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to participate as lecturers.
Slim Hole Technology
Roger Hough
Shell Canada
This presentation will:
Give an overview of slim hole
technology
 Define why it is only now gathering
momentum
 Provide some case histories
 Explore the prospects for the future

Slim Hole Technology
What is slim hole?
 Types of slim hole drilling
 Why slim hole?
 Problems and solutions

What is Slim Hole?
SHDEC: Drilling , evaluation and
completion technology which allows
fully engineered 6 1/4" and smaller
holes at TD.
 Slimline well: Well with a cost-effective
design around an optimal production
conduit.
 Logging: Anything smaller than 4 3/4",
or minimum 2 7/8". Tool OD 2 1/4"

Types of slim hole drilling:
Shallow Rotary
 Continuous coring
 Downsized Conventional
 Combination
 Small horizontal sidetracks
 Coiled tubing drilling

Why Slim Hole?
Exploration in immature areas
 Exploration in mature areas
 Production applications
 High pressure / temperature wells
 Safety
 Environmental
 Logistics
 Economics

Why Slim Hole?
Exploration in immature areas
 Exploration in mature areas
 Production applications
 High pressure / temperature wells
 Safety
 Environmental
 Logistics
 Economics

Why Slim Hole?
Exploration in immature areas
 Exploration in mature areas
 Production applications
 High pressure / temperature wells
 Safety
 Environmental
 Logistics
 Economics

Why Slim Hole?
Exploration in immature areas
 Exploration in mature areas
 Production applications
 High pressure / temperature wells
 Safety
 Environmental
 Logistics
 Economics

Completion Technology
10
20”
13
3
7
“
/8
1
3
9
5/
8
/
3
/4
5/
8“
L
PBR tie-back
“ tubing
2
5
“
“
1
/
“L
2
7”
Conventional
Monobore
Rotating liner
hanger
Monobore Toolkit
Restriction
Full bore
High rate jet cleaner
Jet cleaner
PLT
Packer flow meter
Full-bore CT mill
Under reamer
Straddle packer
TTBP
Retrievable straddle
Electro line set bridge plug
Typical 3 1/2” monobore completion
Standard 3 1/2” flow
control equipment
with 2.813 seal bore ID
Side pocket mandrels
with 2.813” seal bore ID
5 1/2” 17 lb/ft
production casing
Liner hanger complete
with tubing tieback
Retrievable straddle
3 1/2” 9.2 lb/ft
production liner
Retrievable or
permanent bridge plug
Slim hole producers

A 3 1/2” monobore can produce 4000 b/d
or 50MMscf/d

Downsizing a completion from 7” to 3
1/2” can reduce well costs by 15-40%
Production Rate vs Tubing Size
100000
100
50000
50
25000
25
Gross 10000
Rate
b/d
500
0
2500
10
Wet
Gas
Rate
MMscf/d
1000
500
20
40
60
8
10
03 1/2” 0
120
4 1/2”
140
5 1/2”
16
0
180
7”
mm
inch
Well Productivity vs Diameter
1.
1
1.05
1.0
Relative PI
0.95
0.9
0.85
0
5
10
15
Bit Diameter (inches)
20
Slim hole producers

For Shell’s existing reservoirs on a
worldwide basis:
– 40% of the oil originally in place would be
produced by existing technology
– 20% would be bypassed
– 20% would be residual oil saturation

Recovery of half the remaining oil would
increase recoverable reserves by 50%.
Why Slim Hole?
Exploration in immature areas
 Exploration in mature areas
 Production applications
 High pressure / temperature wells
 Safety
 Environmental
 Logistics
 Economics

Why Slim Hole?
Exploration in immature areas
 Exploration in mature areas
 Production applications
 High pressure / temperature wells
 Safety
 Environmental
 Logistics
 Economics

Why Slim Hole?
Exploration in immature areas
 Exploration in mature areas
 Production applications
 High pressure / temperature wells
 Safety
 Environmental
 Logistics
 Economics

Why Slim Hole?
Exploration in immature areas
 Exploration in mature areas
 Production applications
 High pressure / temperature wells
 Safety
 Environmental
 Logistics
 Economics

Why Slim Hole?
Exploration in immature areas
 Exploration in mature areas
 Production applications
 High pressure / temperature wells
 Safety
 Environmental
 Logistics
 Economics

