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Final Exam Key
PGE 331
Fundamentals of Reservoir Engineering
Open book, notes.
Read each problem carefully and show all work.
1. Definitions
(2 points each)
In your own words define the following:
a.
Grid block
A finite region of space over which material balances are written in reservoir simulation.
b.
Saturation pressure
The pressure at which another phase appears
c.
Explicit
Explicit means in plain sight.
In simulation it is a sequential (marching) procedure in
which pressures at one time level are calculated directly from another, without matrix
inversion.
d.
Well model
An equation describing the relationship between a well rate and the pressure drawdown
(cell pressurewell pressure) in a numerical simulator.
e.
Solution gas drive
A mechanism of primary production wherein the reservoir pressure is partially supported
by gas evolution from solution.
f.
Constraint
A recurrent quantity specified as input to a numerical simulation, usually as an upper or
lower limit.
g.
Stabilized flow
A flow condition where all the pressures in a reservoir decrease at the same rate,
The rate
of decrease may be zero.
2.
Depletion Schematics.
There is no calculation required in this problem.
I expect
your curves to be internally consistent and to be correct with respect to the points we
have covered in class and in the text.
1
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View Full Document The figures on the next pages show the depletion history (dotted lines) of a singlelayer
reservoir being drained by a two wells in primary recovery.
Both wells have the same
bottom hole flowing pressure and the same productivity index.
At the times indicated
below, one of the wells is shut in.
Sketch (no calculation required) the curves (use solid
lines) for the reservoir rate, the bottom hole flowing pressure in the remaining well, the
average pressure, and the cumulative production after shut it.
a.
(10 points)
The second well is closed in the constant rate period when the flow is
stabilized.
Grading:
2 pts. start of stabilized flow
4 pts.
doubling of drawdown
2 pts. decrease of plateau length
2 pts. consistency of diagram
b.
(10 points)
The second well is closed at the exact onset of the twowell depletion
period.
Grading:
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This note was uploaded on 02/13/2012 for the course PGE 323K taught by Professor Lake during the Spring '08 term at University of Texas at Austin.
 Spring '08
 Lake

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