Exploration Insights September 2020 - Page 24

Exploration Insights | 13


We have updated 24 of the 52 time slices currently available , and added two new ones in the Cretaceous . These new time slices are also delivered unreconstructed to present-day geography , in order to integrate source‐to‐sink in your workflows .
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The hydrocarbon potential of the Late Cretaceous , post-rift stratigraphy on the Equatorial and South Atlantic Margins of Brazil is often overlooked , because discoveries to date are focused in syn-rift , pre-salt plays . To assess the temporal and spatial variation of Late Cretaceous coarse-grained siliciclastic rocks along the South American margin , we employed Neftex ® understanding of Cretaceous paleoclimate and paleodrainage .
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INVESTIGATING THE VENUS PROSPECT THROUGH 1D BASIN MODELING The highly anticipated drilling of the Venus Prospect offshore Namibia is due to start in Q3 of 2020 . However , in such a frontier area , what are the chances of success ?
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Exploration Handbook | 25 By: Andrew Davies WHAT ARE PALEOCLIMATE MODELS? Climate models are 4-dimensional computer simulators capable of reproducing the Earth system, including the atmosphere (e.g. wind strength), hydrosphere (e.g. ocean currents), biosphere (e.g. land plant productivity), cryosphere (e.g. sea ice concentration), and lithosphere (e.g. soils) (Figure 1). They do this by identifying and solving equations that describe the basic physical laws that govern how the Earth system behaves. The resulting climate simulations have a high degree of reliability and accuracy (Figure 2). Climate models were originally developed to predict the weather and the impact of future climate change, but they can also be used to simulate past conditions. In this context, they are known as paleoclimate models, even though the underlying climate simulator is the same. Paleoclimate models have revolutionized our understanding of the Earth system (Haywood et al., 2019). When applied to exploration, they allow us to use a robust, physics-based approach to test our conceptual exploration models (e.g. Barron, 1985). This is because climate has a strong influence on sedimentary systems and, in turn, many aspects of petroleum systems. The information paleoclimate models provide can, therefore, be used to predict whether source rocks, reservoirs, and seals are likely to have been deposited at a given location and time. As an example, consider oolitic limestones; these comprise some of the world’s most important reservoirs and only form in shallow, tropical waters where clastic input is limited. Paleoclimate models can tell us where these conditions occurred back through geological time (e.g. Davies et al., 2019; Michel et al., 2019) (Figure 3). To generate a climate simulation, climate models need to be given a set of input data, also known as boundary conditions. The most important are the bathymetry of the seas and oceans, the topography of the land, and the position of the coastline. Climate models also require information on the location of major lakes, the routes of major river systems, the concentration of CO 2 in the atmosphere, and the level of incoming solar radiation (Figure 1). For paleoclimate studies, the generation of reliable boundary conditions requires significant effort, involving the compilation and interpretation of large sets of diverse data to develop a plate tectonic model, paleogeographic maps, and paleo digital elevation models. Luckily, this is what Neftex ® has been undertaking for the past two decades! Shortwave radiation There are many different types of climate models. The simplest models are only able to simulate a single aspect of the climate system. For example, atmospheric general Longwave radiation Definitions Paleoclimate simulations are the outputs of climate models. Observed Versus Simulated Mean Annual Sea Surface Temperature Atmosphere Above> An example paleoclimate simulation — as shown under the tear. These can be used to better understand exploration potential. Paleoclimate models are numerical simulators capable of reproducing the climate. PALEOCLIMATE MODELING CONCEPTS 35 30 25 Sea Ice e h e S n tio eta g Ve et Ic Soil Paleoclimate Models in Exploration R 2 = 0.9847 20 15 10 5 Heat & Gas Exchange © 2020 Halliburton 0 Ocean -5 0 -5 Lithosphere © 20 20 n to ur llib Ha Figure 1> Diagrammatic representation of a fully coupled atmosphere and ocean general circulation model. Modified from Dippe et al., 2018. 5 10 15 20 25 30 35 Observed SST (°C) Figure 2> Comparison between observed sea surface temperatures (SST) in the modern ocean and those simulated by the climate model HadCM3. Although there are discrepancies, overall, the model is doing an excellent job of reproducing the ocean temperature. (n=41088). Boundary conditions are the inputs prescribed by the modeler. Examples include bathymetry, elevation, incoming solar radiation, and composition of the atmosphere. 24 | Halliburton Landmark