Journal of Canadian Petroleum Technology, Vol.49, No.7, 47-59, 2010
Simulation Analysis of the Effects of Fractures' Geometrical Properties on the Performance of Vapour Extraction Process
Vapour extraction (VAPEX), a newly developed heavy oil recovery (HOR) method, has been extensively studied, both theoretically and experimentally, in conventional sandstone models. However, the applicability of this process to naturally fractured reservoirs has not yet been addressed. The objective of this work is to evaluate the effects of fractures' geometrical properties, such as orientation, length of extension, discontinuity in both the upper well region (UWR) and the far well region (FWR) and vertical fracture location on VAPEX performance. Additionally, the effects of horizontal and vertical fracture dispersion in various density, dispersion scheme and networking on the performance of the VAPEX process are assessed. A fracture's discontinuity effect has also been scrutinized in the presence of parallel-piped networked fractures, which confirmed the results in the case of either horizontal or vertical fracture systems. It was found that the VAPEX process enhances performance in the case of longer vertical fractures, lower horizontal fracture dispersion, shorter horizontal fracture extension and lower vertical fracture discontinuity. Vertical fracture dispersion scheme also affects performance. The ultimate oil recovery, in the case of networked fractures, will be higher than the conventional model if the horizontal fractures have poor connectivity to each other.