Steve Fitzel Downhole Testing

1. Downhole
Testing for
Refrac
A new downhole tool for testing
individual zones in multi-stage
wells

2. Features
Straddle packer with downhole pump
Multiple tests with one run
Drawdown and buildup tests
Fluid identification
Pump Bypass for flowing wells
E-coil conveyed – mono-conductor cable
Small O.D. for 4-½" casing
Flow past the tool for cleaning debris, etc
Emergency planning

3. Bypass
Valve Sensors
Check
Valve
Coil
Tubing
Shift Down
Unloader Upper
Packer
Flow Rate
Valve
Burst
Disk
Anchor
Lower
Packer
Intake
Piston
Pump

4. Specifications
Tool O.D. 3.6"
Min hole size 4.0"
Max hole size 7-¼"
Tool length 15.8 m ( 52 ft)
Max pressure 10,000 psi
Max temp 350 degF

5. Downhole pump
Reciprocating piston
pump
Pump Rate 0.1 -
2.0 ltr/min 0.9 -
18 bpd
Precision stroke 0.5
- 332 cc
Pump from between
packers to
coil/casing annulus
Custom check
valves for dirty fluids
Bypass valve for
flowing gas or oil
wells

6. Packers set and released
by coiled tubing flow and
movement
Packer Assembly
&
Intake Sub
Lower Packer
Upper Packer
Unloader

7. Important factors with
transient testing
Permeability
Fluid type
Volume of drawdown
Minimize storage effect
Pressure sensor
Resolution
Reaction time
Stability

8. ✓Fast acting MEMS sensor
✓Resolution is 0.00005% of FS
✓Accuracy 0.01% FS
✓10,000 psi FS
Pressures Measured
Flowline
Coiled tubing
Annulus
Pistonchamber(Optional)

9. Fluid identification sensors
Conductivity Optical
Bubble counting
can show
continuous phase

10. NMR sensor
• 14 isotopes monitored simultaneously
• Programmable for other isotopes
• Multi-phase flowrate
• Real time AI analysis
• Density, viscosity, temperature and pH
• Gas composition

11. Applications
Fracturing
information
Zones producing
excessive water
or gas
Water flood
monitoring
Reservoir
knowledge
Identify
communication
between zones
or wells
Reason for poor
production

12. Fracturing
information
• Zones fracture effectiveness
• Depleted zones
• Fracture effectiveness
• Fracture geometry
• Communication with other zones
or wells
• Before and after frac
comparison

13. Pressure transient
analysis
See fracture properties by slope
change
Permeability, reservoir pressure
and production by stage
Minimized wellbore storage
Validate reservoir models

14. Job procedure
1
Pull tubing
and pump
from the
well. Wait
for stable
fluid level.
2
Monitor data
while running
in well on e-
coil
3
Correlate
depth with
real
time CCL
4
Position and
set packers
by pumping
down
coil faster
than
threshold vel
ocity
5
After
straddle
packers set
maintain
coil pressure
6
Use downhol
e pump to
drawdown
pretest
volume for
buildup test
7
Pump from
reservoir
into annulus
until fluid
type mixture
is constant.
8
Shift coil to
unload coil
pressure and
de-
energize pac
kers
9
Move to the
next stage

15. Real Time Software Control
❑High speed telemetry – up to
350 kbps
❑Real Time Pump Control and
Sensor Monitoring
❑Normal sampling rate of 10
points per second per sensor

16. Pumping at different rates

17. Full test at 200 m

18. Fluid ID transition during test

19. Logging out

20. Report and Analysis

21. Summary
Reduce cost
Improve fracking
parameters
Reservoir
knowledge