Page 27 - Introduction to Petroleum Engineering

PETROLEUM ECONOMICS 11
and vertical sweep efficiency is defined as
sweptnet thickness
E V (1.10)
totalnet thickness
Recovery efficiency RE is the product of displacement efficiency and volumetric
sweep efficiency:
RE E D E Vol E D E A E V (1.11)

Displacement efficiency, areal sweep efficiency, vertical sweep efficiency, and
recovery efficiency are fractions that vary from 0 to 1. Each of the efficiencies that
contribute to recovery efficiency can be relatively large and still yield a recovery
efficiency that is relatively small. Reservoir management often focuses on finding the
efficiency factor that can be improved by the application of technology.

Example 1.5 Recovery Efficiency
Calculate volumetric sweep efficiency E and recovery efficiency RE from
Vol
the following data:

S oi 0.75
S oa 0.30
Area swept 750 acres
Total area 1000 acres
Thickness swept 10 ft
Total thickness 15 ft
Neglect FVF effects since B ≈ B
oi oa
Answer
/
SB S /B S S
Displacementefficiency: E oi oi oa oa oi o oa 06
.
D
/
SB oi S oi
oi
sweptarea
Areal sweep efficiency: E . 075
A
totalarea
sweptnet thickness
Vertical sweep efficiency: E 0 667
.
V
totalnet thickneess
Volumetric sweep efficiency: E E E . 05
vol A V
Recovery efficiency: RE E E . 03
D Vol
1.4 PETROLEUM ECONOMICS

The decision to develop a petroleum reservoir is a business decision that requires an
analysis of project economics. A prediction of cash flow from a project is obtained
by combining a prediction of fluid production volume with a forecast of fluid price.