Construction Of Geological Model Research Articles

Integrated Approach to the Construction of Geological Models Based on Facies Analysis

Integrated Approach to the Construction of Geological Models Based on Facies Analysis

Active thickness estimation and failure simulation of translational landslide using multi-orbit InSAR observations: A case study of the Xiongba landslide

The active thickness of the translational landslides plays a pivotal role in evaluating its hazards and simulating its instability. Existing techniques have difficulties in estimating the accurate active thickness due to the limitations of observation conditions and imaging geometry, leading to deviations in failure simulations. To overcome these challenges, this study proposes an enhanced method that utilizes multi-orbit Interferometric Synthetic Aperture Radar (InSAR) observations to estimate the active thickness of the translational landslides and subsequently conduct more accurate instability simulations. The method involves integrating multi-orbit InSAR imaging parameters with the spatial geometry of the landslide to establish a slope coordinate system. This system enables the projection of one-dimensional InSAR Line Of Sight (LOS) displacements onto the three-dimensional displacements of the landslide. Subsequently, the active thickness is estimated by combining InSAR three-dimensional displacements with the mass conservation method. Finally, the estimated thickness is incorporated into the geological model construction to simulate the dynamic movement of the landslide. The method was applied to the Xiongba translational landslide in Gongga County, Tibet Autonomous Region, China. The results show that the deformation is mainly concentrated at its forefront, with maximum three-dimensional deformation rates of 4.7 m/a, 2.3 m/a, and 1.24 m/a. The landslide encompasses an estimated area of around 5.33 square kilometers, and its active thickness varies from 0 to 106.59 m. The maximum displacement distance reaches 1469.76 m, with a peak velocity of 60.37 m/s. The proposed method provides scientific support for assessing, analyzing, and preventing landslide disasters.

Petrophysical substantiation of geological section elastic-velocity property recovery potential based on TEM data

The geological section of Eastern and Western Siberia (Russia) is a very complicated object for seismic exploration. The research presented in the article is aimed at studying a petrophysical relation between electrical resistivity and P-wave velocity, as a basis for predicting the velocity model of the upper part of the section based on TEM sounding. Having performed a numerical modeling of petrophysical function, the authors calculated the dependency curves of electrical resistivity on the P-wave velocity. The obtained results of mathematical modeling and field experiments have proved the effectiveness of the proposed methodology as it increases the accuracy of geological model construction and enhances prediction reliability. Based on the dependences obtained, conclusions were drawn about the geological conditions favorable for a steady transition of section geoelectric characteristics to the velocity ones. The proposed technology is shown to provide a reliable reconstruction of the velocity model of the upper part of the section. The use of the developed methodology allows to improve the quality of seismic data processing and increase the accuracy of geological section boundary mapping at minimum cost based on the nature of the problem under investigation.

Obtaining initial data for forecast engineering geological model construction

Objective and relevance. Technologies in mining and geology are intensely developing making the present research particularly relevant. The research considers the problems of obtaining reliable and high-quality data on the degree and nature of rock mass fracturing in a solid mineral deposit. These are fundamental data required to construct a forecast engineering geological model of a deposit. The engineering geological model is usually based on a structural geological model with the addition of various geomechanical parameters used in generally accepted international classifications for rock stability analysis, in particular, RMR (Bieniawski), MRMR (Laubscher), and Q-system (Barton). Methods of research. The authors describe the procedure for obtaining classification geomechanical parameters of a rock mass according to the data from oriented and non-oriented core drilling of special engineering geological (geomechanical) boreholes. Research results. The main factors and conditions for reliable data acquisition are given. Among the most important ones are: economic feasibility and validity of geomechanical boreholes drilling as well as their number; features of the geological and structural composition of a deposit as a condition for borehole location selection; proper organization of the drilling process aimed at obtaining high-quality core material; characteristics of geomechanical description of the core, depending on the rating system of rock mass classification applied. Scope of results. By way of example, deposits with different geological and structural conditions are listed where the described procedure was applied. High-quality and reliable information about the structural and tectonic features of the rock mass allows to create and fill the engineering geological model with data and solve the problems of stability analysis for almost any area of the future mine working.

