Page 221 - Hydrocarbon Exploration and Production Second Edition

208 Reservoir Drive Mechanisms

gas injector
gas injector

oil producers
gas injector
oil producers

OWC
Steep Dip Shallow Dip
Figure 9.5 Location of wells for gas cap drive.

P i
Produced
Produced
GOR
GOR
Oil Rate
Oil Rate

Reservoir
Pressure

R si Water Cut
Water Cut

Time (Years)
First Oil RF = 20 - 50%
Figure 9.6 Characteristic production pro¢le: gas cap drive.

9.2.3. Water drive

Natural water drive occurs when the underlying aquifer is both large (typically greater
than ten times the oil volume) and the water is able to flow into the oil column, that
is it has a communication path and sufficient permeability. If these conditions are satisfied,
then once production from the oil column creates a pressure drop the aquifer