Rm. Butler et Ij. Mokrys, CLOSED-LOOP EXTRACTION METHOD FOR THE RECOVERY OF HEAVY OILS AND BITUMENS UNDERLAIN BY AQUIFERS - THE VAPEX, Journal of Canadian Petroleum Technology, 37(4), 1998, pp. 41-50
Citations number
6
Categorie Soggetti
Energy & Fuels","Engineering, Chemical","Engineering, Petroleum
In previous papers((1,2,3)) the authors described the results of injec
ting saturated ethane or propane vapours into a scaled two-dimensional
model to recover heavy oils and bitumen at or slightly above the rese
rvoir temperature. The results were encouraging; Although the scaled o
il production rates were lower than those obtained with SAGD((4)), the
y showed that it may be possible to recover heavy oils and bitumens ec
onomically using this method in conjunction with long horizontal wells
. Apart from the low heat requirement inherent in the use of satu rate
d propane, additional advantages derived from vapex are a partial in S
itu deasphalting and a reduction in the content of heavy metals. The r
esulting oil can be lighter, of a higher quality and better suited for
a direct refining. In this paper these ideas are expanded further: a
development of a closed-loop extraction is described and a technique f
or spreading the hydrocarbon vapour underneath the oil bearing payzone
is proposed to simulate the performance of a planar well Using this c
oncept the vapour-oil contact is greatly increased and improved produc
tion rates are obtained. The paper discusses scaled physical model res
ults for Peace River bitumen and Lloydminster heavy oil. The mechanism
involved is believed to be similar to that which was described earlie
r on rising fingers of liquid solvent((5)). Experiments are presented
that show that the rate of mobilization is a function of the areal dis
tribution of the solvent vapour. The results demonstrate that oil prod
uction rates exceed those of the SAGD in spite of the fact that no ext
raneous heat is injected into the reservoir. This strategy may permit
the economic production of marginal heavy oil and bitumen reservoirs.