Adel, Ali Bakr, Mohammed Fathy et Nader Moatasem. « 3D Geological Modeling for Characterizing the Bahariya Formation and Abu Roash G Dolomite Unit, Horus Field, North Western Desert, Egypt ». Iraqi Geological Journal 56, n^o 1B (28 février 2023) : 107–27. http://dx.doi.org/10.46717/igj.56.1b.9ms-2023-2-17.

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The Horus field is considered one of the most important hydrocarbon producers within the Alamein basin, Western Desert of Egypt. This area was affected by different tectonic movements throughout geological history. The re-evaluation and characterization of the Horus area, especially its main reservoirs of Lower Bahariya, middle Bahariya, upper Bahariya, and AR/G Dolomite units, because of its low production of oil tend (only 1100 BBD). Despite this, the Alamein basin is large and very rich in hydrocarbon. This study depends on the interpretation of thirty 2D seismic lines in addition to open-hole logs in the form of Resistivity, SP, GR, Density, Neutron, and Sonic logs for the five studied wells in order to delineate the subsurface structure and reservoir petrophysical characteristics of the Horus field. The data is tried to the formation tops and seismic lines by using synthetic seismograms. The main surfaces were mapped to proceed with the further static modeling. The work flow of the 3D geological modeling in the Horus area for characterization of the Bahariya Formation and AR/G Dolomite Unit. The processes that were carried out during the construction of the geological structure in the study area respectively, fault modeling, pillar gridding, skeleton grid, horizon modeling, zonation, and layering, and then distributed the facies and petrophysical parameters (Vsh, Sw and Φe) in this model. The main objective of this study is to delineate the seismic phenomena for structural, petrophysical, and facies modelling of the Bahariya Formation (Lower, Middle, and Upper) and AR/G Dolomite unit. The depth structure contour map on top of the Bahariya formation and the AR/G Dolomite unit indicated that the Horus area affected by NW-SE and WNW-ESE faults related to the lower Cretaceous. The study discussed the possibility of new structural traps that benefit in increasing the production of the area. All the results were consistent and confirmed that the Bahariya Formation and AR/G Dolomite are excellent reservoirs. Integrating multidisciplinary methods of seismic interpretation, static modeling, property modeling and well log analysis to design 3D structural and property models, helped predict new exploratory promising areas and structural traps to increase in production and the reserves in the study area, also decreasing the uncertainty of hydrocarbon exploration.

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Saxena, Asha, Giovanni Toscani, Lorenzo Bonini et Silvio Seno. « Three-Dimensional Modelling Approach for Low Angle Normal Faults in Southern Italy : The Need for 3D Analysis ». Geosciences 15, n^o 2 (5 février 2025) : 53. https://doi.org/10.3390/geosciences15020053.

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This paper presents three 3D reconstructions of different analogue models used to reproduce, interpret, and describe the geological setting of a seismogenic area in Southern Italy—the Messina Strait. Three-dimensional analysis is a technique that allows for less sparse and more congruent and coherent information about a study zone whose complete understanding reduces uncertainties and risks. A thorough structural and geodynamic description of the effects of low-angle normal faulting in the same region through analogue models has been widely investigated in the scientific literature. Sandbox models for fault behaviour during deformation and the effects of a Low Angle Normal Fault (LANF) on the seismotectonic setting are also studied. The deformational patterns associated with seismogenic faults, rotational behaviour of faults, and other related problems have not yet been thoroughly analysed. Most problems, like the evolution of normal faults, fault geometry, and others, have been cited and briefly outlined in earlier published works, but a three-dimensional approach is still significant. Here, we carried out a three-dimensional digital model for a complete and continuous structural model of a debated, studied area. The aim of this study is to highlight the importance of fully representing faults in complex and/or non-cylindrical structures, mainly when the shape and dimensions of the fault(s) are key parameters, like in seismogenic contexts.

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Basargin, Andrey, Alexander Satsiuk et Sergey Chedzhemov. « Application of spatial geological modeling to assess the mineral resources of the udokanskoye copper deposit, Chita Region ». Sustainable Development of Mountain Territories 16, n^o 3 (30 septembre 2024) : 988–99. https://doi.org/10.21177/1998-4502-2024-16-3-988-999.

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Introduction. The main goal of this study is to integrate geostatistical interpolation methods with a variety of geological and geophysical information to determine 3D-spatial and temporal relationships and cause - and - effect processes between ore bodies, altered rocks, metallogenic layers, and intrusive rocks. Materials and methods. The article present geostatistical methods used to create spatial models of porphyry copper deposits. These models include a variety of geological information about mineralization in the study region, such as geological, geophysical, geochemical, well and section data. Using this data, three - dimensional metallogenic geological objects were constructed that describe the distribution of mineralization in the rock mass. Results. The modelling results showed that the digital deposit model allows for accurate determination of copper grades for multiple ore bodies and the identification of continuous variations in copper grade within a single ore body. Discussion. It is known that many authors show great interest in the extraction and processing of spatiotemporal data. This also applies to geological and structural modeling of mineral deposits. However, these works do not cover, or do not cover in sufficient detail, the features of modeling complex geological systems at a high level of abstraction, without taking into account small details. In this article, the authors developed a methodology that is designed to study data on a mineral deposit, analyze anomalies and optimally display interpolation surfaces, as well as the uncertainties associated with them. In addition, this methodology allows for a more in - depth and detailed analysis of quantitative and qualitative characteristics based on a digital model of the deposit. The methodology for creating digital models of deposits based on geostatistical analysis methods can find wide application in forecasting the development of the deposit as a whole. Conclusions. Based on the study, a spatial relational database was obtained containing geological information about mineralization in the study area of the Udokanskoye deposit. 3D-models of metallogenic geological objects were built, including mineralization sequence, granodiorite, hydrothermal rocks and magnetic anomaly, which can be used to predict and identify potential mineralization targets. Resume. The modelling results showed that the digital deposit model allows for accurate determination of copper grades for multiple ore bodies and the identification of continuous variations in copper grade within a single ore body. Suggestions for practical applications and directions for future research. Further development of this method is possible due to the analysis of the work of a group of deposits, i.e. the assessment of indicators will be carried out for a separate deposit with subsequent aggregation of the studied processes using Markov chains and multi - channel mass service systems with failures. In the future, this will make it possible to use systemically significant assessments in making global decisions at all stages of the work of a mineral deposit.

