Improving Simulation Accuracy by Seamlessly Linking Static and Dynamic Models Through a Single High-Resolution Grid System

Riou, Jeremy (Baker Hughes, a GE company) | Ganzo, Alejandro (Baker Hughes, a GE company) | Gilmour, Douglas (Baker Hughes, a GE company) | Arief Wibowo, Bagus (Baker Hughes, a GE company)

OnePetro 

Abstract

One major challenge with the current subsurface modeling workflows is the difficulty to transfer the high complexity of static geological models to simulation. This paper describes an improved gridding technology that overcomes the shortcomings of existing corner-point stair-step and pillar-based grids in capturing the complex geological features of hydrocarbon reservoirs. It also highlights the seamless use of this new gridding technology in flow simulation.

The reservoir's geologic features are initially interpreted as 3D surfaces that are later connected to form structural models. The volume between these surfaces is then discretized into a grid object in order to represent the petrophysical, fluid, and flow properties. This paper introduces a new orthogonal, semi-structured gridding algorithm that uses a truncated cell approach to precisely capture the geometry of faults and unconformities.

After reviewing the different types of grids commonly used in geological modeling, the benefits of the new approach will be detailed, while highlighting its compatibility with commercial flow simulators.

Common modeling practices that use corner-point stair-step and pillar-based grids fail to preserve the geometry of most geological objects. This is especially true in highly faulted and erosional environments. The new gridding algorithm presented in this paper addresses three major shortcomings of the current approaches by providing an efficient way to:

Accurately represent any type of geological structures in a 3D grid. The appeal of the technique is its simplicity. The gridding algorithm relies on three components only: a surface-based structural model, a stratigraphic model and a 3D cell resolution.

Capture complex sedimentological geometries across geological structures. Several examples are provided to highlight the way the orthogonal, semi-structured grid handles geostatistical simulations.

Connect the grid to commercial flow simulators to preserves any type of structure and sedimentology in dynamic simulations.

This is the first high-accuracy gridding system that is designed to be simulator agnostic. This means that the approach is open and flexible enough to be used by any commercial flow simulators, giving simulation engineers a unique opportunity to run models without the need for any explicit grid system conversion.