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.com
Volume 8, Issue 4 (Suppl)
J Pet Environ Biotechnol, an open access journal
ISSN: 2157-7463
Oil Gas Expo 2017
July 13-14, 2017
Oil and Gas
July 13-14, 2017 Berlin, Germany
3
rd
International Conference and Expo on
J Pet Environ Biotechnol 2017, 8:4 (Suppl)
DOI: 10.4172/2157-7463-C1-035
Experimental investigation of the extent to which different concentrations of C
3
H
8
, CH
4
and CO
2
affect
CSI performance
Farshid Torabi
and
Arash Ahadi
University of Regina, Canada
C
yclic Solvent Injection (CSI) technique holds great promise as a viable approach to produce heavy oil from thin reservoirs where
thermal and gravity-dominated recovery methods fail to produce oil. CO
2
and C
3
H
8
(due to their high solubility) are the main
solvents that have been used in CSI. However, CO
2
is not always accessible and it causes corrosion problems during implementation.
In addition, low saturation pressure of C
3
H
8
limits the application of pure C
3
H
8
for heavy oil extraction. On the other hand, CH
4
is
widely accessible and has high saturation pressure. In this study, different concentrations of C
3
H
8
in CH
4
stream (i.e., 15, 30, and 50
mole %) are tested. A sandpack model with porosity and permeability of 32.4% and 9.7 d, and a heavy crude oil with viscosity of 6430
mPa.s are used to represent a typical thin heavy oil formation. First, different ratios of C
3
H
8
to CH
4
stream are examined to quantify
the optimum solvent concentration. Second, CO
2
is introduced to the optimum CH
4
-C
3
H
8
concentration to investigate the extent to
which CSI behavior changes by partially replacement of CH
4
with CO
2
. Results show that ultimate recovery factor (RF) increases from
24.3% to 33.4% original oil in place (OOIP) when C
3
H
8
concentration increases from 15 to 50 mole% in the CH
4
stream. CSI tests
with higher C
3
H
8
concentration reaches the maximum cyclic recovery with lower number of injection cycles due to higher solubility
of C
3
H
8
compared with CH
4
. Solvent utilization factor (SUF) data also confirms this as lesser volume of solvent with higher C
3
H
8
concentration is required to produce oil. Virtual observations also shows that the foamy oil produced during the process lasts longer
with higher concentration of C
3
H
8
(2 min for 85% CH4-15% C3H8 case and 180 min for 50% CH
4
-50% C
3
H
8
case). Upon addition of
CO
2
to the mixture, the oil production is slightly improved as the ultimate RF increases to 35.9% OOIP. The produced foamy oil also
lasts for 197 min for 50% C
3
H
8
-35% CH
4
-15% CO
2
case. In general and for all cases, the solvent oil ratio (SOR) increases with cycle
numbers, specifically during the last two cycles, highlighting that large portion of the injected solvent is produced instead of diffusing
into the oil phase.
farshid.torabi@uregina.ca