Publications
67 results found
Jacquemyn C, Jackson MD, Hampson GJ, et al., 2024, Sketch-based geological modelling with flow diagnostics: the digital back-of-the-envelope for 3D geology and subsurface flow
<jats:p>Sketch-based geological modelling with flow diagnostics provides an interactive and intuitive prototyping approach to quickly build geomodels and generate quantitative results to evaluate volumetrics and flow behaviour. This approach allows users to rapidly test the sensitivity of model outputs to different geological concepts and uncertain parameters, and informs selection of geological concepts, scales and resolutions to be investigated in more detailed models. Here we apply the sketching and prototyping approach to different aspects of geo-energy modelling and use in geoscience and engineering training.Rapid Reservoir Modelling (RRM) is a free open-source sketch-based geological modelling tool with an intuitive interface that allows users to rapidly sketch geological models in 3D (bitbucket.org/rapidreservoirmodelling/rrm). Geological models that capture the essence of heterogeneity of interest and related uncertainty can be created within minutes. Geological operators ensure correct truncation relationships between these 3D surfaces by the modelling engine. Flow diagnostics then computes key indicators of predicted flow and storage behaviour within seconds. Example use cases and how models can be shared, will be discussed, including:(1) Scenario screening to identify heterogeneities with the most impact on CO2 storage. Capturing uncertainty in geological concepts cannot be achieved by changing a numerical variable but can be varied easily by sketching the different concepts, such as lateral connectivity, continuity and geometry of geological heterogeneities that act as flow barriers and pathways. Capturing multiple different concepts in conventional modelling approaches is time-consuming and in practice not often carried out.(2) Use of mini-models and hierarchical models to derive effective properties. Models with varying complexity of heterogeneity are sketched at smallest relevant scale, and effective properties are calculated. Calculated effecti
Bahlali M, Woitischek J, Jacquemyn C, et al., 2024, Integrated Modeling of Cu-Rich Fluid Migration and Mineralization in the Katangan Basin, Central African Copperbelt: Insights from Numerical Experiments
<jats:p>Sediment-hosted Cu deposits are a significant global source of copper. This study employs a mineral system approach, focusing on basin-scale groundwater flow as a key mechanism for Cu transport from source to trap. Numerical experiments using the open-source IC-FERST code investigate the controls on Cu transport in the Katangan Basin, Central African Copperbelt. The models developed for early and late stages of basin evolution incorporate fluid flow, heat and solute transport, and dynamic mesh optimization to enhance computational efficiency.The early-stage model, corresponding to the salt deposition period, attributes the formation of saline brine to a dense residual phase resulting from evaporite formation. In the late-stage model, corresponding to Cu mobilization and mineralization, Cu dissolution and mineralization are simulated using a partition coefficient informed by experimental data.Results reveal that density gradients induced by salinity and temperature variations play a crucial role in initiating convective groundwater flow. Highly saline, dense brines generated during salt deposition or dissolution form complex, downward-propagating plumes influenced by flow instabilities and geologic heterogeneity. Permeable faults and fractures in basement rocks enable groundwater to percolate, potentially mobilizing Cu from intra- or extra-basinal source rocks. Salinity and temperature gradients drive upwelling plumes, transporting Cu from deeper source rocks to shallower, organic-rich sedimentary rocks where mineralization occurs.</jats:p>
Firth H, Jacquemyn C, Hampson G, et al., 2024, Impact of Aquifer Heterogeneity on LT-ATES Performance: A Case Study from the Chalk Aquifer, London, UK
<jats:p>The Chalk comprises a highly heterogeneous dual porosity aquifer, characterized by intervals of high permeability formed by fracturing and/or karstification of a low-permeability matrix. Many boreholes in London show evidence of a high-permeability flow zone at the top of the Chalk. Despite this, models used to predict ATES system operation in the Chalk aquifer in London have typically assumed a homogeneous aquifer, so that simulated warm and cold plumes have a simple cylindrical geometry around the wells. In this study, we investigate the impact of aquifer heterogeneity on system operation.We examine an operating LT-ATES installation. The system employs 4 cold wells and 4 warm wells and is sized to deliver peak heating of 1.8 MW and peak cooling of 2.75 MW. Analysis of flowrate and temperature data shows that the system has a well-balanced energy ratio of 0.09 and exhibits a low but increasing thermal recovery which is currently ca. 40% for warm storage and 25% for cold storage.We use a Surface-Based Modelling (SBM) approach to represent geological heterogeneity, which allows us to accurately and realistically capture geometrically complex subsurface features. We develop a range of parametrised 3D models of different geological scenarios, to capture uncertainty in geological heterogeneity between the wells. Flow and heat transport during ATES operation are simulated using the Imperial College Finite Element Reservoir Simulator (IC-FERST). The models are calibrated using Nelder-Mead methods to match pressure transient data and well inflow logs obtained from the boreholes prior to commissioning. Temperature and flowrate data collected during operation are subsequently employed in thermal simulations using the calibrated models.Our findings suggest that aquifer heterogeneity has a significant impact on the formation of the warm and cold plumes. Heterogeneity has resulted in a thermal recovery bias toward warm water, despite ambient aquifer temperature be
Jacquemyn C, Jackson MD, 2024, Impact of aquifer properties, well spacing and vertical offsetting of warm and cool plumes on ATES systems.
