Page 80 - Primer on Enhanced Oil Recovery
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Thermal EOR 71
Figure 8.4 Steam generator unit.
Figure 8.5 Utilization of downhole steam generator.
The second method involved utilization of downhole steam generator. As can be
seen on the Fig. 8.5 an oil burner is inserted into the well while fuel, air and water
are pumped from the surface. All three essential components for steam generation
are injected at high pressure. Almost all steam produced keeps the thermal energy
while reaching the oil bearing strata. Additional benefit is produced by carbon diox-
ide and nitrogen. The carbon dioxide is produced by the oil burning; the nitrogen is
just leftovers from the air after all oxygen is consumed in burning process. All burn-
ing products are injected into the oil formation and do not damage the environment.
During cyclic steam injection (see Fig. 8.6) the process is divided onto three
stages. During the first stage steam is injected into a well. This stage can last up to