A Case Study on Integrated Modeling of Spatial Information of a Complex Geological Body

Abstract To ensure the safety of project construction and reduce development costs, it is necessary to obtain a reasonable design before project initiation and to analyze and study geological information from multiple perspectives to achieve intuitive and effective project planning. Therefore, it is proposed to integrate above- and underground information to realize integrated spatial information expression. Generally, geological body model construction is based on drilling data, but most geological bodies are not simple layered structures, and complex geological phenomena usually occur, such as faults, lenses, and fissures. It is difficult to construct a high-quality geological body model with only limited drilling data. To fully consider existing geological information in complex geological areas with limited geological data information available, profile maps are considered in the modeling process. This article focuses on the geological model construction of a primary school in Shuicheng County, Guizhou Province, using the GoCAD platform. The Structure and Stratigraphy Workflow is applied in three-dimensional geological body structure model establishment, the stratum rock mass is outlined, and the complex geological structure (karst cave) is embedded into the geological surface. The model can be sliced at any angle to accomplish integrated spatial information expression of above- and underground building information combined with the same platform’s geological body to obtain engineering information and analyze future construction problems.

Open-Pit Mine Geological Model Construction and Composite Rock Blasting Optimization Research

In this paper, the blasting parameters are designed based on the drilling data of the exploration geological stage, the geophysical and mechanical parameters of the mining area, and the geological age information, and the numerical simulation of the blasting of the layered rock steps is carried out to optimize the blasting parameters. Multiple sets of blasting tests were carried out on-site, and the large block rate, average block size satisfaction rate, large block satisfaction rate, cost satisfaction rate, shovel loading efficiency, and blasting effect satisfaction rate were set as the blasting effect evaluation indicators, which verified the feasibility of the optimized scheme.

Production Dynamic Prediction Method of Waterflooding Reservoir Based on Deep Convolution Generative Adversarial Network (DC-GAN)

The rapid production dynamic prediction of water-flooding reservoirs based on well location deployment has been the basis of production optimization of water-flooding reservoirs. Considering that the construction of geological models with traditional numerical simulation software is complicated, the computational efficiency of the simulation calculation is often low, and the numerical simulation tools need to be repeated iteratively in the process of model optimization, machine learning methods have been used for fast reservoir simulation. However, traditional artificial neural network (ANN) has large degrees of freedom, slow convergence speed, and complex network model. This paper aims to predict the production performance of water flooding reservoirs based on a deep convolutional generative adversarial network (DC-GAN) model, and establish a dynamic mapping relationship between well location deployment and output oil saturation. The network structure is based on an improved UNet framework. Through a deep convolutional network and deconvolution network, the features of input well deployment images are extracted, and the stability of the adversarial model is strengthened. The training speed and accuracy of the proxy model are improved, and the oil saturation of water flooding reservoirs is dynamically predicted. The results show that the trained DC-GAN has significant advantages in predicting oil saturation by the well-location employment map. The cosine similarity between the oil saturation map given by the trained DC-GAN and the oil saturation map generated by the numerical simulator is compared. In above, DC-GAN is an effective method to conduct a proxy model to quickly predict the production performance of water flooding reservoirs.

APPLICATION OF A MULTIDIMENSIONAL DETERMINISTIC-STATISTICAL NUMERICAL CORRELATION MODEL TO REFINE THE STRUCTURE OF THE AS11 HORIZON OF THE ZAPADNO-KAMYNSKOYE FIELD

One of the primary and significant tasks in the construction of geological models of oil and gas reservoirs and development facilities is the problem of correlation of productive layers. This task, as a rule, is reduced to the identification and areal tracing of presumably even-aged oil and gas strata, horizons, and layers characterized by clear boundaries between sand strata and clay layers overlapping them. The practice of work related to modeling the structure of oil and gas horizons, layers and strata indicates that the correlation is not always unambiguous. The ambiguity is especially noticeable when correlating strata characterized by a clinoform structure, one of the examples is the Achimov strata. The most reliable basis for well correlation is GIS materials and lithological features of the interlayers forming individual layers. Clay interlayers and clay strata separating productive deposits provide valuable information when choosing a correlation model in sedimentary sections. These interlayers are characterized by the greatest consistency in area and are most clearly displayed on geophysical diagrams by the nature of the drawings of GIS curves. However, even in this case, i. e. when using the entire accumulated volume of the most diverse lithological and field-geophysical information, the correlation models of the sections turn out to be different and often even opposite. In this paper, the authors had to face a similar situation when correlating the horizon AS11 of the Zapadno-Kamynskoye field. The paper describes a method for clarifying the position of the chops of the productive horizon of oil and gas deposits using a multidimensional deterministic-statistical numerical model of the correlation of sedimentary strata. The proposed approach allows us to uniquely determine the positions of the chops in the conditions of a complex geological structure of the object, high thin-layered heterogeneity. A concrete example shows the advantages of the proposed approach in comparison with the traditional one.