<jats:p>Aquifer Thermal Energy Storage (ATES) can store and supply a high capacity of seasonal heating and cooling. Well-balanced and well-designed ATES systems provide a very efficient energy storage, up to around 70-90% and thereby play an important role in providing a sustainable, and low-carbon solution for heating and cooling. Factors affecting the efficiency and capacity of ATES deployments are mainly subsurface properties and related design decisions. We set up a framework to test the impact of a wide range subsurface and design parameters to deduce their impact on ATES system performance. Aquifer thickness, lateral permeability and permeability anisotropy are considered as main aquifer properties, and cool-warm well lateral spacing and vertical offsetting of cool and warm plumes as main design decisions. The thickness of the injection and production interval can be dictated by aquifer permeability variations and/or be chosen by varying screen length. &#160;The parameters listed above are combined into dimensionless numbers, such as effective aspect ratio of the system and effective lateral spacing of wells to summarize and group different aquifers and possible ATES deployment designs. For a wide range of effective aspect ratios and effective well spacing ATES system behaviour is predicted by flow simulation and key performance indicators computed, including thermal efficiency, CO2 savings, cool/warm plume sizes and stored energy density. The first two indicate the potential expected capacity of ATES systems. The latter provide recommendations for best use of land area, especially if multiple ATES systems are planned in areas with high concentration of cooling and heating demand. Given heating and cooling demand, specific aquifer conditions and land area available for use, the predicted behaviour metrics will help design optimal ATES deployments and show the potential for energy savings across multiple different settings.Results indicate that AT
Alshakri J, Hampson GJ, Jacquemyn C, et al., 2023, A screening assessment of the impact of sedimentological heterogeneity on CO2 migration and stratigraphic-baffling potential: Sherwood and Bunter Sandstones, UK, Enabling Secure Subsurface Storage in Future Energy Systems, Publisher: Geological Society of London, Pages: 245-266
We use a combination of experimental design, sketch-based reservoir modelling, and flow diagnostics to rapidly screen the impact of sedimentological heterogeneities that constitute baffles and barriers on CO2 migration in depleted hydrocarbon reservoirs and saline aquifers of the Sherwood Sandstone Group and Bunter Sandstone Formation, UK. These storage units consist of fluvial sandstones with subordinate aeolian sandstones, floodplain and sabkha heteroliths, and lacustrine mudstones. The predominant control on effective horizontal permeability is the lateral continuity of aeolian-sandstone intervals. Effective vertical permeability is controlled by the lateral extent, thickness and abundance of lacustrine-mudstone layers and aeolian-sandstone layers, and the mean lateral extent and mean vertical spacing of carbonate-cemented basal channel lags in fluvial facies-association layers. The baffling effect on CO2 migration and retention is approximated by the pore volume injected at breakthrough time, which is controlled largely by three heterogeneities, in order of decreasing impact: (1) the lateral continuity of aeolian-sandstone intervals; (2) the lateral extent of lacustrine-mudstone layers, and (3) the thickness and abundance of fluvial-sandstone, aeolian-sandstone, floodplain-and-sabkha-heterolith and lacustrine-mudstone layers. Future effort should be focussed on characterising these three heterogeneities as a precursor for later capillary, dissolution and mineral trapping.
Petrovskyy D, Jacquemyn C, Geiger S, et al., 2023, Rapid flow diagnostics for prototyping of reservoir concepts and models for subsurface CO2 storage, International Journal of Greenhouse Gas Control, Vol: 124, Pages: 1-16, ISSN: 1750-5836
Sketch-based interface and modelling is an approach to reservoir modelling that allows rapid and intuitive creation of 3D reservoir models to test and evaluate geological concepts and hypotheses and thus explore the impact of geological uncertainty on reservoir behaviour. A key advantage of such modelling is the quick creation and quantitative evaluation of reservoir model prototypes. Flow diagnostics capture key aspects of reservoir flow behaviour under simplified physical conditions that enable the rapid solution of the governing equations, and are essential for such quantitative evaluation. In this paper, we demonstrate a novel and highly efficient implementation of a flow diagnostics framework, illustrated with applications to geological storage of CO2. Our implementation permits ‘on-the-fly’ estimation of the key reservoir properties that control CO2 migration and storage during the active injection period when viscous forces dominate. The results substantially improve the efficiency of traditional reservoir modelling and simulation workflows by highlighting key reservoir uncertainties that need to be evaluated in subsequent full-physics reservoir simulations that account for the complex interplay of viscous, gravity, and capillary forces.The methods are implemented in the open-source Rapid Reservoir Modelling software, which includes a simple to use graphical user interface with no steep learning curve. We present proof-of-concept studies of the new flow diagnostics implementation to investigate the CO2 storage potential of sketched 3D models of shallow marine sandstone tongues and deep water slope channels.