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Tan, Yan Eng, Chee Meng Choong, Nur Huda M Jamin et Muhammad Aslam Md Yusof. « Structural analysis using 3D digital outcrop model : A case study in Kebun 500 outcrop, Kedah, Peninsular Malaysia ». Warta Geologi 50, n^o 3 (31 décembre 2024) : 172–83. https://doi.org/10.7186/wg503202402.

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Photogrammetry and digital outcrop modelling are the latest techniques used by various geoscience groups for Earth visualisation and research. This study showcases the structural analysis of a digital outcrop model in the Kebun 500 area, Kedah, involving drone photo collection, digital model construction, structural data extraction, and geological interpretation. The outcrop represents folded and fractured sedimentary rocks of the Permian-Triassic Semanggol Formation, situated adjacent to a major fault, the Bok Bak Fault. The digital model revealed a N-S strike direction and steep dips to the east in the sedimentary beds at the Kebun 500 outcrop. The rocks experienced flexural slipping on the bedding planes and locally folded into close-to-open folds. They can also be further classified into gently plunging-upright folds, gently plunging and moderately inclined folds, and moderately plunging and steeply inclined folds. The beds/folds are cross-cut by N-S striking, steeply dipping fractures, and NNW-SSE striking, inclined dipping reverse faults. The folds that occurred in the Kebun 500 outcrop are interpreted as parasitic folds. The identified fractures are also potentially associated with the Bok Bak fault system.

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Stoch, Ben, Ian James Basson et Jodie A. Miller. « Implicit Geomodelling of the Merensky and UG2 Reefs of the Bushveld Complex from Open-Source Data : Implications for the Complex’s Structural History ». Minerals 10, n^o 11 (1 novembre 2020) : 975. http://dx.doi.org/10.3390/min10110975.

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The Bushveld Complex (BC) is the world’s largest source of platinum group metals. Extensive studies on the complex have focused on its geochemistry, magma and platinum group mineral genesis, mineral characterization and intrusion mechanisms. However, relatively little work has been undertaken on the overall 3D geometry of the complex, which detracts from the adequate contextualization of such studies. Furthermore, the absence of a broader 3D model of the complex does not permit the identification of structural trends and mineralization patterns. This contribution details the construction of 3D implicitly-modelled Merensky and UG2 Reefs across the Rustenburg Layered Suite of the BC, using Seequent’s Leapfrog software. Multiple open-source and public-domain data sources and modelling workflows were explored to account for disparities in data resolution, data spacing and clustering, and the resolution of model outputs. Key outcomes are (1) a representative, fully-implicit, dynamic geological model of the Merensky and UG2 Reefs over the main chamber of the BC; (2) identification of modelled features that augment the current understanding of the BC’s kinematic history and cumulative deformation; and (3) identification and analysis of subtle geometrical trends and patterns, such as inter-reef spacing and modelled depths, as well as structural domains that may not have been apparent from numerous, more focused or isolated petrological or geochemical studies. It is anticipated that this baseline 3D model will form the foundation for future, possibly localized, dynamic updates as further information becomes available. The addition of proprietary (viz., non-open-source) data, such as 2D seismic sections and 3D seismic surveys, would enhance the overall resolution and quality of such a model and resulting interpretations.

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Mackie, S. I., et C. M. Gumley. « THE DIRKALA SOUTH OIL DISCOVERY : FOCUSSING ON COST-EFFICIENT RESERVOIR DELINEATION ». APPEA Journal 35, n^o 1 (1995) : 65. http://dx.doi.org/10.1071/aj94004.

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The Dirkala Field is located in the southern Murta Block of PEL's 5 and 6 in the southern Cooper and Eromanga Basins. Excellent oil production from a single reservoir sandstone in the Jurassic Birkhead Formation in Dirkala-1 had indicated a potentially larger resource than could be mapped volumetrically. The hypothesis that the resource was stratigraphically trapped led to the need to define the fluvial sand reservoir seismically and thereby prepare for future development.A small (16 km2) 3D seismic survey was acquired over the area in December 1992. The project was designed not only to evaluate the limits of the Birkhead sand but also to evaluate the cost efficiency of recording such small 3D surveys in the basin.Interpretation of the data set integrated with seismic modelling and seismic attribute analysis delineated a thin Birkhead fluvial channel sand reservoir. Geological pay mapping matched volumetric estimates from production performance data. Structural mapping showed Dirkala-1 to be optimally placed and that no further development drilling was justifiable.Seismic characteristics comparable with those of the Dirkala-1 Birkhead reservoir were noted in another area of the survey beyond field limits. This led to the proposal to drill an exploration well, Dirkala South-1, which discovered a new oil pool in the Birkhead Formation. A post-well audit of the pre-drill modelling confirmed that the seismic response could be used to determine the presence of the Birkhead channel sand reservoir.The acquisition of the Dirkala-3D seismic survey demonstrated the feasibility of conducting small 3D seismic surveys to identify subtle stratigraphically trapped Eromanga Basin accumulations at lower cost and risk than appraisal/development drilling based on 2D seismic data.

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Manka, Anna, Glen Buick, Rob Menpes, Luke Gardiner, Cameron Jones et Khalid Amrouch. « Effects of near surface lithology on velocity modelling and time–depth relationships in the Cooper–Eromanga–Lake Eyre Basin ». APPEA Journal 58, n^o 1 (2018) : 321. http://dx.doi.org/10.1071/aj17158.

