Compact Stacked Contour Applied to Full Field Simulation Lifecycle

Middya, Usuf (Saudi Aramco) | Crumpton, Paul (Saudi Aramco)

OnePetro 

Abstract

The objective is to enable a full simulation lifecycle of multi-billion cell reservoir models for gigantic Middle Eastern reservoirs utilizing parallel hardware. Debugging, building and developing models with this resolution is not possible without seamlessly changing the scale of the reservoir model and applying a portfolio of boundary conditions to fit the current workflow.

Throughout the lifecycle of the full-field reservoir model a variety of simulations are needed, including small, single and multiple well sensitivity studies (O(108) cells), regional models (O(107) cells), and ultimately full-field modeling (O(109) cells). It is crucial this can be achieved in a way to exploit the current hardware, with a minimum memory and computational overhead, and have a quick and seamless way to maintain the integrity of the full-field model, without the need for complex pre- and post-processing tools. This is achieved here by the definition of a compact stacked contour; this is cheap enough to be read by every processor in the current run, and by exploiting advanced parallel IO techniques; only the portion of the full-field grid to be simulated needs be imported to core memory. This definition easily lends itself as a natural way to apply boundary conditions to model aquifers, fluxes derived from larger models, and pressure boundary conditions.

The techniques described here will be demonstrated on a number of workflows. Firstly, in aquifer modelling, to exclude the large number of aquifer cells that often arises from simulating on a geological level model, and replace these cells with an analytical model. An external program takes the area of interest, and using the convex hull of the area of interest generates a stacked contour, which is subsequently used to define a Fetkovich aquifer. Secondly, a pressure boundary condition is applied to an area of interest within a full-field model to mimic the decline.

The definition of a stacked compact contour enables the large reservoir model to be analyzed at local, regional and full-field scale while maintaining the integrity of the full-field model. A variety of boundary conditions are applied to the stacked compact contour.