Problems and Solutions

Problem
Solution

Cementing


Fishing
Drillstring failures

Well control

Limited evaluation

Small clearances,
high ECDs, hole
problems
Bit life, poor
penetration rate
Enhanced liners, improved
slurries
Fishing tools
Vibration mitigation, high
torque drillstring
Accurate flow in / out
measurement
Slim hole logging and
testing tools
Shear thinning fluids /
formates, thruster to
replace DC
PDC bits, anti-whirl bits,

Problems and Solutions

Problem
Solution

Cementing


Fishing
Drillstring failures

Well control

Limited evaluation

Small clearances,
high ECDs, hole
problems
Bit life, poor
penetration rate
Enhanced liners, improved
slurries
Fishing tools
Vibration mitigation, high
torque drillstring
Accurate flow in / out
measurement
Slim hole logging and
testing tools
Shear thinning fluids /
formates, thruster to
replace DC
PDC bits, anti-whirl bits,

Slim hole fluid pressure drops
0
Formate mud
3 1/2” DP
Chalk mud
7”
5”
2 7/8” DP
4 1/8” Bit
5000 m
0
250 bar
Problems and Solutions

Problem
Solution

Cementing


Fishing
Drillstring failures

Well control

Limited evaluation

Small clearances,
high ECDs, hole
problems
Bit life, poor
penetration rate
Enhanced liners, improved
slurries
Fishing tools
Vibration mitigation, high
torque drillstring
Accurate flow in / out
measurement
Slim hole logging and
testing tools
Shear thinning fluids /
formates, thruster to
replace DC
PDC bits, anti-whirl bits,

Problems and Solutions

Problem
Solution

Cementing


Fishing
Drillstring failures

Well control

Limited evaluation

Small clearances,
high ECDs, hole
problems
Bit life, poor
penetration rate
Enhanced liners, improved
slurries
Fishing tools
Vibration mitigation, high
torque drillstring
Accurate flow in / out
measurement
Slim hole logging and
testing tools
Shear thinning fluids /
formates, thruster to
replace DC
PDC bits, anti-whirl bits,

Kick detection system
BNP
SPM
SPP P
Flow in
Flow out
Max
Min
P
BOP
Computer
Alarm
Problems and Solutions

Problem
Solution

Cementing


Fishing
Drillstring failures

Well control

Limited evaluation

Small clearances,
high ECDs, hole
problems
Bit life, poor
penetration rate
Enhanced liners, improved
slurries
Fishing tools
Vibration mitigation, high
torque drillstring
Accurate flow in / out
measurement
Slim hole logging and
testing tools
Shear thinning fluids /
formates, thruster to
replace DC
PDC bits, anti-whirl bits,

Standard Thruster
Hookload
Drillpipe
Drillcollars
No thruster
Thruster
Mud Motor
Bit
Thruster
in use
Soft Torque Rotary Table
SCR
Rotary
Drive
motor
Drillpipe
Field Validation of MKII STRS
ON
Time = 60s
Problems and Solutions

Problem
Solution

Cementing


Fishing
Drillstring failures

Well control

Limited evaluation

Small clearances,
high ECDs, hole
problems
Bit life, poor
penetration rate
Enhanced liners, improved
slurries
Fishing tools
Vibration mitigation, high
torque drillstring
Accurate flow in / out
measurement
Slim hole logging and
testing tools
Shear thinning fluids /
formates, thruster to
replace DC
PDC bits, anti-whirl bits,

Problems and Solutions

Problem
Solution

Cementing


Fishing
Drillstring failures

Well control

Limited evaluation

Small clearances,
high ECDs, hole
problems
Bit life, poor
penetration rate
Enhanced liners, improved
slurries
Fishing tools
Vibration mitigation, high
torque drillstring
Accurate flow in / out
measurement
Slim hole logging and
testing tools
Shear thinning fluids /
formates, thruster to
replace DC
PDC bits, anti-whirl bits,

Integration is important
mwd
p
pump strokes
GPM
pd
pda
mud viscosity
mud density
pc
pca
mud temperature
pt
ecd
pm
dp RPM
WOB
torque
pb
bit TFA
bit aggressiveness
Case Histories - Exploration
BP - West Africa
Slim Hole Well Configuration
10 /4 in
cond
3
20 in
conductor
17
12
8
1 /2
1/
1
6
/
4
2
9
7/
8
6
3
/8
4.8
Reservoir
3000 m
3.8
SPE/IADC 25724
Slim Hole Wellsite
Environmental Impact
Slimhole
site
60 m
120 m
75 m
Conventional site
150m
•Hole diameters reduced by 50%
•Mud consumption and cuttings reduced by 75%
•Site reduced by 75%
•Overall costs reduced between 40% and 50%
SPE/IADC 25724
Case Histories - Exploration
Guatemala
Positive Learnings
Lower day rate
 Lower material costs
 Lower location preparation costs
 Lower Mob/ demob costs
 Less waste disposal
 Smaller crew