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Structural closures on the western flank of the Patchawarra Trough in the Cooper–Eromanga Basin are truly low relief; drilling opportunities regularly target hydrocarbon columns of similar magnitude to the uncertainty of depth prediction. Improving the accuracy and precision of depth prediction will reduce risk for drilling opportunities, and improve drilling success rates. A detailed study of the near surface geology (surface to ~500 m depth) of the western flank of the Patchawarra Trough has been undertaken to better understand the effect of observed geological variations of the near surface on depth prediction at deeper target levels. The stratigraphic interval investigated includes the top of the Eromanga Basin and the entire Lake Eyre Basin, which is sparingly studied and routinely overlooked in the statics and velocity modelling process. This study analysed recently acquired cased-hole sonic logs in conjunction with gamma logs and mudlog data to map out the observed geological variations, and construct a 3D velocity model of the near surface. Variations of layer thickness and seismic velocity were input into Monte Carlo simulations to investigate sensitivities of each formation on two-way travel time and depth prediction. This investigation has found that velocity variations of the Weathered Winton Formation, and thickness variations of the Namba Clastics have the greatest impact on imaging of structures at depth. Independently, these have the potential to completely conceal or create structures in the time domain. Continued efforts in improved understanding of the near surface will subsequently lead to enhanced imaging of structures, which can then be used in the mapping of structural closures in petroleum exploration and development.

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Calista, Monia, Francesco Mascioli, Valeria Menna, Enrico Miccadei et Tommaso Piacentini. « Recent Geomorphological Evolution and 3D Numerical Modelling of Soft Clastic Rock Cliffs in the Mid-Western Adriatic Sea (Abruzzo, Italy) ». Geosciences 9, n^o 7 (12 juillet 2019) : 309. http://dx.doi.org/10.3390/geosciences9070309.

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Geomorphological evolution, erosion and retreat processes that affect the rocky coasts of the mid-western Adriatic Sea (Abruzzo, Central Italy) are the subject of this research. This coastal sector, one of the few examples of clastic soft rock coasts in the Mediterranean Sea, is characterized by active, inactive and paleo cliffs, as well as coastal slopes, composed of the clayey-sandy-arenaceous-conglomeratic marine sequence (Early-Middle Pleistocene) covered by continental deposits (Late Pleistocene-Holocene). This study provides geomorphological and 3D modelling stability analyses of the cliffs of Torre Mucchia, Punta Lunga, Punta Ferruccio (Ortona, CH) and Punta Aderci (Vasto, CH), which are popular tourist sites included in natural reserve areas. They are representative of two main types of active cliffs on soft clastic rocks: cliffs on sandstone and cliffs on conglomerate with notches. In order to evaluate the processes and factors that induce cliffs to retreat and their recent evolution, the research was based on a DEM analysis (LIDAR 2 × 2 m data), aerial photos and an orthoimages interpretation, detailed geological–geomorphological surveys, and a structural analysis; field and remote investigations were combined with numerical modelling with a FLAC3D calculation code. Geological and geomorphological field data provided reliable 3D models, and FLAC3D numerical analyses allowed the definition of the most critical and/or failure areas, and the evaluation of the controlling factors, evolution mechanisms of the slopes and the sliding kinematics of gravitational instability phenomena. Different retreat mechanisms have been observed all along the investigated coastal sectors, induced by gravitational processes due to coastal erosion cycles at the foot of the cliffs, and controlled by lithological features and joints systems. The geomorphological analysis combined with the 3D modelling (i) showed that the retreat process of the cliffs is connected to translational slides and rockfalls (cliffs on sandstone), combined rockfalls, and topples (cliffs on conglomerate), largely controlled by main joints; (ii) defined the most critical areas along the cliffs. These results are of great interest in the assessment of hazard connected to potential sliding on the cliffs. Their implementation within Geographical Information Systems provides a valuable contribution to the integrated management of coastal areas, strongly improving the identification and prediction of landscape changes and supporting a new geomorphological hazards assessment, in areas of high tourism, as well as natural and cultural landscape value.

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Husson, Eglantine, Antonio Guillen, Michel Séranne, Gabriel Courrioux et Renaud Couëffé. « 3D Geological modelling and gravity inversion of a structurally complex carbonate area : application for karstified massif localization ». Basin Research 30, n^o 4 (23 février 2018) : 766–82. http://dx.doi.org/10.1111/bre.12279.

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Alias, M. F., W. S. Udin et M. K. Piramli. « High-Resolution Mapping Using Digital Imagery of Unmanned Aerial Vehicle (UAV) at Quarry Area, Machang, Kelantan ». IOP Conference Series : Earth and Environmental Science 1102, n^o 1 (1 novembre 2022) : 012019. http://dx.doi.org/10.1088/1755-1315/1102/1/012019.

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Traditional structural and engineering geological survey data can only be acquired at the bottom of slopes or by climbing high rock walls in most quarries; these data frequently provide an incomplete picture of the area. UAV technology enables the safe study of difficult-to-access or hazardous locations. The key to future advancements in mining efficiency is the acquisition of high-precision, high-resolution 3D-positioned data. The goal of this research is to produce a high-resolution mapping from photographs captured by UAV. A DJI Mavic Pro 2 captured an image of a 0.131 km2 region of the Bukit Buloh Quarry Center. The final outputs in the forms of Orthomosaic and Digital Surface Model (DSM) were generated using Pix4Dmapper software. By comparing the coordinates of 6 Ground Control Points (GCPs) with coordinates determined using the RTK GPS method, the horizontal and vertical accuracies of the obtained UAV products were calculated. The vertical Root Mean Square Error (RMSE) for the geometric correctness of the data based on the 6 GCPs was 0.044 m. For large-scale maps, the resulting model met the American Society for Photogrammetry and Remote Sensing (ASPRS) accuracy standards. In a conclusion, UAV photogrammetry has evolved into a strong technology that can be used as a viable alternative to traditional mapping methods, particularly the use of expensive measurement equipment and labour. Besides its ability to analyze output data in qualitative or quantitative form, accurate mapping data is essential not only for 3D modelling but also for predicting geological risk in the quarry area.

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Torba, Dmitriy I., Alexander V. Bochkarev, Yuriy V. Ovcharenko, Alexandra E. Glazyrina, Yuriy S. Berezovskiy et Denis V. Metelkin. « Integrated modelling approach to oil recovery increase of Achimov formation ». PROneft’. Proffessional’no o nefti 6, n^o 3 (5 octobre 2021) : 103–13. http://dx.doi.org/10.51890/2587-7399-2021-6-3-103-113.