Geological Model for Khasib Formation of East Baghdad Field Southern Area

Geological model construction is an important phase of reservoir study as the production capacity of a reservoir depends on its structural and petrophysical characteristics. The economic benefit of the reservoir is evaluated by estimating the formation petrophysical properties and calculating the oil reserves. East Baghdad southern area field is a newly developing oil field in the middle region of Iraq, where Khasib formation is its main reservoir. The aim of this study is to estimate the petrophysical properties and determine the pay units of the formation under study and the initial oil in place. Sequential Gaussian Simulation was used here to distribute the petrophysical properties as the statistical method and volumetric method was used to calculate the oil in place. The results show that the main reservoir units of the formation are K2 and K3 units, and the estimated oil reserves equal to 2179 mmSTB (346.43 million cubic meters).

Research on 3D geological modeling method based on multiple constraints

In the past three-dimensional geological modeling process, only vertical geological data, i.e. borehole or profile drawn from borehole, was used as the modeling data source. However, the plane geological map either does not participate in the modeling at all, or only serves as a reference data in the modeling process, and its role is not fully played. In view of the appeal, this paper puts forward a plane section modeling method based on multiple constraints. This method combines the vertical geological data and the horizontal geological data to participate in the modeling work. The surface part of the 3D geological model constructed by this modeling method is completely consistent with the plane geological map. In addition, there are both vertical data source and horizontal data source, which greatly improves the accuracy of the model. In this paper, taking the kangyangju area of Huaying Mountain in Guang’an City as an example, using the plane section modeling method with multiple constraints, the three-dimensional geological model construction of kangyangju area is carried out, which proves that the method is reliable and useful, and is worth popularizing.

Application of Tracer-Based Workflow for Calibrating Reservoir Heterogeneity

SummaryCapturing the correct reservoir heterogeneity in a geological model is critical for designing and accurately forecasting expected production benefits from improved/enhanced oil recovery processes. In simple terms, reservoir heterogeneity is often considered as a measure of statistical variation of static properties, such as porosity and permeability. The Lorenz coefficient and Dykstra-Parsons coefficient are two such measures of reservoir heterogeneity that account for these static effects. These measures are considered simplistic because the spatial distribution and arrangement of these properties is more critical for reservoir characterization than its statistical variation. The dynamic Lorenz coefficient is one such measure that accounts for the spatial distribution and arrangement of porosity and permeability. The dynamic Lorenz coefficient cannot be directly measured in the field but can be implicitly inferred from tracer data. This inferred heterogeneity will be influenced by the spatial distribution of static properties and can also be significantly influenced by multiphase flow effects, such as viscous fingering and gravity over/underride, which often arise from the differences in the viscosities and densities of the different phases involved. The dynamic Lorenz coefficient interpreted from a tracer test response lumps both static and multiphase (dynamic) effects into one measure of heterogeneity. During geological model construction, the dynamic Lorenz coefficient is also used to rank the model in terms of heterogeneity to select the most representative model. However, the geological models are ranked using fast single-phase/streamline simulations and are devoid of complications caused by adverse mobility or density effects. This creates a disconnect between the heterogeneity measures used to characterize a geological model and those available to characterize a reservoir. Thus, calibrating a geological model to field data is a laborious task.In this paper, we present a workflow that bridges this gap by decoupling the effect of adverse mobility to obtain an approximate measure of heterogeneity that can be cross-checked against the geological realizations to select the most representative model. The workflow developed in this paper is for inverted, seven-spot patterns and is mainly focused on water-wet reservoirs.

Geological model Construction for Yamama Formation at Faihaa Oil Field- South of Iraq

A construction of a 3D geological model of Yamama Formation to explain the distribution of petrophysical properties (shale volume, effective porosity and hydrocarbon saturation) by using Petrel software. Five wells were selected in order to build structural and petrophysical models based on interpretation of well logs and petrophysical properties. Yamama reservoir is divided into four main units (YA, YB, YC, and YD), YA is divided into five secondary reservoir units (YA1, YA2, YA3, YA4, and YA5), YB is divided into two secondary reservoir units (YB1 and YB2), YC is divided into two secondary reservoir units (YC1 and YC2) and YD is divided into three secondary reservoir units (YD1, YD2, and YD3). Structural model showed Faihaa oil field represented by anticlinal fold with double plunging. Petrophysical models (shale volume, effective porosity and hydrocarbon saturation) constructed for each subunit of Yamama reservoir using sequential Gaussian simulation executed with Petrel software. According to data analyzes and the results from modeling, the subunits for both YB and YB are good reservoir units regarding its good petrophysical properties (high effective porosity and high hydrocarbon saturation) and considered as the most important productive units in Yamama Formation

