Muddy interlayer forecasting and an equivalent upscaling method based on tortuous paths: A case study of Mackay River oil sand reservoirs in Canada

Abstract

Based on the abundant core data of oil sands in the Mackay river in Canada, the termination frequency of muddy interlayers was counted to predict the extension range of interlayers using a queuing theory model, and then the quantitative relationship between the thickness and extension length of muddy interlayer was established. An equivalent upscaling method of geologic model based on tortuous paths under the effects of muddy interlayer has been proposed. Single muddy interlayers in each coarse grid are tracked and identified, and the average length, width and proportion of muddy interlayer in each coarse grid are determined by using the geological connectivity tracing algorithm. The average fluid flow length of tortuous path under the influence of muddy interlayer is calculated. Based on the Darcy formula, the formula calculating average permeability in the coarsened grid is deduced to work out the permeability of equivalent coarsened grid. The comparison of coarsening results of the oil sand reservoir of Mackay River with actual development indexes shows that the equivalent upscaling method of muddy interlayer by tortuous path calculation can reflect the blocking effect of muddy interlayer very well, and better reflect the effects of geological condition on production.

Keywords

• oil sands
• muddy interlayer
• distribution prediction
• geological model
• tortuous path
• equivalent upscaling