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Background. Tight sand deposits development has always been a challenging process that frequently requires application of innovative approaches. Horizontal drilling in non-uniform lithology is frequently accompanied by circulation, wellbore stability losses and other complications. Hydraulic fracturing stimulation does not always result in productivity increase, which reduces profitability of development. Due to the incomplete understanding of geological and geomechanical specifics of Achimov deposits, — formations with complex heterogenous structure, low permeability, presence of low-amplitude structural dislocations, — the controlled use of features of formation is hindered and, in turn, makes it necessary to develop an innovative strategy of their surveillance and stimulation. Aim. In purpose to optimize an existing development strategy of Achimov deposits in Vingayakhinskoe oilfield, we have developed and applied an approach involving complex cross-segment modelling. At the same time, verification of hypothesis on possibility to identify and activate naturally fractured zones. Materials and methods. To form criteria for verification of hypothesis of fracture network generation in Achimov deposits, a 1D and 3D geomechanical models have been built in view of the applied approach, along with a model of natural fractures. Development of hydraulic fracturing designs, efficiency of which has been evaluated with respect to such reservoir modeling results as predicted production rate and cumulative production, have been the next step, performed for different geological and geomechanical conditions. Thus, the principal feature of applied approach is coupling between geomechanical modeling, complex multivariant hydraulic fracturing modeling and reservoir modeling with the target to maximize production. Results. The well stimulation strategy, selected based on the results of multivariate integrated modeling, was successfully implemented as part of the pilot high-flow hydraulic fracturing operation, which led to an almost twofold increase in the initial production rates of project wells versus off set wells. Conclusions. The obtained results of the work confirm that the developed integrated modeling approach can serve as a reliable basis for optimizing the development of heterogeneous and low-permeability formations such as Achimov deposits.

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Torba, Dmitriy I., Alexander V. Bochkarev, Yuriy V. Ovcharenko, Alexandra E. Glazyrina, Yuriy S. Berezovskiy et Denis V. Metelkin. « Integrated modelling approach to oil recovery increase of Achimov formation ». PROneft’. Proffessional’no o nefti 6, n^o 3 (5 octobre 2021) : 103–13. http://dx.doi.org/10.51890/2587-7399-2021-6-3-103-113.

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Background. Tight sand deposits development has always been a challenging process that frequently requires application of innovative approaches. Horizontal drilling in non-uniform lithology is frequently accompanied by circulation, wellbore stability losses and other complications. Hydraulic fracturing stimulation does not always result in productivity increase, which reduces profitability of development. Due to the incomplete understanding of geological and geomechanical specifics of Achimov deposits, — formations with complex heterogenous structure, low permeability, presence of low-amplitude structural dislocations, — the controlled use of features of formation is hindered and, in turn, makes it necessary to develop an innovative strategy of their surveillance and stimulation. Aim. In purpose to optimize an existing development strategy of Achimov deposits in Vingayakhinskoe oilfield, we have developed and applied an approach involving complex cross-segment modelling. At the same time, verification of hypothesis on possibility to identify and activate naturally fractured zones. Materials and methods. To form criteria for verification of hypothesis of fracture network generation in Achimov deposits, a 1D and 3D geomechanical models have been built in view of the applied approach, along with a model of natural fractures. Development of hydraulic fracturing designs, efficiency of which has been evaluated with respect to such reservoir modeling results as predicted production rate and cumulative production, have been the next step, performed for different geological and geomechanical conditions. Thus, the principal feature of applied approach is coupling between geomechanical modeling, complex multivariant hydraulic fracturing modeling and reservoir modeling with the target to maximize production. Results. The well stimulation strategy, selected based on the results of multivariate integrated modeling, was successfully implemented as part of the pilot high-flow hydraulic fracturing operation, which led to an almost twofold increase in the initial production rates of project wells versus off set wells. Conclusions. The obtained results of the work confirm that the developed integrated modeling approach can serve as a reliable basis for optimizing the development of heterogeneous and low-permeability formations such as Achimov deposits.

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Chisambi, Joshua, Bjorn von der Heyden, Muofhe Tshibalanganda et Stephan Le Roux. « Gold Exploration in Two and Three Dimensions : Improved and Correlative Insights from Microscopy and X-Ray Computed Tomography ». Minerals 10, n^o 5 (23 mai 2020) : 476. http://dx.doi.org/10.3390/min10050476.

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In this contribution, we highlight a correlative approach in which three-dimensional structural/positional data are combined with two dimensional chemical and mineralogical data to understand a complex orogenic gold mineralization system; we use the Kirk Range (southern Malawi) as a case study. Three dimensional structures and semi-quantitative mineral distributions were evaluated using X-ray Computed Tomography (XCT) and this was augmented with textural, mineralogical and chemical imaging using Scanning Electron Microscopy (SEM) and optical microscopy as well as fire assay. Our results detail the utility of the correlative approach both for quantifying gold concentrations in core samples (which is often nuggety and may thus be misrepresented by quarter- or half-core assays), and for understanding the spatial distribution of gold and associated structures and microstructures in 3D space. This approach overlays complementary datasets from 2D and 3D analytical protocols, thereby allowing a better and more comprehensive understanding on the distribution and structures controlling gold mineralization. Combining 3D XCT analyses with conventional 2D microscopies derive the full value out of a given exploration drilling program and it provides an excellent tool for understanding gold mineralization. Understanding the spatial distribution of gold and associated structures and microstructures in 3D space holds vast potential for exploration practitioners, especially if the correlative approach can be automated and if the resultant spatially-constrained microstructural information can be fed directly into commercially available geological modelling software. The extra layers of information provided by using correlative 2D and 3D microscopies offer an exciting new tool to enhance and optimize mineral exploration workflows, given that modern exploration efforts are targeting increasingly complex and low-grade ore deposits.

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Le, Hong Quan, Dong Tran, Van Tien Nguyen et Dac The Nguyen. « A machine learning approach for calibrating seismic interval velocity in 3D velocity model ». Petrovietnam Journal 10 (1 novembre 2022) : 12–18. http://dx.doi.org/10.47800/pvj.2022.10-02.