Mueller M, Walter BF, Swart PK, et al., 2022, A TALE OF THREE FLUIDS: FLUID-INCLUSION AND CARBONATE CLUMPED-ISOTOPE PALEOTHERMOMETRY REVEALS COMPLEX DOLOMITIZATION AND DEDOLOMITIZATION HISTORY OF THE LATEMAR PLATFORM, JOURNAL OF SEDIMENTARY RESEARCH, Vol: 92, Pages: 1141-1168, ISSN: 1527-1404
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- Citations: 2
Jackson WA, Hampson GJ, Jacquemyn C, et al., 2022, A screening assessment of the impact of sedimentological heterogeneity on CO2 migration and stratigraphic-baffling potential: Johansen and Cook formations, Northern Lights project, offshore Norway, International Journal of Greenhouse Gas Control, Vol: 120, Pages: 1-23, ISSN: 1750-5836
We use a method combining experimental design, sketch-based reservoir modelling, and single-phase flow diagnostics to rapidly screen the impact of sedimentological heterogeneities that constitute baffles and barriers to CO2 migration in the Johansen and Cook formations at the Northern Lights CO2 storage site. The types and spatial organisation of sedimentological heterogeneities in the wave-dominated deltaic sandstones of the Johansen-Cook storage unit are constrained using core data from the 31/5-7 (Eos) well, previous interpretations of seismic data and regional well-log correlations, and outcrop and subsurface analogues. Delta planform geometry, clinoform dip, and facies-association interfingering extent along clinoforms control: (1) the distribution and connectivity of high-permeability medial and proximal delta-front sandstones, (2) effective horizontal and vertical permeability characteristics of the storage unit, and (3) pore volumes injected at breakthrough time (which approximates the efficiency of stratigraphic baffling). In addition, the lateral continuity of carbonate-cemented concretionary layers along transgressive surfaces impacts effective vertical permeability, and bioturbation intensity impacts effective horizontal and vertical permeability. The combined effects of these and other heterogeneities are also influential. Our results suggest that the baffling effect on CO2 migration and retention of sedimentological heterogeneity is an important precursor for later capillary, dissolution and mineral trapping.
Regnier G, Salinas P, Jacquemyn C, et al., 2022, Numerical simulation of aquifer thermal energy storage using surface-based geologic modelling and dynamic mesh optimisation, HYDROGEOLOGY JOURNAL, Vol: 30, Pages: 1179-1198, ISSN: 1431-2174
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- Citations: 3
Hamzehloo A, Bahlali ML, Salinas P, et al., 2022, Modelling saline intrusion using dynamic mesh optimization with parallel processing, ADVANCES IN WATER RESOURCES, Vol: 164, ISSN: 0309-1708
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- Citations: 2
Mueller M, Jacquemyn C, Walter BF, et al., 2022, Constraints on the preservation of proxy data in carbonate archives – lessons from a marine limestone to marble transect, Latemar, Italy, Sedimentology, Vol: 69, Pages: 423-460, ISSN: 0037-0746
<jats:title>Abstract</jats:title><jats:p>This work evaluates an exceptionally complex natural laboratory, the Middle Triassic Latemar isolated platform in the northern Italian Dolomite Mountains and explores spatial and temporal gradients in processes and products related to contact metamorphism, dolomitization and dedolomitization of marine limestones. The relation between petrographic change and re‐equilibration of geochemical proxy data is evaluated from the perspective of carbonate‐archive research. Hydrothermal dolomitization of the limestone units is triggered by dykes and associated hydrothermal fluids radiating from the nearby Predazzo Intrusion. Detailed petrography, fluid inclusion analysis, δ<jats:sup>13</jats:sup>C and δ<jats:sup>18</jats:sup>O data and <jats:sup>87</jats:sup>Sr/<jats:sup>86</jats:sup>Sr isotope ratios shed light on the extreme textural and geochemical complexity. Metamorphic and diagenetic patterns include: (i) peak‐metamorphic and retrograde‐metamorphic phases including three dolomite marbles, two dedolomite marbles, brucite, magnesium silicates and late‐stage meteoric/vadose cement at the contact aureole; (ii) four spatially defined episodes of dolomitization, authigenic quartz, low magnesium calcite and late‐stage meteoric cement at the Latemar isolated platform; and (iii) kilometre‐scale gradients in δ<jats:sup>13</jats:sup>C values from the contact aureole towards the platform interior. Results shown here are relevant for two reasons: first, the spatial analysis of alteration products ranging from high‐grade metamorphic overprint of marbles at temperatures of 700°C in the contact aureole to moderately altered limestones in the platform interior at temperatures <100°C, allows the observation of processes that commonly occur along vertical (prograde) gradients from shallow burial to metamorphism at depths >20 k
Hampson G, Alshakri J, Jackson W, et al., 2022, FAST SCREENING ASSESSMENTS OF THE IMPACT OF SEDIMENTOLOGICAL HETEROGENEITY ON CO2 MIGRATION AND STORAGE, Pages: 2969-2973
We use a method combining experimental design, sketch-based reservoir modelling, and flow diagnostics to rapidly screen the impact of sedimentological heterogeneities on CO2 migration and storage by stratigraphic trapping. Experimental design allows efficient exploration of a wide parameter space, sketch-based modelling enables rapid construction of deterministic models of interpreted geological scenarios, and flow diagnostics provide computationally cheap approximations of full-physics, multiphase simulations that are reasonable for many subsurface-flow conditions. Integrated sketch-based reservoir modelling and flow diagnostics are implemented in open source research code (Rapid Reservoir Modelling, RRM). The method is applied to two case studies: (1) the Triassic Sherwood Sandstone Group and Bunter Sandstone Formation, UK, which comprise fluvial-aeolian sandstones, floodplain and sabkha heteroliths, and lacustrine mudstones; and (2) the Jurassic Johansen and Cook formations, offshore western Norway, which record progradation of a wave-dominated delta system. Results for the two case studies are compared using effective permeability (kx, ky, kz) and pore volume injected at breakthrough time (a measure of how much injected fluid is stored in the model volume as a result of stratigraphic trapping).