ИССЛЕДОВАНИЕ ВЛИЯНИЯ АНИЗОТРОПИИ ПРОНИЦАЕМОСТИ НА РАЗРАБОТКУ МОДЕЛЬНОГО БЛОКА ТЕРРИГЕННОГО НЕФТЕНАСЫЩЕННОГО КОЛЛЕКТОРА В ХОДЕ ГИДРОДИНАМИЧЕСКИХ РАСЧЁТОВ

Актуальность исследования состоит в существовании проблемы недостаточности информации при сборе и анализе геологических и физико-химических свойств разрабатываемых залежей. В частности, такая проблема касается анизотропии проницаемости, значение которой можно узнать первоначально лишь на основе керновых данных, получаемых в результате бурения с керноотборниками. Зачастую данная операция является затратной для недропользователя. Однако при построении геолого-гидродинамической модели величина анизотропии проницаемости является одной из ключевых характеристик пласта и значительно влияет на его поведение. В цели данной работы входило провести подбор оптимального значения вертикальной анизотропии на основе доступных данных и предложить варианты по улучшению существующей системы разработки в ходе гидродинамических расчётов анизотропной модели. Объектом исследования является одно из нефтяных месторождений Томской области, состоящее из терригенных отложений. Особенностью месторождения является его месторасположение в системе сложных локальных поднятий разного порядка. Основной продуктивный коллектор представлен юрскими отложениями, сформировавшимися в регрессивно-трансгрессивную серию осадконакопления и имеющими сложное распределение фильтрационно-емкостных свойств. Методы: изучение особенностей течения флюидов в пористой среде, измерение и подбор значения вертикальной анизотропии проницаемости, а также проведение гидродинамических вычислений с учётом предлагаемых улучшений системы разработки. В результате исследования удалось узнать, что повышение значения вертикальной анизотропии не всегда приводит к увеличению выработки запасов в зоне работы скважины. Так, при значении вертикальной анизотропии 0,5 величина накопленной добычи нефти составила 1,968 млн м3, в то время как для значения 0,86 эта величина равнялась 1,913. Такой результат связан с геологическими особенностями продуктивного пласта и подчеркивает важность влияния анизотропии проницаемости. Кроме этого, выполнены гидродинамические расчёты на изотропной и анизотропной моделях, позволившие выделить оптимальные варианты оптимизации текущей системы разработки. Коэффициент извлечения нефти для изотропной модели составил 23,4 %, а для анизотропной модели – 22,8 % относительно размера извлекаемых геологических запасов. Таким образом, полученная разница в 0,6 % вновь показывает важность явления анизотропии проницаемости и необходимость как можно бо́льшего количества данных.

Integrated workflow in 3D geological model construction for evaluation of CO2 storage capacity of a fractured basement reservoir in Cuu Long Basin, Vietnam

Carbon dioxide (CO2) capture, utilization, and storage (CCUS) have been proposed as a possible technique to mitigate climate change. In this vein, CO2 storage through enhanced oil recovery (EOR) in depleted hydrocarbon reservoirs is touted as a most effective approach because it synergistically increases oil production and enables permanent sequestration into the reservoirs. However, the construction of a reasonable 3D geological model for this storage reservoir is a major challenge. Thus, this study presents an efficient workflow for constructing an accurate geological model for the evaluation of CO2 storage capacity in a fractured basement reservoir in the Cuu Long Basin, Vietnam. Artificial neural network (ANN) has been used to predict porosity and permeability values through seismic attributes and well log data. The predicted values were selected using high correlation factors with well log data. Subsequently, the Sequential Gaussian Simulation and co-kriging methods were applied to generate a 3D static geological model by using azimuth and dip parameters. Finally, drill stem test matching was performed to validate the accuracy of the porosity and permeability models through dynamic simulation. A validation 3D reservoir model, which integrates geophysical, geological, and engineering data from fractured basement formation in Cuu Long Basin, was further constructed to calculate theoretical CO2 storage capacity. As a result, the calculated storage capacity for the fractured basement reservoir ranged from 7.02 to 99.5 million metric tons. These estimated results demonstrate that fractured basement reservoir has a combined potential for CO2 storage and EOR in the Cuu Long Basin.