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Velocity model technique is routinely used to convert data from the time-to-depth domain to support prospect evaluation, reservoir modelling, well engineering, and further drilling operation. In Vietnam, the conventional velocity model building workflow oversimplifies the interval velocities as only well interval velocities are populated into 2D grids for depth conversion or oversimplified calibration interval velocities by applying a single scaling factor function. This study explores the 3D velocity model workflow to obtain accurate and high-resolution interval velocities using a machine learning approach for both fields A and B in Cuu Long basin, offshore Vietnam. To design an effective approach to depth conversion, the anisotropy factor analysis was performed to understand the differences between the seismic and well interval velocities in geological layer in the 3D structural model. The seismic interval velocity was multiplied by the anisotropy factor to achieve the scaling seismic interval velocity. The scaling seismic interval velocity, elastic attributes, geometric attributes, structural and stratigraphic attributes were used as training features (variables) for predicting interval velocity using the supervised learning algorithm in the machine learning model. Supervised learning offers an opportunity to develop an expert-knowledge-based automated system, which incorporates both domain knowledge and quantitative data mining [1]. The random forest regression algorithms were selected for predicting interval velocity after evaluating several machine learning algorithms. To provide insight into the uncertainty of final interval velocity, a depth uncertainty analysis was conducted using a blind well test for 24 wells and 7 horizons. The comprehensive 3D velocity model using machine learning approach was built for the first time in Cuu Long basin, offshore Vietnam. The result showed the machine learning algorithm can address the disadvantages of conventional velocity calibration to create highly accurate depth representations of the subsurface including a measure of the uncertainty.

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Gantimurova, Svetlana, et Alexander Parshin. « Combined Methodology for Rockfall Susceptibility Mapping Using UAV Imagery Data ». Remote Sensing 16, n^o 1 (31 décembre 2023) : 177. http://dx.doi.org/10.3390/rs16010177.

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Gravitational processes on cut slopes located close to infrastructure are a high concern in mountainous regions. There are many techniques for survey, assessment, and prognosis of hazardous exogenous geological processes. The given research describes using UAV data and GIS morphometric analysis for delineation of hazardous rockfall zones and 3D modelling to obtain an enhanced, detailed evaluation of slope characteristics. Besides the slope geomorphometric data, we integrated discontinuity layers, including rock plains orientation and fracture network density. Cloud Compare software 2.12 was utilised for facet extraction. Fracture discontinuity analysis was performed in QGIS using the Network GT plugin. The presented research uses an Analytical Hierarchy Process (AHP) to determine the weight of each contributing factor. GIS overlay of weighted factors is applied for rockfall susceptibility mapping. This integrated approach allows for a more comprehensive GIS-based rockfall susceptibility mapping by considering both the structural characteristics of the outcrop and the geomorphological features of the slope. By combining UAV data, GIS-based morphometric analysis, and discontinuity analysis, we are able to delineate hazardous rockfall zones effectively.

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Tilbury, L., et T. Barter. « NEW TECHNOLOGY—A MAJOR IMPACT ON A PRODUCING FIELD : NORTH RANKIN GAS FIELD, NORTH WEST SHELF, AUSTRALIA ». APPEA Journal 32, n^o 1 (1992) : 20. http://dx.doi.org/10.1071/aj91003.

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New technology, especially the significant advances in 3D seismic interpretation techniques and drilling technology, has had a major impact on the development planning for the North Rankin Field.Significant advances have been made through the application of: horizon attribute processing, seismic amplitude analysis and long-reach drilling technology.Horizon attribute processing, including image processing techniques, has led to a better understanding of the structurally complex region on the northern flank of the field. These studies, coupled with new geological concepts related to opposing fault regimes, have concluded that good reservoir communication should exist across a fault zone previously thought to subdivide the field into compartments. The drilling of expensive, long-reach wells into the northern sector has thus been deferred, and may never be required, because of the newly developed structural model.Seismic amplitude analysis, coupled with geological modelling, upgraded the North Rankin West area and culminated in the recent significant appraisal/development well NRA22. This well was drilled from the North Rankin 'A' (NRA) platform to a target outside the main North Rankin Field in the adjacent Searipple Graben. NRA22 encountered well developed gas-bearing sands of Bathonian age which flowed at high rates (140 MMSCFGD).The application of long-reach drilling technology within Woodside has also had significant impact on development planning. The original development plan for North Rankin included a second platform in the northeast of the field. Better than expected production performance from NRA, related to across-fault reservoir communication, removed the necessity for a second platform. Large gas reserves in the Lower Jurassic 'NC' unit in the northeast have, however, required dedicated wells to improve ultimate recovery from this unit. The drilling of long-reach wells (at record drift) into the NC unit has provided better access to these reserves.Although North Rankin has been producing for over seven years with a total of 23 development wells drilled, understanding of the geological structure is still being improved by using new technology and ideas.

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Adhikary, Deepak P., Marc Elmouttie, Vincent Lemiale et Brett Poulsen. « Recent advances in the stability assessment of natural and engineered rock slopes ». Journal of Nepal Geological Society 50, n^o 1 (21 décembre 2016) : 65–72. http://dx.doi.org/10.3126/jngs.v50i1.22866.

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Science’s understanding of the failure mechanisms of large natural and engineered slopes has been improved considerably over the past 15 years. Significant improvements have been realized in innovative methods of data acquisition through field measurement and monitoring, as well as numerical modelling techniques. However, inadequate understanding of complex geology and landslide processes means that any interpretation of landslide data remains mostly subjective. This causes major uncertainty in landslide risk assessment. Over the past decade, Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO; http://www.csiro.au/) has developed novel techniques to facilitate efficient assessment of rock slope stability. These include SirovisionTM, Siromodel, and three CSIRO numerical codes: CSIRO‑SPH, CSIRO‑DEM and CSIRO‑COSFLOW. SirovisionTM is a geological/geotechnical mapping and analysis system that generates accurate, scaled 3D images of rock faces from stereo photographs of exposed rock surfaces, allowing for rapid rock mass structural mapping. Siromodel is a polyhedral modelling system that reads the SirovisionTM data, generates discrete fracture networks (DFN) and performs polyhedral (rock block) modelling and a first‑pass stability analysis. CSIRO‑SPH, CSIRO‑DEM and CSIRO‑COSFLOW are all used for detailed stress‑deformation analysis of rock slopes; however, each code has its own problem‑specific advantage. CSIRO‑SPH is suited for large deformation problems, and can simulate large scale fluid flow problems, such as modelling a dam breakage. CSIRO‑DEM is suited for rock breakage process analysis, and assessment of the runout distance of failure debris. CSIRO‑COSFLOW is designed specifically for efficient, accurate stress‑deformation analysis of stability of structures on bedded sedimentary rocks, where failures along the preexisting bedding planes and through the intact rock layers occur simultaneously.

