Palaeogeographic and Palaeoclimatic evolution of Papua New Guinea: The Role of Palaeo-Earth Systems Models and Palaeo-tidal Models in Modelling and Mapping Potential Carbonate Reservoir Facies
The distribution of carbonate reservoir facies and the lateral variations in carbonate reservoir quality are significant uncertainties for exploration teams. This is particularly true in little explored or frontier basins, such as those surrounding New Guinea, where complex Cenozoic tectonics have produced collision, obduction, deformation and extension in the surrounding basins. Palaeogeographic, palaeo-climatic and palaeo-tidal evolution and temporal variation are major controls on stratigraphy, reservoir distribution, and ultimately resource potential. Accurate prediction of potential carbonate reservoir facies and quality therefore necessitates modelling a range of paleogeographic, palaeo-climatic and palaeo-tidal parameters. In this study these parameters have been derived using deformable Plate Kinematics reconstructions and regional – data led – palaeogeographic, palaeotopographic and palaeobathymetric mapping, followed by palaeo-Earth systems modelling (UK Met Office HadCM3 palaeo-climate model) and palaeo-tidal modelling (Imperial College, UK, ICOM tide model). Together, the outputs of these models were used to develop a new carbonate reservoir facies predictive approach based on the integration of tectonic setting, palaeogeography, palaeotopography and palaeobathymetry, clastic sediment supply (in turn controlled by physiography and climate), sea surface temperature and salinity, oceanic currents, tidal range, tidal bed stress and wave energy. Further controls on carbonate reservoir quality including mineralogy, reef or grain type and biota were also considered in order to build a more comprehensive picture of carbonate reservoir architecture. This predictive approach has been applied for the Middle Miocene of South East Asia, including the regions surrounding New Guinea. In the Gulf of Papua, palaeo-Earth systems model data were supplemented with publicly available gravity and magnetics data, cross sections and known reservoir control point data sets to facilitate predictive mapping of depositional carbonate reservoir facies, revealing unique predictive insights into carbonate depositional facies, texture and reef type. To validate the predictive approach, outputs were tested against the known distribution of lithological or palaeo-climatic indicators. Uncertainty is inherent at each stage of the process described. At a first order, tectonic regime and climate control elevation, but in areas of tectonic complexity and/or where data is limited there remains significant uncertainty over palaeobathymetry and palaeotopography and so alternative models were considered. When combined with an analysis of the other essential play elements, this unique predictive tool can be employed to identify potential new play concepts in any underexplored area.
AAPG Datapages/Search and Discovery Article #90371 © 2020 AAPG Asia Pacific Region, The 1st AAPG/EAGE PNG Geosciences Conference, PNG’s Oil and Gas Industry: Maturing Through Exploration and Production, Port Moresby, Papua New Guinea, February 25-27, 2020