Abstract
Advances in computing technology have allowed the development of sophisticated 3D cellular modelling and visualisation software which has found a variety of applications in the oil industry. This includes spatial attribute modelling and the visualisation of hydrocarbon reservoirs to improve the understanding of the geological structure including internal features, the distribution of formation properties and the movement of fluids once field production begins.
This paper discusses experiences gained in building a geological 3D model of the West Flank of the Alwyn North reservoir and the subsequent manipulation and transfer of this data into a 3D reservoir simulator for initialisation. The techniques used differ considerably from the traditional method using 2D surface mapping packages. The advantages of both geoscientist and reservoir engineer being able to see and review the 3D image of the reservoir at an early stage in the project is discussed. The paper covers the modelling of the reservoir's complex heterogeneities, the handling of both vertical and sloping fault surfaces, deviated wells and the contrasts in the number of cells of the geological model compared with the number of blocks in the reservoir simulation model. Procedures for up-scaling from geological to reservoir model are discussed along with the errors introduced in the transfer of data and subsequent re-sampling by different software packages.
The paper concludes with suggestions for future developments of software to further enhance this effective method of modelling.