Negative Learnings
Poor hydraulics
 High ECDs - unable to get desired mud
weight
 Hole erosion due to high annular velocities
 Limited choice of bits
 Non standard tools
 3 1/2” logging tools unsuitable for 4 1/4” hole

Case Histories - Exploration
Madagascar
Madagascar
Slim vs Conventional
MDZ-1
MDS-1
9 5/8 “
7”
5”
2500m
Cost 100%
8.1/2” 2200m
4.1/4”
60%
Madagascar Cost Comparisons
12
$US
millions
8
4
0
Well 1
Well 2
Well 3
Slim-hole
well
Positive Learnings
Reduced tonnage, location, construction work
and waste material
 Reduced driving hazards (1/2 the trucks)
 Reduced environmental impact
 Kick detection - 20L detected
 Antivibration technology -> gauge 4 1/4” hole
 Good quality logs

Negative Learnings
Assorted rig packages
 5000 psi design - 3600psi available
 Bit TFA too high - bit selection poor
 Mud pump used for cementing

Case Histories - Production
Germany
Field Experience Retrofit SHD
18
24 2”
1
/
5/
8
“
5/
8
13 3 /8“
13 3 /8”
9
18
”
9
5000 m
Well costs
Cuttings volume
5/
8
“
13 3 /8“
9
5/
8
“
7”L
OH
100%
100%
“
7“L
7”L
8 1 /2“
5/
8
5” L
1
7
5 /8“
5”L
OH
75%
60%
4 /8“
1
3 / 2“ L
OH
60%
30%
Case Histories - Production
House
Mountain
Hole Geometry
25 deg/30 m
2120m
3
565 m
7
/
8
“
Where is slim-hole going?
Slim hole technologies are proven and
reliable.
 The industry is beginning to embrace
slim hole - first operators and service
companies, now the drilling contractors.
 A start can be made with retrofit systems
before committing to a dedicated rig.
 New applications are emerging.

New Applications

Coiled tubing drilling
– Ultra Short Radius Jetting
– Underbalanced drilling
– Expandable Tubulars
– Coiled Tubing Completions

Dedicated Slim Hole Rigs
Typical slim hole casing schemes
8.3/4" - 8.3/8"
7"
10.3/4"
or
9.5/8”
10.3/4"
or
9.5/8”
12.1/4"
9.7/8" - 8.3/8"
6.1/4" - 5.7/8"
7.5/8" - 7"
5"
7.5/8" - 7"
6.3/4" - 5.3/4"
4.1/4" - 4.1/8"
5.1/2" - 5"
5.1/2" - 5"
3.1/2"
3.1/2"
Tubing
Monobore
4.3/4" - 4.1/8"
2.7/8" - 2.5/8"
3.1/2"
4" - 3.1/2"
3.3/8" - 2.5/8"
BHI SH
manual
RE-ENTRY
EXPLORATION
2.7/8" - 2.5/8"
DEVELOPMENT / PRODUCTION
Case Histories - Production
Peace River
New Generation Slim Hole
Rigs
Euroslim (Forasol / Elf / Total / DBS)
 Simpler (Sedco-Forex)
 Kenting Rig 11
 Hybrid CT units

Slim Hole Wellsite the shrinkage continues
Simpler
16.5
44
Foraslim
32m
60 m
26m
Slimhole
75 m
Conventional site
150 m
120 m
Multidisciplinary Crew

Rig Team
 Maintenance Team
 MWD / Logging
 Total
8 (15)
3 (5)
1 (3)
13 (23)

Conventional Operations (40)
Next Steps
Good planning and integration of a slim-hole
campaign is needed with all parties.
 Design the well from inside out.
 Compromises may be needed, but the result
should be better information for less cost,
reduced finding / lifting costs, increased
reserves, better safety and S.D.
 Slim hole is coming - it’s up to oil company
and contractor alike to benefit from it.
