Page 144 - Primer on Enhanced Oil Recovery

134 Primer on Enhanced Oil Recovery

Figure 11.9 Formation parameters for WAG implementation.

corresponding complicated wellhead equipment is necessary. Reduction of capital
investment can be achieved by applying acceptable technological and technical
solutions. It is necessary to provide the ability to control the injected agents flow
and employ benefits of gravitational effects through optimal well locations and well
operation parameters.

11.3 Implemented projects

In the completed WAG technology projects air, hydrocarbon gas, nitrogen and car-
bon dioxide are used as gas. Since the 1950s to the present, about 100 WAG pro-
jects have been implemented, with the vast majority in the United States, less than
10% of them were unsuccessful. Fig. 11.10 shows the implemented WAG technol-
ogy projects.
As can be seen from the figure, WAG technologies with miscible gas injection
are most effective. The maximum additional oil recovery was obtained at the
Slaughter Estate and Wasson fields where the oil recovery increased by 14.9%.
Fig. 11.11 shows results of WAG applications with hydrocarbons when the
injected agents were delivered to the oil strata by different methods.
It can be seen from the figure that regardless of the method of supplying injected
agents, on average, fairly high additional oil recovery factors (2.5 19%) were
obtained.