Li J, Geiger S, Gomes JC, et al., 2022, Fast assessment of the impact of multi-scale geological heterogeneities on flow behaviour in complex carbonate reservoirs, Pages: 562-566
We discuss the application of the new open-source Rapid Reservoir Modelling software (RRM) to create a suite of 3D reservoir models of a complex carbonate formation where each model is increasingly more refined such that progressively more small-scale geological structures are preserved. Using flow diagnostics we then calculate key metrics for the dynamic reservoir behaviour to quantify the similarities and dissimilarities of the flow behaviour across the different models. This analysis allows us to identify at which scale geological heterogeneities need to be resolved in the reservoir model to capture the essential flow behaviours. The workflow presented in this study hence allows us to efficiently and effectively test different geological concepts and analyse how multi-scale geological heterogeneities that may need to be represented in a reservoir model impact the predicted dynamic response, so as to design more reliable and robust reservoir models for a broad range of geoenergy applications.
Jacquemyn C, Hampson GH, Jackson MD, et al., 2022, SKETCH-BASED GEOLOGICAL MODELLING AND FLOW DIAGNOSTICS FOR GEOTHERMAL AND HEAT STORAGE APPLICATIONS, Pages: 3039-3043
Production of subsurface heat from geothermal sources and subsurface storage of heat (and cool) are important for energy transition. Doublets for geothermal and warm- and cold wells for aquifer thermal energy storage (ATES) depend on circulation of fluids and heat. Estimating the potential and feasibility of such systems requires a careful analysis with simulation of fluid flow and heat transport. As building models and running simulations are time-consuming, a prototyping approach is beneficial to quickly assess viability and sensitivity of such systems. Sketch-based geological modelling combined with flow diagnostics forms the ideal for such a prototyping approach. Geological models can be sketched in 3D in a couple of minutes. Flow diagnostics then provides several key metrics on predicted flow behaviour. The quick turnaround time from sketching to quantitative results is key to understand the impact of heterogeneity on flow and helps to decide which detailed geological models and flow simulations are useful to carry out. This prototyping approach is applied to aquifers in shallow marine deposits, as proxy for thermal breakthrough time in geothermal doublet system and to estimate well spacing between cold and hot wells for ATES.
Jacquemyn C, Hampson GJ, Jackson MD, et al., 2021, Rapid Reservoir Modelling: Sketch-Based Geological Modelling with Fast Flow Diagnostics, Abu Dhabi International Petroleum Exhibition & Conference, Publisher: Society of Petroleum Engineers
Rapid Reservoir Modelling (RRM) is a software tool that combines geological operators and a flow diagnostics module with sketch-based interface and modelling technology. The geological operators account for all interactions of stratigraphic surfaces and ensure that the resulting 3D models are stratigraphically valid. The geological operators allow users to sketch in any order, from oldest to youngest, from large to small, or free of any prescribed order, depending on data-driven or concept-driven uncertainty in interpretation. Flow diagnostics assessment of the sketched models enforces the link between geological interpretation and flow behaviour without using time-consuming and computationally expensive workflows. Output of RRM models includes static measures of facies architecture, flow diagnostics and model elements that can be exported to industry-standard software. A deep-water case is presented to show how assessing the impact of different scenarios at a prototyping stage allows users to make informed decisions about subsequent modelling efforts and approaches. Furthermore, RRM provides a valuable method for training or to develop geological interpretation skills, in front of an outcrop or directly on subsurface data.
