Behaviour of gravity drainage in heavy oil fractured reservoirs under steam injection
- Univ. of Alberta, Edmonton (Canada)
Interest in understanding thermal processes in fractured reservoirs containing heavy oil has grown considerably because of encouraging results of experimental and theoretical studies as well as pilot tests. However, the published literature lack consistency in identifying the major mechanisms involved in the processes. In this paper the fracture-matrix heat transfer accompanied by gravity drainage is investigated. This is accomplished first by interpreting the results of a previous experimental study, where heat transfer was governed by convective effects. Next, scaling techniques and analytical methods are used to investigate the behaviour of a typical matrix block in a fractured reservoir. By comparing the characteristic time for heat and fluid flow mechanisms it is found that for field conditions heating of a single block under gravity drainage is governed by conduction. This permits resolving the contradictory results of the previous experimental and theoretical studies, and interpreting the dual behaviour of thermal gravity drainage under different conditions. It is also found that thermal gravity drainage is a slow process for recovery of heavy oil from fractured reservoirs with low matrix permeability. Finally, the criterion is given for design and performance of physical models used for investigating the behaviour of gravity drainage in fractured heavy oil reservoirs under steam injection.
- OSTI ID:
- 269585
- Report Number(s):
- CONF-9502114--Vol.1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Gas gravity drainage in fractured reservoirs through new dual-continuum approach
Improvement of gravity drainage by steam injection into a fractured reservoir; An analytical evaluation