Annulus Management Plan For KN Deep
Annulus Management Plan For KN Deep
Annulus Management Plan For KN Deep
KN Deep Wells
Kinabalu Development
Project
18 October 2013
Presentation Outline
Cement Reliability
Cement Stress Analysis
Annulus Fluid Expansion
Comparison of Annulus Management Option
WELLCAT Modeling
Nitrogen Cushion Option
Cement Reliability
1. Key objective is to achieve
reliable isolations across
hydrocarbon sections and
prevent gas migration
throughout lifecycle of the
well.
2. Use of premium cement
gas tight blends. Rids use
of gas tight extended lead
and tail.
3. 10 ppg cement needed to
mitigate losses. Extended
classical leads:
1. Form very low compressive
strength & tend to fail.
2. Are generally quite
permeable for cement and
are prone to allowing gas
migration.
3. Take a very long time to set,
thus, get damaged during
pressure testing & general
well operations.
B Annulus
A Annulus
C Annulus
Multiple layers
of depleted
sands
Diferential
Pressure (psi)
1. Impact of Annulus
Pressure Build Up due
to fluid expansion was
assessed using
MultiString Analysis in
WELLCAT
2. Highest temperature
profile: Steady State
production at full rate
(100MMSCF/day)
3. WELLCAT output then
become input for
CemSTRESS
4. 3 cases were
assessed:
Trapped Annulus
13-3/8
FAIL
10-3/4 x 9-5/8
FAIL
5-1/2 FAIL
13-3/8
PASS
10-3/4 x 9-5/8
PASS
5-1/2
PASS
psi
bbl
Est.
Fluid
Drop (ft)
+ Nitrogen
Cushion
psi
+200 psi
(at cold
temp)
10,283
21.2
506 ft
29
229
9,734
15.8
478 ft
36
236
8,611
13.0
93 ft
10
210
The casings
will fail if the annulus Vent
are left trapped
D
Advantages
Disadvantages
1. Simple
2. Removes reliance on
human
3. Removes risk air being
drawn into annuli.
Opt 3: Use of
active glycol and
N2
1. Removes reliance on
human
2. Ensures well annuli
pressure compensated
during well cooling.
1. Complex system
2. Indirectly dependent on human
interaction for maintenance.
3. Risk of rapid release of HC from
tubing to annulus.
1. Removes reliance on
human
2. Ensures well annuli
pressure compensated
during well cooling.
3. Less complex and
dependency on
instruments reliability.
KN-Deep Annulus Management
4. Actively locking out annuli
10
Kinabalu AMS
2/3/15
12/6