A New Simulation Grid Type is Demonstrated for the Giant Troll Oil and Gas Field

Abstract

A new type of grid used in the dynamic simulation model of the giant Troll Field is presented. The grid consists of a stratigraphic and a horizontal layered part. Hence, it is named hybrid grid. The horizontal part encompasses the thin oil zone and a small distance into the gas cap and water zone, the rest of the grid follows the stratigraphy. The reason for choosing such a grid for the Troll Field is the dipping stratigraphic layering, a thin oil column, and the large area that the field covers.Another factor is the long horizontal wells that drain the oil. The horizontal grid has a high vertical resolution of 2 m to accurately capture the thin oil column, and for satisfactorily representing horizontal wells close to the fluid contacts. Above and below the horizontal grid the layers follow the stratigraphy to represent the geology with a minimum number of grid blocks. The paper shows why the hybrid grid is superior compared to other grid types for a gas field with a thin oil column, and covering a large area. The paper also describes how to build a hybrid grid, and the work processes for up-scaling and history matching the model. The new Troll model has currently replaced the 15 simulation models that previously were used to represent dynamically the Troll Field.

Three-dimensional modeling of clinoforms in shallow-marine reservoirs: Part 1. Concepts and application

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Closed-Loop Feedback Control for Production Optimization of Intelligent Wells Under Uncertainty

“…The total oil column thickness is 15m. We adopted a 'hybrid' gridding approach, consistent with previous studies, to capture the vertical movement of the initial horizontal gas-oil and oil-water interfaces towards the horizontal production well, whilst still honoring the morphology of geologic features (Vinje et al 2011;Pettersen 2012). In the gas cap and aquifer, the vertical layering is stratigraphic, conforming to the surfaces which delimit parasequence and facies boundaries, with a single layer for each M-and C-sand (Figures 3.3).…”

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