This study enabled us to highlight the various difficulties encountered at the time of the setting in production of heavy oil fields. Their very high viscosity returns the primary depletion impossible, and led to advanced techniques of recovery, while minimizing the technical costs.
The first studied process, the vapor injection so as to reduce the oil viscosity, and to enable it to flow down in the content of the reservoir, showed its effectiveness on simple configurations. The rates of recovery can be relatively important (60% - 80%), but at the price of a high steam requirement,  which need to be heated as a preliminary, therefore source of greenhouse effect gas.

In the second time, we thus compared the process considering the vapor alone with a mix including a light hydrocarbon solvent. The results on heterogeneous fields showed that a cocktail of 75% vapor and 25% solvent allowed a recovery quasi equivalent to the case of pure vapor, but with a saving made on the heating of the very substantial vapor (10m3 of water by day on our case)

Lastly, we tested various solvents, under the same conditions of injection, which led us to show that the hexane injection made it possible to increase the production appreciably (almost doubly compared to the couple vapor/methane). That can be explained by the interesting characteristics of hexane under the reservoir conditions.




For our two months project, we were supported by Arjan Kamp, who works as a chief of staff in a Total research lab, in Pau (Fr), and by Hussein Faddaei, PhD student at IMFT, Toulouse, and former ENSPM graduate. They both were very helpful during our project, as available as possible, and helped us a lot in the progress of our work.



[1] Enhanced oil Recovery – Larry W. Lake

[2] Four Day SAGD modelling – F. Skoreyko – version 2007.10 - CMG

[3] Optimisation of SAGD processes by injection of light/heavy hydrocarbons – Gilles Darche - Total

[4] New hybrid Steam-Solvent processes for the recovery of heavy oil and bitumen – T.N. Nasr, O.R. Ayodele – SPE 101717