This document outlines the procedures for conducting a well completion test program to determine key properties of a geothermal well prior to production. The program includes static temperature tests, water loss surveys to identify permeable zones, injectivity tests to measure permeability, pressure fall-off tests to analyze reservoir properties, monitoring the heat up period to observe temperature changes over time, and stimulation and discharge steps to clear the well and initiate flow. The results of these tests provide critical information on formation temperature, permeable zones, injectivity, reservoir characteristics, and help design an optimal production and monitoring program.

1. GEOTHERMAL WELL TESTING
& MEASUREMENT (GE 423)
Completion Test
Program / Design
Engr. Angel M. Honculada
GEOTHERMAL ENGINEERING, NORSU - CEA

2. COURSE OUTLINE
Introduction
Well Testing Equipment / Tools
Pressure and Temperature Surveys
Well Test Designs / Programs
Well Data Analysis & Output Measurement
Well Test Designs / Programs
Completion Test Design
Well Monitoring Program
Other Well Testing
Procedures
GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA

3. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
WELL COMPLETION TEST PROGRAM
- A series of tests and surveys performed
during / after drilling to determine
temperature, pressure, feed zones / permeable
zones, injectivity index of a particular well prior
to discharge.

4. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
STATIC FORMATION
TEMPERATURE TEST
WATER LOSS
SURVEY
INJECTIVITY
TEST
PRESSURE
FALL-OFF TEST
HEAT UP
PERIOD
STIMULATION
& DISCHARGE
WELL
COMPLETION
TEST DESIGN

5. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
1. STATIC FORMATION TEMPERATURE TEST (SFTT)
Objective: To provide an estimate of the static formation temperature.
Process: Temperature element is lowered in the open hole to the depth
of the bit. Indexed every hour and retrieved after 12 hours.
Generally, three tests are carried out during drilling. First, at 9
5/8” casing shoe, at the bottomhole and the third is at an
appropriate depth in between.
Preferable to run tandem temperature instrument to
minimize the risk of lost information and save time during
failure.

6. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
Plotting:
Temperature 0C
vs Time log [(Tc +ΔT)/ΔT]
(Horner type - having a line
directed toward temperature
after infinite time.)
Temperature
Time (Horner)
2750C -
2500C -
2250C -
2000C -
1750C -
1500C -
1250C -
1000C -
0.1 0.2 0.3 0.4 0.5 0.6
Formation Temperature
at infinite time plotting line using least square method

7. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
2. WATER LOSS SURVEY
Objective: To determine possible permeable zone along the well.
Process: Temperature surveys (two or three) are run while pumping
water downhole. Water is pump at 10 liters/second and
20 liters/second for the first and second temperature
surveys respectively. The rate on the third survey depends
on the preceeding two surveys. In cases where the well
appears to cool down and an increased in pumping
rates will osbscure further result, the third survey could be run in
a zero flow rate.

8. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
Process: The first temperature survey has its instrument stops
generally spread evenly over the uncased hole (nominally
every 100m), especially to depth where drilling losses and
permeable zones were indicated by petrology /
geosciences during drilling.
The second survey is run to better define the loss zone as
indicated on the first survey.
The third survey is run to determine the major loss zone
and locate the lowest loss zone in the well. It can also wash
away all loss circulation materials near the well bore.

9. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
Plotting:
Depth in meters
vs Temperature in 0C.
Major loss zone can be
determined where there is
sudden curve in the graph.
Depth m
Temperature 0C
1500 -
1750 -
2000 -
2250 -
2500 -
2750 -
3000 -
3250 -
50 100 150 200 250 300
KT 1 @ 10 l/s
KT 2 @ 20 l/s
KT 3 zero flow
permeable zone

10. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
3. INJECTIVITY TEST
Objective: To ascertain the degree to which the well accepts various
rates of water injection thus indicates its permeability.
Process: The pressure instrument is lowered to the depth of the
major loss zone as indicated in the water loss survey.
Pumping of water (4, 5, 6, 8, 10, 12 bpm) at different rates
for 30min each rate.
After completion of the maximum flow rate, pumping is
stopped, leaving the pressure element until the clock time
expires to record an initial pressure fall-off.

11. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
Plotting:
Injection flow in
liters/second vs
Pressure in MPa.
Pressure of different
pumped rate is then
graphed and getting
the slope of the best fit
line will determine the
well’s injectivity index.
Flow L/s
Pressure MPa
5 -
10 -
15 -
20 -
25 -
30 -
35 -
40 -
17.25 17.5 17.75 18.0 18.25 18.5
INJECTIVITY INDEX (L/s-Mpa)
= slope of the line

12. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
4. PRESSURE FALL-OFF TEST (PFO)
Objective: With analysis on the test, it would indicate permeability-
thickness of the reservoir. It also helps determine the
permeability condition adjacent to the well (skin effect).
Process: Pressure element is lowered to the same depth as for the
injectivity test. Water is pumped for one hour then shut off.
The instrument remains in the well for a period long
enough to fully monitor the fall off (3hrs to 3 days), but
sufficient data can generally be obtained in six to
twelve hours. Approximation of time can be determine
from the initial PFO conducted at the end of the injectivity test.

13. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
Process: The initial run should not exceed six hours and having
successful result, the rig pumps can be released as early as
possible. The instrument can be re run at an appropriate
time if the pressure recovery is not complete after six hours.

14. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
Plotting:
The plot of
Pressure (shut in kPa)
vs Time
(in min on semi log graph)
can show two
distinct functions
(rates of pressure
fall-off). The first is
the well-bore
storage and the
second on the
reservoir.
Shut in
pressure in kPa
Shut in time in
minutes
8000 -
-
7000 -
-
6000 -
-
-
5000 -
101 102 103
skin effect
reservoir permeability

15. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
5. HEAT UP PERIOD
Objective: Monitor the heat build up and provide further
information on loss zones.
Process: After Pressure Fall-off Test the well is shut in and allowed
to heat up.
Temperature and pressure surveys are run after 1, 2, 6, 12
and 24 days to monitor heat up on the well.

16. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
Plotting:
Depth in meters
vs Temperature in 0C.
Possible production zone
and provide initial estimate
of fluid enthalpy.
Depth m
Temperature 0C
1500 -
1750 -
2000 -
2250 -
2500 -
2750 -
3000 -
3250 -
50 100 150 200 250 300
1 Day shut
3 days shut
6 days shut
Production zone
12 days shut
24 days shut

17. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
Plotting:
Depth in meters
vs Pressure in MPa
Pressure control point
can be determine
Depth m
Pressure MPa7.0 8.0 9.0 10.0 11.0 12.0
1500 -
1750 -
2000 -
2250 -
2500 -
2750 -
3000 -
3250 -
1 Day shut
6 days shut
24 days shut
PRESSURE
CONTROL
POINT (PCP)

18. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
6. STIMULATION & DISCHARGE
DISCHARGE:
After the shut in period, discharge of the well should be followed to
clear the well from cuttings and remaining drilling fluids and to assist
the speeding up of temperature and pressure stabilization. It could be
done vertically then to a silencer in order to determine flow rate.
STIMULATION:
When a well will not discharge naturally it must be stimulated
artificially. By injecting steam from adjacent wells or by portable boilers,
it will raise the temperature of the water column that can cause
flashing.

19. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
VERTICAL DISCHARGE DISCHARGE THROUGH A
SILENCER

20. GEOTHERMAL WELL TESTING & MEASUREMENT (GE 413)
Honculada, A. GEOTHERMAL ENGINEERING, NORSU - CEA
STATIC FORMATION
TEMPERATURE TEST
WATER LOSS
SURVEY
INJECTIVITY
TEST
PRESSURE
FALL-OFF TEST
HEAT UP
PERIOD
STIMULATION
& DISCHARGE
SUMMARY
FORMATION
TEMPERATURE
PERMEABLE ZONE
INJECTIVITY
INDEX
PERMEABILITY
& SKIN EFFECT
LOSS/FEED ZONES
CLEAR WELL /
INITIAL FLOW