This paper discusses the results of an innovative methodology using Dionisos 4D forward stratigraphic modelling of Middle Eastern carbonate reservoirs on a field scale. Traditional stochastic techniques do not sufficiently capture carbonate reservoir heterogeneities, reducing the accuracy of static and dynamic models. The methodology applied to three Lower Cretaceous UAE reservoirs, uses a deterministic approach that aims to define carbonate heterogeneity and provides a structure to develop a more accurate and usable static and dynamic model for field development. Dionisos uses a predefined sequence stratigraphic scheme as a framework. A reference case model is manually calibrated to environmental parameters, followed by automated multi-realisations that generate several other plausible calibrated models. A sensitivity analysis provides an indication of the influencing environmental parameters controlling facies and texture distribution.The calibrated forward stratigraphic models resulted in the generation of 14 carbonate textures for the three reservoirs using a 200x200 m grid size and a 50 kyrs time step. Carbonate lithology production (mud, fine, coarse, bioconstructions) varies between 0 and 350 m/Ma, wave direction is SW (200 -260°); wave action depth 7-18 m while wave energies vary between 0 and 140 kW/m. Sediment diffusion coefficients by wave transport range from 0.1 (mud) to 0.0008 km 2 /kyr (bioconstructions) while gravity driven transports from 0.1 to 0.001 km 2 /kyr. The lower part of Reservoir A is characterised by low angle TST sequences dominated by algal boundstones-floatstones. Deposition continued with the development of a low relief margin with aggradational to progradational architectures comprising rudist shoals. This defined a topographic split into platform, slope and basin with lateral texture heterogeneities showing a northward deepening trend. The successive clinoform top sets (Seq4a, b) are rich in rudist boundstones-floatstones with lower slope dominated by packstones-wackestones.Reservoir B and C are isopach with strong lateral variability in carbonate texture as evidenced by well data. The overall architecture of the sedimentary systems consists of low relief interconnected algal boundstone-floatstone mounds separated by gentle depressions dominated by fine grained sedimentation. The numerical simulation of these systems was driven by a carbonate production law as a function of the substratum energy and bathymetry under dynamic subsidence/uplift conditions. The innovative workflow applied at field scale allowed the modelling of complex carbonate geometries and associated textures honouring lateral and vertical heterogeneities observed at wells. The application of this workflow as alternative/complement to stochastic methodologies brings further insights on the proposed sequence stratigraphic framework allowing the confidence and predictability of static and dynamic facies models to be increased.

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With the continuous acquisition of worldwide multi-disciplinary datasets, geoscientists face the need for more integration. The combination of diverse expertise and multi-scale datasets has lately been supported by a fast rise in technological advances in data acquisition and processing (e.g., well logs, 3D seismic inversion and characterization) as well as by integrated 4D forward stratigraphic and basin modeling approaches. This work discusses the results of innovative methodologies developed in order to tackle rising challenges linked to the exploration of new hydrocarbon resources. The use of geomorphological, geological and geophysical constraints in process-based forward stratigraphic models shed light on the complex driving mechanisms that influence sediment transport and/or production and deposition along continuously evolving landscapes. The impact of subsidence rates, accommodation, climate evolution, drainage systems as well as eustatic variations on sedimentary bodies geometries and associated facies is investigated in various depositional settings (continental, transitional and marine). Lateral and vertical facies variations are consequently modelled taking into account the diversity of impacting environmental parameters. Coupled with petrophysical analysis as well as seismic inversion and characterization, this approach permits a 3D prediction of lithology, TOC and porosity distributions for the generation of integrated structural, facies and kerogen maps used in basin models in order to simulate the impact the architectural and thermal evolution on source rock burial, maturation, hydrocarbon generation, migration and trapping. These workflows set new grounds for the generation of Play Fairway Maps, Common Risk Maps for the different petroleum systems elements (reservoir, seal, trap and charge) as well as Composite Common Risk Maps permitting to produce innovative ideas and reflections around the exploration and production of hydrocarbon resources.

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