Teoh CP, Jacquemyn C, Laya JC, 2021, The effects of dolomite geobodies within carbonate clinoforms on fluid flow and connectivity: Insights from an outcrop analogue on Bonaire, The Netherlands (South Caribbean), Marine and Petroleum Geology, Vol: 134, Pages: 1-18, ISSN: 0264-8172
Carbonate clinoforms are often challenging to characterize and model due to their complex geometries and additional heterogeneity introduced by diagenetic processes. Dolomitization can influence petrophysical properties resulting in either an increase or reduction in porosity and permeability of the host rock and forms geobodies of varied shapes depending on pre-dolomitization permeability patterns and dolomitization mechanism. Therefore, in partially or fully dolomitized successions, the prediction of fluid flow behavior is not trivial. This study uses a well-studied outcrop analogue of Mio-Pliocene partially dolomitized clinoforms at Seru Grandi (Bonaire) to better understand fluid flow in different dolomitization scenarios. Clinothems consist of heterogeneous coralline algal facies overlying bioclastic facies, with dolomite geobodies truncated on their upper and lower bounds by clinoform surfaces. Digital outcrop models were used to characterize geometry and spatial relationship of facies and heterogeneity, such as clinoform dip, length, height, and spacing. Multiple realizations of clinoform and dolomite body geometries are modelled using a surface-based modelling (SBM) approach coupled with an unstructured mesh flow simulator (IC-FERST). Two scenarios are considered, in which dolomitization has resulted in either a decrease in porosity and permeability as observed in outcrop, or a relative increase of porosity and permeability values as a potential subsurface scenario. Flow simulation results reveal an exponential relationship between water breakthrough times and flow rates versus dolomite proportions. Additionally, the arrangement of the dolomite bodies (aligned vs. disjoined) exhibits very similar fluid flow behavior across a wide range of dolomite proportions. Sensitivity of flow behavior to the geological models is strongly dependent on dolomite permeability relative to precursor limestone. Dolomite body arrangement is more important for flow behavior at hi
Titus Z, Heaney C, Jacquemyn C, et al., 2021, Conditioning surface-based geological models to well data using artificial neural networks, Computational Geosciences: modeling, simulation and data analysis, Vol: 26, Pages: 779-802, ISSN: 1420-0597
Surface-based modelling provides a computationally efficient approach for generating geometrically realistic representations of heterogeneity in reservoir models. However, conditioning Surface-Based Geological Models (SBGMs) to well data can be challenging because it is an ill-posed inverse problem with spatially distributed parameters. To aid fast and efficient conditioning, we use here SBGMs that model geometries using parametric, grid-free surfaces that require few parameters to represent even realistic geological architectures. A neural network is trained to learn the underlying process of generating SBGMs by learning the relationship between the parametrized SBGM inputs and the resulting facies identified at well locations. To condition the SBGM to these observed data, inverse modelling of the SBGM inputs is achieved by replacing the forward model with the pre-trained neural network and optimizing the network inputs using the back-propagation technique applied in training the neural network. An analysis of the uncertainties associated with the conditioned realisations demonstrates the applicability of the approach for evaluating spatial variations in geological heterogeneity away from control data in reservoir modelling. This approach for generating geologically plausible models that are calibrated with observed well data could also be extended to other geological modelling techniques such as object- and process-based modelling.
Salinas P, Regnier G, Jacquemyn C, et al., 2021, Dynamic mesh optimisation for geothermal reservoir modelling, Geothermics, Vol: 94, Pages: 1-13, ISSN: 0375-6505
Modelling geothermal reservoirs is challenging due to the large domain and wide range of length- and time-scales of interest. Attempting to represent all scales using a fixed computational mesh can be very computationally expensive. Application of dynamic mesh optimisation in other fields of computational fluid dynamics has revolutionised the accuracy and cost of numerical simulations. Here we present a new approach for modelling geothermal reservoirs based on unstructured meshes with dynamic mesh optimisation. The resolution of the mesh varies during a simulation, to minimize an error metric for solution fields of interest such as temperature and pressure. Efficient application of dynamic mesh optimisation in complex subsurface reservoirs requires a new approach to represent geologic heterogeneity and we use parametric spline surfaces to represent key geological features such as faults and lithology boundaries. The resulting 3D surface-based models are mesh free; a mesh is created only when required for numerical computations. Dynamic mesh optimisation preserves the surfaces and hence geologic heterogeneity. The governing equations are discretised using a double control volume finite element method that ensures heat and mass are conserved and provides robust solutions on distorted meshes. We apply the new method to a series of test cases that model sedimentary geothermal reservoirs. We demonstrate that dynamic mesh optimisation yields significant performance gains, reducing run times by up to 8 times whilst capturing flow and heat transport with the same accuracy as fixed meshes.