Construction of geological model of a shallow super-viscous oil deposit based on core analyses and geophysical monitoring data

Deficiency of fossil minerals, limited reserves of conventional hydrocarbon raw materials indicates the need to involve in the fuel and energy complex of other sources of hydrocarbons. Fields of super-viscous oil are one of the sources. Development of super-viscous oil deposits opens new challenges in the field of building geological models associated with the shallow occurrence of these deposits. This article is devoted to the study of sediments of the Permian sedimentary complex containing super-viscous oil deposits. Study object is Sheshmian sandstone pack of the Ufimian stage. The pack is composed of sands and sandstones with different degree of carbonate cementation with small interlayers of siltstones. Cementation is the main factor which affect reservoir quality. In the process of analysis and preparation of the initial data and, subsequently, the geological model construction, the main features of the super-viscous oil deposits were revealed.

Emprego de krigagem ordinária para estimar a distribuição espacial de litofácies permeáveis: exemplo do Aquíferio Rio Claro em Paulínia/SP

A distribuição de valores de condutividade hidráulica representa uma informação crucial para elaboração de modelos matemáticos de fluxo e transporte de contaminantes, bem como para o planejamento e implantação de sistemas de remediação para remoção de contaminantes em subsuperfície. É prática comum a construção dos campos de condutividade hidráulica de informações discretas, obtidas a partir da construção de modelos geológicos. Contudo, tal abordagem apresenta como limitação a subjetividade na elaboração de tais modelos, uma vez que a adoção de critérios para definição da distribuição de fácies e contatos litológicos envolve algum grau de subjetividade. No presente trabalho é proposta uma abordagem distinta, em que informações geológicas de subsuperfície são convertidas em valores de condutividade hidráulica. Estes valores são empregados como dados de entrada para construção de campos tridimensionais de condutividade hidráulica, utilizando o método geoestatístico Krigagem ordinária. A distribuição dos valores de condutividade hidráulica acima de um ponto de corte indica a geometria e a conectividade das fácies permeáveis. Esta abordagem foi testada no Aquífero Rio Claro, em Paulínia (SP), a partir de dados geológicos de subsuperfície coletados em 255 pontos. Os resultados indicam que os valores elevados de condutividade hidráulica se distribuem ao longo de uma faixa contínua, de direção leste-oeste, e refletem o contexto deposicional do Aquífero Rio Claro na área. A geometria dos corpos arenosos tem importantes implicações para determinação da arquitetura de fácies da Formação Rio Claro no munícipio de Paulínia e, de maneira similar, no comportamento do fluxo de água subterrânea e transporte de contaminantes no aquífero raso local

Geostatistical 3D geological model construction to estimate the capacity of commercial scale injection and storage of CO2 in Jacksonburg-Stringtown oil field, West Virginia, USA

As concerns around global warming increase, carbon capture, utilization and geological storage (CCUS) is a promising way to reduce the emissions of anthropogenic CO2 into the atmosphere. Sequestering the CO2 into depleted hydrocarbon reservoirs with associated enhanced oil recovery (EOR) is the most achievable approach under current economic constraints since it increases recovery of existing oil reserves, and bridges the gap between regional-scale CO2 capture and geologic sequestration. However, one of the challenges is the paucity of modern subsurface data required for adequate reservoir characterization and storage estimates. The Upper Devonian fluvial sandstone reservoirs in the Jacksonburg-Stringtown oil field in West Virginia, which have produced over 22 million barrels of oil since 1895, are ideal candidates for CO2 sequestration coupled with EOR. Reservoir storage capacity and oil recovery factors are keys for the evaluation of coupled CO2 storage and CO2-EOR process. Regression relationships between wireline logs and core measured data for porosity, permeability are constructed by artificial neural network and support vector machine in core-scale; then extended from core-scale to well-scale, where wells do not have porosity and permeability wireline logs; finally a 3D static geological model is generated based on the Random Gaussian Function simulation method and well-established variogram models generated by detailed data analysis. A static 3D reservoir model, which integrates detailed geological knowledge and existing legacy geological data from Jacksonburg-Stringtown oil field, is constructed to estimate theoretical CO2 storage capacity. Depending on the proposed 3D geological model, the best regions for coupled CCUS-EOR are located in southern portions of the field, and the estimated CO2 theoretical storage capacity for Jacksonburg-Stringtown oil field varies from 24 to 383 million metric tons. The estimated results of CO2 sequestration indicate that the Jacksonburg-Stringtown oilfield has significant potential for CO2 storage and value-added EOR.