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Zwaan, Frank, Guido Schreurs, Susanne J. H. Buiter, Oriol Ferrer, Riccardo Reitano, Michael Rudolf et Ernst Willingshofer. « Analogue modelling of basin inversion : a review and future perspectives ». Solid Earth 13, n^o 12 (16 décembre 2022) : 1859–905. http://dx.doi.org/10.5194/se-13-1859-2022.

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Abstract. Basin inversion involves the reversal of subsidence in a basin due to compressional tectonic forces, leading to uplift of the basin's sedimentary infill. Detailed knowledge of basin inversion is of great importance for scientific, societal, and economic reasons, spurring continued research efforts to better understand the processes involved. Analogue tectonic modelling forms a key part of these efforts, and analogue modellers have conducted numerous studies of basin inversion. In this review paper we recap the advances in our knowledge of basin inversion processes acquired through analogue modelling studies, providing an up-to-date summary of the state of analogue modelling of basin inversion. We describe the different definitions of basin inversion that are being applied by researchers, why basin inversion has been historically an important research topic and what the general mechanics involved in basin inversion are. We subsequently treat the wide range of different experimental approaches used for basin inversion modelling, with attention to the various materials, set-ups, and techniques used for model monitoring and analysing the model results. Our new systematic overviews of generalized model results reveal the diversity of these results, which depend greatly on the chosen set-up, model layering and (oblique) kinematics of inversion, and 3D along-strike structural and kinematic variations in the system. We show how analogue modelling results are in good agreement with numerical models, and how these results help researchers to better understand natural examples of basin inversion. In addition to reviewing the past efforts in the field of analogue modelling, we also shed light on future modelling challenges and identify a number of opportunities for follow-up research. These include the testing of force boundary conditions, adding geological processes such as sedimentation, transport, and erosion; applying state-of-the-art modelling and quantification techniques; and establishing best modelling practices. We also suggest expanding the scope of basin inversion modelling beyond the traditional upper crustal “North Sea style” of inversion, which may contribute to the ongoing search for clean energy resources. It follows that basin inversion modelling can bring valuable new insights, providing a great incentive to continue our efforts in this field. We therefore hope that this review paper will form an inspiration for future analogue modelling studies of basin inversion.

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Popovici, Traianus, et Marius Mosoarca. « Conservation, consolidation and restoration of the Holy Annunciation Church, Vatasesti village, region of Oltenia, Romania - Architectural and structural particularities ». MATEC Web of Conferences 396 (2024) : 20009. http://dx.doi.org/10.1051/matecconf/202439620009.

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The present article discusses the process of architectural and structural diagnosis of a late 18th century, brick masonry built, Christian church located in Vătășești village, Vâlcea county, Romania, presenting the particularities discovered. The church is dedicated to Saint John the Baptist and The Holy Annunciation and it is listed under the LMI code (List of historical monuments of Romania) VL-II-m-B-09968. Its registration in the list of historical monuments inscribed in the National Cultural Heritage of Romania was realized especially thanks to its original byzantine style mural paintings (frescoes) still left almost intact on the interior walls, the only serious damage made to it being found on the paintings once found on the outside walls. In order to properly conserve, consolidate and restore the vernacular monument, the process of diagnosis had to include research and investigations of various and complementary areas such as 3D scanning using laser scan technology, the archaeological report, the mural paintings restoration experts report, the chemical analysis of the painted surface, the biological analysis of different materials, humidity reports, stratigraphy research, the geological and topographical reports, the compression strength of bricks test and structural analysis using 3D modelling and the Etabs software. The materials and techniques used for the consolidation and restoration works had to be non-invasive, ecological and reversible, using steel nets and hydraulic lime for the consolidation of the brick masonry. The architectural interventions on the drainage system, facades, roof, interior floors, lighting system, and all the interventions that the article describes were subordinated by the need to preserve and highlight the Romanian orthodox frescoes that give great value to the monument. This article explains the importance of proper research and measurements ought to be done in order to have a well-coordinated process later, designing the consolidation and restoration project.

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Stalker, Linda, David Dewhurst, Yanhua Zhang, Peter Schaubs, Ben Clennell, Yohan Suhardiman, Andrew Maxwell et al. « Evaluation of the Petrel Sub-basin as a northern Australia CO2 store : future decarbonisation hub ? » APPEA Journal 60, n^o 2 (2020) : 765. http://dx.doi.org/10.1071/aj19180.

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The Northern Australia CO2 Store Project has extended investigations for safe, long-term containment of large volumes of CO2 (up to 100 million tonnes) to support liquefied natural gas and other industries in a decarbonised future. Most natural gas fields in the Petrel Sub-basin and the surrounding region have relatively high native CO2 content. This collaborative project improved storage characterisation, evaluated geomechanical risks and estimated engineering demands necessary to progress the concept to ‘prospect’ and ‘resource’. New data have significantly advanced the geological and structural understanding in the region, improving chrono- and litho-stratigraphic correlations, with new well ties across the basin. However, the re-mapping has thrown up new questions that require additional data (e.g. new stratigraphic wells, 3D seismic data) to address those knowledge gaps. Geomechanical modelling in the area has tested (to extreme levels) the potential impact of injection on faults in the area, further de-risking the likelihood of upward migration and leakage. The region could utilise an abundance of energy and feedstocks in the form of solar, natural gas, hydrogen and CO2 to become a future decarbonisation and industrial hub while managing major emissions with offshore CO2 storage.

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Drouiller, Yvon, Franck Hanot, Eric Gillot, Jean-Charles Ferran et Loic Michel. « 3D seismic for design and derisking of dual geothermal boreholes in sedimentary sequences and new prospects in the Paris Basin (Adapted methodology using petroleum industry techniques) ». Oil & ; Gas Science and Technology – Revue d’IFP Energies nouvelles 74 (2019) : 32. http://dx.doi.org/10.2516/ogst/2018106.