Jacquemyn C, Pataki MEH, Hampson GJ, et al., 2021, Sketch-based interface and modelling of stratigraphy and structure in three dimensions, Journal of the Geological Society, Vol: 178, Pages: 1-17, ISSN: 0016-7649
Geological modelling is widely used to predict resource potential in subsurface reservoirs. However, modelling is often slow, requires use of mathematical methods that are unfamiliar to many geoscientists, and is implemented in expert software. We demonstrate here an alternative approach using sketch-based interface and modelling, which allows rapid creation of complex three-dimensional (3D) models from 2D sketches. Sketches, either on vertical cross-sections or in map-view, are converted to 3D surfaces that outline geological interpretations. We propose a suite of geological operators that handle interactions between the surfaces to form a geologically realistic 3D model. These operators deliver the flexibility to sketch a geological model in any order and provide an intuitive framework for geoscientists to rapidly create 3D models. Two case studies are presented, demonstrating scenarios in which different approaches to model sketching are used depending on the geological setting and available data. These case studies show the strengths of sketching with geological operators. Sketched 3D models can be queried visually or quantitatively to provide insights into heterogeneity distribution, facies connectivity or dynamic model behaviour; this information cannot be obtained by sketching in 2D or on paper.
Jacquemyn C, Pataki MEH, Jackson MD, et al., 2021, SKETCH-BASED RESERVOIR MODELLING: FAST PROTOTYPING OF RESERVOIR MODELS TO EXPLORE INTERPRETATION-BASED UNCERTAINTY, Pages: 1317-1321
Sketch-based interface and modelling (SBIM) is a new approach that uses intuitive sketches to build 3D models. Rapid Reservoir Modelling (RRM) is an implementation of SBIM for subsurface modelling, that allows the user to sketch concepts or to trace interpretations over existing data in order to produce 3D reservoir models in a very short timeframe (minutes). These reservoir models can then be interrogated for a series of static parameters, and a flow diagnostics module provides a first estimate of dynamic behaviour. The user can quickly generate a suite of models representing different scenarios or interpretations and compare or rank them using multiple derived parameters. RRM can be used to quickly test what the effect could be of different interpretations or modelling decisions, before a reservoir modelling approach is finalised, or specific detailed models are built. It may help to decide on modelling parameters such as grid size, but also inform the inputs for uncertainty workflows, as uncertainty associated with different concepts can be translated into RRM model outputs. Here we will illustrate how sketches of different geological interpretations of the same dataset are used to construct 3D models using RRM, and show the impact these have on resulting model properties.
Costa Sousa M, Silva J, Silva C, et al., 2020, Smart modelling of geologic stratigraphy concepts using sketches, Smart Tools and Applications in computer Graphics (STAG) 2020, Publisher: The Eurographics Association, Pages: 89-100
Several applications of Earth Science require geologically valid interpretation and visualization of complex physical structures in data-poor subsurface environments. Hand-drawn sketches and illustrations are standard practices used by domain experts for conceptualizing their observations and interpretations. These conceptual geo-sketches provide rich visual references for exploring uncertainties and helping users formulate ideas, suggest possible solutions, and make critical decisions affecting the various stages in geoscience studies and modelling workflows. In this paper, we present a sketch-based interfaces and modelling (SBIM) approach for the rapid conceptual construction of stratigraphic surfaces, which are common to most geologic modelling scales, studies, and workflows. Our SBIM approach mirrors the way domain users produce geo-sketches and uses them to construct 3D geologic models, enforcing algorithmic rules to ensure geologically-sound stratigraphic relationships are generated, and supporting different scales of geology being observed and interpreted. Results are presented for two case studies demonstrating the flexibility and broad applicability of our rule-based SBIM approach for conceptual stratigraphy.
Yekta A, Salinas P, Hajirezaie S, et al., 2020, Reactive transport modeling in heterogeneous porous media with dynamic mesh optimization, Computational Geosciences: modeling, simulation and data analysis, Vol: 25, Pages: 357-372, ISSN: 1420-0597
This paper presents a numerical simulator for solving compositional multiphase flow and reactive transport. The simulator was developed by effectively linking IC-FERST (Imperial College Finite Element Reservoir SimulaTor) with PHREEQCRM. IC-FERST is a next-generation three-dimensional reservoir simulator based on the double control volume finite element method and dynamic unstructured mesh optimization and is developed by the Imperial College London. PHREEQCRM is a state-of-the-art geochemical reaction package and is developed by the United States Geological Survey. We present a step-by-step framework on how the coupling is performed. The coupled code is called IC-FERST-REACT and is capable of simulating complex hydrogeological, biological, chemical, and mechanical processes occurring including processes occur during CO2 geological sequestration, CO2 enhanced oil recovery, and geothermal systems among others. In this paper, we present our preliminary work as well as examples related to CO2 geological sequestration. We performed the model coupling through developing an efficient application programming interface (API). IC-FERST-REACT inherits high-order methods and unstructured meshes with dynamic mesh optimization from IC-FERST. This reduces the computational cost by placing the mesh resolution where and when necessary and it can better capture flow instabilities if they occur. This can have a strong impact on reactive transport simulations which usually suffer from computational cost. From PHREEQCRM the code inherits the ability to efficiently model geochemical reactions. Benchmark examples are used to show the capability of IC-FERST-REACT in solving multiphase flow and reactive transport.
