CPE 627
Petroleum Production Engineering
Practice Exam I
1. A well (E-1) has been tested at 400 STB/D with a bottomhole pressure
of 3000 psia. The bubble point pressure was estimated by correlation
to be 4000 psia. The static pressure was 3800 psia.
(Assuming the Vogel Relationship to hold):
a) find the maximum rate for this well.
b) plot the IPR.
2. Most of the wells in this field are found to be outproducing this well. A
buildup test is performed to assess the cause of the poor performance.
The test indicated a positive "skin" of 12 and the following data:
μ o = 0.85 cp
Bo= 1.23 BBL/STB
kh= 16,000 md*ft
re = 1000 feet
a) calculate the theoretical maximum for this well (IPR only)
b) a frac job is expected to reduce the "skin" to -2.5. In this
case, calculate:
i) the maximum flow rate possible
ii) the natural flow rate
3. Reservoir engineering calculations estimate that the reservoir pressure
will decline by 20% over a three year period. No change in
permeability is expected. Calculate the production rate in three years
with the above assumption.
4. We are concerned that we may see water coning in a few months. If
we want to forestall that by reducing the completion to 40% of the pay
zone .. starting at the mid line, what reduction in rate would you
expect (starting from the rate in problem 1) (rw = .46 ft , h = 46 ft, re
