Publications

Subsurface modeling requirements have changed significantly over recent years: higher oil prices have made exploration and development of more complex reservoirs feasible, and substantially more data is available for predicting and monitoring performance. It becomes an opportunity but also a challenge to integrate this data in more accurate subsurface models for better decision-making. We have analyzed the genuine requirements of geological and dynamic modelling, covering also integration loops with geophysical (4D) data and geomechanical responses to changes in the reservoir. While pillar gridding has been the standard for 3D reservoir modelling in recent years, its features do not map very well onto the evolving tasks of integrated reservoir management with oil and gas assets. Alternative 3Dgridding methods have been developed lately, among which the faulted s-grid of JewelSuite, which shows a better match with critical conditions. Accurate full-field modelling can only be done with grid types that are insensitive to fault directions. Infill drilling with smallish targets requires 3dgrid models with a high geometrical fidelity. Integration of data from different sources means dealing with measurements at different scales. Fully consistent property models can only be built with 3Dgrid types that support scaleindependent geometry handling. Integration of reservoir models with geophysical and geomechanical models is only properly possible if faults are not represented in a stairstepped fashion. Gravity-driven processes can only be simulated accurately in grid types based on vertical cell stacks. With such varied and often conflicting requirements there is no single grid type that optimally addresses all cases. We hope that the information provided in this presentation will assist operators to analyze current and future requirements of their specific asset portfolio to select a 3Dgrid type that optimally supports decisions on their structurally complex subsurface assets for the years to come.