Page 170 - Fundamentals of Enhanced Oil and Gas Recovery

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to surface upgrading. However, other thermal recovery processes including SAGD,
steam flooding, CSS, and ISC need upgrading at the surface.
One drawback for processes containing catalyst is its deactivation as a result of
coke, heavy metals, and asphaltene deposition in catalyst pores. To study the mecha-
nism of catalyst fouling in oil well, a fixed bed microreactor was applied. The main
issues regarding this process include
• Produces oils with commercial grade which is suitable for refinery applications.
• Increases the global need of the energy.
• Decreases the volume of light oil in reservoirs along with increasing its
temperature.
• Increases in the recovery of heavy oil and bitumen sources which are managed to
be exploited. The number of reservoirs which is forecasted for heavy oil and bitu-
men is eight trillion which could be applied as a source of energy in the future.
This process starts with combustion of a portion of oil in the reservoir by reacting
the injected oil with heavy oil. This process is accompanied by creating high tempera-
ture oxidation (HTO) [39]. As depicted in Fig. 5.6, this process starts at toe position
and there is a continuous front which propagates to the production well’s heel [41].
The mobilization of heavy oil at the advance of the front is due to the gravity into
producer well. Application of the catalyst in this integrated process leads to conversion
of the products to the light oil in horizontal well and elimination of the upgrading
process at the surface. This idea was first accomplished by cooperation of Petroleum
Recovery Institute, Calgary and University of Bath Improved Oil Recovery group.
They equipped the existing system with active layer of catalyst which is placed in slot-
ted liners of the production well [42,43].

Figure 5.6 Schematic representation of the THAI CAPRI process [40]. THAI, toe-to-heel air
injection.