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The use of existing geological and structural maps, previous 2D seismic profiles, boreholes and correlation models between these data is sufficient to understand basin structure and thermal systems on a regional scale. However, this is not sufficient on a scale of a geothermal site to be sure of the hydraulic connectivity (or of the presence of a permeability barrier) between two boreholes 1.5 or 2 km apart. To ensure that there is enough hydraulic connectivity, it i s necessary to understand the controls on the network of fractures which affects the aquifer (fracture permeability) and the physical properties of the rock, namely the porosity and clay content in order to obtain a matrix permeability. The latest generation of broadband (six octaves) 3D seismic reflection will provide the following information: the similarity attribute will give an accurate structural map of the fault network at the seismic resolution and, in many cases, at a higher resolution than seismic; seismic velocity anisotropy analysis techniques will make it possible to visualize a 3D volume of information on the fracture network [Michel et al. (2013) Application of Azimuthal Seismic Inversion for Shale Gas Reservoir – Proceedings of the 11th SEGJ International Symposium, Yokohama]; acoustic impedance inversion or petrophysical inversion techniques will predict the porosity throughout the whole volume of the aquifer from a porosity log recorded in a pilot-hole. It allows a real 3D mapping of predicted porosity inside the aquifer much more reliably than from modelling alone. These seismic techniques were initially developed for petroleum exploration and development. They have rapidly progressed throughout the last decade, both in acquisition, processing and interpretation with new methodologies and high-performance softwares. They are efficient for modelling reservoirs to be produced. And, consequently, they can be used for geothermal applications as data to design dual deviated drillings with horizontal drains in carbonate and clastic reservoirs – not only for new projects, but also to revisit old ones to improve their performance or develop another reservoir. Broadband 3D seismic will secure the exploration of Triassic sandstones which stay an interesting prospect for deep geothermal projects. New prospects are proposed in the Paris Basin: Regional faults overlap the substratum. Inside faulted zones, hydrothermal circulations arriving by convection at the top of granitic basement could be geothermal objectives, as in the Alsace Upper Rhine Graben. A production pilot site is suggested to test superimposed aquifers and a regional fault and, at the same time, two different architectures of boreholes doublets: horizontal drains for aquifers and deviated wells for crossing a regional fault. The first site that will use this approach could be instrumented and used as an experiment with a small addition of measurements and sensors, thus becoming a showcase for geothermal energy in France. The objective of this experiment would be to determine the transit time, the heating time of the re-injected water and the circulation speed to define the optimal direction, spacing and length of drains, and also, to realize the thermal modelling of the site for different options.

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Vu, Hung Viet, Dong Duc Nguyen, Gia Phuoc Phan, Vu Minh Le et Hai Hoang Ninh. « 3D dynamic fault sealing capacity modelling to improve history matching : a case study in Oligocene reservoir, Tay Ho Field, Blocks A, Cuu Long basin, Offshore ». Journal of Mining and Earth Sciences 64, n^o 1 (1 février 2023) : 50–66. http://dx.doi.org/10.46326/jmes.2023.64(1).06.

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Fault transmissibility multipliers are a simple way of accounting for the effects of faults on fluid flow across fault plans in history matching of production simulation models. Fault transmissibility multipliers can be calculated using parameters such as fault clay, fault smear, thickness, and permeability. In this study, three emperical methods given by Manzocchi et al. (1999), Jolley et al. (2007), and Sperrevik et al. (2002) have been applied to the Oligocene sandstone reservoir, Tay Ho Field. The Oligocene reservoir is a complicated sandstone that was deposited in alluvial-fluvial and lacustrine environments, trapped by both stratigraphic and structural types, sandbody isolated by multi-activated faults. Fault sealing is one of the key factors controlling hydrocarbon accumulations and trap volume and can have a significant influence on reservoir performance during production. Furthermore, the prospective of structural or combination traps in stacked clastic reservoir settings that are typically found in many of the known hydrocarbon provinces in the Cuu Long basin, often critically hinges on the presence of a working fault side seal. Based on a thorough understanding of the key controls on fault seal risk and retention capacity, a consistent methodology to access these factors across a prospect portfolio is essential to achieve a balanced prospect ranking and an accurate assessment of prospect success volumes. In the process workflow built by PVEP Blocks 01/97 & 02/97, the assessment of fault seal capacity and compartmentalization in the Oligocene reservoir have been incorperated by using fault deformation, displacement, juxtaposition, fault zone thickness, shale gouge ratio (SGR), shale smear factor (SSF), clay smear potential (CSP), fault thickness and permeability. In our research, the Sperrevik et al. (2002) method provides the best historical match and most logical geological evidence; thus, it shall be used for dynamic models and further studies.

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Malavieille, Jacques, Stephane Dominguez, Chia-Yu Lu, Chih-Tung Chen et Elena Konstantinovskaya. « Deformation partitioning in mountain belts : insights from analogue modelling experiments and the Taiwan collisional orogen ». Geological Magazine 158, n^o 1 (11 juillet 2019) : 84–103. http://dx.doi.org/10.1017/s0016756819000645.

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AbstractMany orogens on the planet result from plate convergence involving subduction of a continental margin. The lithosphere is strongly deformed during mountain building involving subduction of a plate composed generally of accreted continental margin units and some fragments of downgoing oceanic crust and mantle. A complex deformation involving strong partitioning of deformation modes and kinematics produces crustal shortening, accompanied by crustal thickening. Partitioning depends on three main factors: (1) rheologic layering of the lithosphere; (2) interaction between tectonics and surface processes; (3) subduction kinematics and 3D geometry of continental margins (oblique convergence, shape of indenters). Here we present an original view and discussion on the impact of deformation partitioning on the structure and evolution of orogens by examining the Taiwan mountain belt as a case study. Major unsolved questions are addressed through geological observations from the Taiwan orogen and insights from analogue models integrating surface processes. Some of these questions include: What is the role played by décollements or weak zones in crustal deformation and what is the impact of structural heterogeneities inherited from the early extensional history of a rifted passive continental margin? What is the relationship between deep underplating, induced uplift and flow of crustal material during erosion (finite strain evolution during wedge growth)? Are syn-convergent normal faults an effect of deformation partitioning and erosion? What is the role of strain partitioning on the location of major seismogenic faults in active mountain belts? What can be learned about the long-term and the present-day evolution of Taiwan?

