Relief Well
Ranging Strategy
L. Wm “Bill” Abel
ABEL Engineering LLP
Houston, Texas 77027 USA
www.Abel-Engr.com
1
Relief Well History
Santa Barbara oil spill occurred in
January 1969 in the Santa Barbara
Channel in Southern California
According to Dr. Preston Moore the first
relief well ever was for this problem and
the objective was to penetrate and produce
the reservoir to blowdown the pressure
and thus “stop” the flow, e.g., RELIEF
WELL “relieved” the pressure in the
reservoir.
2
Why do we drill relief wells?
Answer: Because we have to!
If there is another solution, it is
taken because time is the driving
factor in any well control event.
SOLUTION MUST BE SOONER
RATHER THAN LATER IN ALL
CASES.
3
GOM Event 2007
Off-bottom Kill Objective
4
N. America HTHP Land
5
Lake Maracaibo crater circa 1988
6
Swamp Barge Rig Marea after a
few hours of exposure to fire
7
Dewi9 on TNE5
with RW in the background
Big crocodiles!
8
How Does Ranging Fit Into the Project
RELIEF WELL TEAM
WELL
PLANNING
PROXMINITY
LOGGING
(Ranging Runs)
FLOW ASSURANCE /
HYDRAULIC
MODELING
Su r
ve y
INTERCEPTION /
COMMUNICATION
Mg
t.
DIRECTIONAL DRILLING /
MWD-LWD
LWA Aug-10
9
Overlapping
responsibilities
Project
Engineering
"Relief Well Team"
Well
Plan
Proximity
Logging
Interception
Stragegy
Hydraulic
Simuation
Directional
Drilling
10
OVER ALL OBJECTIVE – STOP
THE FLOW – STABILIZE THE
WELL
Flow stopped
+
+
-
R
s lan
s
re e-p
P
f pr
o
ty ans
i
l
a s
u
Q se s
a
ele
Time
Image sans
pre-plan
???
Quality of Press Releases
ge
wit
ha
pre
-pl
a
n
Flow stopped
Im
a
Incident
begins
Qu
Rele ality of P
a se s
r
with ess
pre-p
lan
Corporate Image
Time Savings
-
11
IMPACT OF TIME
al
t
Time Savings
lan
P
Pre
ne
ro
dP
je
u
ct C
rve
Pollution stopped
Pollution saved
N/
UTIO LOST
L
L
PO TION
DUC
PRO
Incident
begins
Flow stopped
Pollution stopped
Produciton Lost /
Pollution
n
Pla
e
Pr C P
B
N
m
or
jec
o
Pr
e
rv
u
C
Cost Savings
Cost of Control
Flow stopped
Time
12
OBJECTIVES
• Allow communication for a pump to kill
operation
• Least risk per ALARP
(as low as reasonably possible)
• Least time possible
(time = exposure in blowout)
13
The “real” Objective
• Hit a VERY small target and make a
communication:
14
Proximity Choices: WL (active) or
MWD (passive)
• Why choose one over the other?
• Both have strength and weaknesses
• Active has greater range (in most
cases)
• Passive uses tools that are already in
the hole (MWD) – no trip out to obtain
data
(provided you are within the detection range)
LOGICAL ANSWER: Use both
15
Relief Well Plans are now part of
the Emergency Response Plan
ERP for high risk (pollution)
16
Angle Impact
(Incident and EOUs size)
17
Ple-10 Relief Well Trajectory
TVD
MD
0.0
0.0
600
KOP
Large
Incident
Angel
662.4
662.4
662.4
ANG = 44.0
Small
EOUs
0.8
cuated
1060.4
X3
MD3
X3
1091.4
TVD3
TD
10.0
Deprt
End Bld
1102.4
Target
1145.6
TD
1101.8
800
1159.9
1010.4
1000
EOU
Ple-10 RW
200.8
1091.4
1,093.8
1101.8
1,091.4
1200
-200
0
200
400
LWA Sept-2015
18
Low
Incident
Angle
Large
EOUs
19
Ranging in small EOU
2m
2m
Well Separation
Re
lief
We
ll
Blowout
Well
10 – 12m '
vendor MWD
Proximity Range
8m
7m
MWD Proximity Range
24m (diameter)
Sum of Surface + RW + Blowout Well
Uncertainty 28m (diameter)
Change in azimuth
MWD Proximity
MWD
Proximity
RangeRange
MWDRange
Proximity
MWD
Range
Proximity
Range
MWDProximity
Proximity
MWD
Range
24m (diameter)
24m (diameter)
24m (diameter)
24m (diameter)
24m
(diameter)
24m (diameter)
Sweeping thru the ellipse to
locate Blowout Well Casing
20
well AZ 277.860
AZ 277.90
Large
Incident
small
EOUs
54m
36m
1590m MD
well AZ 277.860
57
m
54m
54m
Active
.
