An integrated approach to define new plays in mature oil basins: the example from the Middle Magdalena Valley basin (Colombia)

An integrated approach to detect new areas of potential interest associated with stratigraphic traps in mature basins is presented. The study was carried out in the Middle Magdalena Valley basin, Colombia. The workflow integrates outcrop and subsurface interpretationsoffacies,activityoffaults,anddistributionofdepocenters and paleocurrents and makes use of them to construct a threedimensionalexploration-scalegeocellularfaciesmodelofthebasin. The outcrop and well log sedimentological analysis distinguished faciesassociationsofalluvialfan,overbank, floodplain,andchannel fill,thelastoneconstitutingthereservoirrock.Theseismicanalysis showedthattectonicactivitywas coevalwiththedepositionofthe productive units in the basin and that the activity ended earlier (before the middle Miocene) along the western margin than along the eastern margin. Paleogeographic reconstructions depict transverse and longitudinal fluvial systems, alluvial fans adjacent to the activebasinmargins,and floodplainfaciesdominatingthestructural highs and the southwestern depositional limit. These reconstructions provided statistical data (lateral variograms) to construct the model. The exploration-scale facies model depicts the complete structureofthebasininthreedimensionsandthegrossdistribution of the reservoir and seal rocks. The predictive capability of the model was evaluated positively, and the model was employed to detect zones of high channel fill facies probability that form bodies that are isolated or that terminate upward in pinchouts or are truncated bya fault. Our approach canprovehelpfulinimproving general exploration workflows in similar settings

Influence and reactivation of pre-existing rift faults during the development of an overlying fault network, northern Browse Basin, NW Australia

Focusing on multiple events and interaction of different fault networks with the time being common in extensional settings such as passive margins and continental rifts. This study aims to better understand the interaction in normal fault networks and the influence of pre-existing structures on fault network growth and development. This is done by interpretation on 3-D reflection seismic volumes in the northern Caswell Sub-basin in the Browse Basin offshore the Australian NW Shelf. The focus is towards structural analysis of geometries, throw, spatial heterogeneity, characterise and analyse interactions and the influence of reactivation on underlying major rift faults. The normal fault network comprise Paleozoic-Mesozoic underlying ENE-trending rift faults setting up series of horsts and grabens. Above the rift-structures, is the ENE- to E-trending Neogene faults mostly spatially arranged as conjugated fault sets in en-echelon arrays. The spatial heterogeneity analysis and throw distribution show areas of distributed faulting with several faults and low throws, and areas of more localised faulting with fewer faults and greater throws. The high throws at Neogene faults match spatially with high throws at the rift faults, often at segments with geometric connection between the two fault populations. Interpretation of time-thickness maps show greatest amount of syn-rift activity in Permian and Triassic and lesser activity in Jurassic and Early Cretaceous, although basin sag is the main mechanism for thickening in Early Cretaceous. Extensional stress imposed in Miocene with similar orientation to pre-existing faults, cause nucleation of Neogene faults that dip-propagate simultaneously as pre-existing faults reactivate. Rotational splays created through the Cretaceous succession, connect the two fault populations by geometric linkage. These fault planes possess a throw minimum at the point of linkage close to the Turonian horizon, which might increase in throw with time as faults reach further equilibration stages. This study generally highlight the importance of pre-existing structures within a multiphase extension fault network, as these function as preferred nucleation sites and control strain distribution within the later developed Neogene fault population. Both through kinematic influence with soft-linkage and geometric control with hard-linkage developed by reactivation. This has implications for the regional geology and exploration, as connected faulting and reactivation might be more extensive than previously thought. This can ultimately cause effects for trap integrity and hydrocarbon migration.Masteroppgave i geovitenskapGEOV39

The AFIT ENgineer, Volume 2, Issue 4

In this issue: AFMC Spark Tank Semi-finalist New AFIT Patents 2020 Graduate School Award Winners Airmen and Artificial Intelligence Nuclear Treaty Monitorin

The AFIT ENgineer, Volume 2, Issue 4

In this issue: AFMC Spark Tank Semi-finalist New AFIT Patents 2020 Graduate School Award Winners Airmen and Artificial Intelligence Nuclear Treaty Monitorin

Development of CAVLAB—A Control-Oriented MATLAB Based Simulator for an Underground Coal Gasification Process

The Cavity Simulation Model (CAVSIM) is a 3D, parameterisable simulator of the Underground Coal Gasification Process (UCG) that serves as a benchmark for UCG prediction. Despite yielding accurate outputs, CAVSIM has some limitations, which chiefly include inadequate graphical capabilities to visualise cavity geometry and gas production, time-ineffectiveness in terms of parametrisation, i.e., it involves editing, compiling multiple files and checking for errors, and lack of tools to synthesise a controller. Therefore, to compensate for these shortcomings, the services of third-party software, such as MATLAB, must be procured. CAVSIM was integrated with MATLAB to utilise its functionalities and toolboxes such as System Identification, Neural Network, and Optimization Toolbox etc. The integration was accomplished by designing C-mex files, and furthermore, the simulation results in both environments exhibit the same behaviour, demonstrating successful integration. Consequently, CAVSIM has also acquired a controllable structure, wherein parametrisation is now a single-click process; this is demonstrated by a case study outlining the implementation of Model Predictive Control (MPC) on a UCG plant. Moreover, the performance metrics, i.e., Mean Average Error (MAE) and Root Mean Square Error (RMSE) of 0.13, 0.23 for syngas heating value, and 0.012, 0.02 for flowrate quantitatively establishes the efficacy of CAVLAB in designing MPC for the UCG system. The novelty of this work lies in making the software package open-source with the aim of streamlining the research of multiple aspects of the UCG process

Influences on continental margin development: a case study from the Santos Basin, South-eastern Brazil

South Atlantic margins display significant variation in structural style along their length. An understanding of factors that influence this variation in structural style is a key component in any understanding of the evolution of the South Atlantic. The Santos basin is an obliquely rifted basin located offshore SE Brazil. Structures in the basin are thought to have been influenced by the reactivation of basement structures and/or fabrics during the onset of the Gondwana breakup. The onshore region adjacent to the Santos Basin offers the chance to test whether basement structures have played a significant role in influencing the initiation and development of syn-rift faults, dykes and fractures. Field and remote sensing studies of the onshore region and on the conjugate margin in Africa show the strong geometric and temporal link between major 135Ma dyke swarms and the development of faults and fractures. 3 structural domains are defined, and correlated with lineament domains from the African margin. Faults, dykes and fractures within the lineament domains in SE Brazil share consistent orientations as large scale morphotectonic lineaments. Brittle structures show orientations and kinematics that are consistent with regional E-W oriented transtension. Little evidence of basement influence can be seen at outcrop scale, although it is speculated that larger scale structures may be reactivated. Faults in the offshore basin share similar geometries to brittle structures onshore. As rifting progressed, and dyke intrusion ceased, NNE-SSW trending structures to the north of the basin ceased to be active, while N-S trending extensional faults continued to deform. N-S trending faults and fractures are also observed to cut dykes in the onshore region. The importance of understanding onshore geology when interpreting offshore basins is highlighted in this study, as is the need to integrate diverse datasets when trying to understand the complex influences on margin development