Utilizing U–Pb CA-TIMS dating to calibrate the Middle to Late Jurassic spore-pollen zonation of the Surat Basin, Australia to the geological time-scale

Wainman, C.C., Hannaford, C., Mantle, D. & McCabe, P.J., April.2018. Utilizing U–Pb CA-TIMS dating to calibrate the Middle to Late Jurassic spore-pollen zonation of the Surat Basin, Australia to the geological time-scale. Alcheringa XX, xx-xx.Spore-pollen palynostratigraphy is commonly used to subdivide and correlate Jurassic continental successions in eastern Australia and thus aid the construction of geological models for the petroleum and coal industries. However, the current spore-pollen framework has only been tenuously calibrated to the geological time-scale. Age determinations are reliant on indirect correlations of ammonite and dinoflagellate assemblages from New Zealand, the North West Shelf of Australia and Southeast Asia to the standard European stages. New uranium-lead chemical abrasion thermal ionization mass spectrometry (U–Pb CA-TIMS) dates from 19 tuff beds in the Middle–Upper Jurassic Injune Creek Group of the Surat Basin enables regional spore-pollen palynostratigraphic zones to be precisely dated for the first time. These results show the base of the APJ4.2 and APJ4.3 subzones are similar in age to previous estimates (Middle Jurassic, Bathonian) from indirect palynostratigraphic correlation. However, the base of the APJ5 Zone and the APJ6.1 Subzone may be somewhat younger than previously estimated, possibly by as much as 2.5 and 4.2 Myrs, respectively. The continued utilization of U–Pb CA-TIMS dates will further refine the absolute ages of these zones, improve the inter- and intra-basinal correlation of Middle–Upper Jurassic strata in eastern Australian basins and greatly enhance intercontinental correlations.Carmine Christopher Wainman [carmine.wainman@adelaide.edu.au] and Peter James McCabe [peter.mccabe@adelaide,edu.au] Australian School of Petroleum, University of Adelaide, SA, 5005, Australia; Carey Hannaford [carey.hannaford@mgpalaeo.com.au] and Daniel Mantle [dan.mantle@mgpalaeo.com.au] MGPalaeo Pty Ltd, 5 Arvida Street, Malaga, WA, 6090, WA, Australia.

Spatial Interpolation Based on ABC-Kriging Algorithm

Kriging interpolation method has a wide range of application in geology and mapping. But the variogram selected and the parameters of the experimental variogram mostly depend on the expertise of geologists, which has a great degree of subjectivity. Introduce the artificial bee colony algorithm (ABC) to optimize the parameters of the Kriging’s variogram, using ABC-Kriging algorithm to experiment with borehole data. The results show that: the Kriging algorithm optimized by artificial bee colony compared with ordinary Kriging algorithm errors were reduced by 35.7%, to overcome the traditional method parameters set subjectivity and make geological model construction with higher precision.

The impact of fine-scale reservoir geometries on streamline flow patterns in submarine lobe deposits using outcrop analogues from the Karoo Basin

Improved prediction of the recovery of oil-in-place in basin-floor fan reservoirs requires accurate characterization and modelling of multiscale heterogeneities. The use of outcrop analogues is a key tool to augment this process by documenting and quantifying sedimentary architecture, hierarchy and sedimentary facies relationships. A 3D geological modelling workflow is presented that tests the impact of fine-scale heterogeneities within basin-floor lobe complexes on reservoir connectivity. Construction of geological models of a basin-floor lobe complex allows realistic depositional architecture and facies distributions to be captured. In addition, detailed models are constructed from channelized areas within a basin-floor lobe complex. Petrophysical modelling and streamline analysis are employed to test the impact on reservoir connectivity between lobe models with: (i) vertically stacked facies with coarsening- and thickening-upwards trends in all locations; and (ii) lateral facies changes with dimensions and distributions constrained from outcrop data. The findings show that differences in facies architecture and, in particular, lobe-on-lobe amalgamation have a significant impact on connectivity and macroscopic sweep efficiency, which influence the production results. Channelized lobe areas are less predictable reservoir targets owing to uncertainties associated with channel-fill heterogeneities. The use of deterministic sedimentary architecture concepts and facies relationships have proven vital in the accurate modelling of reservoir heterogeneities.