Osman H, Graham GH, Moncorge A, et al., 2020, Is cell-to-cell scale variability necessary in reservoir models?, Mathematical Geosciences, Vol: 53, Pages: 271-296, ISSN: 1573-8868
Reservoir models typically contain hundreds-of-thousands to millions of grid cells in which petrophysical properties such as porosity and permeability vary on a cell-to-cell basis. However, although the petrophysical properties of rocks do vary on a point-to-point basis, this variability is not equivalent to the cell-to-cell variations in models. We investigate the impact of removing cell-to-cell variability on predictions of fluid flow in reservoir models. We remove cell-to-cell variability from models containing hundreds of thousands of unique porosity and permeability values to yield models containing just a few tens of unique porosity and permeability values grouped into a few internally homogeneous domains. The flow behavior of the original model is used as a reference. We find that the impact of cell-to-cell variability on predicted flow is small. Cell-to-cell variability is not necessary to capture flow in reservoir models; rather, it is the spatially correlated variability in petrophysical properties that is important. Reservoir modelling effort should focus on capturing correlated geologic domains in the most realistic and computationally efficient manner.
Zhang Z, Geiger S, Rood M, et al., 2020, Fast flow computation methods on unstructured tetrahedral meshes for rapid reservoir modelling, Computational Geosciences, Vol: 24, Pages: 641-661, ISSN: 1420-0597
Subsurface reservoir models have a high degree of uncertainty regarding reservoir geometry and structure. A range of conceptual models should therefore be generated to explore how fluids-in-place, reservoir dynamics, and development decisions are affected by such uncertainty. The rapid reservoir modelling (RRM) workflow has been developed to prototype reservoir models across scales and test their dynamic behaviour. RRM complements existing workflows in that conceptual models can be prototyped, explored, compared, and ranked rapidly prior to detailed reservoir modelling. Reservoir geology is sketched in 2D with geological operators and translated in real-time into geologically correct 3D models. Flow diagnostics provide quantitative information for these reservoir model prototypes about their static and dynamic behaviours. A tracing algorithm is reviewed and implemented to compute time-of-flight and tracer concentrations efficiently on unstructured grids. Numerical well testing (NWT) is adopted in RRM to further interrogate the reservoir model. A new edge-based fast marching method is developed and implemented to solve the diffusive time-of-flight for approximating pressure transients efficiently on unstructured tetrahedral meshes. We demonstrate that an implementation of the workflow consisting of integrated sketch-based interface modelling, unstructured mesh generation, flow diagnostics, and numerical well testing is possible.
Zhang Z, Geiger S, Rood M, et al., 2020, Fast flow computation methods on unstructured tetrahedral meshes for rapid reservoir modelling, 16th European Conference on the Mathematics of Oil Recovery (ECMOR), Publisher: SPRINGER, Pages: 641-661, ISSN: 1420-0597
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- Citations: 5
Jackson CA-L, Magee C, Jacquemyn C, 2020, Rift-related magmatism influences petroleum system development in the NE Irish Rockall Basin, offshore Ireland, Petroleum Geoscience, Vol: 26, Pages: 511-524, ISSN: 1354-0793
Large volumes of hydrocarbons reside in volcanically influenced sedimentary basins. Despite having a good conceptual understanding of how magmatism impacts the petroleum systems of such basins, we still lack detailed case studies documenting precisely how intrusive magmatism influences, for example, trap development and reservoir quality. Here we combine 3D seismic reflection, borehole, petrographical and palaeothermometric data to document the geology of borehole 5/22-1, NE Irish Rockall Basin, offshore western Ireland. This borehole (Errigal) tested a four-way dip closure that formed to accommodate emplacement of a Paleocene–Eocene igneous sill-complex during continental break-up in the North Atlantic. Two water-bearing turbidite-sandstone-bearing intervals occur in the Upper Paleocene; the lowermost contains thin (c. 5 m), quartzose-feldspathic sandstones of good reservoir quality, whereas the upper is dominated by poor-quality volcaniclastic sandstones. Palaeothermometric data provide evidence of anomalously high temperatures in the Paleocene–Eocene succession, suggesting the poor reservoir quality within the target interval is likely to reflect sill-induced heating, fluid flow, and related diagenesis. The poor reservoir quality is also probably the result of the primary composition of the reservoir, which is dominated by volcanic grains and related clays derived from an igneous-rock-dominated, sediment source area. Errigal appeared to fail due to a lack of hydrocarbon charge: that is, the low bulk permeability of the heavily intruded Cretaceous mudstone succession may have impeded the vertical migration of sub-Cretaceous-sourced hydrocarbons into supra-Cretaceous reservoirs. Break-up-related magmatism did, however, drive the formation of a large structural closure, with data from Errigal at least proving high-quality, Upper Paleocene deep-water reservoirs. Future exploration targets in the NE Irish Rockall Basin include: (i) stratigraphically trappe
Salinas P, Pain C, Osman H, et al., 2020, Vanishing artifficial diffusion as a mechanism to accelerate convergence for multiphase porous media flow, Computer Methods in Applied Mechanics and Engineering, Vol: 359, Pages: 1-15, ISSN: 0045-7825
Numerical solution of the equations governing multiphase porous media flow is challenging. A common approach to improve the performance of iterative non-linear solvers for these problems is to introduce artificial diffusion. Here, we present a mass conservative artificial diffusion that accelerates the non-linear solver but vanishes when the solution is converged. The vanishing artificial diffusion term is saturation dependent and is larger in regions of the solution domain where there are steep saturation gradients. The non-linear solver converges more slowly in these regions because of the highly non-linear nature of the solution. The new method provides accurate results while significantly reducing the number of iterations required by the non-linear solver. It is particularly valuable in reducing the computational cost of highly challenging numerical simulations, such as those where physical capillary pressure effects are dominant. Moreover, the method allows converged solutions to be obtained for Courant numbers that are at least two orders of magnitude larger than would otherwise be possible.