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Raiber, M., J. A. Webb, D. I. Cendón, P. A. White et G. E. Jacobsen. « Environmental isotopes meet 3D geological modelling : Conceptualising recharge and structurally-controlled aquifer connectivity in the basalt plains of south-western Victoria, Australia ». Journal of Hydrology 527 (août 2015) : 262–80. http://dx.doi.org/10.1016/j.jhydrol.2015.04.053.

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Kosović, Ivan, Bojan Matoš, Stefano Casiraghi, Gabriele Benedetti, Tihomir Frangen, Kosta Urumović, Ivica Pavičić et al. « Hydrogeological parameterisation of the Daruvar thermal aquifer : integration of fracture network analysis and well testing ». Geologia Croatica 77, n^o 2 (21 juin 2024) : 99–125. http://dx.doi.org/10.4154/gc.2024.11.

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Highly fractured Mesozoic carbonate rocks are the main reservoir of many geothermal resources in northern Croatia, being of environmental, cultural, and economic value for the local and regional communities. The Daruvar thermal springs (temperatures < 50°C) represent the outflow area of an intermediate scale, tectonically controlled, hydrothermal system hosted in Triassic carbonate rocks. Several investigations have been conducted in the Daruvar area detailing the architecture of regional and local fracture networks and quantifying the hydrogeological parameters of the thermal aquifer. In this work, an integrated approach based on structural and hydrogeological investigations was employed to model the network of fractures in the reservoir and quantify its impact on the hydraulic properties. Structural investigations were conducted in the Batinjska Rijeka quarry, considered as an outcrop analogue of the thermal aquifer, employing both a classical field approach and the virtual quantitative analysis of a 3D digital outcrop model. Structural analysis of the digital outcrop model allowed identification of two sub-vertical systems of discontinuities, dipping to the NW and the WSW respectively, in accordance with the data collected through direct field measurements. The main geometric features of the discontinuity network and their statistical distributions were employed to construct discrete fracture network models at both the outcrop scale (approximately 100 m) and the aquifer scale in Daruvar (approximately 700 m). Calibration of the input parameters allowed modelling of porosity and permeability values that reproduce the field values assessed through pumping tests, well tests, and well logging. This work highlights the importance of integrating geological and hydrogeological investigations to obtain a more reliable reconstruction and quantification of the processes driving the fluid flow in fractured aquifers and affecting the spatial distribution of their hydraulic properties.

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Veldkamp, A., M. W. Van den Berg, J. J. Van Dijke et R. M. Van den Berg van Saparoea. « Reconstructing Late Quaternary fluvial process controls in the upper Aller Valley (North Germany) by means of numerical modeling ». Netherlands Journal of Geosciences - Geologie en Mijnbouw 81, n^o 3-4 (décembre 2002) : 375–88. http://dx.doi.org/10.1017/s0016774600022666.

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AbstractThe morpho-genetic evolution of the upper Aller valley (Weser basin, North Germany) was reconstructed using geological and géomorphologie data integrated within a numerical process model framework (FLUVER-2). The current relief was shaped by Pre-Elsterian fluvial processes, Elsterian and Saalian ice sheets, followed by Weichselian fluvial processes. Structural analysis based on subsurface data and morphological interpretations were used to reconstruct uplift/subsidence rates. A detailed analysis led to the hypothesis that we are dealing with either a NNW-SSE or a WSW-ENE oriented compression leading to uplift in the upper Aller valley. It is also hypothesised that the NNW-SSE compression might have caused strike-slip deformation leading to differential block movement and tilt. Two different uplift rate scenarios were reconstructed and used as a variable parameter in numerical modelling scenarios simulating the Late Quaternary longitudinal dynamics of the Aller. Each different scenario was run for 150.000 years and calibrated to the actual setting. The resulting model settings were consequently evaluated for their plausibility and validity. Subsequently, regional semi-3D simulations of valley development were made to test the two tectonic stress hypotheses. Differential tectonic uplift and regional tilt seems to have played an important role in shaping the current valley morphology in the upper Aller. Unfortunately, due to the uncertainties involved, we were unable to discriminate between the two postulated tectonic stress scenarios.

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Baron, Julie, Ilaria Primofiore, Peter Klin, Giovanna Vessia et Giovanna Laurenzano. « Investigation of topographic site effects using 3D waveform modelling : amplification, polarization and torsional motions in the case study of Arquata del Tronto (Italy) ». Bulletin of Earthquake Engineering 20, n^o 2 (3 décembre 2021) : 677–710. http://dx.doi.org/10.1007/s10518-021-01270-2.

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AbstractThe combined effect of topography and near-surface heterogeneities on the seismic response is hardly predictable and may lead to an aggravation of the ground motion. We apply physics-based numerical simulations of 3D seismic wave propagation to highlight these effects in the case study of Arquata del Tronto, a municipality in the Apennines that includes a historical village on a hill and a hamlet on the flat terrain of an alluvial basin. The two hamlets suffered different damage during the 2016 seismic sequence in Central Italy. We analyze the linear visco-elastic seismic response for vertically incident plane waves in terms of spectral amplification, polarization and induced torsional motion within the frequency band 1–8 Hz over a 1 km2 square area, with spatial resolution 25 m. To discern the effects of topography from those of the sub-surface structure we iterate the numerical simulations for three different versions of the sub-surface model: one homogeneous, one with a surficial weathering layer and a soil basin and one with a complex internal setting. The numerical results confirm the correlation between topographic curvature and amplification and support a correlation between the induced torsional motion and the topographic slope. On the other hand we find that polarization does not necessarily imply ground motion amplification. In the frequency band above 4 Hz the topography-related effects are mainly aggravated by the presence of the weathering layer, even though they do not exceed the soil-related effects in the flat-topography basin. The geological setting below the weathering layer plays a recognizable role in the topography-related site response only for frequencies below 4 Hz.

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