Page 90 - Primer on Enhanced Oil Recovery

Thermal EOR 81

Figure 8.13 Deep gas-air heater.

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process it is necessary to pump between 20 and 250 thousand m of air per day.
The air pressure should be in the region from 20 to 90 atm. The choice of compres-
sor is carried out on the basis of the calculation of the required air volume and
injection pressure. There are three types of compressors used: piston, centrifugal
and axial types. Axial compressors are selected when the need for high air volume
flow is required, while in case of a need to increase the outlet pressure, centrifugal
compressors are installed.
The mouth of the ignition well is prepared as shown on Fig. 8.14 for the case of
the downhole ignitor. In the case of ignition of reservoir oil with a submerged fired
heater, the mouth of the ignition well is arranged as shown on Fig. 8.15. As can be
seen that the implementation of the process of in situ combustion does not require
too special wellhead reconstruction.