54m
36m
55°
RW AZ 277.90
54m
1590m MD
AZ
27
7.9 0
1079.6m TVD
29.8 x 12m
36m
Passive
highside
36m
well AZ 277.
86 0
lowside
36m
84°
29.8 x 14.8m
1079.6m TVD
38
m.
OPEN HOLE POTENTIAL
UNPLANNED
COMMUNICATION
LWA Sept-2015
21
Small EOU but high
Incident angle
RW Gyro
Major Axis x Vert.
@ Intercept
37 x 24m
Major Axis x Vertical
@ 9-5/8" Casing Shoe
118 x 46m
Active 35 deg
Incident angle
EOU Combined
Major Axis x Vertical
@ 9-5/8" Casing Shoe
155 x 70m
43.6m
19m
30.6m
Passive
9-5/8" 43.5 lbs/ft
Gryo Major Axis x Vert.
@ Intercept
19.6 x 14.4m
LWA Sept-15
Major Axis x Vertical
@ 9-5/8" Casing Shoe - 146 x 19m
EOU Combined
Major Axis x Vertical
@ 9-5/8" Casing Shoe
165 x 23.4m
43.6m
19m
30.6m
Passive
9-5/8" 43.5 lbs/ft
Active 35 deg
Incident angle
22
Blowout well
(Target)
LWD/MWD Ranging
Relief well
LWD/MWD tool
range
Trace across the
ellipse of uncertainty
Calculated
well location
Ellipse of uncertainty
R2
RR1 1
Investigated area
Actual well
location
Area left to investigate
Well Planning Extends
Range-of-Detection
Detection point
Intercept and
communication point
23
136.6 x 52.2m
15.3m.
1267m TVD
Major x Vertical
154.7 x 59m
19m
19m
30.6m
19m
1267 mTVD
30.6m
30.6m
19m
30.6m
1234 mTVD
19m
19m
30.6m
19m
19m
9.0°
30.6m
1205 mTVD
117.3 x 45.2m
Maj x Vert
30.6m
19.4m.
1184.6 mTVD
30.6m
Sweep thru the EOU holding
angle
1282 mTVD
24
Example Strategy for Ranging
0 (RT)
500
KOP 642m
RW Phase
Build @ 10/10m
AZ 1660
750
8-¼” Phase Blowout
Vertical section
MWD Bit
Sub Anticollision
1000
Line up to
parallel
AZ 1760
Match AZ and
parallel @ 4 to 7 m
separation
Hold
AZ 1660
Inc 810
Case well
after lined
up to hit
Blowout Well
Drill out with slim
BHA and hit well to
communicate
Check shots
9-5/8"
MWD Ranging at
50m separation
1250
NOTE: Hold trajectory is
maintained until casing is
detected with proximity logs.
1500
2000
2250
Detection,
mapping of
relative position
SEE NOTE
2500
Check shots
Nudge away if
needed to avoid
unplanned
collision
2750
End Hold
@ far side of EOU
AZ 1660 Inc 810
3000
9-5/8"
PUMP TO KILL
WELL CONTROLLED
Line up to
intercept 4-60
attack angle
3250
3500
25
ABEL Generalized Ranging
Strategy
• Aim at a point where the EOU is
manageable (not all that big if possible)
• Use near-bit inc. and MWD as anticollision and ranging
• Drill to that point where calcs say
detection should have happened
• If no go Log the hole with WL and or
EMS run or continuous MWD to
increase detection range
26
USE DEMMING MODEL
Assess risks v.
benefits
Evaluate Available
Resources
Emergency Event
Determine
Possible Actions
Identify Actions
Identify Real
Problems
Hazards to people/environment?
Damage to property
Incident Response Needs
Timeframe
No
Improve
future
response
capabilities
Identify personnel roles
Determine desired activities
Request resources`
Get It
Done
Monitor Results
Problem Solved?
Yes
Use ICS systems
Ensure safety of personnel
Communicate Actions Clearly
Stop work &
record
activities
27
END OF PRESENTAION
HTHP
Land
N. America
2013
28