Titus Z, Pain C, Jacquemyn C, et al., 2020, Conditioning surface-based geological models to well data using neural networks
Generating representative reservoir models that accurately describe the spatial distribution of geological heterogeneities is crucial for reliable predictions of historic and future reservoir performance. Surface-based geological models (SBGMs) have been shown to better capture complex reservoir architecture than grid-based methods; however, conditioning such models to well data can be challenging because it is an ill-posed inverse problem with spatially distributed parameters. Here, we propose the use of deep Convolutional Neural Networks (CNNs) to generate geologically plausible SBGMs that honour well data. Deep CNNs have previously demonstrated capability in learning representative features of spatially correlated data for large scale and highly non-linear geophysical systems similar to those encountered in subsurface reservoirs. In the work reported here, a CNN is trained to learn the relationship between parameterised inputs to SBGM, the resulting geometry and heterogeneity distribution, and the mis-match between model surfaces and well data. We show that the trained CNN can generate a range of geologically plausible models that honour well data. The method is demonstrated for a 2D example model, representing a shallow marine reservoir and a 3D extension of the model that captures typical heterogeneities encountered in the subsurface such as parasequences, clinoforms and facies boundaries. These test cases highlight the improvement in reservoir characterisation for realistic geological cases. We present here a method of generating geologically consistent reservoir models that match well data. The developed method will allow the generation of new high-fidelity realizations of subsurface geology conditioned to information at wells, which is the most direct observational data that can be acquired. Technical Contributions - The use of surface-based modelling to describe even complex geological features compared to grid-based modelling significantly decreases the co
Salinas P, Jacquemyn C, Heaney C, et al., 2020, Well location optimisation by using surface-based modelling and dynamic mesh optimisation
Predictions of production obtained by numerical simulation often depend on grid resolution as fine resolution is required to resolve key aspects of flow. Moreover, the controls on flow can depend on well location in a model. In some cases, it may be key to capture coning or cusping; in others, it might be the location of specific high permeability thief zones or low permeability flow barriers. Thus, models with a suitable grid resolution for one particular set of well locations may fail to properly capture key aspects of flow if the wells are moved. During well optimisation, it is impossible to predict a-priori which well locations will be tested in a given model. Thus, it is unlikely to know a-priori if the grid resolution is suitable for all possible locations tested during a well optimisation procedure on a single model, and the problem is even more profound if well optimisation is tested over a range of different models. Here, we report an optimisation methodology based on Dynamic Mesh Optimisation (DMO). DMO will produce optimised meshes for a given model, set of well locations, pressure (and other key fields) distribution and timelevel. Grid-free Surface-Based Modelling (SBM) models are automatically generated in which well trajectories are introduced (also not constrained by a mesh), respected by DMO. For the optimization of the well location a Genetic Algorithm (GA) approach is used, more specifically the open-source software package DEAP. DMO ensures that all the models automatically generated and simulated in the optimisation process are modelled with an equivalent mesh resolution without user interaction, in this way, the local pressure drawdown and associated physical effects (such as coning or cusping) can be properly captured if they appear in any of the many scenarios that are studied . We demonstrate that the method has wide application in reservoir-scale models of oil and gas fields, and regional models of groundwater resources.
Jacquemyn C, Jackson MD, Hampson GJ, 2019, Surface-based reservoir modelling: Automatic assembly for multiple stochastic realizations
© 81st EAGE Conference and Exhibition 2019. All rights reserved. Surface-based reservoir modelling for hydrocarbon or geothermal reservoirs is a modelling approach that represents subsurface heterogeneity by surfaces. All heterogeneity of interest is modelled only by its bounding surfaces, free from a predefined grid. This overcomes grid-related limitations of conventional modelling approaches such as stair-stepping, loss of connectivity or continuity and resolution limitations to capture small features that are essential to flow. Creating surface-based models relies on generating 100's of surfaces of different geometries, scales and relationships, all representing a boundary between volumes with different properties. We show how adding metadata to every surface enables automatic assembly of all these individual surfaces into a surface-based reservoir model. Metadata signifies why a surface exists and includes what properties are on either side of a surface, which volume it intersects and the level of detail it represents. Multiple model realisations can now be built automatically from stochastically generated bounding surfaces.
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