Abstract
The presence of homogeneous porous media allows a uniform sweep during a waterflooding process, but it is very rare to find homogeneous reservoirs. The typical heterogeneous character of most formations causes an uneven production from different permeability sands in the reservoir. The preferential movement of the injected water to zones with less resistance to flow causes earlier water breakthrough time than if the formation was homogeneous. This phenomenon will exacerbate at offshore reservoirs and the wells with water production potential. To suggest a solution to this problem, the use of emulsions as a mobility control and selective plugging agent has been studied here. Three different W/O emulsion formulations were injected into high-permeable heavy oil saturated waterflooded sandpacks and the one with the best recovery factor was injected to sandpacks with different permeabilities. The change in oil recovery pattern is considered as the main aim of this work. Experiment results revealed that invert W/O emulsions with high viscosities could act as a selective plugging agent and help the displacement process.
NOMENCLATURE
Nc | = | Capillary number |
M | = | Mobility ratio |
η | = | Displacing phase viscosity, Pa.sec |
ν | = | Displacing phase velocity, m/s |
σ | = | Interfacial tension, N/s |
D | = | Mobility of the displacing phase at the back of the displacement front |
O | = | Mobility of the displaced phase in front of the displacement front |
hp | = | Horsepower |
OOIP | = | Original oil in place |
RPM | = | Revolutions per minute |
RRF | = | Residual resistance factor |
ΔP | = | Pressure difference |
Q | = | Injection rate |
K | = | Permeability |
bt | = | Before treatment |
at | = | After treatment |